Cationic carbonyl complexes of rhodium(I) with imidazoles

Cationic complexes of Rh(I) of the type [Rh(CO)​2L3]​ClO4 (L = Ph3P or Ph3As) react with imidazoles to give 4-​coordinate complexes [Rh(CO)​QL2]​ClO4 and 5-​coordinate complexes [Rh(CO)​ZL2]​ClO4 [Q = imidazole, benzimidazole, or substituted benzimidazole, and Z = 2-​(α-​pyridyl)​benzimidazole]​. [Rh(CO)​2Z]​ClO4 and [Rh(CO)​2L'2]​ClO4 (L' = 2-​phenylbenzimidazole) were also isolated. Structures were assigned to all the complexes on the basis of IR and NMR data