Liaisons Métal–Métal et Spectres Raman de Préresonance du Compose Co4(CO)12

Abstract

AbstractRaman spectra of Co4(CO)12 compound in heptane solutions have been investigated in the cobalt‐cobalt bond stretching vibrations range (250–100 cm−1). For comparison, the i.r. spectrum (300–30 cm−1) of this compound in the solid state has been recorded. Using the model of one M′M3 cage, the valence force constants of cobalt‐cobalt bonds have been calculated; the force constants are compared with those of RhRh and IrIr bonds in Rh4(CO)12 and Ir4(CO)12 clusters. The compound Co4(CO)12 has also been found to display preresonance Raman spectra when irradiated with 6471, 5145, 4965, 4880, 4579 and 4545 Å excitations. This preresonance effect has been analysed by the relative intensities measurements of the totally symmetric stretching bands.