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151 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
152 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
153 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
154 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
155 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
156 Morse, Michael DavidResonant two-photon ionization spectroscopy of jet-cooled PtSiJet-cooled diatomic PtSi, produced in a laser ablation supersonic expansion source, has been spectroscopically investigated between 17 400 and 24 000 cm-1 by resonant two-photon ionization spectroscopy. Two vibrational progressions are observed and identified as the [15.7]?'=1 ?X 1?+ and [18.5]?'=1 ...1999
157 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
158 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
159 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
160 Miller, Joel StevenSynthesis of layered (2-D) V-based bimetallic oxalates from non-aqueous media that cannot be synthesized from aqueous mediaThe reaction of (NBu4)3[VIII(ox)3] (1, ox = oxalate) and M(II) (M= Fe, Co, Ni, Cu) ions in MeCN, leads to the isolation of V-based coordination polymers of [N(n-Bu)4][FeIIVIII(ox)3]? 0.30{[N(n-Bu)4](BF4)} (2), [N(n-Bu)4][CoIIVIII(ox)3]?0.75{[N(n-Bu)4](BF4)} (3), [N(n-Bu)4][NiIIVIII(ox)3]?0.20{[N(n...Magnetic; Coupling; Diffraction2006
161 Morse, Michael DavidOptical spectroscopy of tungsten carbide (WC)Resonant two-photon ionization spectroscopy has been used to study the diatomic transition-metal carbide, WC. A low-resolution scan revealed a five-member vibrational progression beginning with the 0-0 band at 17 585 cm-1. Analysis of this progression yielded a vibrational frequency of ?'e8(184W12C)...2002
162 Morse, Michael DavidRotationally resolved spectroscopy of jet-cooled NbMoRotationally resolved resonant two-photon ionization spectra of jet-cooled NbMo are reported for the first time. A vibronic spectrum of NbMo was recorded in the 17 300?22 300 cm?1 spectral region. Although the observed bands could not be grouped into electronic band systems, four excited vibronic le...2007
163 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
164 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
165 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
166 Morse, Michael DavidResonant two-photon ionization spectroscopy of coinage metal trimers: Cu?Ag, Cu?Au, and CuAgAuThe jet-cooled coinage metal triatomic molecules Cu, Ag, Cu, Au, and CuAgAu have been investigated using resonant two-photon ionization spectroscopy. One band system, labeled as the ?-x system, has been observed for each species, with origin bands at 13 188, 17 217, and 17 470 cm -?, respectively. ...1991
167 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
168 Armentrout, Peter B.Threshold collision-induced dissociation of Sr2+ (H2 O) x complexes (x=1-6): an experimental and theoretical investigation of the complete inner shell hydration energies of Sr2+The sequential bond energies of Sr2+(H2O)x complexes, where x=1-6, are determined by threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer equipped with an electrospray ionization source. The electrospray source produces an initial distribution of Sr2+(H2O)x compl...2010
169 Morse, Michael DavidResonant two-photon ionization spectroscopy of jet-cooled PdSiThe spectra of diatomic PdSi have been investigated for the first time, using the technique of resonant two-photon ionization spectroscopy. A number of vibronic transitions have been observed in the 20 400?22 000 cm?1 range. It is difficult to group the bands into band systems, although one likely...2011
170 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
171 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
172 Armentrout, Peter B.Threshold behavior of endothermic reactions: C+(2P) + H2 → CH+ + HThe reaction C+(2p) + H2 → CH+ + H (1) and its deuterium analog is a model system in ion-molecule chemistry. It is of interest due to its astrophysical significance, because it is an endothermic process, and because the interaction involves several potential energy surfaces. Experimental work ha...Endothermic reactions; Translational energy; Threshold behavior1984
173 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
174 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
175 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
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