@article {2525, title = {Detection and assignment of phosphoserine and phosphothreonine residues by C-13-P-31 spin-echo difference NMR spectroscopy}, journal = {Journal of Biomolecular Nmr}, volume = {43}, number = {1}, year = {2009}, note = {ISI Document Delivery No.: 379QKTimes Cited: 0Cited Reference Count: 31McIntosh, Lawrence P. Kang, Hyun-Seo Okon, Mark Nelson, Mary L. Graves, Barbara J. Brutscher, Bernhard}, month = {Jan}, pages = {31-37}, type = {Article}, abstract = {A simple NMR method is presented for the identification and assignment of phosphorylated serine and threonine residues in C-13- or C-13/N-15-labeled proteins. By exploiting modest (similar to 5 Hz) 2- and 3-bond C-13-P-31 scalar couplings, the aliphatic H-1-C-13 signals from phosphoserines and phosphothreonines can be detected selectively in a P-31 spin-echo difference constant time H-1-C-13 HSQC spectrum. Inclusion of the same P-31 spin-echo element within the C-13 frequency editing period of an intraHNCA or HN(CO)CA experiment allows identification of the amide H-1(N) and N-15 signals of residues (i) for which C-13(alpha)(i) or C-13(alpha)(i - 1), respectively, are coupled to a phosphate. Furthermore, P-31 resonance assignments can be obtained by applying selective low power cw P-31 decoupling during the spin-echo period. The approach is demonstrated using a PNT domain containing fragment of the transcription factor Ets-1, phosphorylated in vitro at Thr38 and Ser41 with the MAP kinase ERK2.}, keywords = {ASSIGNMENT, CENTER-DOT-OP, CONSTANT-TIME, Ets-1, MAP kinase, NUCLEIC-ACIDS, OP HYDROGEN-BONDS, P-31-C-13 scalar coupling, Phosphoprotein, PHOSPHORYLATION, POINTED DOMAIN, PROTEIN, QUANTITATIVE J-CORRELATION, RESONANCE, SCALAR COUPLINGS, TRANSCRIPTION FACTOR}, isbn = {0925-2738}, url = {://000261411100004}, author = {McIntosh, L. P. and Kang, H. S. and Okon, M. and Nelson, M. L. and Graves, B. J. and Brutscher, B.} } @article {2333, title = {Dipole excitation of ions in linear radio frequency quadrupole ion traps with added multipole fields}, journal = {International Journal of Mass Spectrometry}, volume = {275}, number = {1-3}, year = {2008}, note = {ISI Document Delivery No.: 338OVTimes Cited: 1Cited Reference Count: 35Zhao, XianZhen Douglas, D. J.}, month = {Aug}, pages = {91-103}, type = {Article}, abstract = {Ion motion with auxiliary dipole excitation and collisional damping in a linear radiofrequency quadrupole ion trap incorporating small amounts of even higher order multipoles is studied analytically. The ion motion is modeled in a pseudopotential that is mostly quadratic with small amounts of higher spatial harmonics. Ion motion along x and y axes is characterized by two uncoupled forced and damped anharmonic oscillator equations. A multiple time scales method is used to solve the equations of motion of ions with a first order perturbation Correction. Analytical relations between the oscillation amplitudes at steady state (the stationary amplitudes) and excitation frequency are calculated. The frequency response Curves show that in some cases bistable behavior might be obtained, i.e., there are two stable stationary amplitudes for a given excitation frequency. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.}, keywords = {BOUNDARY, higher order multipole, ion excitation, linear ion trap, MASS-SPECTROMETER, MOTION, nonlinear, OCTOPOLE FIELD, PAUL TRAPS, RESONANCE, RESONANCE EJECTION, SCAN, SIMULATION}, isbn = {1387-3806}, url = {://000258518200011}, author = {Zhao, X. Z. and Douglas, D. J.} } @article {1461, title = {The rotational spectrum and hyperfine structure of arsenic monophosphide, AsP}, journal = {Journal of Molecular Spectroscopy}, volume = {238}, number = {1}, year = {2006}, note = {ISI Document Delivery No.: 061MMTimes Cited: 4Cited Reference Count: 40Leung, Flora Cooke, Stephen A. Gerry, Michael C. L.}, month = {Jul}, pages = {36-41}, type = {Article}, abstract = {Arsenic monophosphide has been prepared by laser ablation of arsenic in the presence of PH3. The J = 2-1 and 1-0 transitions in both the ground and first excited vibrational states have been measured with a cavity pulsed jet Fourier-transform microwave spectrometer. An improved equilibrium internuclear distance (r(e)) has been obtained. Hyperfine structure in the rotational spectrum of AsP has been resolved and has led to the first determinations of the As nuclear quadrupole coupling constant and both nuclear spin-rotation constants. The data enable the electronic structure of AsP to be compared with those of other mixed Group 15 diatomic molecules. (c) 2006 Elsevier Inc. All rights reserved.}, keywords = {arsenic monophosphide microwave rotational spectrum, BiP, CONSTANTS, DENSITY-FUNCTIONAL THEORY, DISTANCE, ENERGY, equilibrium internuclear, Fourier transform, laser ablation, microwave spectrum, MOLECULES, of arsenic monophosphide, ORDER REGULAR APPROXIMATION, RESONANCE, SPIN-ROTATION, TENSORS}, isbn = {0022-2852}, url = {://000238876600004}, author = {Leung, F. and Cooke, S. A. and Gerry, M. C. L.