1 - 200 of 338
Number of results to display per page
CreatorTitleDescriptionSubjectDate
1 Poulter, Charles Dale(S)-Geranylgeranylglyceryl phosphate synthase. Purification and characterization of the first pathway-specific enzyme in archaebacterial membrane lipid biosynthesisThe first pathway-specific step in the biosynthesis of the core membrane diether lipids in archaebacteria is the alkylation of the primary hydroxyl group in (S)-glyceryl phosphate by geranylgeranyl diphosphate. The reaction is catalyzed by (S)-3-O-geranylgeranylglyceryl phosphate ((S)-GGGP) synthase...Polyacrylamide gel; Molecular weight1993-10-15
2 Poulter, Charles Dale; Davis, Darrell R.15N labeled e. coli tRNAMet, tRNAGlu, tRNATyr, and tRNAPhe. Double resonance and two dimensional NMR of H-N1 units in pseudouridineThe N1 imino units in Escherichia coli tRNAfMet, tRNAGlu, tRNAPhe, and tRNATyr were studied by 1H-15N NMR using three different techniques to suppress signals of protons not attached to 15N. Two of the procedures, Fourier internuclear difference spectroscopy and two-dimensional forbidden echo spectr...Escherichia coli; Magnetic resonance spectroscopy; Nucleic acid conformation1985-08-15
3 Poulter, Charles Dale; Davis, Darrell R.15N-labeled Escherichia coli tRNAfMet, tRNAGlu, tRNATyr, and tRNAPhe. Double resonance and two-dimensional NMR of N1-labeled pseudouridine.The N1 imino units in Escherichia coli tRNAfMet, tRNAGlu, tRNAPhe, and tRNATyr were studied by 1H-15N NMR using three different techniques to suppress signals of protons not attached to 15N. Two of the procedures, Fourier internuclear difference spectroscopy and two-dimensional forbidden echo spectr...Escherichia coli; Magnetic resonance spectroscopy; Nitrogen; Nucleic acid conformation1985-08-15
4 Poulter, Charles Dale; Davis, Darrell R.15N-labeled tRNA. Identification of 4-thiouridine in Escherichia coli tRNASer1 and tRNATyr2 by 1H-15N two-dimensional NMR spectroscopy.Uridine is uniquely conserved at position 8 in elongator tRNAs and binds to A14 to form a reversed Hoogsteen base pair which folds the dihydrouridine loop back into the core of the L-shaped molecule. On the basis of 1H NMR studies, Hurd and co-workers (Hurd, R. E., Robillard, G. T., and Reid, B. R. ...Magnetic resonance spectroscopy1986-09-15
5 Poulter, Charles Dale; Davis, Darrell R.15N-labeled tRNA. Identification of dihydrouridine in Escherichia coli tRNAfMet, tRNALys, and tRNAPhe by 1H-15N two-dimensional NMR.The N3 imino units of dihydrouridine were identified in samples of 15N-labeled Escherichia coli tRNAfMet, tRNALys, and tRNAPhe by 1H-15N two-dimensional NMR. The peaks for dihydrouridine had high field 1H (9.7-9.8 ppm) and 15N (147.8-149.5 ppm) chemical shifts. Assignments were made by 1H-15N chemic...Hydrogen Bonding; Magnetic Resonance Spectroscopy; Magnetic Resonance Spectroscopy1986-03-15
6 Miller, Joel Steven1H NMR investigation of the magnetic spin configuration in the molecule-based ferrimagnet [MnTFPP][TCNE]1H NMR line-shape measurements have been performed in the linear chain molecule-based ferrimagnet [MnTFPP][TCNE].xPhMe (TFPP=tetrakis(4-fluorophenyl)porphinato; TCNE=tetracyanoethylene) as a function of temperature. Hyperfine shifts of opposite sign were observed indicating the presence of two oppo...Magnetization; Magnets; Paramagnetic2002
7 Morse, Michael DavidThe 3d?Ni(?F)3d10Cu???*? manifold of excited electronic states of NiCuDiatomic NiCu has been supersonically cooled in a molecular beam and investigated by resonant two-photon ionization spectroscopy. A total of nine band systems connecting the ground 3d?Ni3??Cu??, X 2?5/2 state to the 3d?Ni(3F)3d??Cu??*?? manifold of states have been found, and bands of eight of these...1992
8 Morse, Michael DavidThe 846 nm A? ???u ? ??? band system of jet-cooled V?The 846 nm band system of jet-cooled 5?V2 has been recorded using resonant two-photon ionization spectroscopy, and is assigned as the A ? 3?u- +X ??g- band system. Both the ?'= 1u? ?" = 1g and ?'= Ou+ ??? = 0g+ subbands of the O-O band have been rotationally resolved and analyzed. Although the trans...1992
9 Morse, Michael David???X??+ band systems of jet-cooled ScCo and YCoRotationally resolved resonant two-photon ionization (R2PI) spectra of ScCo and YCo are reported. The measured spectra reveal that these molecules possess ground electronic states of 1?+ symmetry, as previously found in the isoelectronic Cr2 and CrMo molecules. The ground state rotational constant...2010
10 Morse, Michael DavidThe ?IIou ?X ???g band system of jet-cooled Ti?A band of jet-cooled ??Ti? has been located in the near infrared by resonant two-photon ionization spectroscopy. Rotational analysis has shown the band to be an ?? =O* ???=1 transition, which is consistent with the 3??g, ground state proposed by Bauschlicher ef al. [J. Chem. Phys. 95, 1057 ( 1991)]...1992
11 Miller, Joel Steven[Cyanil]2 2- dimers possess long, two-electron ten-center (2e-/10c) multicenter bondingA long, two-electron ten-center (2e-/10c) [8 carbon plus 2 oxygen] bond in diamagnetic dimers of radical-anion tetracyano-1,4-benzoquinoneide (cyanil, [Q]2 2-, is described by B2LYP and CASSCF92,2)/MCQDPT calculations.Carbon bonds; Cyanil2008
12 Miller, Joel Steven[Et4N]2[TCNE]2 (TCNE = tetracyanoethylene) - an example of an exceptionally long 2.827 Ã CC bondInterest in organic compounds exhibiting unusually long CC bonds has been the subject of several recent studies.1-3 The longest sp3-sp3 C-C single bond reported to date is 1.73 A°,1,2 whereas several [TCNE]22- (TCNE = tetracyanoethylene) dimers have been recently reported to form cation-assisted, l...Synthesis; Crystal; Solution2001
13 Miller, Joel Steven[MeNC5H5]2[TCNE]2 (TCNE = tetracyanoethylene). Single crystal X-ray and neutron diffraction characterization of an exceptionally long 2.8 Å C-C bondThe reaction of N-methylpyridinium iodide, Mepy+I-, and tetracyanoethylene (TCNE) forms [Mepy]2[TCNE]2, which possesses [TCNE]2 2' with an intradimer C-C bond distance of 2.806(1)Å at 50 K from X-ray diffraction, and 2.801(4)Å at 50 K from neutron diffraction. In the IR it exhibits nChN absorption...C-C bond; Tetracyanoethylene; Neutron diffraction; X-ray diffraction; Multicenter C-C bonding2009
14 Morse, Michael DavidA pair potentials study of matrix-isolated atomic zinc. II. Intersystem crossing in rare-gas clusters and matricesThe mechanism of 4p 1P1?4p 3PJ intersystem crossing (ISC) following excitation of the 4p 1P1 level of matrix-isolated atomic zinc is investigated using a pair potentials approach. This is achieved by extending earlier ISC calculations on the Zn?RG2 and Zn?RG3 complexes to the square planar Zn?RG4 ...1998
15 Voth, Gregory AlanAb initio calculations of reactive pathways for ?-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (?-HMX)Using the BLYP and B3LYP level of density functional theory, four possible decomposition reaction pathways of HMX in the gas phase were investigated: N?NO2 bond dissociation, HONO elimination, C?N bond scission of the ring, and the concerted ring fission. The energetics of each of these four mechan...Ab initio calculations; Reactive pathways; HMX2000
16 Armentrout, Peter B.Activation of methane by gold cations: guided ion beam and theoretical studiesThe potential energy surface for activation of methane by the third-row transition metal cation, Au+, is studied experimentally by examining the kinetic energy dependence of this reaction using guided ion beam tandem mass spectrometry. A flow tube ion source produces Au+ primarily in its 1S0 (5d10) ...2006
17 Armentrout, Peter B.Activation of methane by size-elected iron cluster cations, Fen+ (n=2-15): cluster-CHx (x=0-3) bond energies and reaction mechanismsThe kinetic energy dependences of the reactions of Fen + (n=2 - 15) with CD4 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. All reactions exhibit thresholds and two main products, FenD+ and FenCD2+, are formed.Metal clusters; Iron ions; Bond energies; Dehydrogenation; Endothermic reactions; Transition metal ions2001
18 Armentrout, Peter B.Alkali metal cation interactions with 12-crown-4 in the gas phase: revisitedQuantitative interactions of alkali metal cations with the cyclic 12-crown-4 polyether ligand (12C4) are studied. Experimentally, Rb+(12C4) and Cs+(12C4) complexes are formed using electrospray ionization and their bond dissociation energies (BDEs) determined using threshold collision-induced dissoc...2012-01-01
19 Miller, Joel Steven; Epstein, Arthur J.Anomalous charge transport phenomena in the molecular-based magnet V(TCNE)x.y(solvent)We present charge transport studies on recently developed molecular-based magnets V(TCNE)x. y(solvent) (TCNE= tetracyanoethylene) which show local magnetic ordering at temperatures, T, as high as 400 K. V(TCNE), .y(solvent) prepared from the solvent CH2Cl2 has o(300 K) - 10-3 S/cm, and that prepar...Frequency; Conductivity; Spin1993
20 Miller, Joel Steven; Epstein, Arthur J.Anomalous magnetoresistance in high-temperature organic-based magnetic seminconducting V(TCNE)x filmsAnomalous positive magnetoresistance (MR) in high temperature organic-based magnet V(TCNE)x (TCNE=tetracynoethylene) thin films is reported. MR increases linearly with applied magnetic field and shows a maximum at the ferrimagnetic ordering temperature. The suggested roles of oppositely spin pola...Spin; Ferrimagnetic; Resistance2003
21 Miller, Joel Steven; Epstein, Arthur J.Anomalous relaxation in a quasi-one-dimensional fractal cluster glassThe low-temperature spin glass state of the quasi-1D organic-based magnet [MnTPP]+[TCNE]- .x(1,3-C6H4Cl2) has unusually long relaxation times due to frustration induced by dipole-dipole interactions between fractal spin clusters. This long relaxation is investigated with in-field relaxation measurem...Sweep rate; Bifurcation; Magnetization2004
22 Minteer, Shelley D.Bio-solar cells incorporating catalase for stabilization of thylakoid bioelectrodes during direct photoelectrocatalysisThylakoid membranes have been proposed for electrochemical solar energy conversion, but they have been plagued with short term instability. In this paper, thylakoid membranes extracted from Spinacia oleracea were physically adsorbed onto Toray paper electrodes with and without catalase, followed by ...2012-01-01
23 Armentrout, Peter B.The bond energy of ReO+: Guided ion-beam and theoretical studies of the reaction of Re+ (7S) with O2The kinetic-energy dependence of the Re+ + O2 reaction is examined using guided ion-beam mass spectrometry. The cross section for ReO+ formation from ground state Re+ (7S) is unusual, exhibiting two endothermic features. The kinetic energy dependence for ReO+ formation is analyzed to determine D0(Re...2013-01-01
24 Morse, Michael DavidThe bond energy of Rh?In a spectroscopic investigation of jet-cooled Rh2 by the resonant two-photon ionization method, an abrupt predissociation threshold is observed in a dense set of vibronic levels at 19 405?4 cm-1. Based on the high density of states expected in the rhodium dimer, the sharp definition of the prediss...1997
25 Truong, ThanhBranching ratio and pressure dependent rate constants of multichannel unimolecular decomposition of gas-phase ?-HMX: an ab initio dynamics studyThe dynamics of the initial thermal decomposition step of gas-phase ?-HMX is investigated using the master equation method. Both the NO2 fission and HONO elimination channels were considered. The structures, energies, and Hessian information along the minimum energy paths (MEP) of these two channels...Thermal decomposition; HMX2001
