J. Appl. Cryst.の発刊に際して

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Several ruthenium-based olefin metathesis catalysts of the formula (PR3)2X2RuCHCHCPh2 have been synthesized, and relative catalyst activities were determined by monitoring the ring-closing metathesis of the acyclic diene diethyl diallylmalonate. The following order of increasing activity was determined:  X = I < Br < Cl and PR3 = PPh3 ≪ PiPr2Ph < PCy2Ph < PiPr3 < PCy3. Additional studies were conducted with the catalyst (PCy3)2Cl2RuCH2 to probe the mechanism of olefin metathesis by this class of catalysts. The data support a scheme in which there are two competing pathways:  the dominant one in which a phosphine dissociates from the ruthenium center and a minor one in which both phosphines remain bound. Higher catalyst activites could be achieved by the addition of CuCl to the reaction.

Well-defined ruthenium olefin metathesis catalysts: Mechanism and activity

Structural chemistry of transition metal complexes of oximes

Chemistry and enzymology of vitamin B12.

Kinetics of aquation of trans-chloro-tertiary phosphine-CoIII-bisdimethylglyoximato complexes

The structure of the 1:1 addition compound of molecular oxygen with NN′-ethylenebis(acetylacetoneiminato) cobalt(II) monopyridinate

Mechanism of formation of trans-chloro-bisdimethylglyoximato-tertiary phosphine cobalt(III) complexes and their isomers 1:1 electrolytes

An Unusual Reaction of Bis(dimethylglyoximato) Complexes: Synthesis and Characterization of Rhodium(III) Complexes Containing an Oxime-Imine Equatorial Moiety

Activation parameters for the axial water substitution reaction in some vit. B12 model compounds

Giovanni Tauzher

Papers

Kinetics of aquation of trans-chloro-tertiary phosphine-CoIII-bisdimethylglyoximato complexes

The structure of the 1:1 addition compound of molecular oxygen with NN′-ethylenebis(acetylacetoneiminato) cobalt(II) monopyridinate

Mechanism of formation of trans-chloro-bisdimethylglyoximato-tertiary phosphine cobalt(III) complexes and their isomers 1:1 electrolytes

An Unusual Reaction of Bis(dimethylglyoximato) Complexes: Synthesis and Characterization of Rhodium(III) Complexes Containing an Oxime-Imine Equatorial Moiety

Activation parameters for the axial water substitution reaction in some vit. B12 model compounds