UScholar Works
 
Filters: Department: "Chemistry" Collection: "ir_uspace"
276 - 300 of 338
Number of results to display per page
CreatorTitleDescriptionSubjectDate
276 Morse, Michael DavidSpectroscopy and electronic structure of jet-cooled NiCuDiatomic nickel-copper, NiCu, has been investigated by resonant two-photon ionization spectroscopy in a jet-cooled molecular beam. Six band systems have been identified over the range 11 500-16 500 cm-1. The ground state of NiCu has been determined to be X 2?5/2, with ?"e = 273.01 ? 1.15 cm-1, ?"exe...1988
277 Morse, Michael DavidSpectroscopy and electronic structure of jet-cooled NiPd and PdPtResonant two-photon ionization spectroscopy of jet-cooled NiPd and PdPt has revealed a dense vibronic spectrum for NiPd and a much more sparse spectrum for PdPt. Four vibrational progressions have been identified for NiPd, and three have been located for PdPt. High resolution investigations of NiPd...1990
278 Morse, Michael DavidSpectroscopy of AlAr and AlKr from 31 000 cm-1 to the ionization limitSpectra of jet-cooled AlAr and AlKr have been collected over the range from 31 000 cm -? to the ionization limit, using the technique of resonant two-photon ionization spectroscopy with mass spectrometric detection. Adiabatic ionization potentials have been accurately measured for both molecules, an...1992
279 Morse, Michael DavidSpectroscopy of diatomic ZrF and ZrCl: 760 ? 555 nmThe optical spectrum of diatomic ZrF has been investigated, with transitions recorded in the range from 14 700 to 18 000 cm?1. Many bands have been observed, several of which can be grouped into three band systems. Rotationally resolved investigations are hampered by perturbations that are rampant ...2011
280 Morse, Michael DavidSpectroscopy of mixed early-late transition metal diatomics: ScNi, YPd, and ZrCoResonant two-photon ionization spectroscopy has been employed to investigate the spectra of the jet-cooled transition metal diatomics ScNi, YPd, and ZrCo, which are isovalent species which possess ~or are thought to possess! an X 2?+ ground state. Several electronic band systems have been observed f...1994
281 Morse, Michael DavidSpectrosopic studies of jet-cooled NiAu and PtCuSpectroscopic investigations of NiAu and PtCu have revealed that both molecules possess 2?5/2 ground electronic states, and are in this respect analogous to the isovalent molecule NiCu. The ground-state bond lengths (r?) have been measured as 2.351?0.001 ? and 2.335?0.001 ? for NiAu and PtCu, respe...1992
282 Morse, Michael DavidSpectrsocopy of Jet-cooled YCuOptical spectra of jet-cooled diatomic YCu have been recorded using resonant two-photon ionization spectroscopy in a supersonic expansion of helium. The ground state is shown experimentally to be of 1?+ symmetry, with a measured bond length of re"=2.6197(6) ? and a vibrational frequency of 193.21(24...1995
283 Miller, Joel StevenSpin 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; Temperature1999
284 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
285 Miller, Joel Steven; Epstein, Arthur J.Spin frustration and metamagnetic behavior in a molecular-based quasi 1-D-ferrimagnetic chain: (MnTPP)(TCNE)We report an experimental observation of spin frustration and metamagnetic behavior in a quasi-1D ferrimagnetic chain, (MnTPP) + (TCNE) -. Metastability, hysteresis effects, and irreversibility of thermal and magnetic histories are observed in magnetization measurements. The "memory" phenomenon is ...Magnetic; Magnetization; Anisotropy1993
286 Morse, Michael DavidSpin-forbidden c??+??X??+ band system of YFOptical spectra of jet-cooled diatomic YF have been recorded using resonant two-photon ionization spectroscopy. A vibrational progression corresponding to the c 3?1+?X 1?+ system has been identified. The vibrational frequency ?e' and anharmonicity ?'exe' of the c 3?+ state are 546.70 and 2.45 cm?1,...2007
287 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 reactions1986
288 Armentrout, Peter B.Spin-orbit state-selected reactions of Xe+(2P3/2 and 2P1/2) with H2, D2, and HDSpin-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 reactions1989
289 Armentrout, Peter B.Statistical modeling of competitive threshold collision-induced dissociationCollision-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; Alcohols1998
290 Armentrout, Peter B.Statistical modeling of sequential collision-induced dissociation thresholdsThermochemistry 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 reactions2007
291 Miller, Joel StevenStructural 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 productThe 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; Polymers1989
292 Miller, Joel StevenStructure 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-quinodimethanideThe 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; Coupling2000
293 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
294 Miller, Joel StevenStructure 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; Spin1997
295 Miller, Joel StevenStructure of CrIIF(NCMe)2BF4. Rietveld refinement of a component of a physical mixture of unknown compositionThe 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; Tetracyanoethylene2008
296 Miller, Joel StevenStructure, 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; Electron2001
297 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
298 Armentrout, Peter B.Supporting information for infrared multiple photon dissociation spectroscopy of cationized methionine: effects of alkali-metal cation size on gas-phase conformationA 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
299 Stang, Peter J.Supramolecular chemistry and molecular design: self-assembly of molecular squaresModem 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 squares1997
300 Miller, Joel Steven; Liao, YiSynthesis and structure of an asymmetric copper(I) dimer with two-coordinate and four-coordinate copper(I) sitesCopper(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; Electrons2000
276 - 300 of 338