A high pressure infrared spectral study of the reactions of dodecacarbonyltetrairidium with carbon monoxide and hydrogen

Abstract

The reactions of Ir₄(CO)₁₂ under pressures of carbon monoxide and hydrogen have been investigated by following i.r. spectral changes in a high pressure spectrophotometric cell in attempts to obtain evidence for the existence of Ir₂(CO)₈ and HIr(CO)₄. Although no reaction has been observed with carbon monoxide alone, the parent carbonyl is partially converted into HIr(CO)₄ by reaction with carbon monoxide and hydrogen (1 : 1 mole ratio) at 430 atm. total pressure and 200°C; no evidence has been obtained for the formation of Ir₂(CO)₈. A convenient synthesis of Ir₄(CO)₁₂ in high yield is also described.