(Ethoxycarbonyl)cobalt tetracarbonyl is hydrogenated at room temperature by H2 or HCo(CO)4 to ethyl formate and Co2(CO)8. The rate of ethyl formate formation, EtOCOCo(CO)4 + 1/2 H2 ↦. EtOCHO + V2Co2(CO)8 and EtOCOCo(CO)4 + HCo(CO)4 ↦ EtOCHO + Co2(CO)8, is first order in EtOCOCo(CO)4, first order in the hydrogenating agent (H2 or HCo(CO)4), and negative first order in CO. The comparison of the rate constants at 25 °C, k = 1.15 X 10-5 s-1 (±5%) and k's = 14.5 X 10-5 s-1 (±10%), shows that HCo(CO)4 reacts about 12 times faster than H2 and explains why HCo(CO)4 could not be detected among the products obtained with H2. The bimolecular reaction between coordinatively unsaturated EtOCOCo(CO)3 and the reducing agent is suggested as the rate-determining step.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry