The transient infrared absorption spectra of the coordinatively unsaturated Cr(CO)x species (x = 5, 4, 3, and 2) that are generated via excimer laser photolysis of gas-phase Cr(CO)6 are presented and discussed. The photofragments produced upon 193-, 248-, and 351-nm photolysis are identified. The results indicate that the gas-phase structures of the Cr(CO)x species are the same as those observed in condensed-phase experiments. It is postulated that Cr(CO)5 adopts a Cu, structure, Cr(CO)4 adopts a C2υ structure, and Cr(CO)3 adopts a C3υ, structure. The coordinatively unsaturated species are, in general, observed to be produced with a significant amount of internal excitation. The rate constants for the reaction of Cr(CO)5, Cr(CO)4, and Cr(CO)3 with CO were measured and found to be 1.5 × 1013, 2.4 × 1013, and 1.8 × 1013 cm3 mol–1 s–1, respectively.
ASJC Scopus subject areas
- Colloid and Surface Chemistry