@inbook {doi:10.1002/9780470034590.emrstm1477, title = {Molecular Hydrogens Dissolved in Liquid Crystals}, booktitle = {eMagRes}, year = {2016}, pages = {901-912}, publisher = {American Cancer Society}, organization = {American Cancer Society}, abstract = {Abstract The NMR spectra of molecular hydrogen isotopologs dissolved and orientationally ordered in nematic liquid-crystal solvents provide a wealth of information. Because they are quantum rotors, the various isotopologs H 2 , D 2 , T 2 , HD, HT, and DT have different order parameters, with larger internuclear distance having smaller order parameter. The signs and magnitudes of the order parameters are liquid-crystal dependent, this being a direct result of the dominant anisotropic intermolecular interaction being that between the solute quadrupole moment and the mean liquid-crystal electric-field gradient (EFG) felt by the solute. Thus, the mixing of different liquid crystals can produce a solvent where molecular hydrogen feels a zero EFG, called a magic mixture. The remaining, dominant anisotropic interaction (for solutes larger than hydrogen) in these magic mixtures involves short-range anisotropic forces that depend on solute size and shape. Studies involving the very symmetrical methane H, D, and T isotopologs point out the important effect on dipolar couplings of molecular vibrations and interactions between molecular vibration and reorientation, effects which make it impossible to utilize fully the high accuracy with which dipolar couplings in general can be measured.}, keywords = {ANISOTROPIC, electric field gradient, HYDROGEN, liquid crystal, METHANE, NMR, order parameter, ordered liquids, ORIENTATION, VIBRATIONS}, isbn = {9780470034590}, doi = {10.1002/9780470034590.emrstm1477}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/9780470034590.emrstm1477}, author = {Burnell, E. Elliott and de Lange, Cornelis A.} } @article {2351, title = {The muonic He atom and a preliminary study of the He-4 mu + H-2 reaction}, journal = {Physica B-Condensed Matter}, volume = {404}, number = {5-7}, year = {2009}, note = {ISI Document Delivery No.: 437ESTimes Cited: 2Cited Reference Count: 12Arseneau, Donald J. Fleming, Donald G. Sukhorukov, Oleksandr Brewer, Jess H. Garrett, Bruce C. Truhlar, Donald G.11th International Conference on Muon Spin Rotation, Relaxation and ResonanceJUL 21-25, 2008Tsukuba, JAPANJapan World Exposit, Commemorat Organizat}, month = {Apr}, pages = {946-949}, type = {Proceedings Paper}, abstract = {The muonic atom He-4 mu has the composition alpha(++)mu(-)e(-), and is formed by stopping negative muons in He doped with a small amount of NH3 (or Xe). It may be regarded as a unique heavy H-atom isotope with a mass of 4.1 amu. As such, the study of its chemical reaction rates and comparison with those of the well-known light Mu atom (0.113 amu) allows unprecedented tests of kinetic isotope effects over a range of 36 in mass. As a first example, and one which is of most fundamental interest, we have begun kinetics studies of the He mu + H-2 -> He mu H + H reaction in the gas phase. The first measurements, at 295 K, give a rate constant of k(He mu) = 4.1 +/- 0.7 X 10(-16) cm(3) molec(-1) s(-1). in comparison, variational transition state calculations give a value of 2.46 x 10(-6) cm(3) molec(-1) s-1, somewhat below the measurement, despite the large error bar, raising the possibility that the calculations, on an essentially exact potential energy surface, have underestimated the amount of quantum tunneling involved, even for this heavy H-atom isotope. (c) 2008 Elsevier B.V. All rights reserved.}, keywords = {effects, He mu atom, Heavy H-atom, HELIUM ATOM, HYDROGEN, INTERVAL, Kinetic isotope, Reaction rate, Variational TST}, isbn = {0921-4526}, url = {://000265469800104}, author = {Arseneau, D. J. and Fleming, Donald G. and Sukhorukov, O. and Brewer, J. H. and Garrett, B. C. and Truhlar, D. G.} } @article {2392, title = {Theoretical study of the electronic spectra of s-triazine vapour}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {87}, number = {8}, year = {2009}, note = {ISI Document Delivery No.: 493VQTimes Cited: 3Cited Reference Count: 37Chong, Delano P.}, month = {Aug}, pages = {1148-1153}, type = {Article}, abstract = {The ionization and excitation spectra of valence and core electrons of s-triazine in the gas phase are studied with ab initio, density functional, and semi-empirical methods. The results are compared with available experimental data and previous calculations. New estimates are proposed for the ionization energies of both valence and core electrons. The calculated excitation energies are consistent with experiment.}, keywords = {AB-INITIO, AZINES, core-electron binding energies, DENSITY-FUNCTIONAL THEORY, DFT, electron spectra, ESCA, EXCHANGE-CORRELATION POTENTIALS, EXCITATION-ENERGIES, excitations, HYDROGEN, IONIZATION-POTENTIALS, ionizations, MOLECULAR CALCULATIONS, N-2, photoelectron spectra, s-triazine, SPECTROSCOPY, UV absorption}, isbn = {0008-4042}, url = {://000269766800008}, author = {Chong, D. P.} } @article {2354, title = {Toward the first study of chemical reaction dynamics of Mu with vibrational-state-selected reactants in the gas phase: The Mu + H-2*(v=1) reaction by stimulated Raman pumping}, journal = {Physica B-Condensed Matter}, volume = {404}, number = {5-7}, year = {2009}, note = {ISI Document Delivery No.: 437ESTimes Cited: 1Cited Reference Count: 9Bakule, Pavel Sukhorukov, Oleksandr Matsuda, Yasuyuki Pratt, Francis Gumplinger, Peter Momose, Takamasa Torikai, Eiko Fleming, Donald11th International Conference on Muon Spin Rotation, Relaxation and ResonanceJUL 21-25, 2008Tsukuba, JAPANJapan World Exposit, Commemorat Organizat}, month = {Apr}, pages = {1013-1016}, type = {Proceedings Paper}, abstract = {Stimulated Raman pumping (SRP) is used to produce H-2 in its first vibrational state, in order to measure, for the first time, the Mu + H-2*(v = 1) -> MuH + H reaction rate at room temperature, as a prototypical example of new directions in gas-phase muonium chemistry, utilizing the pulsed muon beam and a new dedicated laser system at the RIKEN/RAL Laboratory. Reported here is a preliminary result but the final results are expected to provide definitive new tests of reaction rate theory on the highly accurate H-3 potential energy surface. The major difficulty in this experiment, compared to the standard SRP process, is to ensure a homogeneous excitation over a volume of several cm(3) and of sufficient intensity to ensure a measurable Mu relaxation rate. The techniques used to accomplish this are described. The experiment utilizes the 2nd harmonic output of a Nd:YAG laser (532 nm) with pulse energies up to 500 mJ at a repetition rate of 25 Hz. Different optical setups have been constructed and tested in order to optimize the number of laser-pumped H-2 molecules and their overlap with the stopping profile of the muon beam in the reaction cell (total volume similar to 100 x 40 x 4 mm(3)). The first result of this experiment gives a measured relaxation rate due to laser excitation of lambda* = 0.085 +/- 0.051 mu s(-1), consistent with theory but limited by both low statistics and particularly a high background relaxation rate. (c) 2009 Elsevier B.V. All rights reserved.