} } @article {1097, title = {Linear ion traps in mass spectrometry}, journal = {Mass Spectrometry Reviews}, volume = {24}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 888OJTimes Cited: 73Cited Reference Count: 145}, month = {Jan-Feb}, pages = {1-29}, type = {Review}, abstract = {Linear ion traps are finding new applications in many areas of mass spectrometry. In a linear ion trap, ions are confined radially by a two-dimensional (2D) radio frequency (RF) field, and axially by stopping potentials applied to end electrodes. This review focuses on linear ion trap instrumentation. Potentials and ion motion in linear multipole fields and methods of ion trapping, cooling, excitation, and isolation are described. This is followed by a description of various mass discrimination effects that have been reported with linear ion traps. Linear ion traps combined in various ways with three-dimensional (3D) traps, time-of-flight (TOF) mass analyzers, and Fourier transform ion cyclotron resonance mass spectrometers are then given. Linear ion traps can be used as stand alone mass analyzers, and their use for mass analysis by Fourier transforming image currents, by mass selective radial ejection, and by mass selective axial ejection are reviewed. (C) 2004 Wiley Periodicals, Inc.}, keywords = {analysis, CYCLOTRON-RESONANCE, ELECTROSPRAY-IONIZATION, EXCITATION, EXTERNAL ACCUMULATION, FRINGING FIELDS, INVERSE FOURIER-TRANSFORM, ion traps, linear multipoles, mass, MOLECULE REACTION, OCTOPOLE FIELDS, OF-FLIGHT, QUADRUPOLE, RADIOFREQUENCY, RESONANCE, space charge, STORAGE ASSISTED DISSOCIATION, SYSTEM}, isbn = {0277-7037}, url = {://000226383800001}, author = {Douglas, D. J. and Frank, A. J. and Mao, D. M.} } @article {1141, title = {Muon implantation in inert gases studied by radio frequency spectroscopy}, journal = {Journal of Physics B-Atomic Molecular and Optical Physics}, volume = {38}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 898AETimes Cited: 1Cited Reference Count: 51}, month = {Jan}, pages = {119-134}, type = {Article}, abstract = {Diamagnetic and muonium (Mu) fractions formed in low-pressure inert gases, by energetic muon implantation, have been studied using the technique of time-delayed radio frequency muon spin resonance (RF-muSR). Results obtained establish the validity of the long-held view that formation of these species is due only to prompt processes, and in turn confirms that the diamagnetic environment is due to a muon molecular ion, MMu(+), and not a bare mu(+). In addition, polarization fractions for the diamagnetic and Mu environments have been determined at different pressures, thereby complementing earlier data, and demonstrating that the RF-muSR technique provides polarization fractions in good accord with those obtained using conventional transverse-field muon spin resonance measurements.}, keywords = {ADDITION-REACTIONS, CHARGE-EXCHANGE COLLISIONS, COMPETING PROCESSES, ELECTRON-SPIN EXCHANGE, MOLECULAR-IONS, NOBLE-GASES, POSITIVE MUONS, RESONANCE, SLOWING-DOWN, SUPERCRITICAL WATER}, isbn = {0953-4075}, url = {://000227047200016}, author = {Johnson, C. and Cottrell, S. P. and Ghandi, K. and Fleming, Donald G.} } @article {1309, title = {An NMR study of translational diffusion and structural anisotropy in magnetically alignable nonionic surfactant mesophases}, journal = {Langmuir}, volume = {21}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 914HPTimes Cited: 9Cited Reference Count: 37}, month = {Apr}, pages = {3311-3321}, type = {Article}, abstract = {The diffusion of both water and surfactant components in aqueous solutions of the nonionic surfactant "C12E6"-which includes hexagonal, cubic, lamellar, and micellar mesophases-has been studied by pulsed-field-gradient NMR. Diffusion coefficients were measured in unaligned samples in all of these phases. They were also obtained in the hexagonal and lamellar phases in oriented monodomain samples that were aligned by slow cooling from the micellar phase in an 11.7 T magnet. Measured water and soap diffusion coefficients in the NMR-isotropic cubic and (high-water-content) micellar phases as well as diffusion anisotropy measurements in the magnetically aligned hexagonal phase were quantitatively consistent with the constituent structures of these phases being identical surfactant cylinders, with only the fraction of surface-associated water varying with the water-soap molar ratio. The values of the water and soap diffusion coefficients in the oriented lamellar phase suggest an increase in defects and obstructions to soap diffusion as a function of increasing water content, while those in the low-water-content micellar phase rule out the presence of inverse micelles.}, keywords = {C12E6/D2O SYSTEM, C16EO6/WATER SYSTEM, CUBIC PHASES, LAMELLAR PHASE, LYOTROPIC LIQUID-CRYSTAL, MICELLAR-SOLUTIONS, OBSTRUCTION, RESONANCE, SELF-DIFFUSION, WATER MESOPHASES}, isbn = {0743-7463}, url = {://000228218700019}, author = {Yethiraj, A. and Capitani, D. and Burlinson, N. E. and Burnell, E. E.} } @article {764, title = {Hot model of muonium formation in liquids}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {81}, number = {3}, year = {2003}, note = {ISI Document Delivery No.: 663NGTimes Cited: 4Cited Reference Count: 22}, month = {Mar}, pages = {199-203}, type = {Article}, abstract = {The mechanism of formation of muonium atoms from positive muons was studied here through measurements of the yield of diamagnetic muon states in dipolar aprotic solvents and for scavenger solutions in hexane and methanol. The results are compared with published data on common solvents covering a full range of the physicochemical properties of liquids that affect an ionic formation mechanism, namely their static dielectric constants, electron mobilities, and radiolysis yields of electrons. It is concluded that muonium is not formed by a thermal charge-neutralization reaction in these chemically-active media, though that mechanism does contribute to muonium formation in inert media like liquefied noble gases. It is clear that muonium materializes on a much shorter timescale than the recently proposed "delayed" mechanism (microseconds) and the earlier "spur" model (nanoseconds). In contrast, the data referring to all these liquids are consistent with the intra-track "hot" model. This is the only Mu-formation model proposed so far in which the immediate precursors of Mu (Mu((hot))) are neither scavengable nor ionic.}, keywords = {delayed-muonium-formation model, diamagnetic yields, FIELD, formation mechanism, GASES, hot model, muonium atoms, RESONANCE, spur model}, isbn = {0008-4042}, url = {://000182011200002}, author = {Walker, D. C. and Karolczak, S. and Gillis, H. A. and Porter, G. B.} } @article {747, title = {Linear quadrupoles with added octopole fields}, journal = {Rapid Communications in Mass Spectrometry}, volume = {17}, number = {20}, year = {2003}, note = {ISI Document Delivery No.: 731CTTimes Cited: 21Cited Reference Count: 29}, pages = {2290-2294}, type = {Article}, abstract = {Two methods of adding relatively small octopole fields to the main quadrupole field of quadrupoles and linear ion traps with cylindrical rods are investigated. The first, {\textquoteright}stretching{\textquoteright} the quadrupole by moving two rods out from the axis, produces a combination of higher order fields with similar magnitudes in which the octopole field is not necessarily the greatest. The quadrupole field strength is changed significantly and a large potential appears on the axis. The second method uses rod pairs of different diameters. It adds octopole components of up to several percent while all other higher order fields remain small. An axis potential is also added, but it is only a few percent of the radio-frequency (RF) voltage and approximately equal to the strength of the octopole field. The axis potential can be removed by moving the larger rod pair out from the axis or applying unbalanced RIF to the electrodes. Copyright (C) 2003 John Wiley Sons, Ltd.}, keywords = {EJECTION, FILTER, HARMONICS, MASS-SPECTROMETER, NONLINEAR ION-TRAP, OF-FLIGHT SYSTEM, RESONANCE, SPATIAL, STORAGE-RING}, isbn = {0951-4198}, url = {://000185867500008}, author = {Sudakov, M. and Douglas, D. J.} } @article {4523, title = {Can global target analysis of the splitting and spin relaxation from a ring-deuterated mesogen produce dynamical information?}, journal = {Molecular Crystals and Liquid Crystals Science and Technology Section a-Molecular Crystals and Liquid Crystals}, volume = {331}, year = {1999}, note = {ISI Document Delivery No.: 241JCTimes Cited: 0Cited Reference Count: 2017th International Liquid Crystal ConferenceJUL 19-24, 1998STRASBOURG, FRANCECaisse Epargne, CNRS, Conseil Gen Bas Rhin, France Telecom, Gordon \& Breach Publishing Grp, Instec Inc, Inst Phys Chimie Materiaux Strasbourg, Reg ALSACE, Rolic Liquid Crystals R\&D Co, STOE \& CIE GmbH, Univ Louis Pasteur, Ville Strasbourg, Int Liquid Crystal Soc, Ecole Chimie, Polymeres Materiaux Strasbourg, Lab Fluides Complexex, Inst Charles SadronPart 4}, pages = {2003-2013}, type = {Proceedings Paper}, abstract = {We report on the measurements of quadrupolar splitting and spectral densities of motion for the phenylthio ring deuterons as a function of temperature in 4-pentylphenylthio-4{\textquoteright}-octyloxy- benzoate ((8) over bar S5 - d(4)). A global analysis of all these observables at 9 different temperatures in the nematic and smectic A phases is shown to give useful information on the core dynamics of (8) over bar S5. Inclusion of the smectic C phase in the global analysis is possible; but gives a poorer overall fitting quality factor.