Electronic and Resonance Raman Spectra of the Hexanuclear Cluster [Ru30(02CCH3)6{(pyrazine)Ru(NH3)5}36+

Abstract
The trinuclear [Ru30(00CCH3)6, (pyrazine)3] cluster reacts with pentaammineruthenium(II) ions, yielding a hexanuclear pyrazine bridged complex. The hexanuclear cluster exhibits a broad absorption band around 1000 nm and a strong band at 533 nm, ascribed to metal-metal and metal-pyrazine charge transfer transitions, respectively. Excitation at the visible band leads to the enhancement of the totally symmetric vibrational modes of pyrazine at 1605, 1230, 1085 and 700 cm−1, and of a vibrational peak at 335 cm−1, ascribed to the Ru(peripheral)-N(pyrazine) stretching mode. The spectroscopic data are consistent with a weak coupling between the central and peripheral ruthenium ions.