}, keywords = {DYNAMICS, HYDROGEN, Laser setups, muonium, reaction, Stimulated Raman pumping}, isbn = {0921-4526}, url = {://000265469800122}, author = {Bakule, P. and Sukhorukov, O. and Matsuda, Y. and Pratt, F. and Gumplinger, P. and Momose, T. and Torikai, E. and Fleming, Donald G.} } @article {1361, title = {Density functional theory calculation of electron spectra of formaldehyde}, journal = {Chemical Physics Letters}, volume = {418}, number = {1-3}, year = {2006}, note = {ISI Document Delivery No.: 005UMTimes Cited: 12Cited Reference Count: 30}, month = {Jan}, pages = {286-291}, type = {Article}, abstract = {Both ionization and excitation spectra for outer valence-shell electrons and inner-shell electrons of formaldehyde are calculated with density functional methods. In addition, both resonant and non-resonant X-ray emission spectra are also computed. For all of these calculations, we use four different basis sets: large and efficient sets, with and without diffuse functions. Choice of method for each type of electron spectroscopy is based on past experience. For excitation spectra, especially when the final states are Rydberg-like in nature, basis sets with diffuse functions are recommended. On the other hand, for ionization spectra and X-ray emission spectra, diffuse functions are apparently unnecessary. Available experimental data for formaldehyde enable us to judge the accuracy of the present density functional calculations. The average absolute deviation from experiment is generally about 0.3 eV or better, confirming the adequacy of our choice of method. (c) 2005 Elsevier B.V. All rights reserved.}, keywords = {EMISSION SPECTRA, EXCITATION-ENERGIES, HYDROGEN, KRYPTON, MOLECULES, ORBITALS, photoabsorption, RAY-ABSORPTION SPECTRA, SLATER-TYPE, VERTICAL IONIZATION-POTENTIALS}, isbn = {0009-2614}, url = {://000234849500055}, author = {Chong, D. P. and Takahata, Y.} } @article {1433, title = {Reaction of H2S with MoRu(CO)(6)(dppm)(2) to give H-2 and a bridged-sulfide product via hydrido-sulfhydryl intermediates (dppm = Ph2PCH2PPh2)}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {84}, number = {2}, year = {2006}, note = {ISI Document Delivery No.: 040YKTimes Cited: 2Cited Reference Count: 29}, month = {Feb}, pages = {330-336}, type = {Article}, abstract = {Oxidative addition of H2S to MoRu(CO)(6)(mu-dppm)(2) (1) at similar to 20 degrees C in toluene yields an isolable complex formulated as Mo(CO)(3)(mu-SH)(mu-CO)(mu-dppm)(2)RuH(CO) (2) via the possible intermediate Mo(CO)(3)(mu-H)(mu-CO)(mu-dppm)(2)Ru(SH)(CO) (4) (dppm = Ph2PCH2PPh2) that is detectable at lower temperatures. Over 2 days, species 2 in toluene loses H-2 (and CO) to yield the bridged-sulfide product, Mo(CO)(2)(mu-CO)(mu-S)(mu-dppm)(2)Ru(CO) (5) that is also formed directly from the reaction of 1 with elemental sulfur. The solid-state molecular structure of 5 is determined by X-ray crystallography. A further hydrido-sulfhydryl species, possibly Mo(CO)(3)(mu-SH)(mu-H)(mu-dppm)(2)Ru(CO)(2) (3), is in equilibrium with 2 at ambient temperature.}, keywords = {bis(diphenylphosphino) methane, bis(diphenylphosphino)methane, BOND ACTIVATION, bridged-sulfide complex, carbonyl complexes, CHEMISTRY, COMPLEXES, hydrido-sulfhydryl species, HYDROGEN, HYDROGEN-SULFIDE, MECHANISTIC ASPECTS, METAL, MO, MOLYBDENUM, RECOVERY, ruthenium, sulfide, SULFUR-DIOXIDE}, isbn = {0008-4042}, url = {://000237417600031}, author = {Khorasani-Motlagh, M. and Safari, N. and Pamplin, C. B. and Patrick, B. O. and James, Brian R.} } @article {1068, title = {NMR as a tool in the investigation of fundamental problems in ordered liquids}, journal = {Solid State Nuclear Magnetic Resonance}, volume = {28}, number = {2-4}, year = {2005}, note = {ISI Document Delivery No.: 998NHTimes Cited: 9Cited Reference Count: 49}, month = {Sep}, pages = {73-90}, type = {Article}, abstract = {An overview is presented of modern NMR techniques and a variety of experimental and theoretical tools employed in the study of solutes dissolved in liquid crystals. The NMR techniques involve multiple quantum and spectral subtraction methods, In addition, various experimental and theoretical tools are discussed, including: the theoretical background of observed order parameters; the use of,magic mixtures{\textquoteright} to separate orientational contributions; the reorientation-vibration interaction; the use of model calculations based on size and shape of the various solutes; and the use of computer simulations. Applications to the benchmark probe molecules hydrogen, methane, ethane, and butane and their isotopomers are treated. (c) 2005 Elsevier Inc. All rights reserved.}, keywords = {ANISOTROPIC LIQUIDS, butane, ethane, H-2 NMR, HYDROGEN, INTERNAL-ROTATION, liquid crystal, METHANE, MOLECULES, MOLEKULAR-STATISTISCHE THEORIE, MULTIPLE-QUANTUM NMR, NEMATISCHEN KRISTALLINFLUSSIGEN PHASE, NMR, NUCLEAR-MAGNETIC-RESONANCE, order parameter, orientational order, PROTON DIPOLAR COUPLINGS, SMALL CHAIN}, isbn = {0926-2040}, url = {://000234325100003}, author = {Burnell, E. E. and de Lange, C. A.} } @article {983, title = {Neutral particle collisional relaxation of suprathermal distributions in aeronomy}, journal = {Planetary and Space Science}, volume = {52}, number = {10}, year = {2004}, note = {ISI Document Delivery No.: 858UKTimes Cited: 3Cited Reference Count: 46}, month = {Aug}, pages = {915-922}, type = {Article}, abstract = {There are numerous situations in laboratory experiments and in atmospheric science that are characterized by distributions of energetic neutral species with extended high-energy tails. This paper provides a detailed analysis of the relaxation of such isotropic nonequilibrium distributions of neutral species. We consider a minor constituent, referred to as the test-particle dilutely dispersed in a second component that acts as a heat bath at equilibrium. A hard sphere cross section is assumed for the collisions of the test particles and the heat bath particles, and collisions between test particles are not included in the analysis. We study the approach to equilibrium with a finite difference method of solution of the Boltzmann equation. The solution of the Boltzmann equation is also presented as an expansion in the eigenfunctions of the Boltzmann collision operator. The main objective of the paper is the calculation of the energy-dependent relaxation times for the distribution function. It is anticipated that these relaxation times will not exhibit a strong energy dependence owing to the energy-independent hard sphere cross section. This relaxation behaviour is important in the characterization of nonthermal populations of energetic atoms in aeronomy. The results are compared with a similar analysis for Coulomb collisions described in the preceeding paper. (C) 2004 Elsevier Ltd. All rights reserved.