Physical Sciences and Mathematics Commons^™

The Lowest-Energy Isomer Of C2si2h4 Is A Bridged Ring: Reinterpretation Of The Spectroscopic Data Based On Dft And Coupled-Cluster Calculations, Jesse J. Lutz, Larry W. Burggraf

Faculty Publications

The lowest-energy isomer of C₂Si₂H₄ is determined by high-accuracy ab initio calculations to be the bridged four-membered ring 1,2-didehydro-1,3-disilabicyclo[1.1.0]butane (1), contrary to prior theoretical and experimental studies favoring the three-member ring silylsilacyclopropenylidene (2). These and eight other low-lying minima on the potential energy surface are characterized and ordered by energy using the CCSD(T) method with complete basis set extrapolation, and the resulting benchmark-quality set of relative isomer energies is used to evaluate the performance of several comparatively inexpensive approaches based on many-body perturbation theory and density functional theory (DFT). Double-hybrid DFT methods are found to …

Determining The Reactivity And Oxidation Intermediates Of An Allylnickel (N-Heterocyclic Carbene) Chloride Complex, Scott W. E. Hendriks

Electronic Thesis and Dissertation Repository

The oxidation of C-H bonds to carbonyl functional groups using molecular oxygen (O₂) is a desirable process as O₂ is environmentally benign and inexpensive. However, oxidations that employ O₂ have lower product selectivity, making it industrially unappealing. The metal complexes NiCl(π-cinnamyl)(NHC) oxidize stoichiometrically with O₂ as the oxidant to selectively form the ketone and aldehyde products.

This thesis details the attempted catalysis with the NiCl(π-allyl)(NHC) complex and the stoichiometric reactivity of NiCl(π-allyl)(NHC) and NiCl(π-cinnamyl)(NHC) complexes upon O₂ exposure. An investigation of the intermediate and decomposition species of the NiCl(π-allyl)(NHC) complex was conducted. The complexes …

Dft Analysis Into The Intermediates Of Nickel Pyridenthiolate Catalysed Proton Reduction, Carolyn N. Virca, Theresa M. Mccormick

Chemistry Faculty Publications and Presentations

Nickel pyridine 2-thiolate (Ni(PyS)₃ −) has shown good stability and activity as a H₂ generation catalyst for use in solar energy storage. The experimentally proposed catalytic pathway is explored using DFT calculations. Free energy changes along the reaction coordinate, spin states, localization of charge and geometry of the intermediates were explored. Calculations were performed using Gaussian 09 with a B3P86/ 6-31+G(d) basis set and a CPCM water solvation model. Of particular interest were our findings that the first reduction occurs at the nickel rather than through non-innocent ligands and that water coordination is not favourable although protonation of …