RESONANCE RAMAN SPECTRA AND EXCITATION PROFILES OF METAL(II)DITHIZONATES

Author Institution: Department of Chemistry Vanderbilt University, Nashville; Institute of Inorganic Chemistry and Metallurgy of Rare Elements, Technical University WroclawResonance Raman (RR) spectra of several metal(II)dithizonates $[M(HDz)_{2}, M = Ni(II), Pd(II), Pt(II), Cu(II), Hg(II)]$ have been recorded with a variety of exciting lines. Excitation profiles of the modes enhanced in the RR spectra of Ni(II) complex resolve the broad electronic absorption band into two separate components which are assigned to two CT metal-ligand transitions. On excitation within the $\pi \rightarrow \pi^{\ast}$ transition of the azo group the band corresponding to $N=N$ stretching vibration shows the largest enhancement and is located in the region $1365-1318 cm^{-1}$ in the RR spectra of metal(II)dithizonates. Vibrational assignments are made. Results obtained allow to explain the changes observed in the vibrational spectra of transient photochromic species of Hg(II)dithizonate