26 Poulter, Charles Dale; Jiang, YunfengBTS1 encodes a geranylgeranyl diphosphate synthase in Saccharomyces cerevisiaeProtein prenylation utilizes different types of isoprenoids groups, namely farnesyl and geranylgeranyl, to modify proteins. These lipophilic moieties attach to carboxyl-terminal cysteine residues to promote the association of soluble proteins to membranes. Most prenylated proteins are geranylgeranyl...Amino Acid Sequence; Cloning, Molecular; Gene Expression1995-09-15
27 Armentrout, Peter B.C+(2P) + H2(D2,HD)→CH+(CD+) + H(D). I. Reaction cross sections and kinetic isotope effects from threshold to 15 eV c.m.Total cross sections for the reactions of carbon (1 + ) ions with isotopic molecular hydrogen (H2, D2 , and HD) to form methyliumylidene (CH+ and C D + ) have been measured using guided ion beam techniques. Cross sections are reported as a function of the translational energy of the reactants fro...Ion-molecule reactions; Isotope effects; Translational energy; Threshold behavior; Endothermic reactions1986
28 Armentrout, Peter B.C+(2P)+H2(D2,HD)→CH+(CD+)+H(D). I. Reaction cross sections and kinetic isotope effects from threshold to 15eV c.m.Total cross sections for the reactions of carbon (1 + ) ions with isotopic molecular hydrogen (H2, D2, and HD) to form methyliumylidene (CH+ and CD+) have been measured using guided ion beam techniques. Cross sections are reported as a function of the translational energy of the reactants from th...Methyliumylidene; Endothermic reactions; Isotope effect; Threshold energy1986
29 Borodai, Anastasia S.C-F bond activationActivation of Carbon-Fluorine Bonds in 2', 3', 4', 5', 6'-Pentafluoroacetophenone through a Transition Metal Complex- Manganese PentacarbonylCarbon; Fluorine; Bond; Activation2014-05-30
30 Poulter, Charles DaleCaaX proteases, Afc1p and Rce1p, have overlapping but distinct substrate specificitiesMany proteins that contain a carboxyl-terminal CaaX sequence motif, including Ras and yeast a-factor, undergo a series of sequential posttranslational processing steps. Following the initial prenylation of the cysteine, the three C-terminal amino acids are proteolytically removed, and the newly fo...Proteins; Enzymes; Hydrophobic2000
31 Orendt, Anita; Pugmire, Ronald J.Carbon-13 chemical shift tensors in polycyclic aromiatic compounds. 9. BiphenyleneThe principal values of the 13C chemical-shift tensors of natural abundance biphenylene were measured at room temperature with the FIREMAT experiment. Of 18 crystallographically distinct positions (three sets of six congruent carbons each), the three primary bands have been resolved into seven singl...Carbon-13; Chemical-shift tensors; Biphenylene; Polycyclic aromiatic compounds; FIREMAT2000
32 Poulter, Charles DaleCatalytic mechanism of Escherichia coli isopentenyl diphosphate isomerase involves Cys-67, Glu-116, and Tyr-104 as suggested by crystal structures of complexes with transition state analogues and irreversible inhibitorsIsopentenyl diphosphate (IPP):dimethylallyl diphosphate (DMAPP) isomerase is a key enzyme in the biosynthesis of isoprenoids. The reaction involves protonation and deprotonation of the isoprenoid unit and proceeds through a carbocationic transition state. Analysis of the crystal structures (2 A) of ...Catalytic Domain; Crystallography; Organophosphorus Compounds2003-04-04
33 Miller, Joel StevenCharacterization of novel TCNQ and TCNE 1 : 1 and 1 : 2 salts of the tetrakis(dimethyamino) ethylene dication, [{(CH3)2N}2C-C{N(CH3)2}2]2+Addition of TCNQ to a solution of tetrakis(dimethylamino)ethylene in MeCN produces the salt [TDAE][TCNQ]2; the dipositive cation, [{(CH3)2N}2C-C{N(CH3)2}2]2+, is nonplanar, with a dihedral angle of 63.9(o), while the TCNQ anions crystallize as [TCNQ]2 2- dimers with an interplanar separation of 3.1...Electron; Oxidations; Transfer1996
34 Minteer, Shelley D.Characterizing efficiency of multi-Enzyme cascade-based biofuel cells by product analysisThe performance of biofuel cells with enzyme cascades have normally been characterized with open circuit potential, power density, and current density measurements. In this work, we demonstrate that with the method of quantitative product analysis by mass spectrometry, we can obtain other valuable i...2014-01-01
35 Miller, Joel StevenCharge transfer complexes of 2,4,6-tricyano-s-triazine with tetrathiafulvalene (TTF) and N,N,N' ,N'-tetramethyl-p-phenylenediamine (TMPD)Reaction of 2,4,6-tricyano-s-triazine (TCT) with tetrathiafulvalene (TTF) and N,N,N',N'-tetramethylp-phenylenediamine (TMPD) leads to 1 : 1 charge transfer complexes. The crystal structures of the TTF[TCT], as well as the decomposition product due to hydrolysis of the [TMPD][TCT], i.e. HTMPD]+[2,4-d...Electron; Solution; Hydrolysis2002
36 Miller, Joel StevenCluster glass state and photoinduced effects on the freezing dynamics in KxCo[Fe(CN)6]y.ZH2O (x-0.16,y-0.72, z-4.4)The magnetic properties and photoinduced magnetization of a Prussian blue analog, KxCo[Fe(Cn)6]y•ZH2O (x-0.16, y-0.72, z-4.4) were systematically studied. The frequency dependence of the linear ac susceptibility, the irreversibility in the field-cooled/ zero-field-cooled magnetization (MFC /MZFC)...Hexacyanide; Illumination; Temperatures2000
37 Armentrout, Peter B.Cobalt carbene ion: reactions of Co+ with C2H4, cyclo-C3H6 and cyclo-C2H4OAn ion beam apparatus is employed to study the formation of the cobalt carbene ion, CoCH2+. This ion is produced in the endothermic reaction of cobalt ions with ethene and cyclopropane and in an exothermic reaction with ethylene oxide. A model is proposed to account for the dependence of experimenta...Cobalt carbine; Ion beam; Bond dissociation energy; Reaction cross section; Endothermic reactions1981
38 Miller, Joel StevenCollinear ferromagnetism and spin orientation in the molecule-based magnets M[N(CN)2]2 (M=Co,Ni)Zero-field unpolarized neutron powder diffraction has been used to study the low-T magnetic structure and T-dependent crystal structure of M[N(CN)2]2 (M=Co,Ni). Both compounds show collinear ferromagnetism with spin orientation along the c axis. The results provide the determination of a complete ma...Magnetic; Diffraction; Structure1999
39 Armentrout, Peter B.Collision-induced dissociation dynamics of the [OCS • C2H2]+ complex. A combined experimental and theoretical studyCollision-induced dissociation (CID) of the [OCS • C2H2]+ complex ion with both Xe and Ar over an energy range of 0 to 10 eV in the center of mass frame is studied using a guided ion beam tandem mass spectrometer. The cross sections of the ionic products observed (C,H2S+, OCS+, C2HJ, and S+) are ...Collision-induced dissociation; Competitive shift; Ethylene Sulfide cation; Kinetic shift; Thioketene cation; Potential energy surface2000
40 Armentrout, Peter B.Collision-induced dissociation of Fen+ (n=2-10) with Xe: ionic and neutral iron binding energiesCross sections for collision-induced dissociation (CID) of Fen+ with Xe, 2≤n≤10, are presented. Experiments were performed on a newly constructed guided ion beam mass spectrometer, the design and capabilities of which are described in detail. The single mechanism for dissociation of iron cluster...1989
41 Armentrout, Peter B.Collision-induced dissociation processes of Nb4+ and Fe4+: fission vs. evaporationDespite the extensive effort devoted to research on gasphase metal clusters, quantitative thermodynamic data on such species are scarce. Such information is key to understanding and predicting the physical and chemical properties of clusters. Presently, bond energies are available primarily for tr...Metal clusters; Nobium ions; Iron ions; Fission; Evaporation1988
42 Truong, ThanhCombined reaction class approach with integrated molecular orbital + molecular orbital (IMOMO) methodology: a practical tool for kinetic modelingWe present a new practical computational methodology for predicting thermal rate constants of reactions involving large molecules or a large number of elementary reactions in the same class. This methodology combines the integrated molecular orbital1molecular orbital (IMOMO) approach with our rece...IMOMO; Kinetic modeling; Thermal rate constants2000
43 Armentrout, Peter B.Communication: Theoretical exploration of Au++ H2, D2, and HD reactive collisionsA quasi-classical study of the endoergic Au+(¹S) + H₂(X¹Σ+g) → AuH+ (²Σ+) + H(²S) reaction, and isotopic variants, is performed to compare with recent experimental results [F. Li, C. S. Hinton, M. Citir, F. Liu, and P. B. Armentrout, J. Chem. Phys. 134, 024310 (2011)]. For this purpose, a ...2011
44 Wight, Charles AlbertCompetitive vaporization and decomposition of liquid RDXThe thermal decomposition of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Activation energies as a function of the extent of conversion, ?, have been determined by model-free isoconversional analysis o...Liquid RDX; Competitive vaporization; Thermal decomposition; Differential scanning calorimetry2000
45 Miller, Joel Steven; Epstein, Arthur J.Complex ac susceptibility studies of the disordered molecular based magnets V(TCNE)x: role of spinless solventThe effect of different spinless solvents on the magnetism of V(TCNE)x . y(solvent) (TCNE= tetracyanoethylene) is studied by temperature (T) dependent ac susceptibility above 2.3 K. Though V(TCNE)x.y(CH2Cl2) has a critical temperature Tc -400 K, for V(TCNEx.y(C4H8O), Tc -205 K and the coercive field...Magnetization; Spin; Temperature1993
46 Fleming Aaron M.Computational studies of electronic circular dichroism spectra predict absolute configuration assignments for the guanine oxidation product 5-carboxamido-5-formamido-2-iminohydantoinOxidation of the guanine heterocycle by two electrons can yield the chiral product 5-carboxamido-5-formamido-2-iminohydantoin (2Ih). The 2Ih free base enantiomers were synthesized from 2'-deoxyguanosine oxidized with a Cu(II)/H2O2 oxidant system followed by hydrolysis of the N-glycosidic bond. These...Guanine oxidation; 2-Iminohydantoin; Electronic circular dichroism; Time-dependent density functional theory2014-12-15
47 Blumenthal, Donald K.; Trewhella, JillConformationally dynamic C helix of the RIalpha subunit of protein kinase A mediates isoform-specific domain reorganization upon C subunit binding.Different isoforms of the full-length protein kinase A (PKA) regulatory subunit homodimer (R2) and the catalytic (C) subunit-bound holoenzyme (R2C2) have very different global structures despite similar molecular weights and domain organization within their primary sequences. To date, it has been th...Protein Isoforms; Global Structures; cAMP2005-10-21
48 Yang, Seung OokConstruction of a protein-based nanoreactor using charge complementarity2012
49 Minteer, Shelley D.Controlled placement of enzymes on carbon nanotubes using comb-branched DNAImmobilization is not only useful for preserving enzyme activity, but also to adhere an enzyme to a surface, such as an electrode, so that the enzyme does not leach into solution during testing. Current immobilization approaches do not readily allow for adjustments to the distance between the enzyme...2014-01-01
50 Miller, Joel StevenConvenient synthesis of C5(CD3)5H. synthesis and characterisation of Fe{n5-C5(CD3)5}2The large scale synthesis of deuterio(pentamethylcyclopentadiene), C5(CD3)5H ([2H30]Cp*H), and subsequent synthesis of [2H30][Fe(n|-Cp*)2] is described, together with i.r., Raman, and solid state 2H n.m.r. spectroscopic characterisation.Organometallic; Catalytic1988
51 Miller, Joel StevenCrystal engineering or crystal mysticism? A case studyThe de novo design and synthesis of a crystalline motif of a substance is a holy grail for a growing number of organic and inorganic synthetic chemists. Achievement of targeted architectural arrangements is less reliable as the complexity increases. Simple substitution of, for example, alkyl penda...Synthesis, Structure, Chemistry2005
52 Miller, Joel StevenCrystal structure and magnetic properties of [Fe{N(CN)2}2(MeOH)2] a 2-D layered network consisting of hydrogen-bonded 1-D chainsA novel 2-D layered network structure [Fe{N(CN)2}2(MeOH)2] was synthesized and characterized by X-ray crystallography, vibrational, and magnetic susceptibility. The neutral 2-D stair-like framework consists of hydrogen-bonded infinite 1-D {Fe[N(CN)2]2} ribbons that pack in a staggered arrangement wh...Solids; Dicyanamide; Ordering1999
53 Miller, Joel Steven; Epstein, Arthur J.Decamethylchromocenium tetracyanoethenide, + [Cr(C5Me5)2]:.+[TCNE].-: a molecular ferromagnet with Tc=3.65 KThe electron-transfer salt 4[Cr(C5Me5)2] + [TCNE].-(TCNE = tetracyanoethylene) has been prepared and structurally characterized by single-crystal X-ray diffraction. It possesses a solid-state motif of parallel 1D chains of alternating radical cations and anions similar to, but not isostructural to, ...Magnetic; Electron transfer; Coupling1993
54 Miller, Joel StevenDecamethylnickelocenium hydrogen-7,7,8,8-tetracyanoperfluoro-p-quinodimethandiide: isolation of the protonated weak base [HTCNQF4]-Unprecedently stable hydrogen-7,7,8,8- tetracyanoperfluoro-p-quinodimethandiide, [HTCNQF4]-, is isolated and crystallographically characterized.Structure; Electron; Transfer1996
55 Morse, Michael DavidDetection of nonpolar lons in 2?3/2 States by Radioastronomy via Magnetic Dipole TransitionsThe possibility of magnetic dipole-induced pure rotational transitions in the interstellar medium is investigated for symmetric Hund?s case (a) linear molecules, such as H-C?C-H+(X~2?3/2u), CO2+ (X~2?3/2g), H-C?C-?C-H+ (X~2?3/2g), and N3 (X~2?3/2g). These species lackan electric dipole moment and th...2011
56 Miller, Joel StevenDimetallic complexes derived from a novel dinucleating chelating symmetric triazole ligand; crystal strcutrue,magnetic properties and ESR study of Bis[μ-3,5-diacetlyamino-1,2,4-triazolato-O',N1,N2,O"]bis[nitrato)(aqua)-copper(II)]Reaction of 3,5-diacetylamino-1,2,4-triazole (Hdaat) with copper(II), nickel(II) and cobalt(II) salts yields dinuclear co-ordination compounds, which were spectroscopically characterized. The crystal and molecular structure of one of the compounds, bis[u-3,5-diacetylamino-1,2,4-triazolato-0'_x0001_,...Susceptibility; Orbitals; Compounds1999
57 Miller, Joel StevenDinuclear iron(II) complex, [(TPyA)FeII(THBQ 2-)FeII(TPyA)](BF4)2 [TPyA = tris(2-pyridylmethyl)amine; THBQ2- = 2,3,5,6-tetrahydroxy-1,4- benzoquinonate] exhibiting both spin crossover with hysteresis and ferromagnetic exchangeDinuclear [(TPyA)FeII(THBQ22)FeII(TPyA)](BF4)2 (1) possesses hydrogen bonding interactions that form a 1-D chain, and p-p interactions between the 1-D chains that give rise to a 2-D supramolecular-layered structure, inducing hysteresis in the spin crossover behavior; 1 has shown spin crossover behav...Dinuclear complexes2008
58 Truong, ThanhDirect ab initio dynamics studies of N + H2<-->NH + H reactionKinetics of the N+H2<-->NH+H reaction have been studied using a direct ab initio dynamics method. Potential energy surface for low electronic states have been explored at the QCISD/ cc-pVDZ level of theory. We found the ground-state reaction is N(4S)+H2-->NH(3Σ-)+H. Thermal rate constants for this ...Ab initio dynamics; Potential energy surfaces; Minimum energy path; Ground-state reaction; Rate constants2000
59 Truong, ThanhDirect ab initio dynamics studies of the hydrogen abstraction reactions of hydrogen atom with fluoromethanesA direct ab initio dynamics study on the gas-phase reactions of atomic hydrogen with different fluoromethanes has been carried out. The thermal rate constants were calculated using canonical variational transition state (CVT) theory augmented by multidimensional semiclassical zero and small curvatur...Hydrogen abstraction reactions; Gas-phase reactions; Fluoromethanes; Thermal rate constants; Moller?Plesset perturbation theory; Hybrid density functional theory1999
60 Miller, Joel Steven; Epstein, Arthur J.Direct evidence of electron spin polarization from an organic-based magnet: [FeII(TCNE)(NCMe)2][FeIII Cl4]Direct evidence of an organic-based magnet with a finite electron spin polarization at the Fermi edge is shown from spin-resolved photoemission of the [FeII(TCNE)(NCMe)2][FeIIICl4] organic-based magnet. The 23% majority-based spin polarization at the Fermi edge is observed at 80 K in zero applied fi...Organic-based magnets; Electron spin polarization2009-05
61 Morse, Michael DavidDispersed fluorsecence spectroscopy of AINi, NiAu, and PtCuDispersed fluorescence studies of AlNi, NiAu, and PtCu have been performed, providing spectroscopic information about the ground and low-lying excited electronic states. Vibrational frequencies are reported for the ground X 2?5/2 state of all three molecules. In the case of AlNi, fluorescence to all...2003
62 Morse, Michael DavidDispersed fluorsecence spectroscopy of jet-cooled AgAu and Pt?Dispersed fluorescence spectroscopy has been used to study jet-cooled AgAu and Pt2 . Fluorescence resulting from the excitation of five bands of the A?X 1?+ system of AgAu was dispersed, and 51 measured ground state vibrational levels were fit to provide ground state vibrational constants of ?"e=198...2001
63 Armentrout, Peter B.Dissociative charge transfer reactions of Ar+, Ne+, and He+ with CF4 from thermal to 50 eVGuided ion-beam techniques are used to measure the cross sections for reaction of CF4 with Ar+, Ne+, and H e + from thermal to 50 eV. Dissociative charge transfer followed by successive loss of F atoms are the major processes observed. Only CFx+ (x = 1,2,3) products are observed in the reactions of ...Ion-molecule reactions; Transfer reactions; Carbon tetrafluoride; Rare gas ions; Exothermic reactions; Endothermic reactions; Plasma systems1990
64 Miller, Joel Steven; Epstein, Arthur J.Dynamic spin fluctuations in the molecular ferromagnet (DMeFc)(TCNE)The static and dynamic magnetic properties of the molecular ferromagnet decamethylferrocenium tetracyanoethenide (DMeFc)(TCNE) are studied via the muon-spin-relaxation technique. Spontaneous order is observed in the ferromagnetic ground state below 5 K, while the muon-spin-relaxation rate in the par...Magnetic; Magnetization; Paramagnetic2001
65 Miller, Joel Steven; Epstein, Arthur J.Effect of disorder on the linear and nonlinear magnetic susceptibilities of two manganeseporphryin-based magnetsWe analyze the effects of disorder on the magnetic properties of two manganeseporphyrins, [MnTPP][TCNE] •. x(o-DCB) and [MnTPP][TCNE] . • y(o-Xy) and (TPP=meso-tetraphenylporphyrinato, TCNE=tetracyanoethylene, o-Xy=o-xylene, o-DCB=o-dichlorobenzene, x<_3,y<_1). We present data for the in- ...Magnetization; Ferrimagnetic; Spins1997
66 Armentrout, Peter B.Effect of kinetic and electronic energy on the reactions of Cr+ with H2, HD, and D2The reactions of atomic chromium ions with H2 , HD, and D2 are examined using guided ion beam tandem mass spectrometry. The ground electronic state (6S) is found to react inefficiently. The thresholds of these data are analyzed to yield a 0 K bond dissociation energy for CrH+ of 1.37 ± 0.09 eV (31...Chromium ions; Hydrogen; Deuteride; Bond energy1987
67 Armentrout, Peter B.Effect of kinetic and electronic energy on the reactions of Mn+ with H2, HD and D2Reactions of several electronic states of Mn+ with H2, HD, and D2 have been examined using guided ion beam mass spectroscopy. The excitation function for the ground state of Mn+ ( 75) has two regions: one of very low reactivity at threshold and another more efficient pathway at higher energies. In ...Ion-molecule reactions; Translational energy; Bond energy; Threshold behavior; Endothermic reactions; Metal ions; Manganese; Hydrogen1986
68 Miller, Joel Steven; Epstein, Arthur J.Effect of solvent on the magnetic properties of the high-temperature V[TCNE]x molecule-based magnetThe different magnetic behaviors of the V[TCNE]x (TCNE=tetracyanoethylene) magnet prepared via the reaction of TCNE and V(CO)6 in CH2Cl2 and the solvent-free chemical vapor deposition (CVD) of TCNE and V(CO)6 onto a glass substrate were determined. It was shown that the presence of noncoordinating C...Magnetization; Molecule2001
69 Miller, Joel StevenEffect of thermal annealing on the ferrimagnetic behavior and ordering of the [MnTXPP]+[TCNE].-.solv (X=F, Cl, Br, I; solv = PhMe, CH2Cl2) family of magnets+5,10,15,20-Tetrakis(4-fluorophenyl)porphyrinatomanganese(III) tetracyanoethenide, [MnTFPP][TCNE], 1F, 5,10,15,20-tetrakis(4-bromophenyl)porphyrinatomanganese(III) tetracyanoethenide, [MnTBrPP][TCNE], 1Br, and 5,10,15,20-tetrakis(4-iodophenyl)porphyrinatomanganese(III) tetracyanoethenide, [MnTIPP][T...Magnetic; Coupling2000
70 Borodai, Anastasia S.The effects of various metal ions on the folding of G-quadruplexesDivalent metal cations inhibit the folding of G-QuadruplexesG-Quadruplex; Divalent cations; Metal ions; Nucleic acids; Guanine; Tetrads2015-03-31
71 Miller, Joel Steven; Epstein, Arthur J.Elastic properties of (N(CH3)3H) (I) (TCNQ)We present the results of a study of the temperature dependence of the Young's modulus and internal friction of (N(CH3 )3H)(I)(TCNQ). The Young's modulus was measured in a direction parallel to the TCNQ (tetracyanoquinodimethane) stacking axis using a vibrating reed technique. The results confirmed ...Metal-like, Conductivity, Magnetic1979
72 Armentrout, Peter B.Electron impact ionization cross section of metastable N2(A Σu+)Extensive studies of electron impact cross sections have been carried out both experimentally and theoretically for a number of ground state atoms and molecules.1 In general, as the electron energy is increased, such cross sections rise from a threshold at the ionization potential to a peak at an e...Ion beam; Nitrogen1981
73 Morse, Michael DavidElectron spin resonance investigation of Sc?+ in neon matrices and assignment of its ground electronic state as X ???. comparison with theoretical calculationsThe discandium radical cation, Sc+2 , has been isolated in neon matrices at 4 K and studied by electron spin resonance (ESR) spectroscopy and theoretical methods. It was produced by the x-irradiation of neon matrix samples containing neutral ScZ which was formed by trapping the products generated fr...1993
74 Morse, Michael DavidElectron-spin resonance studies of the titanium cation (Ti+,3d?, ?F) in rare gas matrices at 4 K: A crystal field interpretationElectron-spin resonance studies of laser-ablated titanium metal isolated in neon and argon display an intense feature which exhibits a symmetric, narrow line and a large matrix-dependent g shift. On the basis of a number of experiments, this is assigned to a matrix isolated 3d3,4F Ti+ ion in an octa...1996
75 Wight, Charles Albert; Anderson, Richard BryanElectronic publication of theses and dissertationsFor many years, the university has required its doctoral students to print and publish their dissertations. After a dissertation has been approved for release by the Graduate School thesis editors and the student has been approved for graduation, the university sends one copy of the manuscript to Pr...Electronic publication; Theses; Dissertations2010
76 Morse, Michael DavidElectronic spectroscopy and electronic structure of diatomic CrCOptical spectra of jet-cooled diatomic CrC have been recorded in the near infrared region using resonant two-photon ionization spectroscopy combined with mass-selective detection of the resulting ions. Several weak transitions have been observed, along with one relatively strong band near 842 nm. Ro...2010
77 Voth, Gregory AlanElectronic structure calculation of the structures and energies of the three pure polymorphic forms of crystalline HMXThe molecular structures and energetic stabilities of the three pure polymorphic forms of crystalline HMX were calculated using a first-principles electronic-structure method. The computations were performed using the local density approximation in conjunction with localized "fireball" orbitals and ...HMX; Crystalline HMX; Molecular geometry2000
78 Morse, Michael DavidElectronic structure of the 4 d transition metal carbides: dispersed fluorsecence spectroscopy of MoC, RuC, and PdCDispersed fluorescence studies of the diatomic molecules MoC, RuC, and PdC are reported. New states identified in MoC and RuC are the [...]2??12??, ?,??? states and the [...]2??12??, ??? state, respectively. Five states are observed by dispersed fluorescence in PdC. The ground state is found to be [...2011
79 Morse, Michael DavidElectronic structure of the 4d transition metal carbides: dispersed fluorescence spectroscopy of MoC, RuC, and PdCDispersed fluorescence studies of the diatomic molecules MoC, RuC, and PdC are reported. New states identified in MoC and RuC are the [...]2?112?1, 3,1?2 states and the [...]2? 312?1, 1?2 state, respectively. Five states re observed by dispersed fluorescence in PdC. The ground state is found to be [...2001
80 Armentrout, Peter B.Endothermic reactions of uranium ions with N2, D2, and CD4The assessment of new technology for isotope separation has revived an interest in the spectroscopy, properties, and reactions of uranium and its compounds. Newer methods which have been demonstrated include the use of lasers to selectively excite a particular uranium isotope with subsequent chemic...Uranium ions; Nitrogen1977
81 Armentrout, Peter B.Energetics and dynamics in the reaction of Si+ with SiF4. Thermochemistry of SiFx and SiFx+ (x=1,2,3)The title reaction is studied using guided ion beam mass spectrometry. Absolute reaction cross sections are measured as a function of kinetic energy from thermal to 40 eV, and three endothermic product channels are observed. The dominant SiF+ + SiF3 channel is only slightly endothermic, while the ...Silicon fluoride; Ion-molecule reactions; Kinetic energy; Threshold behavior; Endothermic reactions1988
82 Armentrout, Peter B.Energy dependence, kinetic isotope effects, and thermochemistry of the nearly thermoneutral reactions of N+(3P) + H2(HD, D2) → NH+(ND+) + H(D)The reactions of N + (3P) ions with H2 , HD, D2 are examined using guided ion beam tandem mass spectroscopy. Absolute reaction cross sections are measured from near thermal energies to 30 eV relative energy. The low energy cross section behavior is analyzed using empirical threshold models and ph...Thermoneutral reactions; Ion-molecule reactions; Translational energy; Bond energy; Threshold behavior; Phase space theory1987
83 Poulter, Charles DaleEnzymes encoded by the farnesyl diphosphate synthase gene family in the big sagebrush Artemisia tridentata ssp. spiciformisFarnesyl diphosphate synthase catalyzes the sequential head-to-tail condensation of two molecules of isopentenyl diphosphate with dimethylallyl diphosphate. In plants the presence of farnesyl diphosphate synthase isozymes offers the possibility of differential regulation. Three full-length cDNAs enc...Amino Acid Sequence; Base Sequence; Molecular Sequence Data2003-08-22
84 Wight, Charles AlbertEstimating realistic confidence intervals for the activation energy determined from thermoanalytical measurementsA statistical procedure is proposed for estimating realistic confidence intervals for the activation energy determined by using an advanced isoconversional method. Nine sets of five thermogravimetric measurements have been produced for the process of gassification of ammonium nitrate at five differe...Thermoanalysis; Activation energy; Isoconversional method2000
85 Miller, Joel Steven; Epstein, Arthur J.Evidence for solitons in conducting organic charge-transfer crystalsMagnetic susceptibility of (N-methylphenazinium)x(phenazine)(1-x (tetracyanoquinodimethanide) [(NMP)x(Phen)1-x(TCNQ)] shows the formation of defect states for 0.5<x<0.54. Diffuse x-ray scattering and g-value studies indicate that these defects are solitons formed in the highly correlated quasi-one-...TCNQ; X-ray scattering1982
86 Miller, Joel StevenFar-infrared powder spectrum of (N(CH3)3D)(I)(TCNQ)We present the powder absorption spectrum of (TMA)(I)(TCNQ) in the far-infrared as a function of temperature. Below 160 K new absorption features appear and others increase in intensity. This behaviour supports the electron- neutron-diffraction evidence of a distortion on the TCNQ chains below the f...Conductivity, Crystals, Electrons1983
87 Miller, Joel StevenFar-infrared properties of trimethylammonium iodide tetracyanoquinodimethaneWe present the powder absorption spectrum of (TMA) (I)(TCNQ) in the far-infrared as a function of temperature. Below 16 K new absorption features appear and others increase in intensity. This behaviour supports the electron and neutron diffraction evidence of a distortion on the TCNQ chains below...Trimethylammonium iodide tetracyanoquinodimethane; TCNQ1983
88 Poulter, Charles DaleFarnesyl diphosphate synthetase: molecular cloning, sequence, and expression of an essential gene from Saccharomyces cerevisiaeFarnesyl diphosphate (FPP) synthetase is a key enzyme in isoprenoid biosynthesis which supplies C15 precursors for several classes of essential metabolites including sterols, dolichols, and ubiquinones. The structural gene for FPP synthetase was isolated on a 4.5-kilobase EcoRI genomic restriction f...Genetics; Transferases; Dimethylallyltranstransferase/biosynthesis1989-11-15
89 Poulter, Charles DaleFarnesyl pyrophosphate synthetase. Mechanistic studies of the 1'-4 coupling reaction with 2-fluorogeranyl pyrophosphate.The mechanism of the 1'-4 coupling reaction between isopentenyl pyrophosphate and geranyl pyrophosphate catalyzed by farnesyl pyrophosphate synthetase from porcine liver was studied with the allylic substrate analogue 2-fluorogeranyl pyrophosphate. 2-Fluorogeranyl pyrophosphate is an alternate subst...Kinetics; Liver; Mass Spectrometry; Organophosphorus Compounds; Protein Binding1978-10-25
90 Miller, Joel StevenFerrimagnetic ordering of a methylthio-substituted planar porphyrin based electron transfer salt, octakis(2,3,7,8,12,13,17,18-methylthio)porphyrinatomanganese(III) tetracyanoethanideThe direct redox reaction between tetracyanoethylene (TCNE) and a planar porphyrinatomanganese(II), octakis(2,3,7,8,12,13,17,18-methylthio)porphyrinatomanganese(II), MnIIOMTP, produced a polymeric electron transfer salt (ETS), that has been structurally and magnetically characterized. The ETS belon...Magnetic; Temperature; Coupling2000
91 Miller, Joel StevenFerrimagnetic ordering of one-dimensional N,N'-dicyanoquinone diimine (DCNQI) electron transfer salts with porphyrinatomanganese(II)*The redox reaction between N,N'-dicyanoquinone diimines (DCNQIs) and porphyrinatomanganese(II) produced electron transfer salts (ETSs), [MnIIITMesP]+[DMeO-DCNQI]-. 1 (MnIIITMesP=meso-tetrakis(2,4,6- trimethylphenyl)porphyrinatomanganese(III), DMeO-DCNQI=2,5-dimethoxy-N,N'-dicyanoquinone diimine) an...Transitions; Interactions; Magnetic2001
92 Miller, Joel Steven; Epstein, Arthur J.Ferrimagnetic resonance in films of vanadium [tetracyanoethanide]x, grown by chemical vapor depositionFerrimagnetic resonance (FMR) measurements in thin films of V[TCNE]x grown by chemical vapor deposition exhibit a series of sharp lines at 300 K. The orientational dependence of these lines is a result of the sample geometry provided the magnetization tracks the applied magnetic field. The FMR inten...Spin; Anisotropy; Magnetization2004
93 Miller, Joel Steven; Epstein, Arthur J.Ferromagnetic behavior and magnetic excitations in a molecular-based alternating-spin chain: decamethylchromocenium tetracyanoethenideWe report the study of magnetic properties of a molecular-based alternating-spin chain: metallocenium electron-transfer salt decamethylchromocenium tetracyanoethanide, [CrCp(*2)] [TCNE]. We give a modified spin-wave theory for the Heisenberg alternating-spin chains. The low-field susceptibility and...TCNE; Magnetization1994
94 Miller, Joel Steven; Epstein, Arthur J.Ferromagnetic behavior of decamethylchromocenium tetracyanoethenide, [CrCp*2][TCNE]Studies on the magnetic properties of decamethylchromocenium tetracyanoethanide, [CrCp*2][TCNE] are reported herein. Near-zero field (H= 150 mG) data indicates a ferromagnetic transition with T(c)=3.65 K. The temperature dependence below T(c) can be fit to a mean-field result M=M(o)(1 - T(o))(1/2)...Magnetic; Magnetization; Transition1993
95 Miller, Joel Steven; Epstein, Arthur J.Ferromagnetic properties of one-dimensional decamethylferrocenium tetracyanoethylenide (1:1): [Fe(n5-C5Me5)2].+[TCNE].-[Fe(C5Me5)2].+ [TCNE].-- has been characterized by magnetic susceptibility to possess dominant ferromagnetic interactions; its structure has been determined by X-ray crystallography.Susceptibility; Crystal; Magnetic1986
96 Miller, Joel Steven; Epstein, Arthur J.Ferromagnetism in molecular decamethylferrocenium tetracyanoethylenide: (DMeFc TCNE)The temperature and magnetic field dependence of the magnetization and susceptibility of single-crystal decamethylferrocenium tetracyanoethenide demonstrate that this material is the first molecular compound with a ferromagnetic ground state. A spontaneous magnetization is observed for T < 4.8 K. T...Magnetization; Ferromagnetic1987
97 Miller, Joel Steven; Epstein, Arthur J.Ferromagnetism in molecular materials: decamethylferrocenium tetracyanoethanide [DMeFc][TCNE] (invited)Ferromagnetism has only recently been observed in molecular materials. We present here a summary of the ferromagnetic phenomena observed in the molecular charge transfer salt, decamethylferrocenium tetracyanoethanide (DMeFc) (TCNE), and related compounds. A spontaneous magnetization is observed i...Magnetic; Magnetization1988
98 Armentrout, Peter B.Fifty years of ion and neutral thermochemistry by mass spectrometryOriginating with the appearance potentials for "positive rays", the ability of mass spectrometry to obtain quantitative information about the energetics of both ions and neutrals has evolved dramatically. About 50 years ago, many of the techniques that are now common place were first implemented, th...2014-01-01
99 Morse, Michael DavidFirst spectroscopic investigation of the 4 d transition metal monocarbide MoCThe first optical spectroscopic investigation of MoC has revealed a complicated vibronic spectrum consisting of about 35 bands between 17 700 and 24 000 cm-1. Analysis has shown the ground state to be the ?=0+ spin?orbit component of a 3?- state that derives from a 10?211?25rr42d 2 configuration. Th...1998
100 Miller, Joel StevenFormation of a zwitterionic donor-acceptor compound based on N,N,N',N'-tetramethly-p-phenylenediamine and 7,7,8,8-tetracyanoperfluoro-p-quinodimethaneThe reaction of the donor N,N,N',N'- tetramethyl-p-phenylenediamine (TMPD) with the acceptor 7,7,8,8-tetracyanoperfluoro-p-quinodimethane (TCNQF4) has led to the isolation of a novel type of zwitterionic donor-acceptor compound whose structure has been determined by X-ray crystallography.Ccrystals; Single bond1988
