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Creator | Title | Description | Subject | Date |
126 |
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Miller, Joel Steven | Crystal engineering or crystal mysticism? A case study | The 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, Chemistry | 2005 |
127 |
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Miller, Joel Steven | Optical 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; Spectrum | 1980 |
128 |
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Morse, Michael David | Interaction of an aluminum atom with a closed subshell metal atom: spectroscopic analysis of AIZn | Resonant 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 |
129 |
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Poulter, Charles Dale | Enzymes encoded by the farnesyl diphosphate synthase gene family in the big sagebrush Artemisia tridentata ssp. spiciformis | Farnesyl 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 Data | 2003-08-22 |
130 |
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Truong, Thanh; Sarofim, Adel F. | Quantum mechanic study of high molecular mass compounds in combustion conditions | Experimental studies on soot formation show interesting trends that can only be explained by a polymerization pathway. These experimental findings are reviewed and ab initio calculations are used to evaluate possible mechanistic pathways. A sequence of chemical reactions between aromatic compounds a... | High molecular mass compounds; Quantum mechanics; Soot formation | 2001 |
131 |
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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, Electrons | 1987 |
132 |
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Armentrout, Peter B. | Effect of kinetic and electronic energy on the reactions of Cr+ with H2, HD, and D2 | The 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 energy | 1987 |
133 |
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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 bond | The 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 bonding | 2009 |
134 |
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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; Nitrogen | 1981 |
135 |
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Miller, Joel Steven | Room temperature molecular/organic-based magnet | The Du Pont / Ohio State University research team made materials in the laboratory, then tested them for magnetism. To do so, they initially moved a magnet along the outside of a sealed tube containing a small blob of experimental material and an inert gas such as argon or nitrogen. "We've done it... | Bis(benzene)vanadium; Vanadium; Tetracyanoethylene; TCNE; Polymeric magnets; Room temperature | 1991 |
136 |
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Poulter, Charles Dale | Catalytic 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 inhibitors | Isopentenyl 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 Compounds | 2003-04-04 |
137 |
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Morse, Michael David | Resonant two-photon ionization spectroscopy of NiC | A spectroscopic investigation of jet-cooled diatomic NiC has revealed a complex pattern of vibronic levels in the wave number range from 21 700 to 27 000 cm-1. Of the more than 50 vibronic bands observed, 31 have been rotationally resolved and analyzed. All are ?'=0+??"=0+ transitions, consistent wi... | | 2002 |
138 |
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Miller, Joel Steven; Epstein, Arthur J. | Magnetic properties and critical behavior of Fe(tetracyanoethylene) 2.x(CH2Cl2): a high-Tc molecule-based magnet | We 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; Spin | 2000 |
139 |
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Miller, Joel Steven | Spin crossover behavior of [FeII(isoxazole)6][BF4]2--a structural study | [FeII(isoxazole)6][BF4]2 undergoes two reversible spin crossover transitions at 91 and 192 K and the single crystal structure determination reveals two different iron sites, Fe1 and Fe2, in a 1 : 2 ratio, with Fe1 attributed to the 91 K transition, and Fe2 attributed to the 192 K transition. This is... | Transition; Magnetic; Temperature | 1999 |
140 |
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Miller, Joel Steven | Optical control of magnetization in a room-temperature magnet: V-Cr Prussian blue analog | We 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 |
141 |
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Poulter, Charles Dale | CaaX proteases, Afc1p and Rce1p, have overlapping but distinct substrate specificities | Many 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; Hydrophobic | 2000 |
142 |
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Morse, Michael David | Electron-spin resonance studies of the titanium cation (Ti+,3d?, ?F) in rare gas matrices at 4 K: A crystal field interpretation | Electron-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 |
143 |
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Armentrout, Peter B. | Collision-induced dissociation processes of Nb4+ and Fe4+: fission vs. evaporation | Despite 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; Evaporation | 1988 |
144 |
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Miller, Joel Steven | Involvement of titanocene and related species in the reduction of dinitrogen and olefins | Summary 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; Pressure | 1972 |
145 |
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Morse, Michael David | Resonant two-photon ionization spectroscopy of jet-cooled PtSi | Jet-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 |
146 |
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Miller, Joel Steven | On 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; Salts | 2002 |
147 |
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Armentrout, Peter B. | Methane activation by cobalt cluster cations, Con+ (n=2-16): reaction mechanisms and thermochemistry of cluster-CHx (x=0-3) complexes | The 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 methane | 2009 |
148 |
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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 structure | The 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; Deuterides | 2002 |
149 |
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Miller, Joel Steven | Synthesis of layered (2-D) V-based bimetallic oxalates from non-aqueous media that cannot be synthesized from aqueous media | The 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; Diffraction | 2006 |
150 |
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Morse, Michael David | Optical 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 |