Knowledge Bank

Vibrational analyses of the even parity, in-plane vibrations of metallo-porphin have been done for Cu and Ni metal $ions.1,2$ A similar analysis for Zn porphin has been performed which yields results not significantly different in either frequencies or eigenfunctions. We have applied the results of these vibrational analyses to the detailed interpretation of the vibronic spectra of Zn porphin using a model of vibronic interaction first applied qualitatively to porphyrins by perrin, et $al.3$ The model requires both vibrational eigenvectors and electronic wavefunctions. Investigations were made using electronic wavefunctions obtained by simple molecular orbital theory, and wavefunctions obtained by the Pariser-Parr-Parr-Pople self-consistent molecular orbital method including configuration interaction. The results are compared to experimental high resolution optical spectra.