The reaction of cyanide, carbon monoxide, and ferrous derivatives led to the isolation of three products, trans- and cis-[Fe(CN)4(CO)2]2- and [Fe(CN)5(CO)]3-, the first two of which were characterized by single-crystal X-ray diffraction. The new compounds show self-consistent IR, 13C NMR, and mass spectroscopic properties. The reaction of trans-[Fe(CN)4(CO)2]2- with Et4NCN gives [Fe(CN)5(CO)]3- via a first-order (dissociative) pathway. The corresponding cyanation of cis-[Fe(CN)4(CO)2]2-, which is a minor product of the Fe(II)/CN-/CO reaction, does not proceed at measurable rates. Methylation of [Fe(CN)5(CO)]3- gave exclusively cis-[Fe(CN)4(CNMe)(CO)]2-, demonstrating the enhanced nucleophilicity of CN- trans to CN- vs CN- trans to CO. Methylation has an electronic effect similar to that of protonation as determined electrochemically. We also characterized [M(CN)3(CO)3]n- for Ru (n = 1) and Mn (n = 2) derivatives. The Ru complex, which is new, was prepared by cyanation of a [RuCl2(C0)3]2 solution.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry