UScholar Works
 
Filters: Department: "Chemistry" Collection: "ir_uspace"
1 - 25 of 33
Number of results to display per page
CreatorTitleDescriptionSubjectDate
1 Stang, Peter J.Studies in the cycloproparene series: cycloaddition reactions of diarylmethylidenecycloproparenesDiarylmethylidenecyclopropanaphthalenes 4b-d add diphenylisobenzofuran (DPIBF) and α-pyrone across the exocyclic double bond to give ring expanded products 11b-d and 13b-d that result from subsequent relief of ring strain in the non-isolable spirocyclic intermediates 10 and 12, respectively. The be...Cycloproparene series; Cycloaddition; Diarylmethylidenecycloproparenes; Ab initio calculations; Strained aromatics; Acetylenic-iodonium salts; Crystal structures; Cyclobutanes, Diels-Alder cycloaddition; norcaradienes2001
2 Miller, Joel StevenPhotoelectron spectra of transition-metal carbonyl complexes: comparison with the spectra of adsorbed COThe uv and x-ray photoelectron spectra of carbon monoxide and transition-metal (TM) carbonyl complexes have been studied. The systematic changes in these spectra were recorded as the number of metal atoms in the complexes was increased and as the bonding configuration of the CO changed. The observat...TM carbonyl complexes; electron binding energies; metal atoms1978
3 Miller, Joel StevenPhotoelectron spectra of transition-metal carbonyl complexes: comparison with the spectra of adsorbed COThe uv and x-ray photoelectron spectra of carbon monoxide and transition-metal (TM) carbonyl complexes have been studied. The systematic changes in these spectra were recorded as the number of metal atoms in the complexes was increased and as the bonding configuration of the CO changed. The observat...TM carbonyl complexes; electron binding energies; metal atoms1978
4 Miller, Joel StevenThree-dimensional network-structured cyanide-based magnetsIntroduction Magnets based on metal oxides have been important for hundreds of years. Magnetite, Fe3O4, Co-doped (y)-Fe2O3, and CrO2 are important examples. The oxide (O2-) bridge between the magnetic metal ions has filled p orbitals (Figure 1a) that provide the pathway for strong spin coup...Magnetic; Ferrimagnetic; Magnetization2000
5 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
6 Miller, Joel Steven; Epstein, Arthur J.Spin dilution in a ferromagnetic chainWe have systematically introduced spinless defects in the quasi-one-dimensional ferromagnetic system decamethylferrocenium tetracyanoethanide, [FeCp(2*)] [TCNE]. The three-dimensional ordering temperature Tc decreases rapidly with the concentration of spinless sites. The rate of decrease of Tc with...Magnetic; Magnetization; Spinless1992
7 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
8 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
9 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
10 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
11 Miller, Joel StevenPreparation and characterization of square-planar tetrakis(cyanoacetylide) complexes: [MII(C=C-C=N)4]2- (M = Ni,Pd, Pt)Complexes [MII(C=C-=N)4]2 - (M = Ni, Pd, Pt) are prepared for the first time and the structure of [NEt4]2[Ni(C=C-C=N)4] is determined to have a square-planar geometryBonding; Structure; Ligand1996
12 Miller, Joel StevenStructure and magnetic properties of MnII[N(CN)2]2(pyrazine). An antiferromagnet with an interpenetrating 3-D network structureMn[N(CN)2]2(pyz) (pyz = pyrazine) orders antiferromagnetically at low temperature and possesses intralayer u-NCNCN and interlayer u-pyz ligands that form a pseudo-ReO3 interpenetrating network structure.Dicyanamide; Polydentate; Temperature1998
13 Miller, Joel Steven; Epstein, Arthur J.Three-dimensional ordering, spin excitations, and dilution effects in the quasi-1-D ferromagnetic (DMeFc)(TCNE)The linear chain S = (1/2) molecular ferromagnet decamethylferrocenium tetracyanoethanide [(DMeFc) (TCNE)] has been studied by frequency-dependent ac susceptibility experiments. (X')(T) and (X") (T) exhibit maxima in the temperature range of 4.8 - 4.9 K, which corresponds to the transition tempe...Temperature; Transition; Magnetic1991
14 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
15 Miller, Joel StevenPressure dependence of magnetic ordering temperature for decamethylferrocenium tetracyanoethenideIt has been demonstrated that the linear-chain charge-transfer salt, decamethylferrocenium tetracyanoethanide (DMeFc) (TCNE), is a ferromagnet with a transition temperature of -4.8 K. This low-temperature 3D ordering has been attributed to a strong intrachain and a weak interchain interaction. To...Ferromagnetic; Transition; Antiferromagnetic1993
16 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
17 Miller, Joel StevenZero field splitting, field-dependent magnetization of mixed-valent S = 3/2 Diruthenium(II,III) tetracarboxylatesThe 2 K field-dependent magnetization, M(H), of S = 3/2 [RunII/III2(OAc)4]+ was studied. [RuII/III 2(OAc)4]+ exhibits an unusually low magnetization with respect to that predicted by the classical Brillouin function. This reduced value is a consequence of the large anisotropy arising from the large ...Spin; Coupling; Expressions2004
18 Miller, Joel Steven; Epstein, Arthur J.Tetracyanoethylene-based organic magnetsSeveral classes of organic magnets based upon the tetracyanoethenide radical anion, [TCNE](.-), either unbound, (u), and (u4) bonded to zero, two and four metal sites have been reported. The putative (u4) bonded V(TCNE)x room temperature magnet has been extended to include M(TCNE)x(M = Mn, Fe, Co,...Magnetization; Magnetic ordering; Oxidation1998
19 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
20 Miller, Joel StevenTwo-dimensional molecular-based ferrimamagnets incorporating decamethylmetallocenium cationsFour new molecular-based magnets have been synthesized, and their magnetic properties have been investigated in detail. Their formulae are [M'(C5Me5)2]2M2[Cu(opba)]3.(DMSO)x(H20)y with M' = Fe, M = Mn, x = 5, y = 4 (1), M' = Fe, M = Co, x = 6, y = 4 (2), M' = Co, M = Mn, x = 5.5, y = 4 (3) and M' = ...Magnetic; Compounds1996
21 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
22 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
23 Miller, Joel StevenSynthesis, structural, and magnetic characterization of substituted benzoimidazole-l-yl N,N'-dioxidesThe crystal structures, EPR spectra and magnetic properties of the novel halogen- and cyano-substituted nitronyl nitroxide radicals 2-(2,6-dichlorophenyl)benzimidazolyl N,N'-dioxide, 6, 2-(2,6-difluorophenyl)benzimidazolyl N,N'- dioxide, 7, 2-(2-chloro-6-fluorophenyl)benzimidazolyl N,N'-dioxide, 8,...Organic; Ferromagnetic; Coupling2004
24 Armentrout, Peter B.Translational energy dependence of O+(4S) + N2 → NO+ + N from thermal energies to 30 eV c.m.Guided ion beam mass spectrometry is used to examine the kinetic energy dependence of the reaction of ground state atomic oxygen ion with molecular nitrogen. An 0 + (4S) source which produces less than 0.06% excited states is described. Cross sections for the NO+ + N product channel decrease with...Ion-molecule reactions; Translational energy; Threshold behavior; Endothermic reactions; Nitrogen; Oxygen1987
25 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
1 - 25 of 33