101 Miller, Joel StevenFormation of Ni[C4(CN)8] from the reaction of Ni(COD)2 (COD = 1,5-cyclooctadiene) with TCNE in THFThe dissolution of Ni(COD)2 (COD = 1,5-cyclooctadiene) into dichloromethane leads to decomposition and formation of a room temperature magnetic material, whereas the reaction of Ni(COD)2 and tetracyanoethylene (TCNE) in THF forms paramagnetic materials including NiII[C4(CN)8](THF)2.xTHF. These resu...Dinuclear complexes2007
102 Miller, Joel Steven; Epstein, Arthur J.Forthcoming attractionsMagnets made from molecules and ions having spins in p orbitals have only been discovered in the past decade. Their solubility in organic solvents and room temperature manufacture means that they should find a variety of applications.Electron; Temperature; Magnets1994
103 Armentrout, Peter B.Fragmentation reactions of thiourea- and urea-compounds examined by tandem MS-, energy-resolved CID experiments, and theoryFragmentation reactions of thiourea- and urea-compounds, which are promising reagents for chemical crosslinking (XL), are investigated in detail by collision-induced dissociation (CID) experiments in a quadrupole ion trap (QIT), energy-resolved CID experiments, and computational modeling. For this s...2012-01-01
104 Voth, Gregory AlanFurther developments in the local-orbital density-functional-theory tight-binding methodQuantum-mechanical methods have become increasingly reliable as a complementary tool to experimental research. A variety of methods exist ranging in complexity from semiempirical methods to density-functional-theory (DFT) methods [using either the local-density approximation (LDA) or the generalize...Sankey-Niklewaki method; Fireball method; Pseudopotential; Exchange-correlation interactions; Gallium nitride; H20 dimer; Copper; gas-phase HMX2001-10
105 Morse, Michael DavidThe ground state and excited ?-hole states of CuAuResonant two-photon ionization spectroscopy has been applied to jet-cooled diatomic CuAu. Eight band systems have been observed, rotationally resolved, and analyzed. The ground state is X??+ in symmetry, deriving from the 3d??Cu 5d??Au, ?? molecular configuration. Its bond length has been determined...1991
106 Armentrout, Peter B.Guided ion beam and theoretical studies of sequential bond energies of water to sodium cysteine cationAbsolute bond dissociation energies of water to sodium cysteine (Cys) cations and cysteine to hydrated sodium cations are determined experimentally by collision-induced dissociation of Na+Cys(H2O)x, where x = 1 - 4, complexes with xenon in a guided ion beam mass spectrometer. Experimental results sh...2010-01-01
107 Armentrout, Peter B.Guided ion beam and theoretical studies of the reaction of Ag+ with CS2: gas-phase thermochemistry of AgS+ and AgCS+ and insight into spin-forbidden reactionsThe gas-phase reactivity of the atomic transition metal cation, Ag+, with CS2 is investigated using guided-ion beam mass spectrometry. Endothermic reactions forming AgS+ and AgCS+ are observed but are quite inefficient. This observation is largely attributed to the stability of the closed shell Ag+(...2010
108 Armentrout, Peter B.Guided ion beam and theoretical studies of the reaction of Ru+ with CS2 in the gas-phase: thermochemistry of RuC+, RuS+, and RuCS+Abstract: The gas-phase reactivity of the atomic transition metal cation, Ru+, with CS2 is investigated using guided-ion beam mass spectrometry (GIBMS). Endothermic reactions forming RuC+, RuS+, and RuCS+ are observed. Analysis of the kinetic energy dependence of the cross sections for formation of ...2010
109 Armentrout, Peter B.Guided ion beam and theoretical study of the reactions of Au+ with H2, D2, and HDReactions of the late third-row transition metal cation Au+ with H2, D2, and HD are examined using guided ion beam tandem mass spectrometry. A flow tube ion source produces Au+ in its 1S (5d10) electronic ground state level. Corresponding state-specific reaction cross sections for forming AuH+ an...2011
110 Armentrout, Peter B.Guided ion beam and theoretical study of the reactions of Hf+ with H2, D2, and HDThe kinetic energy dependences of reactions of the third-row transition metal cation Hf+ with H2, D2, and HD were determined using a guided ion beam tandem mass spectrometer. A flow tube ion source produces Hf+ in its 2D (6s25d1) electronic ground state level. Corresponding state-specific reaction c...2010-01-01
111 Armentrout, Peter B.Guided ion beam and theoretical study of the reactions of Os + with H 2, D 2, and HDReactions of the third-row transition metal cation Os+ with H2, D2, and HD to form OsH+ (OsD+) were studied using a guided ion beam tandem mass spectrometer. A flow tube ion source produces Os+ in its 6D (6s15d6) electronic ground state level. Corresponding state-specific reaction cross sections are...2011
112 Armentrout, Peter B.Guided ion beam studies of the reaction of Nin+ (n=2-16) with D2: nickel cluster-deuteride bond energiesThe kinetic-energy dependences of the reactions of Nin+ (n=2-16) with D2 are studied in a guided ion beam tandem mass spectrometer. The products observed are NinD+ for all clusters and NinD2 + for n=5-16. Reactions for formation of NinD+ are observed to exhibit thresholds, whereas cross sections for...Metal clusters; Nickel ions; Bond energies; Deuterides; Collision-induced dissociation; Endothermic reactions2002
113 Armentrout, Peter B.Guided ion beam studies of the reactions of Crn + (n=2-18) with O2: chromium cluster oxide and dioxide bond energiesThe kinetic energy dependence of the reactions of Crn+ (n=2-18) with O2 are studied in a guided ion beam mass spectrometer. A variety of CrmO2+, CrmO+, and Crm+ product ions, where m≤n, are observed, with the dioxide cluster ions dominating the products for all larger reactant cluster ions. React...Metal clusters; Chromium ions; Oxygen; Oxygen; Bond energies; Exothermic reactions1998
114 Armentrout, Peter B.Guided ion beam studies of the reactions of Crn+ (n=1-18) with CO2: chromium cluster oxide bond energiesThe kinetic energy dependence of the reactions of Crn+ (n=1-18) with CO2 are studied in a guided ion beam mass spectrometer. The primary product ions are CrnO+, which then decompose by sequential loss of chromium atoms as the kinetic energy is increased. Simple collision-induced dissociation to form...Metal clusters; Chromium ions; Oxygen; Bond energies; Exothermic reactions; Endothermic reactions1998
115 Armentrout, Peter B.Guided ion beam studies of the reactions of Nin+ (n=2-18) with O2: nickel cluster oxide and dioxide bond energiesThe kinetic energy dependences of the reactions of Nin + (n=2 - 18) with O2 are studied in a guided ion beam tandem mass spectrometer. A variety of NimO2+, NimO+, and Nim+ product ions, where m<n, are observed, with the dioxide cluster ions dominating the products for all larger reactant cluster io...Metal clusters; Nickel oxide; Nickel dioxide; Bond energies; Collision-induced dissociation; Exothermic reactions2003
116 Armentrout, Peter B.Guided ion beam studies of the reactions of Vn+ (n = 2-13) with D2: cluster-deuteride bond energies as a chemical probe of cluster electronic structureThe kinetic energy dependencies of the reactions of Vn+ (n=2 - 13) with D2 are studied in a guided ion beam tandem mass spectrometer. Products observed are VnD1 for all clusters and VnD2 + for n=4 - 13. All reactions are observed to exhibit thresholds, except for formation of VnD2 + for n =4,5,7,9,1...Metal clusters; Vanadium ions; Bond energies; Endothermic reactions; Collision-induced dissociation; Transition metal ions; Deuterides2002
117 Armentrout, Peter B.Guided ion beam study of collision-induced dissociation dynamics: integral and differential cross sectionsThe low energy collision-induced dissociation (CID) of Cr(CO)6+ with Xe is investigated using a recently modified guided ion beam tandem mass spectrometer, in the energy range from 0 to 5 eV in the center-of-mass (CM) frame. The additions to the instrument, updated with a double octopole system, and...Collision-induced dissociation; Bond energies; Chromium carbonyl; Xenon2001
118 Armentrout, Peter B.Guided ion-beam studies of the kinetic-energy-dependent reactions of Con+ (n=2-16) with D2: cobalt cluster-deuteride bond energiesThe kinetic-energy-dependent cross sections for the reactions of Con + (n=2-16) with D2 are measured as a function of kinetic energy over a range of 0-8 eV in a guided ion-beam tandem mass spectrometer. The observed products are ConD+ for all clusters and ConD2+ for n=4,5,9-16.Cobalt ions; Metal clusters; Deuteride; Collision-induced dissociation; Endothermic reactions; Bond energies2005
119 Armentrout, Peter B.Guided ion-beam studies of the reactions of Con + (n=2-20) with O2: cobalt cluster-oxide and -dioxide bond energiesThe kinetic-energy dependence for the reactions of Con + (n=2-20) with O2 is measured as a function of kinetic energy over a range of 0 to 10 eV in a guided ion-beam tandem mass spectrometer. A variety of Com+ , ComO+, and ComO2 + (m<n) product ions is observed, with the dioxide cluster ions domina...Metal clusters; Cobalt ions; Collision-induced dissociation; Bond energies; Exothermic reactions; Endothermic reactions2005
120 Truong, ThanhHigh level ab initio and density functional theory evaluation of combustion reaction energetics: NO2 and HONO elimination from dimethylnitramineDimethylnitramine (DMNA) is used as a model system for investigating accurate and efficient electronic structure methods for nitramines. Critical points on the potential energy surfaces of DMNA, CH3NCH3, CH3NCH2, NO2, HONO, and the transition state to HONO elimination were located through geometry o...Dimethylnitramine; DMNA; Nitramines; Combustion reaction energetics1999
121 Minteer, Shelley D.High performance glucose/O2 biofuel cell: effect of utilizing purified laccase with anthracene-modified multi-walled carbon nanotubesLaccase, a blue multicopper oxidoreductase enzyme, is a robust enzyme that catalyzes the reduction of oxygen to water and has been shown previously to perform improved direct electron transfer in a biocathode when mixed with anthracene-modified multi-walled carbon nanotubes. Previous cathode constru...2012-01-01
122 Armentrout, Peter B.Hydrogen atom transfer reactions of He+ and Ne+ with H2, D2, and HDThe hydrogen atom transfer reactions of helium (1 +) and neon(1+) ions with isotopic molecular hydrogen (H2 , D2 , and HD) are investigated using guided ion beam techniques. These reactions are exothermic, but are known to be extremely slow at thermal energies. The cross sections for formation of...Transfer reactions; Ion-molecule reactions; Exothermic reactions; Hydrogen; Helium ions; Neon ions; Threshold behavior; Isotope effects1987
123 Voth, Gregory Alan; Sarofim, Adel F.Identification of pathways for polyaromatic growth using molecular dynamicsReaction pathways for polyaromatic growth in combustion environments are explored theoretically using molecular dynamic techniques. The reaction systems considered include cyclization reactions that involve H atom migration. Specifically we examine the absorption of acetylene on an aromatic ring rad...2004
124 Truong, ThanhImportance of polarization in simulations of condensed phased energetic materialsAn embedded cluster model is used to estimate the molecular dipole moment of crystalline dimethylnitramine (DMNA). The electrostatic potential due to the crystal is included in the calculation via the SCREEP (surface charge representation of the electrostatic embedding potential) approach. The resul...Dimethylnitramine; DMNA; Embedded cluster model1999