}, keywords = {deuteron spin relaxation, LIQUID-CRYSTAL PHASES, MOLECULAR ORDER, MOTIONS, NMR, RESONANCE, ROTATIONAL DIFFUSION, smectogen}, isbn = {1058-725X}, url = {://000082878400020}, author = {Dong, R. Y. and Bates, G. S. and Shen, X.} } @article {4458, title = {Electronic spectra of YOH and YOD in the visible region: Strong vibronic coupling between the (B)over-tilde(1)II and (C)over-tilde(1)Sigma(+) states}, journal = {Journal of Molecular Spectroscopy}, volume = {196}, number = {1}, year = {1999}, note = {ISI Document Delivery No.: 208RCTimes Cited: 7Cited Reference Count: 41}, month = {Jul}, pages = {45-69}, type = {Article}, abstract = {Laser excitation spectra of yttrium monohydroxide, YOH, have been recorded in the 500-625 nm wavelength region. Rotational analysis of bands of YOH and YOD has shown that the ground state is (X) over tilde(1)Sigma(+), with the structure r(0)(Y-O) = 1.948(6) Angstrom, r(0)(O-H) = 0.920(6) Angstrom; the bending frequency (nu(2), pi) is 313.73 cm(-1) (237.43 cm(-1) in YOD) and the Y-O stretching frequency (nu(3), sigma(+)) is 673.83 cm(-1) (655.34 cm(-1)). Two excited electronic states have been identified; they are assigned as (B) over tilde(1)Pi (16 449 cm(-1)) and (C) over bar(1)Sigma(+) (18 509 cm(-1)). Unusually strong vibronic coupling through the bending vibration occurs between these two states, which causes their vibrational structures to be highly irregular; assignments have only been possible following extensive wavelength-resolved fluorescence experiments. The vibronic coupling raises the bending frequency of the (C) over tilde(1)Sigma(+) state to 457 cm(-1) and reduces that of the lower Born-Oppenheimer component of the (B) over tilde(1)Pi state (which has A{\textquoteright} symmetry in the C, point group) to the extent that the molecule becomes nonlinear, with a potential barrier at the linear configuration of about 120 cm(-1). The presence of the potential barrier is clearly demonstrated by the level structure of YOD, where the Sigma(+) vibronic component of the 010 vibrational level (linear molecule notation) lies 1.4 cm(-1) below the 000 level. The upper Born-Oppenheimer component, which has A " symmetry, is unaffected; its bending frequency is similar to that of the ground state. Perturbations occur in both the (B) over tilde(1)Pi and (C) over tilde(1)Sigma(+) states; some of these represent local interactions between the two of them, but others are caused by higher vibrational levels of lower-lying "dark" electronic states. Over 40 ground state vibrational levels have been identified for both YOH and YOD from the wavelength-resolved fluorescence spectra. (C) 1999 Academic Press.}, keywords = {15-K, laser spectroscopy, METHYLIDYNE, ORBITAL ANGULAR-MOMENTUM, RESONANCE, SYSTEM, TRANSITION, TRIATOMIC-MOLECULES, VANADIUM, WATER}, isbn = {0022-2852}, url = {://000081004300006}, author = {Adam, A. G. and Athanassenas, K. and Gillett, D. A. and Kingston, C. T. and Merer, A. J. and Peers, J. R. D. and Rixon, S. J.} } @article {4428, title = {N-14 hyperfine structure in the pure rotational spectrum of (MgNC)-Mg-24-N-14-C-12}, journal = {Journal of Molecular Spectroscopy}, volume = {189}, number = {1}, year = {1998}, note = {ISI Document Delivery No.: ZM048Times Cited: 12Cited Reference Count: 44}, month = {May}, pages = {40-45}, type = {Article}, abstract = {The pure rotational spectrum of (MgNC)-Mg-24-N-14-C-12, between 11.9 and 23.9 GHz, has been measured using a pulsed jet Fourier transform microwave spectrometer. The hyperfine structure due to the N-14 nucleus has been measured, and the nuclear quadrupole coupling, Fermi contact, and dipole-dipole interaction constants have been determined. The ionic character of the metal-isocyanide bond has been investigated through the nuclear quadrupole and magnetic hyperfine parameters. (C) 1998 Academic Press.}, keywords = {ABINITIO, INTERSTELLAR, IRC+10216, MG-BEARING MOLECULE, MILLIMETER, PARAMETERS, PREDICTION, RESONANCE, SEARCHES, spectroscopic constants}, isbn = {0022-2852}, url = {://000073499500005}, author = {Walker, K. A. and Gerry, M. C. L.} } @article {4222, title = {A new linear ion trap time-of-flight system with tandem mass spectrometry capabilities}, journal = {Rapid Communications in Mass Spectrometry}, volume = {12}, number = {20}, year = {1998}, note = {ISI Document Delivery No.: 130DBTimes Cited: 92Cited Reference Count: 64}, pages = {1463-1474}, type = {Article}, abstract = {A new hybrid linear ion trap time-of-flight mass spectrometer has been constructed and the first results for tandem-in-time MS/MS in a 2-dimensional Paul trap are presented. The instrument consists of an electrospray ionization source and two radio frequency (RF) only quadrupoles operating at a pressure of 7 mTorr N-2 which are coupled orthogonally to a linear TOFMS. Ions are trapped in an RF-only quadrupole through the application of timed stopping potentials on the entrance and exit apertures. Through the coupling of an auxiliary waveform generator on one pair of the ion trap rods a small dipolar excitation voltage is superimposed on the quadrupolar electric field. This voltage is used for precursor isolation via broadband excitation and collision induced dissociation through mass selective resonant excitation. Instrumental performance and choice of operating parameters are demonstrated by recording fragment spectra for +3 ions of renin substrate and fl ions of reserpine. TOFMS mass resolution (m/Delta m)(FWHM) is as high as 740 at m/z = 609. Fragmentation efficiency is greater than 50\% and excitation mass resolution is 60-75. (C) 1998 John Wiley \& Sons, Ltd.