High-Pressure Raman Study on the Decomposition of Polycrystalline Molybdenum Hexacarbonyl

High pressure Raman scattering on Mo(CO)(6) up to 37.7 GPa at ambient temperatures are recorded inside the Diamond-Anvil-Cell (DAC). The Raman spectra of the molybdenum hexacarbonyl completely vanish at 23.3 GPa, signifying novel pressure induced decomposition. The decomposed Raman spectrum recovered at ambient conditions has the characteristic features of a highly dense polymer with delta(OCO) units possibly attached to metal centers, C=O functional group, and graphitic carbon; and also CO adsorbed to molybdenum metal centres. The so formed highly dense metal mediated polymer upon relaxation from high pressure conditions and upon exposure to 514.5 nm argon ion laser outside the DAC transforms to MoO3 in the presence of disordered carbon as characterized by the Raman modes.