125 Minteer, Shelley D.Improved performance of a thylakoid bio-solar cell by incorporation of carbon quantum dotsCarbon quantum dots (CQDs) were incorporated into thylakoid bioanodes capable of direct photobioelectrocatalysis in order to increase the photocurrent generation. More thylakoids are in contact with the increased surface area which allows for greater direct electron transfer (DET). Additionally, the...2014-01-01
126 Minteer, Shelley D.In recognition of Adam Heller and his enduring contributions to electrochemistryRecent progress in diverse scientific fields ranging from bioelectrochemistry to battery technology to photoconversion has been deeply influenced by the contributions of Professor Adam Heller of the University of Texas at Austin to electrochemistry and materials science. This focus issue recognizes ...2014-01-01
127 Stang, Peter J.Incorporation of flexible pyridine-functionalized ligands into discrete supramolecules via coordination-driven self-assemblyFlexible, pyridine-functionalized ligands were self-assembled into discrete supramolecules of differing stoichiometries upon combination with various organoplatinum molecules. They are characterized by electrospray ionization mass spectrometry, 31P(iHI and 'H NMR. Despite its inherent flexibility, 3...Self-assembly; Coordination-driven; Transition-metal-mediated; Flexible ligands; Pyridyl ligands; Supramolecules2004
128 Morse, Michael DavidInfrared diode laser spectroscopy of jet-cooled NiCO, Ni(CO)?(??CO), and NI(CO)?(c??O)Gas phase infrared spectroscopic investigations of the CO vibration of jet-cooled NiCO, Ni(CO)3(13CO), and Ni(CO)3(C18O) are reported. The spectra were obtained using a recently assembled pulsed-discharge slit-jet IR diode laser spectrometer. The rotationally resolved spectrum of NiCO was collected ...2006
129 Armentrout, Peter B.Infrared multiple photon dissociation spectroscopy of cationized cysteine: effects of metal cation size on gas-phase conformationAbstract The gas-phase structures of cationized cysteine (Cys) including complexes with Li+, Na+, K+, Rb+, and Cs+, as well as protonated Cys, are examined by infrared multiple photon dissociation (IRMPD) action spectroscopy utilizing light generated by a free electron laser, in conjunction with q...2010
130 Armentrout, Peter B.Infrared multiple photon dissociation spectroscopy of cationized methionine: effects of alkali-metal cation size on gas-phase conformationPlease note that as of 11-07-2012, access to this article through USpace had to be restricted. The gas-phase structures of alkali-metal cation complexes of the amino acid methionine (Met) as well as protonated methionine are investigated using infrared multiple photon dissociation (IRMPD) spectros...2010
131 Armentrout, Peter B.Infrared multiple photon dissociation spectroscopy of protonated histidine and 4-phenyl imidazoleThe gas-phase structures of protonated histidine (His) and the side-chain model, protonated 4-phenyl imidazole (PhIm), are examined by infrared multiple photon dissociation (IRMPD) action spectroscopy utilizing light generated by the free electron laser FELIX. To identify the structures present in t...2012-01-01
132 Miller, Joel StevenInnovation in crystal engineeringThe first CrystEngComm discussion meeting on crystal engineering has demonstrated that the field has reached maturity in some areas (for example: design strategies, characterization of solid compounds, topological analysis of weak and strong non-covalent interactions), while the quest for novel pro...Research; Design; Molecular2002
133 Morse, Michael DavidInteraction of an aluminum atom with a closed subshell metal atom: spectroscopic analysis of AIZnResonant two-photon ionization spectroscopy has been employed to investigate diatomic AlZn produced by laser vaporization of a 1:2 Al:Zn alloy target disk in a supersonic expansion of helium. Several discrete transitions are reported in the energy range from 18 400 to 19 100 cm-?. Most of these are...1994
134 Morse, Michael DavidInteraction of an aluminum atom with an alkaline earth atom: spectroscopic and ab initio investigations of AICaA spectroscopic analysis of diatomic AlCa generated by laser vaporization of a 2:1 AI:Ca metal alloy followed by supersonic expansion has been completed using resonant two-photon ionization spectroscopy. Four excited electronic states have been identified and investigated in the energy region from 1...1994
135 Miller, Joel StevenInterpenetrating three-dimensional rutile-like frameworks. Crystal structure and magnetic properties of MnII[C(CN)3]2The interpenetrating double-density rutile-like structure and magnetic properties of MnII[C(CN)3]2 are determined.Spin; Bond; Coupling1998
136 Minteer, Shelley D.Investigating the reversible inhibition model of laccase by hydrogen peroxide for bioelectrocatalytic applicationsThe reversible inhibition of laccase by H2O2 as a bioelectrocatalyst was studied in mediated- and direct electron transfer-based configurations to understand the differences in mechanism. The reversible inhibition of laccase follows a noncompetitive inhibition model when 2,2-azino-bis(3-ethylbenzoth...2014-01-01
137 Miller, Joel StevenInvolvement of titanocene and related species in the reduction of dinitrogen and olefinsSummary Four sequential products have been spectrally detected in the reduction by sodium of dicyclopentadienyltitanium(iv) dichloride: [(77-Cp)2TiCl]2, [(77-Cp)2-Ti]1-2, [(77-Cp)(C5H4)TiH]x, and (77-Cp)(C5H4)TiH2Ti- (C5H4)(77-Cp) ("stable titanocene"); the second of these reacts rapidly and rever...Hydrolysis; Sodium; Pressure1972
138 Armentrout, Peter B.IR spectroscopy of cationized aliphatic amino acids: stability of charge-solvated structure increases with metal cation sizeAbstract Gas-phase structures of alkali metal cationized (Li+, Na+, K+, Rb+, Cs+) proline (Pro) and N-methyl alanine have been investigated using infrared multiple photon dissociation (IRMPD) spectroscopy utilizing light generated by a free electron laser and computational modeling. Measured IRMPD...2010-11
139 Miller, Joel StevenIsolation and structural determination of octacyanobutanediide, [C4(CN)8]2-; precursors to M(TCNE)x magnets(**)The reaction of MI2.xMe3CN (M = Mn, Fe) and TCNE (tetracyanoethylene) leads to unprecedented [C4(CN)8]2-U4-metal complexes which have been crystallographically characterized and are precursors to M(TCNE)x-yS magnets.Absorptions; Magnets; Bond1998
140 Miller, Joel StevenIsolation and structural determination of {(1,1,2,2-tetracyano-1,2-ethanediyl)bis[imino(cyanomethylene)]}bis-(cyanamide) ion(2--), [C12N12]2--, a new cyanocarbonThe oxidative degradation of [N(PPh3)2]3[Mnilll(CN)6] leads to the isolation of the unprecedented [C12N12]2- dianion, which is characterized by single-crystal X-ray diffraction and spectroscopic techniques.Cyanogen; Bond; Absorptions1995
141 Poulter, Charles DaleIsolation of Schizosaccharomyces pombe isopentenyl diphosphate isomerase cDNA clones by complementation and synthesis of the enzyme in Escherichia coliIsopentenyl diphosphate (IPP) isomerase catalyzes an essential activation step in the isoprene biosynthetic pathway. The Saccharomyces cerevisiae gene for IPP isomerase, IDI1, was recently isolated and characterized (Anderson, M. S., Muehlbacher, M., Street, I. P., Proffitt, J., and Poulter, C. D. (...Carbon-Carbon; Biosynthesis; Genetics1995-05-12
142 Miller, Joel StevenIsolation of two salts from the reduction of TCNE with [(n-C3H7)4N]I. A further example of long 2.87 Ã pi-C-C bonding in pi-[TCNE]22-Reduction of tetracyanoethylene, TCNE, with tetrakis(n-propyl)ammonium iodide, [Pr4N]I, results in a new example of long pi*-CC bonded pi-[TCNE]22- dimers with a 2.870(4) A(°) intradimer CC bond, which is structurally and spectroscopically characterized. This reaction also results in isolation of ...Synthesis; Intradimer; Crystals2002
143 Miller, Joel StevenIsomeric conformations in a pentaco-ordinated ruthenium compound: crystal and molecular structures of the orange and violet isomers of (Ph3P)2[(CF3)2C2S2]Ru(CO)Summary The molecular conformations of two square pyramidal species, one violet the other orange, both composition (Ph3P)2[(CF3)2C2S2]Ru(CO) are described.Pyramidal, Radiation,1973
144 Poulter, Charles DaleIsopentenyl diphosphate:dimethylallyl diphosphate isomerase. An improved purification of the enzyme and isolation of the gene from Saccharomyces cerevisiae.Isopentenyl diphosphate:dimethylallyl diphosphate isomerase (IPP isomerase) is an enzyme in the isoprenoid biosynthetic pathway which catalyzes the interconversion of the primary five-carbon homoallylic and allylic diphosphate building blocks. We report a substantially improved procedure for purific...Amino Acid Sequence; Base Sequence; Chromatography, Gel; Chromatography, Ion Exchange1989-11-15
145 Poulter, Charles DaleIsoprenyl diphosphate synthases: protein sequence comparisons, a phylogenetic tree, and predictions of secondary structureIsoprenyl diphosphate synthases are ubiquitous enzymes that catalyze the basic chain-elongation reaction in the isoprene biosynthetic pathway. Pairwise sequence comparisons were made for 6 farnesyl diphosphate synthases, 6 geranylgeranyl diphosphate synthases, and a hexaprenyl diphosphate synthase...Catalytic site; Evolution; Farnesyl diphosphate; Geranylgeranyl diphosphate; Prenyltransferase; Substrate binding:1994
146 Armentrout, Peter B.Kinetic energy dependence of Al+ + O2→AlO+ + OThe endothermic reaction of Al+ with O2 is studied using a guided ion-beam apparatus. The reaction cross section is measured as a function of kinetic energy from 0 to 20 eV. The threshold energy for the reaction, E0, is determined from an empirical model to be 3.64 ± 0.04 eV.Ion-molecule reactions; Translational energy; Threshold behavior; Endothermic reactions; Aluminum; Oxygen1986
147 Armentrout, Peter B.Kinetic energy dependence of association reactions. A new thermokinetic method for large systemsThe reactions of bare alkali metal ions (M+5Li+, Na+, or K+) with dimethoxyethane (CH3OCH2CH2OCH3 , (DXE) are studied using guided ion beam tandem mass spectrometry. The bimolecular reaction forms an associative M1(DXE) complex that is long-lived and dissociates back to the reactants. The kinetic en...Collision-induced dissociation; Association reactions; Bond energies; Dimethoxyethane; Alkali metal ions2003
148 Armentrout, Peter B.Kinetic energy dependence of dissociative charge-transfer reactions of He+, Ne+, Ar+, Kr+, and Xe+ with silaneGuided ion-beam techniques are used to measure the cross sections as a function of kinetic energy for reaction of SiH4 with He +, Ne +, Ar +, Kr +, and Xe +. State-specific data for the 2P3/2 ground spin-orbit states of Kr+ and Xe+ are also obtained.Silane; Charge-transfer reactions; Ion-molecule reactions; Ion energy; Rare gas ions; Plasma systems1990
149 Wight, Charles AlbertKinetic study of stabilizing effect of oxygen on thermal degradation of poly(methyl methacrylate)The thermal degradation of poly(methyl methacrylate) (PMMA) has been studied in both pure nitrogen and oxygen-containing atmospheres. The presence of oxygen increases the initial decomposition temperature by 70 °C. The stabilizing effect of oxygen may be explained by forming thermally stable radica...Poly(methyl methacrylate); PMMA; Thermal degradation; Isoconversional method1999
150 Armentrout, Peter B.Kinetic-energy dependence of competitive spin-allowed and spin-forbidden reactions: V++CS2The kinetic-energy dependence of the V++CS2 reaction is examined using guided ion-beam mass spectrometry. Several different ion sources are used to systematically vary the V+ electronic state distributions and elucidate the reactivities of both the ground and excited state V+ cation.Carbon disulfide; Vanadium ions; Transition metal ions; Bond energies; Endothermic reactions; Exothermic reactions1999
