Production of binary oxides by photolysis of M(CO)6 molecules (M = Cr, Mo, or W) isolated in O2-doped argon matrices
Abstract
Oxides of the metals chromium, molybdenum, and tungsten have been generated by u.v. photolysis of O2-doped argon matrices containing [M(CO)6] molecules (M = Cr, Mo, or W) at ca. 20 K. In addition to CO and CO2, produced irrespective of the nature of M, the final products of photolysis are MO2(M = Cr) and MO3(M = Mo and W). The MO3 molecules are produced from another metal oxide species, (X), and studies involving 18O substitution for the tungsten version suggest that (X) is a peroxide (η2-O2)WO2. U.v. photolysis of (X) yields MO3 and O atoms in the excited 1D state. The presence of the O(1D) atoms is demonstrated by experiments in which O3 is produced in pure dioxygen matrices, N2O in O2-doped dinitrogen matrices, and CH3OH and H2CO in O2-doped methane matrices.