}, keywords = {DECOMPOSITION, EJECTION, ELECTROSPRAY-IONIZATION, FREQUENCY STANDARD APPLICATIONS, MOLECULE REACTION, PARAMETERS, PERFORMANCE, PROTEINS, QUADRUPOLE, RESONANCE, SPECTROSCOPY}, isbn = {0951-4198}, url = {://000076503200007}, author = {Campbell, J. M. and Collings, B. A. and Douglas, D. J.} } @article {4418, title = {Structural, spectroscopic, thermodynamic and kinetic properties of copper(II) complexes with tripodal tetraamines}, journal = {Inorganic Chemistry}, volume = {37}, number = {16}, year = {1998}, note = {ISI Document Delivery No.: 110GETimes Cited: 87Cited Reference Count: 38}, month = {Aug}, pages = {4022-4029}, type = {Article}, abstract = {Spectroscopic, thermodynamic, and kinetic measurements have been made on aqueous solutions of copper(II) complexes of hexamethylated tren and trimethylated tren (one methylation per primary amine group of tren) with the objective of correlating: the influence of geometry (trigonal bipyramidal, evident from UV/vis spectroscopy) and N-alkyl substitution in the ligand on these inherent properties. At 25.0 degrees C the protonation constants of Me(3)tren are not significantly different from those of tren and Me(6)tren, and the stability constant for the Cu(II) complex is of the same order of magnitude as that for the [Cu(tren)(H2O)](2+) complex ion; The pK(a) for deprotonation of the coordinated water molecule of [Cu(Me(3)tren)(H2O)](2+) is intermediate between the values for the complexes containing the unsubstituted and the fully substituted tren ligand. Substitution (pyridine for water) kinetics measurements employing stopped-flow and temperature-jump methods revealed different patterns of reactivity: pyridine replaces water in [Cu(Me(3)tren)(H2O)](2+) with a second-order rate constant of (4.4 +/- 0.8) x 10(2) M-1 s(-1) at 25.0 degrees C, whereas the corresponding process for [Cu(Me(6)tren)(H2O)](2+) is relatively complex and is discussed in more detail. Substitution in the former complex ion is characterized in the forward and reverse directions, by Delta H-double dagger = 60 +/- 8 and 51.9 +/- 0.9 kJ mol(-1), Delta S-double dagger = 5 +/- 27 and -23 +/- 3 J mol(-1) K-1, and Delta V-double dagger = -8.7 +/- 4.6 and -6.2 +/- 1.1 cm(3) mol(-1), respectively, It is concluded that this reaction follows an I-a mechanism, similar to that reported for the comparable reaction of [Cu(tren)(H2O)](2+). An X-ray structural determination on a crystal of [Cu-2(Me(3)tren)(2)(CN)] (ClO4)(3) . 2CH(3)CN demonstrated trigonal bipyramidal geometry about each copper(II) center. As has been found in comparable complexes of tren and Me(6)tren, the axial nitrogen to copper bond is shorter than the equatorial nitrogen-copper bonds, and the angle made by N(axial)-Cu-N(equatorial) is less than 90 degrees (84.6-85.4 degrees), signifying that each copper ion lies below the plane of the equatorial nitrogen atoms.}, keywords = {AQUEOUS-SOLUTION, CRYSTAL-STRUCTURE, ELECTRONIC-PROPERTIES, IMIDAZOLE, ION, MECHANISM, PHENANTHROLINE, PRESSURE-DEPENDENCE, RESONANCE, SUBSTITUTION KINETICS}, isbn = {0020-1669}, url = {://000075371200019}, author = {Thaler, F. and Hubbard, C. D. and Heinemann, F. W. and vanEldik, R. and Schindler, S. and Fabian, I. and Dittler-Klingemann, A. M. and Hahn, F. E. and Orvig, Chris} } @article {3891, title = {(2)Pi-(X)over-tilde(2)Sigma(+) electronic bands of titanium methylidyne, TiCH, near 725 nm wavelength}, journal = {Journal of Molecular Spectroscopy}, volume = {181}, number = {1}, year = {1997}, note = {ISI Document Delivery No.: WA945Times Cited: 24Cited Reference Count: 27}, month = {Jan}, pages = {168-179}, type = {Article}, abstract = {Electronic bands assigned to the linear TiCH and TiCD radicals have been recorded by laser-induced fluorescence in the 610-725 nm wavelength region, following the reaction of laser-ablated Ti atoms with methane under supersonic jet-cooled molecular beam conditions. Rotational analyses of high-resolution spectra have given the ground state substitution structure X(2) Sigma(+): r(g)(C-H) = 1.085 +/- 0.002 Angstrom: r(g)(Ti-C) = 1.7277 +/- 0.0003 Angstrom. The electronic upper state appears to be a very strongly perturbed (2) Pi start, with many extra rotational and vibrational levels appearing; it has nor barn possible to make vibrational assignments, though the Omega{\textquoteright} values have been established for some of the levels. Wavelength-resolved fluorescence spectra have given two of the three ground state vibrational frequencies: TiCH: nu(2)(bend) = 578 cm(-1), nu(3)(Ti-C stretch) = 855 cm(-1) TiCD: nu(2) = 442 cm(-1), nu(3) = 815 cm(-1) Vibrationally forbidden transitions to the ground state bending fundamental appear prominently in many of these spectra, as a result of strong vibronic coupling. No evidence for nu(1)(pi) (the C-Il stretching vibration) has been found. (C) 1997 Academic Press, Inc.