A Initio Calculations on Chiral Cobalt
Ab initio calculations of the optical activity in chiral complexes of Co(III) were performed. The complex ions studied were tris(ethylenediamine)cobalt(III), tris(1,3 -diaminopropane)cobalt(III), tris(oxalato)cobaltate(III) and hexaamminecobalt(III). The Restricted Hartree-Fock/Random Phase Approximation was used for the calculation of the chiroptical spectra. Several higher level calculations were performed to improve the excitation energies and to explore correlation effects in the ground state. The results from the RPA calculations were analyzed by means of the resulting transition density matrices, RPA vectors and Mulliken populations. The predicted spectra were compared to experimental results, and the RPA method was found to yield good agreement with the experiment. Tentative interpretations of the mechanisms by which optical activity is induced in the complexes of interest were made on the basis of the RPA calculations. Strong interactions between the occupied Cobalt d-orbitals and occupied ligand bonding orbitals were found to dominate the electronic structure of the states of interest. The effective electric dipole chromophore was found to extend well past the primary coordination sphere and to consist of the ligating atoms and all centers which participate in bonding interactions with the ligating atoms. Connections between the results from the RPA calculations presented in this thesis and previous works were established.
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- III) COMPLEXES (CIRCULAR DICHROISM;
- Chemistry: Physical; Physics: Molecular; Chemistry: Inorganic