151 Wight, Charles AlbertKinetics of thermal decomposition of cubic ammonium perchlorateThe methods of thermogravimetric analysis (TGA) and differential scanning calorimettry (DSC) have been used to study the thermal decomposition of ammonium perchlorate (AP). TGA curves obtained under both isothermal and nonisothermal conditions show a characteristic slowdown at the extents of convers...Thermal decomposition; Cubic ammonium perchlorate; Differential scanning calorimetry1999
152 Morse, Michael DavidLaser excitation spectroscopy of the A and B states of jet-cooled copper dimer: evidence for large electronic isotope shiftsFluorescence excitation spectra recorded for the A-X system of jet-cooled Cu2 show conclusive evidence of a ?? = 0 transition, and the A state is thereby definitively assigned as ??u+. A previous assignment of the B state as ??u+ is confirmed, but the vibrational levels of this state are complicated...1989
153 Morse, Michael DavidLaser vaporization generation of the SiB and SiAi radicals for matrix isolation electron spin resonance studies: comparison with theoretical calculations and assignment of their electronic ground states as X ??The first experimental spectroscopic study of the SiB and SiAl diatomic radicals is reported. Electron spin resonance results indicate that both molecules have X 4? ground electronic states, in agreement with earlier theoretical calculations. The SIB and SiAl radicals were generated in neon matrices...1993
154 Morse, Michael DavidLaser vaporization generation of Y ??B+, Y ??B+, and YAI+ for electron spin resonance studies in neon matrices at 4 K: comparison with theoretical calculationsThe first spectroscopic investigation of 89Y 10B+, 89Y 11B+, and 89Y 27Al+ is reported, revealing that both of these diatomic cation radicals have X 4?- electronic ground states. The ions were generated by three high energy techniques in combination with neon matrix isolation at 4 K and studied by e...1992
155 Miller, Joel Steven; Epstein, Arthur J.Lattice- and spin-dimensionality crossovers in a linear-chain-molecule-based ferrimagnet with weak spin anisotropy[MnOEP][HCBD], a member of the metalloporphyrin family of donor-acceptor molecule-based magnets, consists of isolated ferrimagnetic chains of alternating S=2, [MnOEP], and s=1/2, [HCBD] units (OEP=octaethylporphyrinato and HCBD=hexacyanobutadiene). Analysis of the exchange pathways reveals an exchan...Magnetic; Magnetization; Interchain1997
156 Poulter, Charles DaleLethal mutations in the isoprenoid pathway of salmonella entericaEssential isoprenoid compounds are synthesized using the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway in many gram-negative bacteria, some gram-positive bacteria, some apicomplexan parasites, and plant chloroplasts. The alternative mevalonate pathway is found in archaea and eukaryotes, includin...Isoprenoids; Mutation; Bacteria; Antimicrobials2006
157 Morse, Michael DavidLigand-field theory applied to diatomic transition metals. Results for the d?Ad?B?? states of Ni?, the d?Nid??cu?? states of NiCu, and the d?Ni(?F)d??cu???*? excited states of NiCuA ligand-field theory has been developed for transition-metal diatomics having electronic configurations of d?Ad??B??, d?Ad?B?? and d?A(?F)d??B???*?. The theory treats each atom as a point charge and includes spin-orbit interactions. No contributions due to d-orbital chemical bonding are included. ...1992
158 Miller, Joel Steven; Epstein, Arthur J.Linear chain ferromagnetic charge transfer compoundsCharge transfer complexes possessing a ... DADA ... structure with both the donor, D, and acceptor, A, being S = 1/2 radicals may exhibit cooperative magnetic phenomena. The complex [Fe(C5Me5)2]+ [TCNQ]-. exhibits metamagnetic behavior. The similarly structured [TCNE]-. and [C4(CN)6]-. complexes ar...Spin; Exchange; Molecular1986
159 Miller, Joel Steven; Epstein, Arthur J.Local structural order in the disordered vanadium tetracyanoethylene room-temperature molecule-based magnetWe determined the vanadium oxidation state and local coordination environment in disordered samples of magnetic V[TCNE]x(x=2) prepared by chemical vapor deposition (CVD). Systematic studies of the x-ray absorption near-edge structure (XANES) in this material and reference compounds show that V ions ...Magnetic; Solvent; Structure2004
160 Miller, Joel Steven; Epstein, Arthur J.Magnetic behavior of octaethylporphyrinatomanganese(III) tetracyanoethenide, [MnOEP][TCNE], and hexacyanobutadienide, [MnOEP][C4(CN)6]: the importance of a uniform chain for stabilizing strong effective ferromagnetic coupling[MnOEP][A] {A=[TCNE]'- and [C4(CN)6]'-} have been isolated as extended 1D coordination polymers with trans-U2"[A] bridging ligands with strong {A=[C4(CN)6].-} and weak {A=TCNE].-} ferromagnetic coupling as evidenced from the fit of the magnetic susceptibility to the Curie-Weiss law (0=5.1 and 67.1 K...Crystals; Inversion; Coupling1995
161 Miller, Joel StevenMagnetic behaviors of the metamagnetic and ferromagnetic phases of [Fe(C5Me5)2][TCNQ] (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane). Determination of the phase diagram for the metamagnetic phaseThe detailed magnetic behaviors of the ferro- (1FO) and metamagnetic (1MM) phases of [FeCp*2][TCNE] (Cp* = pentamethylcyclopentadienide; TCNE = tetracyanoethylene) aligned parallel to the applied magnetic field, H, were obtained using eicosane (E). The Tc for 1FO is 3.1 K from the maximum in the fr...Properties; Temperature; Ordering2006
162 Miller, Joel Steven; Epstein, Arthur J.Magnetic bistability and nucleation of magnetic bubbles in a layered 2D organic-based magnet [Fe(TCNE)(NCMe)2][FeC14]The 2D layered organic-based magnet [Fe(TCNE)(NCMe)2][FeCl4] (TCNE ¼ tetracyanoethylene) exhibits a unique macroscopic magnetic bistability between the field-cooled and zero-field-cooled states, which cannot be explained by either superparamagnetic behavior or spin freezing due to spin glass orde...Organic-based magnets; Tetracyanoethylene; Magnetic bistability; Nucleation2008-11
163 Miller, Joel Steven; Epstein, Arthur J.Magnetic phase diagram of a molecule-based ferrimagnet: weak ferromagnetism and multiple dimensionality crossoversA detailed study of the magnetic behavior of the molecule-based magnet, [MnOEP][HCBD], (OEP=mesooctaethylporphyrinato, HCBD=hexacyanobutadiene) from 1.7 to 20 K was performed. The earlier reported magnetic transition at 19.6 K, ascribed to a crossover from a one-dimensional Heisenberg-like ferrimag...Transition; Temperature; Magnetization1997
164 Miller, Joel Steven; Epstein, Arthur J.Magnetic properties and critical behavior of Fe(tetracyanoethylene) 2.x(CH2Cl2): a high-Tc molecule-based magnetWe report magnetic studies of Fe(TCNE)2•x(CH2Cl2), a member of the family of high-Tc molecule-based magnets, M(TCNE)x•y (solvent) (M=V, Mn, TCNE=tetracyanoethelyne). Based on extensive static and dynamic magnetic measurements we show that this system has a complex magnetic behavior, with a mixtu...Solvent; Anisotropy; Spin2000
165 Miller, Joel StevenMagnetically ordered molecule-based assembliesThe development of molecules and assemblies of molecules exhibiting technologically important bulk properties, such as magnetic ordering, is an important worldwide research focus. Organic- and molecule-based magnets have been discovered and several families have been reported with magnetic orderin...Organic-based; Lattices; Magnets2006
166 Miller, Joel Steven; Epstein, Arthur J.Magnetization and dynamics of reentrant ferrimagnetic spin-glass [MnTPP]::+[TCNE].-.2PhMeWe present direct current (dc) magnetization M(T,H) and alternating current (ac) susceptibility Xac(T,H,f) data for the quasi-one-dimensional molecule-based ferrimagnet [MnTPP]::+[TCNE].-.•2PhMe (TPP=meso-tetraphenylporphyrinato, TCNE=tetracyanoethylene). Static scaling of the real part X' of ...Ferrimagnetic order; Magnetism1996
167 Miller, Joel StevenMagnetization and static scaling of high-Tc disordered molecular-based magnet V(tetracyanoethylene)x¢y(CH3CN) with x ~ 1.5 and y ~ 2)We report field (H) and temperature (T) -dependent magnetization (M) of a member of the new class of high-Tc molecular-based magnets V(tetracyanoethylene)x .y(solvent) with Tc in an accessible range (solvent =CH3CN). The M (H) at low T saturates slowly with increasing H. The random magnetic anisotro...Temperature; Magnetic; Random1993
168 Miller, Joel StevenManganese(II)octabutoxynaphthalocyanine and its ferrimagnetic electron-transfer salt with TCNEThe magnetic susceptibility (x) of 1,6,10,15,19,25,28,32- octa-n-butoxynaphthalocyaninatomanganese(III) tetracyanoethanide can be fit to a Curie-Weiss expression with O=54 K for T>150 K, and the xT(T) data are consistent with linear chains and can be fit to a Seiden expression for alternating S=2 a...Magnetic; Ordering; Magnetization2000
169 Armentrout, Peter B.Mechanism of proton exchange: guided ion beam studies of the reactions, H(H2O)n+ (n=1-4) + D2O and D(D 2O)n+ (n=1-4) + H2OReactions of protonated water clusters, H(H2O)n+ (n=1-4) with D2O and their "mirror" reactions, D(D2O)n+ (n=1-4) with H2O, are are studied using guided-ion beam mass spectrometry. Absolute reaction cross sections are determined as a function of collision energy from thermal energy to over 10 eV.Collision-induced dissociation; Proton exchange; Protonated water clusters; Exothermic reactions; Deuterium oxide2004
170 Armentrout, Peter B.Methane activation by cobalt cluster cations, Con+ (n=2-16): reaction mechanisms and thermochemistry of cluster-CHx (x=0-3) complexesThe kinetic energy dependences of the reactions of Con + (n=2-16) with CD4 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. The main products are hydride formation, ConD+, dehydrogenation to form ConCD2 +, and double dehydrogenation yielding ConC+.Cobalt ions; Transition metal ions; Bond energies; Endothermic reactions; Dehydrogenation; Deuterated methane2009
171 Armentrout, Peter B.Methane activation by nickel cluster cations, Nin+ (n=2-16): reaction mechanisms and thermochemistry of cluster-CHx (x=0-3) complexesThe kinetic energy dependences of the reactions of Nin+ (n=2-16) with CD4 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. The main products are hydride formation NinD1, dehydrogenation to form NinCD2 1 , and double dehydrogenation yielding NinC1.Nickel ions; Metal clusters; Deuterated methane; Collision-induced dissociation; Endothermic reactions; Bond energies; Dehydrogenation2004
172 Miller, Joel Steven; Epstein, Arthur J.Microwave response of confined soliton pairs (Bipolarons) in (N-Methylphenazinium) x (Phenazine) 1-x (Tetracyanoquinodimethanide)The temperature-dependent dielectric response and conductivity at =1010 Hz is reported for the title compound, (NMP)x(Phen)i-x(TCNQ), in the regime 0.50<-x<-0.59, spanning commensurate, bipolaron, and incommensurate regimes. The large and strongly temperature-dependent dielectric constant and o-(101...Dielectric, Proposed, Electrons1987
173 Miller, Joel StevenMnII(N3)2(pyrazine).A 2-D layered structure consisting of ferromagnetically coupled 1-D {Mn(U-1,1-N3)2}n chainsMn(N3)2(pyz) (pyz = pyrazine) consists of ferromagnetically coupled linear chains of {Mn(N3)2}n comprised of u-1,1-azido bridges together with u-pyz ligands to afford 2-D planar layers.Ferromagnetic; Coupling; Magnetic1999
174 Miller, Joel StevenMnII(TCNE)3/2(I3)1/2-A 3D network-structured organic-based magnet and comparison to a 2-D analogOrganic-based magnets utilize unpaired electrons residing on organic species to form magnetically ordered materials. Unlike traditional atom/ion-based magnets, they enable the controllable modulation and combination of magnetic properties with other technologically important properties (e.g., electr...2010