}, keywords = {EXCITATION SPECTRUM, FLUORESCENCE, FREQUENCY, MONOXIDE, PERTURBATIONS, RESONANCE, SPECTROSCOPY, STATES, SYSTEM}, isbn = {0022-2852}, url = {://A1997WA94500020}, author = {Barnes, M. and Merer, A. J. and Metha, G. F.} } @article {4095, title = {Addition reactions and longitudinal field spin relaxation of small radicals in gases: Mu+CO and Mu+N2O}, journal = {Hyperfine Interactions}, volume = {106}, number = {1-4}, year = {1997}, note = {ISI Document Delivery No.: XB055Times Cited: 4Cited Reference Count: 297th International Conference on Muon Spin Rotation, Relaxation, ResonanceAPR 15-19, 1996NIKKO, JAPANUniv Tokyo, Meson Sci Lab, Inst Phys \& Chem Res, Muon Sci Lab}, pages = {181-186}, type = {Proceedings Paper}, abstract = {Muon spin relaxation has been measured in longitudinal magnetic fields for Mu + CO and Mu + N2O reactions. The interpretation of the results for these small molecules, which are quite different than those obtained in larger molecule systems (e.g., Mu-ethyl and Mu-t-butyl radicals), are made with the phenomenological model for Mu-radical spin relaxation previously proposed. Proper fitting procedures are important in these cases and are discussed in the present paper.}, keywords = {DEPENDENCE, DYNAMICS, EXCHANGE, HYPERFINE COUPLING-CONSTANTS, PHASE, RESONANCE}, isbn = {0304-3843}, url = {://A1997XB05500026}, author = {Pan, J. J. and Arseneau, D. J. and Senba, M. and Shelley, M. and Fleming, Donald G.} } @article {3960, title = {Hyperfine coupling constants of muonium-substituted cyclohexadienyl radicals in the gas phase: C(6)H(6)Mu, C(6)D(6)Mu, C(6)F(6)Mu}, journal = {Applied Magnetic Resonance}, volume = {13}, number = {1-2}, year = {1997}, note = {ISI Document Delivery No.: YE729Times Cited: 13Cited Reference Count: 33}, pages = {181-194}, type = {Article}, abstract = {Muon spin rotation (mu SR) and avoided level crossing resonance (ALCR) have been used to determine the hyperfine coupling constants (hfcs) of the muonium-substituted cyclohexadienyl radicals C(6)H(6)Mu, C(6)D(6)Mu and C(6)F(6)Mu in the gas phase, at pressures similar to 1 and 15 atm and temperatures in the range 40-80 degrees C. Equivalent studies of polyatomic free radicals in gases, by electron spin resonance (ESR) spectroscopy, are generally not possible in this pressure range. The present gas phase results support the findings of earlier studies of cyclohexadienyl radicals in the condensed phase, by both mu SR and ESR. Minor but not insignificant (similar to 1\%) effects on the hfcs are observed, which can be qualitatively understood for such nonpolar media in terms of their differing polarizabilities. This is the first time that comparisons of this nature have been possible between different phases at the same temperatures. These mu SR/ALCR gas-phase results provide a valuable benchmark for computational studies on radicals, free from possible effects of solvent or matrix environments.}, keywords = {ETHYL RADICALS, LEVEL-CROSSING SPECTROSCOPY, ORGANIC FREE-RADICALS, RESONANCE, SPECTRA, SPIN ROTATION}, isbn = {0937-9347}, url = {://A1997YE72900015}, author = {Fleming, Donald G. and Arseneau, D. J. and Pan, J. J. and Shelley, M. Y. and Senba, M. and Percival, P. W.} } @article {3837, title = {Theory of muon spin relaxation of gaseous C(2)H(4)Mu}, journal = {Physical Review A}, volume = {54}, number = {6}, year = {1996}, note = {ISI Document Delivery No.: VX714Times Cited: 5Cited Reference Count: 32}, month = {Dec}, pages = {4815-4829}, type = {Article}, abstract = {A theoretical study of the muon spin relaxation of the gaseous muonated ethyl radical C(2)H(4)Mu is expanded in this paper to include both longitudinal and transverse signals. This study is based upon an operator expansion of the spin-density operator for the radical with its time dependence described by the linearized quantum Boltzmann equation. Relaxation is due to collisions which reorient the radical{\textquoteright}s rotational angular momentum while effects on the muon{\textquoteright}s spin are due to couplings between the muon{\textquoteright}s spin, the radical{\textquoteright}s free-electron spin, and the radical{\textquoteright}s rotational angular momentum. The coefficients of the radical{\textquoteright}s spin Hamiltonian and the collisional lifetimes (cross sections) are used as fitting parameters to describe the transverse signals. A fit to the transverse data by itself and a global fit to both the transverse and longitudinal data are obtained with good accuracy.