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Creator | Title | Description | Subject | Date |
276 |
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Armentrout, Peter B. | Spin-orbit state-selected reactions of Kr+(2P3/2 and 2P1/2) with H2, D2, and HD from thermal energies to 20 eV c.m. | Spin-orbit state-selected reactions of K r + (2Pj), J = 3/2 and / = 1/2, with isotopic molecular hydrogen (H2 , D2 , and HD) to form KrH+ and Kr D+ are investigated using guided ion beam techniques. Reaction cross sections for each spin-orbit state are measured as a function of the relative trans... | Spin-orbit; Krypton ions; Hydrogen isotopes; Isotope effects; Potential energy surfaces; Ion-molecule reactions | 1986 |
277 |
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Armentrout, Peter B. | Spin-orbit state-selected reactions of Xe+(2P3/2 and 2P1/2) with H2, D2, and HD | Spin-orbit state-selected reactions of X e + (2Pj ), j = 3/2 and 1/2, with isotopic molecular hydrogen (H2 , D2 , and HD) to form X e H + and XeD + are studied using guided ion beam mass spectrometry. Reaction cross sections are determined as a function of reactant kinetic energy from near thermal ... | Spin-orbit; Xenon ions; Hydrogen isotopes; Isotope effects; Ion-molecule reactions | 1989 |
278 |
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Armentrout, Peter B. | Statistical modeling of competitive threshold collision-induced dissociation | Collision-induced dissociation of (R1OH)Li+(R2OH) with xenon is studied using guided ion beam mass spectrometry. R1OH and R2OH include the following molecules: water, methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol. In all cases, the primary products formed correspond to endothermic loss of... | Collision-induced dissociation; Xenon ions; Alcohols | 1998 |
279 |
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Armentrout, Peter B. | Statistical modeling of sequential collision-induced dissociation thresholds | Thermochemistry determined from careful analysis of the energy dependence of cross sections for collision-induced dissociation (CID) reactions has primarily come from the primary dissociation channel. Higher order dissociations generally have thresholds measured to be higher than the thermodynamic ... | Collision-induced dissociation; Endothermic reactions | 2007 |
280 |
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Miller, Joel Steven | Structural and magnetic characterization of a- and B-2,4-hexadiyne-1,6-diyl Bis(2,2,5,5-tetramethyl-1-oxyl-3-pyrroline-3-carboxylate) and its thermal degradation product | The search for ferromagnetic organic compounds and polymers is the focus of contemporary research.1 - 5 Polymerization of di-iminoxyl diacetylene monomers has been suggested as a means to prepare a high spin potentially ferromagnetically coupled polymers3 and the thermal, photochemical, and glow di... | Ferromagnetic; Magnetization; Polymers | 1989 |
281 |
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Miller, Joel Steven | Structure and magnetic properties of meso-tetrakis(2,4,6-trimethylphenyl)porphyrinatomanganese(III) 7,7,8,8-tetracyano 2,5-dimethyl-p-quinodimethanide with a 2.3 K Tc. The first example of cis-coordination of a tetracyano-p-quinodimethanide | The crystal structure of meso-tetrakis(2,4,6-trimethylphenyl)porphyrinatomanganese(III) 7,7,8,8-tetracyano-2,5-dimethyl-p-quinodimethanide, [MnTMesP][DMTCNQ]-2p-C6H4Me2 provides the first example of a cis-1,2-u-coordination motif having an infinite zigzag chain structure. [MnTMesP][DMTCNQ]-2p-C6H4Me... | Magnets; Interactions; Coupling | 2000 |
282 |
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Miller, Joel Steven | Structure and magnetic properties of MnII[N(CN)2]2(pyrazine). An antiferromagnet with an interpenetrating 3-D network structure | Mn[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; Temperature | 1998 |
283 |
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Miller, Joel Steven | Structure and physical properties of hexacyanomanganate(IV), [MnIV(CN)6]2- | Hydrolytically unstable d3 [MnI V(CN)6]2- as the [N(PPh3)2]+ salt is crystallographically, spectroscopically, and magnetically characterized. | Absorption; Magnetic; Spin | 1997 |
284 |
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Miller, Joel Steven | Structure of CrIIF(NCMe)2BF4. Rietveld refinement of a component of a physical mixture of unknown composition | The reaction of CrII(NCMe)4(BF4)2 and [NBun 4][TCNE] (TCNE ¼ tetracyanoethylene) in CH2Cl2 forms a solid that is a mixture of an amorphous reduced-TCNE containing phase(s) and a crystalline component. Rietveld refinement of the high-resolution, synchrotron X-ray powder pattern enabled the determi... | Organic-based magnets; Powder X-ray diffraction; Tetracyanoethylene | 2008 |
285 |
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Miller, Joel Steven | Structure, optical and magnetic behaviour of meso-tetraphenyl-porphyrinatoiron(III) tetracyanoethenide, [FeIII(TPP)]+[TCNE].-* | The direct redox reaction between tetracyanoethylene (TCNE) and meso-tetraphenylporphyrinatoiron(II), [FeII(TPP)], formed the electron transfer salt (ETS) [FeIII(TPP)][TCNE], which has been structurally, spectroscopically, and magnetically characterized. It has an extended one-dimensional linear ch... | Magnets; Spin; Electron | 2001 |
286 |
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Stang, Peter J. | Studies in the cycloproparene series: cycloaddition reactions of diarylmethylidenecycloproparenes | Diarylmethylidenecyclopropanaphthalenes 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; norcaradienes | 2001 |
287 |
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Armentrout, Peter B. | Supporting information for infrared multiple photon dissociation spectroscopy of cationized methionine: effects of alkali-metal cation size on gas-phase conformation | A description of the structures of Met and M+(Met) for M+ = Li+, Na+, K+, Rb+, and Cs+. Two figures (S1a and S1b) depicting the 298 K Gibbs free energies calculated at the R/6- 311+G(2d,2p)//B3LYP/6-311+G(d,p) (M+ = Li+, Na+, K+) and R/HW*/6-311+G(2d,2p)// B3LYP/HW*6-311+G(d,p) (M+ = Rb+ and Cs+) le... | | 2010 |
288 |
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Stang, Peter J. | Supramolecular chemistry and molecular design: self-assembly of molecular squares | Modem supramolecular chemistry has been described as organized polymolecular systems held together by noncovalent interactions and represents one of the major frontiers in the chemical sciences.'-' At present the field is dominated by the hydrogen bonding motif that mimics biological systems and th... | Molecular design; Molecular squares | 1997 |
289 |
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Miller, Joel Steven; Liao, Yi | Synthesis and structure of an asymmetric copper(I) dimer with two-coordinate and four-coordinate copper(I) sites | Copper(I) coordination compounds have been studied intensively due to their biological relevance, catalytic properties, and theoretical interests. Numerous mononuclear and polynuclear copper(I) complexes with different coordination numbers have been prepared and characterized. Recently the possible ... | Polynuclear; Nitrogens; Electrons | 2000 |
290 |
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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 |
291 |
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Miller, Joel Steven | Synthesis, structural, and magnetic characterization of substituted benzoimidazole-l-yl N,N'-dioxides | The 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; Coupling | 2004 |
292 |
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Poulter, Charles Dale | Tetartohedral twinning in IDI-2 from Thermus thermophilus: crystallization under anaerobic conditions | Type-2 isopentenyl diphosphate isomerase (IDI-2) is a key flavoprotein involved in the biosynthesis of isoprenoids. Since fully reduced flavin mononucleotide (FMNH2) is needed for activity, it was decided to crystallize the enzyme under anaerobic conditions in order to understand how this reduced co... | | 2014-01-01 |
293 |
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Miller, Joel Steven; Epstein, Arthur J. | Tetracyanoethylene-based organic magnets | Several 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; Oxidation | 1998 |
294 |
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Armentrout, Peter B. | Theoretical investigation and reinterpretation of the decomposition of lithiated proline and N-Methyl Proline | Lithium cation complexes of proline (Pro) and N-methyl proline (NMP) have been collisionally activated with xenon in a guided ion beam tandem mass spectrometer (GIBMS). In addition to the loss of the intact ligand, Pro and NMP, we observed two prominent fragmentation pathways involving the loss of (... | | 2014-01-01 |
295 |
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Wight, Charles Albert | Thermal analysis of high explosives: liquid state decomposition of RDX | Nonisothermal thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been applied to the thermal decomposition of RDX. Model-free isoconversional analysis of TGA and DSC traces show that RDX primarily evaporates in an open pan with an activation energy of Eα -100 kJ ... | RDX; Plastic explosives; Decomposition; Thermogravimetric analysis; Differential scanning calorimetry | 2000 |
296 |
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Armentrout, Peter B. | Thermochemistry of small cationic iron-sulfur clusters | The kinetic energy dependences of the reactions of Fen 1 with COS (n=2-6) and CS2 (n=2-5) are studied in a guided-ion beam tandem mass-spectrometer. The main products arise from sulfur transfer and subsequent losses of Fe atoms. In the case of CS2 , this reactant also formally replaces one Fe atom ... | Iron-sulfur clusters; Endothermic reactions; Bond energy | 2002 |
297 |
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Armentrout, Peter B. | Thermochemistry of the activation of N2 on iron cluster cations: guided ion beam studies of the reactions of Fen+ (n=1-19) with N2 | The kinetic energy dependences of the reactions of Fen + (n=1-19) with N2 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-15 eV. In addition to collision-induced dissociation forming Fem + ions, which dominate the product spectra, a variety of FemN2+ and FemN+ p... | Metal clusters; Iron ions; Dinitrogen; Endothermic reactions; Collision-induced dissociation; Bond energies | 2006 |
298 |
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Armentrout, Peter B. | Thermodynamics and mechanism of protonated cysteine decomposition: a guided ion beam and computational study | A quantitative molecular description of the decomposition of protonated cysteine, H+Cys, is provided by studying the kinetic energy dependence of threshold collision-induced dissociation (CID) with Xe using a guided ion beam tandem mass spectrometer (GIBMS). Primary dissociation channels are deamida... | | 2014-01-01 |
299 |
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Armentrout, Peter B. | Thermodynamics and mechanisms of protonated diglycine decomposition: a guided ion beam study | We present a full molecular description of fragmentation reactions of protonated diglycine (H+GG) by studying their collision-induced dissociation (CID) with Xe using a guided ion beam tandem mass spectrometer (GIBMS). Analysis of the kinetic energy-dependent CID cross sections provides the 0 K barr... | | 2012-01-01 |
300 |
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Armentrout, Peter B. | Thermodynamics and mechanisms of protonated diglycine decomposition: a computational study | We present a full computational description of the fragmentation reactions of protonated diglycine (H+GG). Relaxed potential energy surface scans performed at B3LYP/6-31G(d) or B3LYP/6-311+G(d,p) levels are used to map the reaction coordinate surfaces and identify the transition states (TSs) and int... | | 2012-01-01 |