}, keywords = {BINARY GASES, Boltzmann equation, CHARGE-EXCHANGE, distribution functions, ENERGY-TRANSFER, FAST NITROGEN-ATOMS, FOKKER-PLANCK EQUATION, HYDROGEN, KINETIC-THEORY, MARS, O(P-3) ATOMS, OXYGEN-ATOMS, relaxation times, suprathermal populations}, isbn = {0032-0633}, url = {://000224217300003}, author = {Shizgal, B. D.} } @article {407, title = {Homo- and heterobimetallic precursor catalysts for the Heck reaction, and a proposal for a general catalytic cooperativity index}, journal = {Advanced Synthesis \& Catalysis}, volume = {344}, number = {10}, year = {2002}, note = {ISI Document Delivery No.: 629XZTimes Cited: 22Cited Reference Count: 58}, month = {Dec}, pages = {1126-1134}, type = {Article}, abstract = {Homo- (Pd-2) and heterobimetallic (PtPd) complexes supported by a P,P-bridging, bis(P,N-chelating) coordination mode of the potentially hexadentate ligand 1,1-bis[di(o-N,N-dimethylanilinyl)phosphino] methane (dmapm) are effective catalyst precursors for the aerobic Heck coupling of iodobenzene and styrene at 100degreesC in DMF/H2O solution containing K2CO3. This medium allows for trivial separation of the trans-stilbene product which precipitates after the reaction mixture is cooled. The bimetallic precursors are more active than predicted from the sum of the activities of complexes chosen to mimic their mono-metallic "half units," suggesting some degree of intermetallic cooperativity during the reaction. A non-linear dependence of initial rate on catalyst concentration implies, however, that the complexes do not remain intact, and may be involved in dissociative equilibria with non-dmapm containing monometallic components that are more active species for the Heck coupling. The complexes are slowly degraded by oxidation at a phosphorus centre. A general index for quantifying the degree of intermetallic cooperativity during a catalytic cycle is proposed and its utility and limitations are discussed.}, keywords = {aerobic), ASYMMETRIC CATALYSIS, bimetallic, CHEMISTRY, cooperativity, COORDINATION, COUPLING, Heck reaction (aqueous, HIGH REGIOSELECTIVITY, homogeneous, HYDROFORMYLATION, HYDROGEN, LIGANDS, NICKEL(II) SITE, palladium, PALLADIUM(II) COMPLEXES, phosphine (anilinyl), platinum, REACTIONS, thermomorphic, VINYLIC SUBSTITUTION-REACTIONS}, isbn = {1615-4150}, url = {://000180078900015}, author = {Jones, N. D. and James, Brian R.} } @article {560, title = {Insertion and removal of protons in single-crystal orthorhombic molybdenum trioxide under H2S/H-2 and O-2/N-2}, journal = {Chemistry of Materials}, volume = {14}, number = {4}, year = {2002}, note = {ISI Document Delivery No.: 542DRTimes Cited: 13Cited Reference Count: 49}, month = {Apr}, pages = {1788-1796}, type = {Article}, abstract = {Using AFM/XRD/XPS methods, in this paper, we investigate protonation and deprotonation processes in single-crystal samples of orthorhombic molybdenum trioxide (alpha-MoO3). At low temperatures, a small part of alpha-MoO3 is changed to needlelike HxMoO3 (x approximate to 0.33) along <203> directions in a H2S/H-2 gas stream. When these elongated crystallites assemble into a maze structure, the growth of HxMoO3 is gradually ceased due to closing entrance for hydrogen. At higher temperatures, the needlelike HxMoO3 crystallites turn to a growth perpendicular to <203>, which leads to the formation of HxMoO3 blocks. It is observed that the basal plane of alpha-MoO3 is severely buckled upon the protonation. Surface sulfidation is also observed. The formed HxMoO3 or surface MOS2, however, can be readily converted back to their original-phase alpha-MoO3 in air at 350-400 degreesC. This oxidation process gives rise to a flattened (010) topography (i.e., debuckling) on which shallowly divided alpha-MoO3 surface blocks bounded with {101} planes are formed. When an alpha-MoO3 (010) plane embedded with nanocrystallites is used to create surface stress or nucleation sites, the insertion mode of hydrogen along <001> is further reconfirmed in this work. A correlation of surface/bulk phases upon various chemical reactions is addressed, and a model to summarize these changes is also proposed.}, keywords = {BRONZES, DECOMPOSITION, GROWTH, HXMOO3, HYDROGEN, MOO3, NUCLEAR-MAGNETIC-RESONANCE, RAY PHOTOELECTRON-SPECTROSCOPY, SILICA SUPPORTS, THIN-FILMS, XPS}, isbn = {0897-4756}, url = {://000175028700050}, author = {Zeng, H. C. and Xie, F. and Wong, K. C. and Mitchell, K. A. R.} } @article {409, title = {Velocity distributions of energetic atoms in planetary exospheres from dissociative recombination}, journal = {Journal of Geophysical Research-Planets}, volume = {107}, number = {E7}, year = {2002}, note = {ISI Document Delivery No.: 610UBTimes Cited: 3Cited Reference Count: 47}, month = {Jul}, pages = {9}, type = {Article}, abstract = {[1] A kinetic theory description of translational energetic atoms in the upper planetary atmosphere is presented. A new analytical result for the velocity distribution of the products of reactive collisions is described. Our calculation takes into account different temperatures of the reactants and arbitrary dependence of the cross section on the relative velocity of the colliding particles. The final result is applied to the production of hot oxygen and carbon by dissociative recombination of O-2(+) and CO+, respectively. The nascent distribution of hot atoms generated in this way is compared with the earlier Monte Carlo calculations. We use the Boltzmann equation to study the thermalization of the hot oxygen via collisions with the thermal oxygen population. The results of this calculation demonstrate quasi-steady state velocity distribution of high-energy oxygen atoms near the exobase of Venus for daytime conditions.}, keywords = {Boltzmann equation, CROSS-SECTIONS, dissociative recombination, ESCAPE, gas kinetic, hot atoms, HOT OXYGEN-ATOMS, HYDROGEN, ION STORAGE-RING, MARS, MONTE-CARLO, NITROGEN-ATOMS, theory, UPPER-ATMOSPHERE, VENUS}, isbn = {0148-0227}, url = {://000178978400004}, author = {Kabin, K. and Shizgal, B. D.} } @article {5013, title = {alpha-agostic interactions in Cp*W(NO)(CH2CMe3)(2) and related nitrosyl complexes}, journal = {Organometallics}, volume = {20}, number = {22}, year = {2001}, note = {ISI Document Delivery No.: 488TLTimes Cited: 22Cited Reference Count: 59}, month = {Oct}, pages = {4492-4501}, type = {Article}, abstract = {The solid-state molecular structure of Cp*W(NO)(CH2CMe3)(2) (1) has been shown to contain one "strongly agostic" and one "weakly agostic" methylene hydrogen atom by a neutron diffraction analysis at 120 K and by an X-ray diffraction analysis at -100 degreesC. The X-ray diffraction analysis of Cp*W(NO)(CH2SiMe3)(2) (2) at -20 degreesC reveals that its solid-state molecular structure possesses a crystallographically imposed mirror plane. Consequently, only the average existence of a relatively strong C-(HM)-M-... interaction for each hydrocarbyl ligand in 2 in the solid state can be established. The H-1 and gated C-13{H-1} NMR spectra of representative Cp{\textquoteright}M(NO)(R)(R{\textquoteright}) (M = Mo, W; R = hydrocarbyl, R{\textquoteright} = hydrocarbyl, halide, amide) complexes exhibit spectral parameters for the alpha -H and alpha -C atoms (i.e., delta (H), delta (C), Delta delta (H), DeltaJ(HC), and