Fourier transform Raman spectroscopic study of pressure‐induced ligand bond activation in a molybdenum–sulfur cluster

Abstract

AbstractFourier transform Raman spectra of the prototype, triangular, transition metal–sulfur cluster anion [Mo3(S2)6S]2− were recorded at pressures up to 60 kbar with the aid of a diamond‐anvil cell (DAC). The pressure dependences (∂ν/∂p) of the Raman bands indicate a structural change at around 10–15 kbar. The SS stretching mode for the bridging disulfide ligands exhibits a slightly negative ∂ν/∂p value (−0.08), suggesting that SS bonds are weakened, i.e. activated, at high pressures. This pressure‐induced activity parallels the observed nucleophilic substitution reactivity of the S2 groups in this molybdenum cluster anion. In view of this, a preliminary investigation of the reaction between [Mo3(S2)6S]2− and CN− was undertaken in the solid state in the DAC under high pressure. Copyright © 2002 John Wiley & Sons, Ltd.