@article {2615, title = {Orientational order of near D-3h solutes in nematic liquid crystals. II. Description via Gay-Berne model with embedded quadrupoles}, journal = {Journal of Chemical Physics}, volume = {130}, number = {15}, year = {2009}, note = {ISI Document Delivery No.: 437KLTimes Cited: 3Cited Reference Count: 19Sokolovskii, R. O. Burnell, E. Elliott}, month = {Apr}, pages = {6}, type = {Article}, abstract = {We perform Monte Carlo simulations of a mixture of soft ellipsoids with embedded quadrupoles as a model of various chloro- and methyl-substituted benzenes dissolved in nematic liquid crystals. We find that oblate Gay-Berne ellipsoids with multiple embedded quadrupoles qualitatively reproduce the trend in the order parameter asymmetry experimentally observed in NMR spectra. The trend is opposite to what is expected on the basis of the interaction of the solute{\textquoteright}s quadrupole with the solvent{\textquoteright}s average electric field gradient "felt" by dissolved dihydrogen molecules. We identify the specific minimum of the solute-solvent interaction energy landscape that may produce the unexpected sign of the order parameter asymmetry that is seen in the experiment and the simulation.}, keywords = {COMPOUNDS, deuterium, dissolving, ELECTRIC-DIPOLE INTERACTIONS, LIQUID MIXTURES, liquid theory, METHODS, Monte Carlo, MONTE-CARLO SIMULATIONS, nematic liquid crystals, nuclear magnetic resonance, ORGANIC, POTENTIALS, SHAPE, SOLVENTS}, isbn = {0021-9606}, url = {://000265486300033}, author = {Sokolovskii, R. O. and Burnell, E. E.} } @article {1572, title = {Synthesis, reactivity, and DFT studies of tantalum complexes incorporating diamido-N-heterocyclic carbene ligands. Facile endocyclic C-H bond activation}, journal = {Journal of the American Chemical Society}, volume = {128}, number = {38}, year = {2006}, note = {ISI Document Delivery No.: 085OFTimes Cited: 25Cited Reference Count: 73Spencer, Liam P. Beddie, Chad Hall, Michael B. Fryzuk, Michael D.}, month = {Sep}, pages = {12531-12543}, type = {Article}, abstract = {The syntheses of tantalum derivatives with the potentially tridentate diamido-N-heterocyclic carbene (NHC) ligand are described. Aminolysis and alkane elimination reactions with the diamine-NHC ligands, (Ar)[NCN]H-2 (where (Ar)[NCN]H-2 = (ArNHCH2CH2)(2)(C3N2); Ar = Mes, p-Tol), provided complexes with a bidentate amide-amine donor configuration. Attempts to promote coordination of the remaining pendent amine donor were unsuccessful. Metathesis reactions with the dilithiated diamido-NHC ligand ((Ar)[NCN]-Li-2) and various ClxTa(NR{\textquoteright}(2))(5-x) precursors were successful and generated the desired octahedral (Ar)[NCN]TaClx(NR{\textquoteright}(2))(3-x) complexes. Attempts to prepare trialkyl tantalum complexes by this methodology resulted in the formation of an unusual metallaaziridine derivative. DFT calculations on model complexes show that the strained metallaaziridine ring forms because it allows the remaining substituents to adopt preferable bonding positions. The calculations predict that the lowest energy pathway involves a tantalum alkylidene intermediate, which undergoes C-H bond activation R to the amido to form the metallaaziridine moiety. This mechanism was confirmed by examining the distribution of deuterium atoms in an experiment between (Mes)[NCN]Li-2 and Cl2Ta(CD2Ph)(3). The single-crystal X-ray structures of (p-Tol)[NCNH]Ta(NMe2)(4) (3), (Mes)[NCNH]Ta=CHPh(CH2Ph)(2) (4), (p-Tol)[NCN]Ta(NMe2)(3) (7), (Mes)[NCCN]Ta((CH2Bu)-Bu-t)(2) (11), and (Mes)[NCCN]-TaCl((CH2Bu)-Bu-t) (14) are included.}, keywords = {COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, EFFECTIVE CORE POTENTIALS, GAUSSIAN-TYPE BASIS, METAL-CARBON BONDS, METHODS, MOLECULAR-ORBITAL, ORGANIC-MOLECULES, SET MODEL CHEMISTRY, STABLE CARBENES, STRUCTURAL-CHARACTERIZATION}, isbn = {0002-7863}, url = {://000240612700055}, author = {Spencer, L. P. and Beddie, C. and Hall, M. B. and Fryzuk,Michael D.} } @article {2989, title = {{LOCAL-DENSITY CALCULATIONS OF STATIC DIELECTRIC-PROPERTIES OF CH4-NCLN}, journal = {Chemical Physics Letters}, volume = {217}, number = {5-6}, year = {1994}, note = {ISI Document Delivery No.: MV301Times Cited: 19Cited Reference Count: 36}, month = {Jan}, pages = {539-543}, type = {Article}, abstract = {{The dipole moments, dipole polarizabilities, and static hyperpolarizabilities of methane and the chloromethanes have been studied at the experimental geometry with the deMon density functional program. Using the local density approximation and large basis sets, we computed the dipole moments of CH4-nCln}, keywords = {BASIS-SETS, DIPOLE, FUNCTIONAL, HALOGENATED METHANES, HYPERPOLARIZABILITIES, IMPERFECT GASES, METHODS, MOLECULES, MOMENT DERIVATIVES, NONLINEAR OPTICAL-PROPERTIES, POLARIZABILITIES, PRESSURE VIRIAL-COEFFICIENTS}, isbn = {0009-2614}, url = {://A1994MV30100011}, author = {Chong, D. P.} }