J(HW)) that provide evidence for the presence of a-agostic interactions in the molecular structures of these complexes in solution. The picture that has emerged from these investigations is that these complexes do adopt an a-agostic structure both in solution and in the solid state when secondary interactions such as pi -electron donation are weak (as in Cp*W(NO)(CH2CMe3)Cl), competitive (as in Cp*W(NO)(CH2CMe3)(CH2Ph)), or not possible (as in Cp*W(NO)(hydrocarbyl)(2) complexes generally). The bis(hydrocarbyl) complexes are probably stereochemically nonrigid in solution, as they appear to interconvert between the two limiting structures having one strongly agostic and one weakly agostic hydrocarbyl ligand. The neopentyl ligand forms alpha -agostic linkages with the metal centers in all neopentyl complexes studied, and these agostic interactions appear to be independent of the nature of the metal or the ancillary cyclopentadienyl ligand. Interestingly, the presence of these groundstate agostic interactions does not correlate with the tendency of the various compounds to undergo intramolecular alpha -H abstraction reactions and form reactive alkylidene complexes.}, keywords = {ALKYL, C-H ACTIVATION, CARBON, COMPLEXES, CRYSTAL-STRUCTURE, DIALKYL COMPLEXES, hydride, HYDROGEN, MOLYBDENUM, TRANSITION-METAL BONDS, TUNGSTEN}, isbn = {0276-7333}, url = {://000171951700012}, author = {Bau, R. and Mason, S. A. and Patrick, B. O. and Adams, C. S. and Sharp, W. B. and Legzdins,Peter} } @inbook {5198, title = {Hot oxygen in the exosphere of Venus}, booktitle = {Rarefied Gas Dynamics}, series = {Aip Conference Proceedings}, volume = {585}, year = {2001}, note = {ISI Document Delivery No.: BT38RTimes Cited: 1Cited Reference Count: 35Proceedings Paper22nd International Symposium on Rarefied Gas DynamicsJUL 09-14, 2000SYDNEY, AUSTRALIASandia Natl Labs, AFOSR/AOARD, ONR IFO Asia, Far E, DLR, USA Res Off, GAB Consulting Pty Ltd, Telstra2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA}, pages = {119-126}, publisher = {Amer Inst Physics}, organization = {Amer Inst Physics}, address = {Melville}, abstract = {It has now been firmly established from both theoretical calculations and observations, that the exospheres of the terrestrial planets have extended coronas of translational energetic oxygen atoms. The current model generally accepted as the source of these hot atoms is the dissociative recombination of OZ, that is, O-2(+) + e(-) {\textendash}> O* + O* where the product O* atoms are translationally energetic. The determination of the extent of this population of superthermal atoms is an important endeavor. The present paper considers a simple model based on the Boltzmann equation for the energy and altitude dependence of the oxygen atom distribution function. The density and temperature distributions are determined with this distribution.}, keywords = {ESCAPE, FRACTIONATION, GEOCORONA, HYDROGEN, KINETICS, MARS, MODEL, NITROGEN-ATOMS, O(P-3) ATOMS, UPPER-ATMOSPHERE}, isbn = {0094-243X0-7354-0025-3}, url = {://000172834300017}, author = {Shizgal, B. D.}, editor = {Bartel, T. J. and Gallis, M. A.} } @article {4666, title = {An analysis of O-H interaction potentials, O-H and O-D collision cross sections, and vibrational states}, journal = {Planetary and Space Science}, volume = {47}, number = {1-2}, year = {1999}, note = {ISI Document Delivery No.: 179JTTimes Cited: 3Cited Reference Count: 29}, month = {Jan-Feb}, pages = {163-174}, type = {Article}, abstract = {A detailed comparison of recently published OH, X(2)Pi, (2)Sigma(-), (4)Pi and (4)Sigma(-) potentials is carried out. These potential functions are important in the accurate determination of O-H and O-D collision cross sections. The isotope effect in the O-H and O-D cross sections plays an important role in the enhanced nonthermal escape of H and D from Mars and Venus. The quantum mechanical elastic scattering cross sections for O-H and O-D collisions are determined with a set of potentials which are constructed with a new interpolation of the short range tabulated potentials and the long range asymptotic behaviour. The important role of the asymptotic radial variation of the potential functions in the determination of the elastic cross sections is studied in detail with a semiclassical analysis, and a comparison is made with previous calculations. The vibrational energies for several different X(2)Pi bound potential functions for OH are also calculated and compared with published results. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.}, keywords = {DISCRETIZATION METHOD QDM, ENERGY, HYDROGEN, MODEL, MOLECULE, OXYGEN, VENUS}, isbn = {0032-0633}, url = {://000079324100017}, author = {Shizgal, B. D.} } @article {4665, title = {Escape of H and D from Mars and Venus by energization with hot oxygen}, journal = {Journal of Geophysical Research-Space Physics}, volume = {104}, number = {A7}, year = {1999}, note = {ISI Document Delivery No.: 211WWTimes Cited: 12Cited Reference Count: 51}, month = {Jul}, pages = {14833-14846}, type = {Article}, abstract = {A kinetic theory collisional production model is used to determine the product velocity distributions of H and D resulting from collisional energy transfer with hot oxygen. The energetic oxygen atoms are the products of the dissociative recombination of O-2(+). Quantum mechanical cross sections for O-H and O-D collisions are used to determine the production distributions. The distributions of the particles entering a collision are assumed to be Maxwellian functions. The fraction of atoms with speeds above the escape speed is determined for Venus and Mars. For Venus, available density and temperature profiles are used to obtain estimates of the H and D escape fluxes and fractionation ratios.}, keywords = {CHARGE-EXCHANGE, dissociative recombination, ENERGY-TRANSFER, FRACTIONATION, HYDROGEN, NITROGEN-ATOMS, O(P-3) ATOMS, REACTIVE SYSTEMS, THERMOSPHERE, UPPER-ATMOSPHERE}, isbn = {0148-0227}, url = {://000081185700036}, author = {Shizgal, B. D.} } @article {4470, title = {{Theoretical predictions and single-crystal neutron diffraction and inelastic neutron scattering studies on the reaction of dihydrogen with the dinuclear dinitrogen complex of zirconium [P2N2]Zr(mu-eta(2)-N-2)Zr[P2N2]}, journal = {Journal of the American Chemical Society}, volume = {121}, number = {3}, year = {1999}, note = {ISI Document Delivery No.: 174NUTimes Cited: 67Cited Reference Count: 29}, month = {Jan}, pages = {523-528}, type = {Article}, abstract = {A single-crystal neutron diffraction analysis along with density functional calculations and incoherent inelastic neutron scattering studies has conclusively shown that the dihydrogen adduct of [P2N2]Zr(mu-eta(2)-N-2)Zr[P2N2] (1) (where P2N2 = PhP(CH2SiMe2NSiMe2CH2)(2)PPh) is [P2N2]Zr(mu-eta(2)-N2H)(mu-H)Zr[P2N2] (2), the complex with a bridging hydride and a N-N-H moiety, and not the dihydrogen complex [P2N2]Zr(mu-eta(2)-N-2)(mu-eta(2)-H-2)Zr[P2N2] (3), as was proposed on the basis of X-ray crystallographic data. In addition, DFT calculations show that the reaction of 1 with both H-2 and SiH4 is exothermic while an endothermic reaction is found for the reaction of 1 with CH4.}, keywords = {CLEAVAGE, FIXATION, HYDROGEN}, isbn = {0002-7863}, url = {://000079041900006}, author = {Basch, H. and Musaev, D. G. and Morokuma, K. and Fryzuk,Michael D. and Love, J. B. and Seidel, W. W. and Albinati, A. and Koetzle, T. F. and Klooster, W. T. and Mason, S. A. and Eckert, J.} } @article {4230, title = {Density-functional calculation of the inner-shell spectra for two stable enol tautomers: acetylacetone and malonaldehyde}, journal = {Journal of Electron Spectroscopy and Related Phenomena}, volume = {94}, number = {1-2}, year = {1998}, note = {ISI Document Delivery No.: 100GBTimes Cited: 10Cited Reference Count: 25}, month = {Jun}, pages = {181-185}, type = {Article}, abstract = {In this paper we report results from our theoretical studies on two P-diketones which exist as stable enol tautomers: acetylacetone and malonaldehyde. We found that density functional theory (DFT) with Becke{\textquoteright}s exchange functional and Perdew{\textquoteright}s correlation functional can accurately predict the core-electron binding energies (CEBEs) of both molecules. The oxygen 1s {\textendash}> pi* inner-shell excitation spectra (ISES) of both tautomers have also been studied using our DFT procedure. The CEBEs for the corresponding carbons and oxygens of the C=O and C-OH groups of malonaldehyde are larger than those of acetylacetone, The first term values corresponding to a core-hole on the carbonyl oxygen were found to be larger than those with a core-hole on the enol oxygen. The observation indicates that the effect of a core-hole in the proximity of pi*: orbital has a stronger effect on increasing the electron affinity of the core-ionized cation. (C) 1998 Elsevier Science B.V. All rights reserved.}, keywords = {APPROXIMATION, ATOMS, core electron binding energies, density, ELECTRON BINDING-ENERGIES, enols of acetylacetone and malonaldehyde, EXCHANGE, functional theory, HYDROGEN, INNER-SHELL EXCITATION, SPECTROSCOPY}, isbn = {0368-2048}, url = {://000074806800018}, author = {Chong, D. P. and Hu, C. H.} } @article {4403, title = {SIMS studies of the effect of H at interfaces formed by oxidized zirconium}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {76}, number = {12}, year = {1998}, note = {ISI Document Delivery No.: 180RKTimes Cited: 2Cited Reference Count: 13}, month = {Dec}, pages = {1796-1799}, type = {Article}, abstract = {Secondary ion mass spectrometry (SIMS) has been used to guide the search for an oxidation procedure that can produce a thin and relatively sharp oxide layer on macroscopic zirconium. A new preparation based on dip coating in H2O2 solution is indicated to be suitable for this purpose. SIMS further indicates that the oxide interface, for such a prepared sample, shows substantial degradation when it is heated in H-2 gas at 300 degrees C. The presence of H appears to facilitate O migration into the metallic region, an observation that supplements those made previously on oxidized thin-film samples of zirconium prepared by deposition under ultrahigh-vacuum conditions.}, keywords = {electron, GROWTH, HYDROGEN, interfacial reactivity, OXIDATION, OXIDE, oxidized, OXYGEN, secondary ion mass spectrometry, SURFACES, THIN-FILMS, XPS INVESTIGATIONS, ZIRCONIUM, ZR(0001)}, isbn = {0008-4042}, url = {://000079398800002}, author = {Shimizu, K. and Flinn, B. J. and Wong, P. C. and Mitchell, K. A. R.} } @article {4161, title = {Chemical properties of a Nb/Zr interface studied by XPS}, journal = {Surface Review and Letters}, volume = {4}, number = {1}, year = {1997}, note = {ISI Document Delivery No.: XA621Times Cited: 1Cited Reference Count: 15}, month = {Feb}, pages = {33-37}, type = {Article}, abstract = {A film of niobium (similar to 15 A thick) deposited under ultrahigh vacuum (UHV) conditions on polycrystalline zirconium was studied by x-ray photoelectron spectroscopy (XPS) as it was taken through a series of sequential treatments. The Nb-Zr interface, associated with a Nb 3d(5/2) peak at 203.4 eV, is indicated to passivate the underlying Zr to oxygen and hydrogen plasma treatments, which in the absence of Nb would yield substantial oxidation. On heating to 500 degrees C, the pure metallic Nb 3d(5/2) component at 202.2 eV appears, and this change is accompanied by removal of the passivation effect on the substrate.}, keywords = {corrosion, electron, HYDROGEN, NUCLEAR-REACTION ANALYSIS, SURFACES, THIN-FILMS, WT-PERCENT NB, ZIRCALOY-2, ZIRCONIUM-OXIDE, ZR}, isbn = {0218-625X}, url = {://A1997XA62100005}, author = {Wong, K. C. and Wong, P. C. and Li, Y. S. and Mitchell, K. A. R.} } @article {4050, title = {Cyclopentadienyl nitrosyl compounds of chromium: aqueous solution chemistry, pi bonding and nitric oxide loss}, journal = {Journal of the Chemical Society-Dalton Transactions}, number = {18}, year = {1997}, note = {ISI Document Delivery No.: XZ144Times Cited: 9Cited Reference Count: 59}, month = {Sep}, pages = {3269-3276}, type = {Article}, abstract = {{The compiler [Cr(eta-C5H5)(NO)(2)(CF3SO3)] 1 was synthesised in order to explore the relationship between a-donor ligands and nitrosyl lability and to investigate the aqueous chemistry of the [Cr(eta-C5H5)(NO)(2)](+) fragment. Treatment of 1 with sigma-donor ligands gave [Cr(eta-C5H5)(NO)(2)(L)][CF3SO3] salts. Potentiometric titrations and H-1 NMR spectroscopic studies of 1 provided evidence for the existence of [Cr(eta-C5H5)(NO)(2)-(H2O)](+) and [Cr(eta-C5H5)(NO)(2)-(OH)] in aqueous solution. When generated in sitic, [Cr(eta-C5H5)(NO)(2)-(OH)] reacted with acetylacetone, pyridinecarboxylic acid, or salicylaldehyde to form paramagnetic, mononitrosyl complexes which were independently synthesised from the mononitrosyl precursor [Cr(eta-C5H5)(NO)-(mu-I)](2). The solid-state molecular structures of [Cr(eta-C5Me5)(NO)(2)(CF3SO3)] 2, [Cr(eta-C5H5)(NO)(2)(N2C5H7)] 9 and [Cr(eta-C5H4)(NO)(O2C5H7)] 10 were determined by X-ray crystallography. Crystals of 2 are monoclinic}, keywords = {ATOM TRANSFER, CHEMISTRY, COORDINATION, HYDROGEN, MECHANISTIC IMPLICATIONS, METHYLPALLADIUM(II) ALKOXIDE COMPLEXES, ORGANOMETALLIC CHEMISTRY, {antitumor agents}, isbn = {0300-9246}, url = {://A1997XZ14400027}, author = {Legzdins,Peter and Rettig, S. J. and Smith, K. M. and Tong, V. and Young, V. G.} } @article {4032, title = {Evidencing intermolecular effects with core-level photoelectron spectroscopy via the accurate density functional calculation of core-electron binding energies on model systems: gamma-APS as a test}, journal = {Journal of Physical Chemistry B}, volume = {101}, number = {49}, year = {1997}, note = {ISI Document Delivery No.: YK291Times Cited: 17Cited Reference Count: 32}, month = {Dec}, pages = {10254-10261}, type = {Article}, abstract = {gamma-Aminopropyltrihydroxysilane (gamma-APS) is a molecule which is used as an adhesion promoter in microelectronics, for the coating of oxidized silicon wafers with polyimide films. The Si/gamma-APS interface has been studied recently using X-ray photoelectron spectroscopy, and evidenced a need for reference spectra of both gamma-APS and its thermal byproducts: as gamma-APS oligomerizes readily upon warming, no gas phase, reference, or XPS spectrum of this compound can be obtained experimentally. Thus, spectral features emerging from Si/gamma-APS interactions are difficult to separate from structural fingerprints of gamma-APS alone, This phenomenon further hinders the follow up by XPS of structural modifications the molecule undergoes upon thermal treatments. A recent procedure of computing very accurate core-electron binding energies (CEBEs) via density functional theory (DFT) is used as a guide to propose a pseudo reference spectrum. The computed CEBEs of the various core levels of the isolated. molecule are found in excellent agreement with the experimental XPS spectra recorded upon spin coating the compound on a silicon wafer at room temperature, with an average absolute deviation (aad) for C Is, Id Is, and O Is levels of only 0,13 eV, i.e., of the order of experimental resolution. The same procedure is then conducted on isolated ionic structures presumably formed when thick gamma-APS layers have undergone thermal treatment in a H2O/CO2 atmosphere, A very bad agreement is found between theory and experiment on these isolated ions, with aad{\textquoteright}s as large as 4.91 V. Upon actually computing the CEBEs on larger molecular models in which (i) ions are paired and then in which (ii) ion pairs are further solvated by one up to four water molecules, the aad reduces to 0,31 eV. We suggest, on the instance of gamma-APS, that (i) the accurate calculation of CEBEs has now come to be a tractable and reliable alternative as a hand for spectrum decomposition when gas-phase reference XPS spectra are not available for calibration and that (ii) the availability of an accurate and tractable theoretical procedure to compute CEBEs, compatible with experimental precision, enables XPS to give some information on intermolecular effects, although this spectroscopy involves core ionizations.}, keywords = {ADHESION, APPROXIMATION, BASIS-SETS, HYDROGEN}, isbn = {1089-5647}, url = {://A1997YK29100017}, author = {Kranias, S. and Bureau, C. and Chong, D. P. and Brenner, V. and George, I. and Viel, P. and Lecayon, G.} } @article {4079, title = {Synthesis and X-ray structure of an H2S complex, RuCl2(P-N)(P(p-tolyl)(3))(SH2) (P-N=o-(diphenylphosphino)-N,N-dimethylaniline)}, journal = {Inorganic Chemistry}, volume = {36}, number = {24}, year = {1997}, note = {ISI Document Delivery No.: YH560Times Cited: 24Cited Reference Count: 25}, month = {Nov}, pages = {5426-\&}, type = {Article}, abstract = {The interaction of transition metal complexes with H2S continues to attract attention. Such chemistry is of relevance in the biological sulfur cycle, in the formation of ores, in hydrodesulfurization catalysis, and in the use of H2S as a source of Hz and elemental sulfur (or organosulfur compounds). Literature dealing with these topics is plentiful and can be traced through recent references.(1,2) However, isolation and characterization of metal complexes containing H2S remain challenging,(2,3) as such species tend to undergo oxidative addition reactions to give products with SH ligands or bridged or terminal sulfide,(4) and only recently has an H2S complex been characterized crystallographically.(2) This was the structure reported by Sellmann et al. of the Ru(II)-complex Ru(SH2)(PPh3)({\textquoteright}S-4{\textquoteright}). THF ({\textquoteright}S-4{\textquoteright} = 1,2-bis[(2-mercaptophenyl)thio]ethane(2-)) formed by the reaction of the polymeric complex [Ru(PPh3)({\textquoteright}S-4{\textquoteright})](x) with liquid H2S at -70 degrees C; the reaction with H2S gas at room temperature in THF resulted in a mixture of the bridging sulfide complex [(mu-S-2){Ru(PPh3)({\textquoteright}S-4{\textquoteright})}(2)] and other uncharacterized products depicting the more typical reactivity of H2S with transition metal complexes.(2)}, keywords = {ACTIVATION, hydride, HYDROGEN, LEWIS-ACIDS, MERCAPTO, REACTIVITY, S-H, sulfide, SULFUR-CONTAINING LIGANDS, TRANSITION-METAL COMPLEXES}, isbn = {0020-1669}, url = {://A1997YH56000003}, author = {Mudalige, D. C. and Ma, E. S. and Rettig, S. J. and James, Brian R. and Cullen, W. R.} } @article {3746, title = {XPS investigations of the reactivities of oxidized Zr/Nb interfaces formed by deposition on a gold substrate}, journal = {Applied Surface Science}, volume = {103}, number = {4}, year = {1996}, note = {ISI Document Delivery No.: VX979Times Cited: 6Cited Reference Count: 18}, month = {Dec}, pages = {389-393}, type = {Article}, abstract = {The interaction of a film of Zr (similar to 38 Angstrom thick) deposited under ultrahigh vacuum (UHV) on to an approximately 12 Angstrom film of NbO on a gold substrate has been studied with X-ray photoelectron spectroscopy (XPS). Evidence is presented for an interfacial conversion from Zr and NbO to ZrO2 and Nb. The reactivity of this sample was studied through a series of sequential treatments. Although changes occur in the topmost layer, the Zr/Nb interfacial region, as identified by a shoulder at similar to 180 eV in Zr 3d and the 203.0 eV peak in Nb 3d, appears to be remarkably inert on heating at 300 degrees C under UHV, as well as on subjecting to O-2 and hydrogen plasma treatments.}, keywords = {corrosion, HYDROGEN, NUCLEAR-REACTION ANALYSIS, THIN-FILMS, WT-PERCENT NB, ZIRCALOY-2, ZIRCONIUM-OXIDE, ZR}, isbn = {0169-4332}, url = {://A1996VX97900009}, author = {Li, Y. S. and Wong, K. C. and Wong, P. C. and Mitchell, K. A. R.} } @article {3402, title = {IONIC-CONDUCTIVITY IN THE WATER-RICH REGION OF AQUEOUS 2-BUTOXYETHANOL}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {73}, number = {8}, year = {1995}, note = {ISI Document Delivery No.: RZ492Times Cited: 4Cited Reference Count: 22}, month = {Aug}, pages = {1294-1297}, type = {Article}, abstract = {Ionic conductivities of HCl, KOH, and KCl were measured in aqueous solutions of 2-butoxyethanol (BE) at 25 degrees C. The quantity, Lambda(j){\textquoteright} = sigma/x(j), which is almost proportional to the molar conductivity, was extrapolated to the infinite dilution x(j) {\textendash}> 0. sigma is the conductivity and x(j) is the mole fraction of j(= HCl, KOH, or KCl). The plots of (0) Lambda(j){\textquoteright}, the value of Lambda(j){\textquoteright} extrapolated to infinite dilution, against x(BE) showed a change in slope at x(BE) = 0.0175. The previous work from this laboratory indicated that the mixing scheme changes qualitatively at the same locus, x(BE) = 0.0175. By mixing scheme we simply mean the way in which BE and H2O molecules mix with each other. Assuming additivity in (0)h(j){\textquoteright} in terms of constituent ions, those values for H+OH- were calculated. Plots of (0) Lambda(H+OH-){\textquoteright} thus calculated as a function of x(BE) in the water-rich region, 0 < x(BE) < 0.0175, suggest that the hydrogen bond probability decreases in the bulk of solution, as x(BE) increases.}, keywords = {AQUEOUS 2-BUTOXYETHANOL, BOND NETWORK, HYDROGEN, IONIC CONDUCTIVITIES, MIXING SCHEME, MIXING SCHEMES, MIXTURES, PARTIAL MOLAR ENTHALPIES, SCATTERING, TRANSITION, VOLUMES}, isbn = {0008-4042}, url = {://A1995RZ49200008}, author = {Koga,Yoshikata and Loo, V. J. and Puhacz, K. T.