Molecular hydrogen (0.8-8 bar) reacts with CoRh(CO)7 at 0°C in the presence of 2 bar carbon monoxide in n-hexane to yield HCo(CO)4 and Rh4(CO)12. When a solution of CoRh(CO)7 (10-3 mmol/1) and 3,3-dimethyl-1-butene (0.2 mol/1) in n-hexane is treated with 2 bar carbon monoxide and 8 bar hydrogen at 0°C, the catalytic formation of 4,4-dimethylpentanal is observed (25% conversion after 24 h). Although the reaction path of the molecular hydrogen activation is not known, the formation of an unobserved intermediate such as H2CoRh(CO)7, and its subsequent fragmentation to give HCo(CO)4 and a very unstable hydridorhodium species such as HRh(CO)3 rapidly yielding Rh4(CO)12 seems likely. The results show that low temperature activation of molecular hydrogen can be achieved at 0°C even in the presence of substantial concentrations of carbon monoxide using CoRh(CO)7.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry