VIBRONIC THEORY OF MAGNETIC VIBRATIONAL CIRCULAR-DICHROISM IN SYSTEMS WITH FOURFOLD SYMMETRY - THEORETICAL-ANALYSIS FOR COPPER TETRAPHENYLPORPHYRIN

A vibronic theory which includes multimode and multistate effects is developed to study magnetic vibrational circular dichroism (MVCD) and absorption spectra for molecular systems with fourfold symmetry. The MVCD and absorption spectra of the e fundamental transition and its combinations with infrared inactive modes are discussed in some detail to demonstrate the importance of electric and magnetic anharmonicity arising from vibronic coupling. The theory is applied to experimental MVCD spectra for the CuTPP molecule.