} } @article {3241, title = {RUTHENIUM COMPLEXES CONTAINING TERTIARY PHOSPHINES AND IMIDAZOLE OR 2,2{\textquoteright}-BIPYRIDINE LIGANDS}, journal = {Inorganica Chimica Acta}, volume = {230}, number = {1-2}, year = {1995}, note = {ISI Document Delivery No.: QN719Times Cited: 26Cited Reference Count: 39}, month = {Mar}, pages = {111-117}, type = {Article}, abstract = {{Complexes RuCl3(PPh(3))L(2) (L=MeIm (1a), Im (1b)) and [RuCl2(PPh(3))(2)(bipy)]Cl . 4H(2)O (2) have been synthesized via the ruthenium(III) precursor RuCl3(PPh(3))(2) (DMA), and characterized, including an X-ray structural analysis for 1a (MeIm=N-methylimidazole}, keywords = {BIPYRIDINE COMPLEXES, CRYSTAL, crystal structures, DERIVATIVES, HYDROGEN, IMIDAZOLE COMPLEXES, ruthenium complexes, TERTIARY PHOSPHINE COMPLEXES, X-ray structure}, isbn = {0020-1693}, url = {://A1995QN71900015}, author = {Batista, A. A. and Polato, E. A. and Queiroz, S. L. and Nascimento, O. R. and James, Brian R. and Rettig, S. J.} } @article {3488, title = {A STRUCTURAL STUDY OF PD/CU(100) SURFACE ALLOYS}, journal = {Surface Science}, volume = {337}, number = {1-2}, year = {1995}, note = {ISI Document Delivery No.: RQ749Times Cited: 33Cited Reference Count: 54}, month = {Aug}, pages = {79-91}, type = {Article}, abstract = {The structures formed by one-half and one monolayer (ML) of Pd evaporated onto Cu(100) at 300 K were studied by low energy electron diffraction (LEED), medium energy ion scattering (MEIS), thermal desorption spectroscopy (TDS), and embedded atom method (EAM) calculations. In the half monolayer case, the LEED I(E) curves are consistent with the established c(2 x 2) surface alloy model. The MEIS data, however, suggest that a fraction of the Pd (similar to 1/4) is in {\textquoteright}{\textquoteright}second layer{\textquoteright}{\textquoteright} sites, in agreement with previous LEIS, TDS and XPS forward scattering measurements. The EAM simulations support the formation of alloy islands, providing a mechanism for the covering of some Pd atoms. As the deposition proceeds, however, this island formation is indicated to occur preferentially over clean copper. In the one monolayer case, a p(2 x 2)-p4g LEED pattern is observed. Analysis of the I(E) curves suggests that this arises from (100) Pd packed above the c(2 x 2) alloy. EAM calculations confirm the stability of this model. Evidence from MEIS and TDS, however, shows that the one monolayer surface as prepared in this work is inhomogeneous. c(2 x 2) and Cu rich surface domains exist in addition to those having the p4g Pd/c(2 x 2)PdCu structure.}, keywords = {(MEIS), ABSORPTION FINE-STRUCTURE, ADSORPTION, CU(100), DIFFRACTION, GROWTH, HYDROGEN, ION-SCATTERING, LOW ENERGY ELECTRON DIFFRACTION (LEED), LOW-ENERGY ELECTRON, MEDIUM ENERGY ION SCATTERING, molecular dynamics, RECONSTRUCTION, SPECTROSCOPY, surface structure, THERMAL DESORPTION, ULTRATHIN PD FILMS}, isbn = {0039-6028}, url = {://A1995RQ74900017}, author = {Pope, T. D. and Vos, M. and Tang, H. T. and Griffiths, K. and Mitchell, I. V. and Norton, P. R. and Liu, W. and Li, Y. S. and Mitchell, K. A. R. and Tian, Z. J. and Black, J. E.} } @article {3187, title = {TENSER LEED ANALYSIS OF THE PD(100)-(ROOT-5X-ROOT-5)R27-DEGREES-O SURFACE-STRUCTURE}, journal = {Surface Science}, volume = {318}, number = {1-2}, year = {1994}, note = {ISI Document Delivery No.: PL286Times Cited: 29Cited Reference Count: 29}, month = {Oct}, pages = {129-138}, type = {Article}, abstract = {A tenser LEED analysis of the Pd(100)-(root 5 x root 5)R27 degrees-O surface structure supports a surface oxide model, as first postulated by Orent and Bader. The detailed model which gives the best correspondence with experimental intensity data has a PdO(001) overlayer stacked on to the Pd(100) surface such that rumpling is induced in both the oxide and topmost Pd(100) layers. The structure can be seen as representing a compromise between the drive toward an ideally flat PdO(001) surface and the need to optimize total bonding at the surface. Pd atoms in the topmost Pd(100) layer appear to displace laterally to minimize corrugations in the top metal layers. The total corrugations in the PdO overlayer and the first Pd(100) layer are indicated to be about 0.26 and 0.51 Angstrom, respectively. The average O-Pd bond length for two-coordinate O on the Pd surface (1.73 Angstrom) remains dose to the predicted value of 1.76 Angstrom based on the structure of bulk PdO.}, keywords = {ADSORPTION, desorption, ENERGY-ELECTRON-DIFFRACTION, HYDROGEN, OXYGEN, PD(100) SURFACE, PHASE, RECONSTRUCTION}, isbn = {0039-6028}, url = {://A1994PL28600019}, author = {Vu, D. T. and Mitchell, K. A. R. and Warren, O. L. and Thiel, P. A.} } @article {2860, title = {ORIENTATIONAL ORDER OF PLANAR SOLUTES IN A ZERO AVERAGE ELECTRIC-FIELD GRADIENT NEMATIC ENVIRONMENT}, journal = {Molecular Physics}, volume = {78}, number = {3}, year = {1993}, note = {ISI Document Delivery No.: KQ355Times Cited: 6Cited Reference Count: 31}, month = {Feb}, pages = {673-685}, type = {Article}, abstract = {The order matrices for 19 dihalobenzenes of C(s) and C2v symmetry have been measured using the NMR spectra of these molecules as solutes in the nematic mixture of 55 wt\% Merck ZLI-1132 and 45 wt\% N-(4-ethoxybenzylidene)-2,6-dideutero-4{\textquoteright}-n-butylaniline. In this liquid crystal, the contribution to the orientational potential from the interaction between the molecular quadrupole moment and the mean electric field gradient of the liquid crystal can be neglected. The results are compared with predictions of a model which describes the anisotropic intermolecular potential in terms of (1) an elastic distortion of the liquid crystal and (2) an anisotropic surface interaction between solute and liquid crystal. Not only are the largest (in magnitude) order parameters very well fitted, but also the calculated anisotropies in the order matrices agree with the experimental ones. It is demonstrated that the results cannot be fitted with a bond-additive approach.}, keywords = {HYDROGEN, LIQUID-CRYSTALS, NMR, SIZE}, isbn = {0026-8976}, url = {://A1993KQ35500010}, author = {Li, K. Y. Z. and Zimmerman, D. S. and Burnell, E. E.} } @article {2928, title = {XPS STUDIES OF THE STABILITY AND REACTIVITY OF THIN-FILMS OF OXIDIZED ZIRCONIUM}, journal = {Applied Surface Science}, volume = {72}, number = {3}, year = {1993}, note = {ISI Document Delivery No.: MF104Times Cited: 21Cited Reference Count: 32}, month = {Nov}, pages = {237-244}, type = {Article}, abstract = {X-ray photoelectron spectroscopy (XPS) has been used to characterize thin films formed by the deposition of zirconium on to gold foil. With deposition rates of the order of 1 angstrom min-1, in the presence of an atmosphere of 10(-9) mbar H2O, the film has an outer region Of ZrO2 and inner regions of a lower oxidation state material, ZrO(x), and Zr-Au alloy. Initially both ZrO(x) and Zr-Au alloy are oxidized by either H2O or O2 at 300-degrees-C, although this process is hindered as the ZrO2 layer gets thicker. However, even with the protective oxide layer, heating in 5 x 10(-7) mbar D2 (with a partial pressure of 10(-9) mbar H2O) can convert ZrO(x) to ZrO2, a reaction apparently facilitated by migrating D atoms.}, keywords = {ADSORPTION, AES, BINDING-ENERGY SHIFTS, electron, HYDROGEN, OXIDATION, OXYGEN, RAY PHOTOELECTRON-SPECTROSCOPY, SINGLE-CRYSTAL, SURFACES, ZR}, isbn = {0169-4332}, url = {://A1993MF10400004}, author = {Wang, Y. M. and Li, Y. S. and Wong, P. C. and Mitchell, K. A. R.} } @article {7111, title = {1-NORMAL-PROPYL-3-HYDROXY-2-METHYL-4-PYRIDINONE AND 1-NORMAL-BUTYL-3-HYDROXY-2-METHYL-4-PYRIDINONE COMPLEXES OF GROUP 13 (IIIA) METAL-IONS}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {69}, number = {5}, year = {1991}, note = {ISI Document Delivery No.: FP799Times Cited: 22Cited Reference Count: 22}, month = {May}, pages = {893-900}, type = {Article}, abstract = {{The aluminum, gallium, and indium tris(ligand) complexes of 3-hydroxy-2-methyl-1-n-propyl-4-pyridinone and 1-n-butyl-3-hydroxy-2-methyl-4-pyridinone have been prepared and characterized. All six compounds were prepared in a one-pot synthesis from maltol, n-propyl-, or n-butylamine and an appropriate metal(III) salt, and were completely characterized (IR, FAB-MS, H-1 NMR, Al-27 NMR, elemental analysis). Three of the six complexes were studied by single-crystal X-ray diffraction and were found to form trihydrates, unlike their 1-methyl and 1-ethyl analogues, which formed dodecahydrates. The n-butylpyridinone complex Al(C10H14NO2)3.3H2O (Al(nbp)3.3H2O) and n-propylpyridinone complexes Al(C9H12NO2)3.3H2O (Al(npp)3.3H2O), and Ga(C9H12NO2)3.3H2O (Ga(npp)3.3H2O) were essentially isostructural, crystallizing in the space group P3BAR with the following crystal parameters for Al(nbp)3.3H2O (Al(npp)3.3H2O, Ga(npp)3.3H2O): a = 15.885(1) (15.328(1), 15.367(2)) angstrom}, keywords = {3-HYDROXY-4-PYRIDINONES, aluminum, bonding, CHELATE COMPLEXES, CHEMISTRY, crystal structures, EXOCLATHRATE, gallium, HYDROGEN, HYDROXYPYRIDINONE LIGANDS, indium, INVIVO, LIGANDS, metal complexes}, isbn = {0008-4042}, url = {://A1991FP79900019}, author = {Simpson, L. and Rettig, S. J. and Trotter, J. and Orvig, Chris} } @article {7111, title = {1-NORMAL-PROPYL-3-HYDROXY-2-METHYL-4-PYRIDINONE AND 1-NORMAL-BUTYL-3-HYDROXY-2-METHYL-4-PYRIDINONE COMPLEXES OF GROUP 13 (IIIA) METAL-IONS}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {69}, number = {5}, year = {1991}, note = {ISI Document Delivery No.: FP799Times Cited: 22Cited Reference Count: 22}, month = {May}, pages = {893-900}, type = {Article}, abstract = {{The aluminum, gallium, and indium tris(ligand) complexes of 3-hydroxy-2-methyl-1-n-propyl-4-pyridinone and 1-n-butyl-3-hydroxy-2-methyl-4-pyridinone have been prepared and characterized. All six compounds were prepared in a one-pot synthesis from maltol, n-propyl-, or n-butylamine and an appropriate metal(III) salt, and were completely characterized (IR, FAB-MS, H-1 NMR, Al-27 NMR, elemental analysis). Three of the six complexes were studied by single-crystal X-ray diffraction and were found to form trihydrates, unlike their 1-methyl and 1-ethyl analogues, which formed dodecahydrates. The n-butylpyridinone complex Al(C10H14NO2)3.3H2O (Al(nbp)3.3H2O) and n-propylpyridinone complexes Al(C9H12NO2)3.3H2O (Al(npp)3.3H2O), and Ga(C9H12NO2)3.3H2O (Ga(npp)3.3H2O) were essentially isostructural, crystallizing in the space group P3BAR with the following crystal parameters for Al(nbp)3.3H2O (Al(npp)3.3H2O, Ga(npp)3.3H2O): a = 15.885(1) (15.328(1), 15.367(2)) angstrom}, keywords = {3-HYDROXY-4-PYRIDINONES, aluminum, bonding, CHELATE COMPLEXES, CHEMISTRY, crystal structures, EXOCLATHRATE, gallium, HYDROGEN, HYDROXYPYRIDINONE LIGANDS, indium, INVIVO, LIGANDS, metal complexes}, isbn = {0008-4042}, url = {://A1991FP79900019}, author = {Simpson, L. and Rettig, S. J. and Trotter, J. and Orvig, Chris} } @article {7007, title = {THE ANALYSIS OF MUONIUM HYPERFINE INTERACTION MEASUREMENTS OF THERMAL RATE CONSTANTS FOR ADDITION-REACTIONS}, journal = {Journal of Chemical Physics}, volume = {94}, number = {4}, year = {1991}, note = {ISI Document Delivery No.: EY070Times Cited: 15Cited Reference Count: 48}, month = {Feb}, pages = {2794-2806}, type = {Article}, abstract = {A new model is developed for the analysis of muon spin relaxation (mu-SR) measurements of muonium (Mu) reaction rates with other chemical species. The kinetics component of the model is specifically developed for addition reactions but can be extended to direct reactions. The polarization component of the model assumes that the adduct formed possesses a single, effective spin precession frequency. The complete model is solved to obtain an analytic expression for the mu-SR signal as a function of time. Both a time-ordered sequence method and a Boltzmann spin equation method give equivalent solutions. These solutions are analyzed under various kinetic conditions. It is concluded that the coefficient controlling the decay of the mu-SR signal is closely related to the adduct formation rate constant, i.e., the high pressure limit of the apparent bimolecular addition rate constant. In the most favorable case, the decay constant gives the adduct formation rate constant directly at all pressures of buffer gas.}, keywords = {CHARGE-EXCHANGE COLLISIONS, COMPETING PROCESSES, DEPENDENCE, HYDROGEN, KINETIC-EQUATIONS, LOW-PRESSURE GASES, MOLECULAR ION, radicals, SPIN-EXCHANGE, TEMPERATURE-RANGE}, isbn = {0021-9606}, url = {://A1991EY07000050}, author = {Duchovic, R. J. and Wagner, A. F. and Turner, R. E. and Garner, D. M. and Fleming, Donald G.} } @article {7018, title = {SYNTHESIS AND REACTIVITY OF RUTHENIUM AMIDE PHOSPHINE COMPLEXES - FACILE CONVERSION OF A RUTHENIUM AMIDE TO A RUTHENIUM AMINE VIA DIHYDROGEN ACTIVATION AND ORTHO METALATION - X-RAY STRUCTURE OF RUCL(C6H4PPH2)[NH(SIME2CH2PPH2)2]}, journal = {Organometallics}, volume = {10}, number = {2}, year = {1991}, note = {ISI Document Delivery No.: EY681Times Cited: 68Cited Reference Count: 38}, month = {Feb}, pages = {467-473}, type = {Article}, abstract = {{The reaction of LiN(SiMe2CH2PPh2)2 with RuCl2(PPh3)3 leads to the formation of the ruthenium amide complex RuCl(PPh3)[N(SiMe2CH2PPh2)2]. This complex reacts with H2 to form two isomeric amine-hydride derivatives of the formula RuCl(PPh3)H[NH(SiMe2CH2PPh2)2]. Reaction of RuCl(PPh3)[N-(SiMe2CH2PPh2)2] with MeLi, Me3SiCH2Li, or H2C = CHCH2MgCl does not lead to the expected hydrocarbyl derivative; rather, ortho metalation occurs to generate Ru(C6H4PPh2)[N(SiMe2CH2PPh2)2]. Attempts to displace the PPh3 ligand of RuCl(PPh3)[N(SiMe2CH2PPh2)2] with PEt3 lead to the formation of RuCl(C6H4PPh2)[NH(SiMe2PPh2)2], having an amine ligand and the ortho-metalated phenyl group. The complex RuCl(C6H4PPh2)[NH(SiMe2CH2PPh2)2] crystallizes in space group P2(1)/n with a = 9.8385 (5) angstrom}, keywords = {5-COORDINATE D6 COMPLEXES, CARBONYL-COMPLEXES, CRYSTAL, formation, HYDROGEN, IRIDIUM, MOLECULAR-STRUCTURE, STEREOSELECTIVE}, isbn = {0276-7333}, url = {://A1991EY68100025}, author = {Fryzuk,Michael D. and Montgomery, C. D. and Rettig, S. J.} }