175 Miller, Joel Steven; Epstein, Arthur J.Molecular magnets V(tetracyanoethylene)x.y(solvent): applications to magnetic shieldingThe specific advantages and limitations of a new class of polymer based magnets [exemplified by V(TCNE)x. y (solvent) (TCNE= tetracyanoethylene)] for static and low frequency magnetic shielding and inductive applications are evaluated using results of dc superconducting quantum interference device ...Frequency; Permeability; Transition1994
176 Miller, Joel Steven; Epstein, Arthur J.Molecule-based magnets - an overviewMolecule-based* magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other proper...Spin; Magnetization; Magnetic ordering2000
177 Voth, Gregory AlanThe multiscale coarse-graining method. VI. Implementation of three-body coarse-grained potentialsMany methodologies have been proposed to build reliable and computationally fast coarse-grained potentials. Typically, these force fields rely on the assumption that the relevant properties of the system under examination can be reproduced using a pairwise decomposition of the effective coarse-grai...2010
178 Voth, Gregory AlanMultiscale coarse-graining of the protein energy landscapeA variety of coarse-grained (CG) models exists for simulation of proteins. An outstanding problem is the construction of a CG model with physically accurate conformational energetics rivaling all-atom force fields. In the present work, atomistic simulations of peptide folding and aggregation equilib...2010-06-24
179 Voth, Gregory AlanNanostructural organization in acetonitrile/ionic liquid mixtures: molecular dynamics simulations and optical Kerr effect spectroscopyIn this paper, the nanostructural organization and subpicosecond intermolecular dynamics in mixtures of acetonitrile and the ionic liquid (IL) 1-pentyl-3-methylimidazolium bis{(trifluoromethane)sulfonyl}amide ([C5mim][NTf2]) were studied as a function of concentration using molecular dynamics (MD) s...2012-01-01
180 Miller, Joel Steven; Epstein, Arthur J.New polymorph of 4,4'-(Butadiyne-1,4-diyl)-bis-(2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl)A new polymorph of the title diradical has been characterized by X-ray diffraction, vibrational spectroscopy, and magnetic susceptibility; its radiation induced polymerization has not been achieved, but thermal treatment turns the crystals black and explosive decomposition occurs at-140 °C.Ferromagnetic; Polymerization; Magnetic1988
181 Morse, Michael DavidNi? revisited: reassignment of the ground electronic stateResonant two-photon ionization spectroscopy was used to study jet-cooled Ni2 produced by pulsed laser ablation of a nickel target in the throat of a supersonic nozzle using argon as the carrier gas. Spectral regions previously investigated using helium as the carrier gas were reinvestigated, and the...1994
182 Minteer, Shelley D.Nickel cysteine complexes as anodic electrocatalysts for fuel cellsCompared to platinum, nickel is an inexpensive catalyst that can oxidize methanol in alkaline media. There is a desire to increase nickel loading during electrodeposition for improved performance. In this paper, a nickel cysteine complex (NiCys) is used as the precursor for electrodeposition on glas...2014-01-01
183 Minteer, Shelley D.Nickel-DNA complexes: bioelectrocatalysis or not?Alkaline fuel cells (AFC) are low temperature, quick-to-start devices that can achieve 50% operating efficiency. Low cost alternatives to platinum group electrocatalysts, which allow for direct reformation are desired. Nickel electrocatalysts are highly active in alkaline for the oxidation of fuels....2013-01-01
184 Miller, Joel Steven; Epstein, Arthur J.Noise in highly correlated commensurate charge transfer saltsWe present the results of a study of the frequency (f) dependent noise power for commensurate charge transer salts with strong coulomb repulsion. f-1 noise is observed with increasing currents. Excess f-1 noise is measured for samples which were chemically doped to form solitons. Frequency indepe...Noise power; Charge-transfer salts1983
185 Miller, Joel Steven; Epstein, Arthur J.Noise-power studies of the nearly commensurate quasi-one-dimensional conductor (N-methylphenazinium)x(phenazine)1-x(7,7,8,8-tetracyano-p-quinodimethane) [(NMP)x(Phen)1-x(TCNQ)We report the noise power of (NMP)x(Phen)1-x(TCNQ) as a function of temperature (100 <_ T <_ 300 K), frequency (1<_f<_10(4) Hz), electric field (0 <_E<_300 V/cm), and conduction-electron density (0.49<_x<_0.59). The results for the commensurate, doped commensurate, and incommensurate regimes are sim...Fluctuations; Solitons1985
186 Miller, Joel StevenNoncollinear antiferromagnetic structure of the molecule-based magnet Mn[N(CN)2]2The crystallographic and magnetic properties of the Mn[N(CN)2]2 compound have been investigated by dc magnetization, ac susceptibility, specific heat, and zero-field neutron diffraction on polycrystalline samples. The magnetic structure consists of two sublattices which are antiferromagnetically cou...Spin; Crystal; Magnetic2000
187 Miller, Joel Steven; Epstein, Arthur J.Novel co-operative magnetic properties of decamethylmanganocenium 2,3-dichloro-5,6-dicyanobenzoquinoneide, 3[Mn(C5Me5)2]:+[DDQ].-The electron-transfer salt 3[Mn(C5Me5)2]: + [DDQ].-, isomorphous to orthorhombic [Fe(C5Me5)2].+[DDQ].-, has been prepared. It exhibits a complex field-dependent magnetic phase diagram at low temperatures with evidence for ferromagnetic coupling as well as a low moment state below 4 K for zero-field ...Ferromagnetic; Electron-transfer salt; Powder diffraction1991
188 Miller, Joel StevenNovel coordination of dicyanamide, [N(CN)2]-: preferential binding of the amide nitrogenCoII[N(CN)2]2(H2BiIm)2, 1, and {CoII[N(CN)2](H- 2BiIm)2}Cl, 2 (H2BiIm = 2,2'-biimidazole) have been structurally, spectroscopically, and magnetically characterized with both containing dicyanamides bound in unprecedented manners; namely, solely via the amide nitrogen for 1, and via an imide N form...Magnetic; Dicyanamide; Electron2002
189 Miller, Joel StevenOn the existence of long C-C bonds between pairs of anions which repel: when and why? A test case on the [TCNE]22- dimers found in ionic crystals*Many of the Cm[TCNE]n (C = cation) salts have intradimer C-C interactions in the range of 2.9 to 3.5 A(°) and show the electronic fingerprints associated with C-C bond formation (IR and UV spectra, magnetic properties, structural changes), despite the fact that two [TCNE].- anions should repel each...Electron; Spectroscopic; Salts2002
190 Stang, Peter J.One-dimensional coordination polymers based on first-row transition metals: a solid-state study of weak backbone interactionsWe present further data on the solid-state structures of one-dimensional coordination polymers based upon dipositive transition metal hexafluoroacetylacetonate (hfacac) complexes. A variety of linking subunits are employed in order to investigate and probe the relatively weak interactions that make...Hexafluoroacetylacetonate complexes; Coordination polymers2001
191 Miller, Joel StevenOptical and electron-energy-loss studies of the monomeric and dimeric phases of decamethylferrocenium tetracyanoquinodimethanide, (DMeFc)(TCNQ)The optical properties of the two crystallographic phases of 1:l decaniethylferrocenium tetracyanoauinodimethanide, (DMeFc)(TCNQ), have been measured from 0.1 to 10 eV. One phase consists of isolated paramagnetic TCNQ anion monomers while the other contains isolated diamagnetic dimers. The spectru...Ions; Spectrum1980
192 Miller, Joel Steven; Epstein, Arthur J.Optical control of magnetic order in molecule-based magnet Mn(TCNE)x.y(CH2Cl2)Studies of photoinduced magnetization and photoinduced absorption in molecule-based magnet Mn(TCNE)x•y(CH2Cl2) (x=2, y-0.8, TCNE=tetracyanoethylene) are reported. Optical excitation in the blue region of spectrum leads to increased magnetization, accompanied by changes in the electronic spectrum...Spectrum; Absorption; Illumination2002
193 Miller, Joel StevenOptical control of magnetization in a room-temperature magnet: V-Cr Prussian blue analogWe report reversible photoinduced magnetic phenomena for a V-Cr Prussian blue analog (Tc~350 K). This molecule-based magnet exhibits a decrease in magnetization upon illumination with UV light (λ~350 nm) and reaches a metastable state that has a long lifetime at low temperatures (>106 s at 10 K). ...2010-09
194 Miller, Joel StevenOptical properties of cesium tetracyanoquinodimethanide, Cs2(TCNQ)3Room-temperature polarized reflectance measurements have been made on cesium tetracyanoquinodimethanide, Cs2(TCNQI3, over the frequency range between the far infrared and the near ultraviolet. The optical properties of the compound were obtained by Kramers-Kronig analysis. These properties are dom...Electrons; Lattice; Molecules1981
195 Miller, Joel Steven; Epstein, Arthur J.Optical properties of quinolinium tetracyanoquinodimethanide, [Qn(TCNQ)2] and (N-methylphenazinium)x(phenazine)1-x (tetracyanoquinodimethane) [(NMP)x(Phen)1-x(TCNQ)]We present here optical-absorption data of quinolinium ditetracyanoquinodimethanide [Qn(TCNQ)2] and (N-methylphenazinium)x(phenazine)1-x(tetracyanoquinodimethanide) [(NMP)x(Phen)1-x(TCNQ)] for 0.5 <_x<_ 0.6. These materials span the range of electronic structure from commensurate, to commensurate ...Commensurate; Lattice; Electron1989
196 Miller, Joel Steven; Epstein, Arthur J.Optical properties of the 1:2 compound of dimethylferrocenium with tetracyanoquinodimethanide: [(Me2Fc)(TCNQ)2]We present the results of a study of the room-temperature polarized reflectance of (1:2) 1,1'-dimethylferrocenium ditetracyanoquinodimethanide [(Me2Fc)(TCNQ)2] over the range between the far infrared and the near ultraviolet. Kramers-Kronig analysis of the reflectance is used to determine the optica...Reflectance; Electrons ; Molecules1987
197 Miller, Joel Steven; Epstein, Arthur J.Optical properties of the cation-deficient platinum chain salt K1.75Pt(CN)4¢1.5H2OThe room-temperature polarized reflectance of a potassium-deficient platinum chain salt K1.75Pt(CN)4.1.5Hz[K0 (def)CP] has been measured in the infrared and visible. The reflectance is strongly anisotropic, with a plasma edge in the red and high reflectance in the infrared for light polarized para...Reflectance; Crystals; Lattice1982
198 Morse, Michael DavidOptical spectroscopy of jet-cooled FeC between 12 000 and 18 100 cm-?Iron monocarbide has been investigated between 12 000 and 18 100 cm21 in a supersonic expansion by resonant two-photon ionization spectroscopy. Six new electronic states have been identified for which origins relative to the ground state have been determined. Three of these possess ?"=3, one possess...1997
199 Morse, Michael DavidOptical spectroscopy of jet-cooled NiSiThe electronic states of gaseous diatomic NiSi have been investigated using the combined techniques of resonant two-photon ionization spectroscopy, dispersed fluorescence spectroscopy, and density functional computations. A single electronic band system, designated as the [8.0]1?X 1?+ system, has be...2003
200 Morse, Michael DavidOptical spectroscopy of RuC: 18 000-24 000 cm ?1The optical spectrum of diatomic RuC has been recorded from 17 800 to 24 200 cm-1. Three previously unidentified excited electronic states were analyzed and identified as having ?'=0, ?'=2, and V853. The ?'=3 state was determined to be a 3?3 state that is suggested to arise from a mixture of the 10?...2004
1 - 200 of 338