RAMAN EXCITATION PROFILES OF METAL DITHIOLENES - COMPARISON BETWEEN THE TRANSFORM METHOD AND TIME-DEPENDENT THEORY

The time-dependent theory of the resonance Raman effect was employed f or the calculation of the Raman excitation profiles and optical absorp tion spectra of the metal dithiolene species [Zn(dmit)(2)](2-) and [Ni (dmit)(2)](2-) (dmit = 4,5-dimercapto-1,3-dithiole-2-thione) The model adopted takes into account the three normal modes notable for their e nhancement at resonance, and embodies the linear non-Condon coupling c ontribution, Previous calculations for these species using the transfo rm method lead to estimates of the relative displacements of potential surface minima for the three modes considered, while the present calc ulations led to absolute values for such displacements, The metal-sulp hur bond length is increased by 0.016 and 0.027 Angstrom in the zinc a nd nickel complexes, respectively.