Photoreactions of chromium hexacarbonyl and chromium tetranitrosyl in frozen gas matrices. Infrared spectral evidence for tricarbonyldinitrosylchromium

Abstract

The photolysis of Cr(C0)6 and NO has been studied in frozen gas matrices. The reaction leads to the formation of Cr(N0)4 in argon and methane matrices. The intermediate complex Cr(C0)3(N0)2, which is not seen in noticeable amounts in hydrocarbon solutions, is shown to be stable in the low-temperature matrices. Isotopically substituted 13C160, I5Nl6O, and 15N180 have been used and a DSh geometry has been established for Cr(C0)3(N0)2 on the basis of infrared spectra. The photolysis of Cr(N0)4 in carbon monoxide matrices gives Cr(C0)3(N0)2 in addition to Cr(C0)6. The photolysis of Cr(N0)4 in argon and methane matrices gives a species Cr(NO)3(NO*), where the asterisk denotes a unique nitrosyl group with an unusually low value of UNO. A reaction scheme for Cr(C0)6 + NO (+hv) - Cr(NO), is proposed in which