}, keywords = {CHARGE-EXCHANGE, CONSTANTS, FREE-RADICALS, GAS-PHASE, IRREDUCIBLE CARTESIAN TENSORS, KINETIC-EQUATIONS, PRESSURE-DEPENDENCE, RESONANCE}, isbn = {1050-2947}, url = {://A1996VX71400033}, author = {Turner, R. E. and Snider, R. F.} } @article {3238, title = {ELECTRONIC-TRANSITIONS OF COBALT CARBIDE, COC, NEAR 750 NM - A GOOD EXAMPLE OF CASE (B(BETA-S)) HYPERFINE COUPLING}, journal = {Journal of Chemical Physics}, volume = {103}, number = {19}, year = {1995}, note = {ISI Document Delivery No.: TE364Times Cited: 56Cited Reference Count: 48}, month = {Nov}, pages = {8360-8371}, type = {Article}, abstract = {The laser induced fluorescence spectrum of jet-cooled CoC near 750 nm has been measured at high resolution following the reaction of laser-ablated cobalt atoms with methane. The X(2) Sigma(+) ground state of CoC is an unusually good example of Hund{\textquoteright}s case (b(beta S)) coupling. Since Co has a nuclear spin I=7/2, each rotational level is split by the Fermi contact interaction into G=3 and G=4 components, where G=I+S; the splitting for N=0 is more than 0.5 cm(-1). The X(2) Sigma(+) state begins to uncouple toward case (b(beta J)) with increasing rotation. Transitions to various (II)-I-2 excited states occur in the region 13 000-14 500 cm(-1); the most prominent of these (for which high resolution spectra have been recorded) lie at 13 079 cm(-1) ((II3/2)-I-2) and 13 343 cm(-1) ((II1/2)-I-2). The (b(beta S)) coupling in the ground state produces some unexpected hyperfine intensity patterns, which have been studied in detail. A very low-lying (2) Delta(i) state, whose Omega=5/2 and Omega=3/2 components lie at 221 and 1173 cm(-1), has been identified. Laser excitation of the (II3/2)-I-2-(2) Delta(5/2) transition has been observed by monitoring the strong (II3/2)-I-2-X(2) Sigma(+) emission, which has allowed the (2) Delta(5/2) state to be characterized at high resolution. A total of 879 rotational-hyperfine transitions between the various (II1/2)-I-2, (II3/2)-I-2, (2) Delta(5/2), and (2) Sigma(+) states have been assigned and fitted. Matrix elements for a (2) Sigma(+) state in case (bps) coupling are listed. (C) 1995 American Institute of Physics.}, keywords = {GROUND-STATE, laser spectroscopy, MNO, MOLECULES, O, O BAND, RESONANCE, SPECTRUM, SYSTEM, VC}, isbn = {0021-9606}, url = {://A1995TE36400006}, author = {Barnes, M. and Merer, A. J. and Metha, G. F.} } @article {3568, title = {FIXATION OF AMMONIACAL COPPER PRESERVATIVES - REACTION OF VANILLIN, A LIGNIN MODEL-COMPOUND WITH AMMONIACAL COPPER-SULFATE SOLUTION}, journal = {Holzforschung}, volume = {49}, number = {6}, year = {1995}, note = {ISI Document Delivery No.: TJ868Times Cited: 21Cited Reference Count: 23}, pages = {483-490}, type = {Article}, abstract = {{A model for the fixation of ammoniacal copper preservatives in wood was examined through reaction of vanillin, a lignin model compound, with ammoniacal copper sulphate solution. The compound produced on evaporation of the aqueous ammoniacal solution has been characterized spectroscopically as di(amine)bis(vanillinato)copper(II); [Cu(vanillin)(2)(NH3)(2)]. Single crystal X-ray crystallographic studies showed that the crystals of [Cu(vanillin)(2)(NH3)(2)] are monoclinic with space group P2(1) with a = 5.4172(9)}, keywords = {AMMONIACAL COPPER PRESERVATIVES, COMPLEXES, DIAMINE, ESR, FIXATION, ION, LIGNIN MODEL COMPOUND, RESONANCE, VANILLIN, WOOD PRESERVATION, X-ray crystal structure}, isbn = {0018-3830}, url = {://A1995TJ86800001}, author = {Xie, C. S. and Ruddick, J. N. R. and Rettig, S. J. and Herring, F. G.} } @article {3311, title = {KINETIC-STUDY OF ATOMIC-HYDROGEN ETCHING OF GAAS(100)}, journal = {Journal of Applied Physics}, volume = {77}, number = {5}, year = {1995}, note = {ISI Document Delivery No.: RC303Times Cited: 3Cited Reference Count: 39}, month = {Mar}, pages = {2155-2159}, type = {Article}, keywords = {GaAs, GALLIUM-ARSENIDE, H-2, OXIDES, PLASMAS, RATE CONSTANTS, RESONANCE, SI, SILICON, SURFACES}, isbn = {0021-8979}, url = {://A1995RC30300054}, author = {Elzey, J. W. and Meharg, P. F. A. and Ogryzlo, E. A.} } @article {3221, title = {{ROTATIONAL AND HYPERFINE-STRUCTURE IN THE B(4)PI-X(4)SIGMA(-) (0,0) BAND OF VO AT 7900 ANGSTROM - PERTURBATIONS BY THE A(2)SIGMA(+)}, journal = {Journal of Molecular Spectroscopy}, volume = {170}, number = {1}, year = {1995}, note = {ISI Document Delivery No.: QL001Times Cited: 28Cited Reference Count: 37}, month = {Mar}, pages = {94-130}, type = {Article}, abstract = {{The (0,0) band of the (BII)-I-4-X(4) Sigma(-) system of VO near 7900 Angstrom has been analyzed from Doppler-limited Fourier transform emission spectra, together with wavelength-resolved laser-induced fluorescence and sub-Doppler intermodulated fluorescence spectra. The (BII)-I-4}, keywords = {laser spectroscopy, LINEAR MOLECULES, multiplicity, PARAMETERS, QUARTET, RESONANCE, SPECTRUM, STATES}, isbn = {0022-2852}, url = {://A1995QL00100008}, author = {Adam, A. G. and Barnes, M. and Berno, B. and Bower, R. D. and Merer, A. J.