Vibrational spectra of transition metal complexes of tetraphenylporphine

Abstract

Abstract The far i.r. spectra of tetraphenylporphine complexes of Pd(II), Co(II), Cu(II), Ag(II) and Zn(II) have been obtained. In order to aid in the assignment of the metal-nitrogen vibrations the metal isotope technique has been applied to the Ni, Cu, and Zn complexes. Vibrations containing contributions from the metal-nitrogen stretching coordinate have been assigned based on these metal isotope data and the results of a normal coordinate analysis of Zn(II)-porphine. The variation of the frequencies of the major bands is shown to be dependent upon the number of d electrons and is explained on the basis of ligand field stabilization energy.