Reactions of Organic Isocyanides with the Mixed-Metal Clusters Cp'2Mo2Co2S3(CO)4 and Cp'2Mo2Co2S4(CO)2
摘要:
The bimetallic cluster Cp'2Mo2Co2S3(CO)4 reacts with tert-butyl or methyl isocyanide to give sequentially the mono-, di-, and trisubstituted clusters CP'2Mo2Co2S3(CO)4-x(L)x. The disubstituted derivatives are formed as a mixture of cis and trans isomers that are readily distinguished by their AMR spectra. Color changes and NMR evidence indicate that the adducts CP'2Mo2Co2S3(CO)4-x+1(L)x are formed prior to the loss of CO in the substitution reactions; the reluctance of the adduct with x = 4 to lose CO is invoked to explain the lack of formation of tetrasubstituted derivatives.