} } @article {2712, title = {ROTATIONAL, FINE, AND HYPERFINE ANALYSES OF THE (0,0) BAND OF THE D(3)PI-X(3)DELTA SYSTEM OF VANADIUM MONONITRIDE}, journal = {Journal of Chemical Physics}, volume = {99}, number = {5}, year = {1993}, note = {ISI Document Delivery No.: LU722Times Cited: 42Cited Reference Count: 45}, month = {Sep}, pages = {3288-3303}, type = {Article}, abstract = {The VN molecule has been produced in a molecular beam apparatus using a laser vaporization source and its D3PI-X3DELTA (0,0) band has been studied by laser-induced fluorescence at low (approximately 0.1 cm-1) and sub-Doppler resolution (approximately 0.004 cm-1). Lifetimes of single rotational levels of the D3PI0 component have been measured and interpreted. Rotational, fine, and hyperfine structures in six of the nine subbands possible for a 3PI <{\textendash} 3DELTA transition have been recorded. Both states exhibit a rapid transition from case (a) {\textendash}> case (b) coupling cases, manifested by reversals in the Lande patterns of the hyperfine structure. The data have been reduced to a set of 35 molecular constants using a modified case (a(beta)) effective Hamiltonian in which two additional magnetic hyperfine parameters are required for each state. The distortions in the hyperfine structure are due almost entirely to second-order spin-orbit interaction between states arising from the same configuration. Analysis of the derived parameters indicates that the X3DELTA state is well represented by the single electron configuration ... 8sigma2 3pi4 9sigma1 1delta1, in which the 9sigma molecular orbital (MO) is a V 4s-4p hybrid (88\% V 4s) and the 1delta MO is-a pure V 3d orbital; the dominant configuration for the D3PI state is ... 8sigma2 3pi4 1delta1 4pi1, in which the 4pi MO is an antibonding orbital composed of at most 82\% V 3dpi. The isoconfigurational a 1DELTA and e 1PI states are calculated to lie 3390 and 2200 cm-1 above their respective high spin companions. The lambda doubling in the D3PI0 component has been interpreted in terms of spin-orbit interactions with the B3SIGMA- and d1SIGMA+ states, both states arising from the ... 8sigma2 3pi4 1delta2 configuration; the d1SIGMA+ state is known [Simard, Masoni, and Hackett, J. Mol. Spectrosc. 136, 44 (1989)] to lie 102 cm-1 above D3PI0, while the B3SIGMA- state probably lies about 8000 cm-1 below.}, keywords = {ABINITIO, ELECTRONIC EMISSION SYSTEM, MOLECULES, NIOBIUM NITRIDE, PARAMETERS, RESONANCE, SPECTROSCOPY, SPECTRUM, STATES, TIN}, isbn = {0021-9606}, url = {://A1993LU72200017}, author = {Balfour, W. J. and Merer, A. J. and Niki, H. and Simard, B. and Hackett, P. A.} } @article {7236, title = {DEMONSTRATION OF THE LIQUID-CRYSTALLINE BEHAVIOR OF A RIGID-BACKBONE POLYESTER IN A MAGNETIC-FIELD}, journal = {Macromolecules}, volume = {25}, number = {5}, year = {1992}, note = {ISI Document Delivery No.: HG439Times Cited: 6Cited Reference Count: 16}, month = {Mar}, pages = {1623-1624}, type = {Letter}, keywords = {AROMATIC POLYESTERS, COPOLYESTER, RESONANCE}, isbn = {0024-9297}, url = {://A1992HG43900043}, author = {Fyfe, C. A. and Fahie, B. J. and Lyerla, J. R. and Economy, J. and Niessner, N. and Muhlebach, A. and Facey, G. A.} } @article {7172, title = {KINETIC ISOTOPE EFFECTS IN GAS-PHASE MUONIUM REACTIONS}, journal = {Acs Symposium Series}, volume = {502}, year = {1992}, note = {ISI Document Delivery No.: JY550Times Cited: 16Cited Reference Count: 101}, pages = {111-137}, type = {Review}, abstract = {The study of the reaction dynamics of muonium (Mu), an ultralight isotope of hydrogen ((m)Mu/(m)H almost-equal-to 1/9), provides a sensitive measure of mass effects in chemical reactions. The remarkable mass difference between Mu and the other hydrogen isotopes produces large kinetic isotope effects, providing a rigorous test of calculated potential energy surfaces (PES) and reaction rate theories. The low Mu mass also necessitates careful consideration of quantum effects, i.e. tunneling in the reaction coordinate. A review of recent results in gas phase Mu chemistry is presented, including comparison with relevant H chemistry and calculated PESs, where available. The magnitude and direction of the kinetic isotope effect is shown to be a sensitive function of the PES, particularly the height and position of the saddle point.}, keywords = {+ HBR(DBR) ABSTRACTION, ACTION, ADDITION-REACTIONS, CALCULATIONS, CHARGE-EXCHANGE, COLLISIONS, LOW-TEMPERATURES, POTENTIAL-ENERGY SURFACES, PRESSURE-DEPENDENCE, RESONANCE, THERMAL RATE CONSTANTS, TRANSITION-STATE THEORY, TUNNELING PATHS}, isbn = {0097-6156}, url = {://A1992JY55000008}, author = {Baer, S. and Fleming, Donald G. and Arseneau, D. and Senba, M. and Gonzalez, A.} }