(Alkoxycarbonyl)- and [(aryloxy)carbonyl]cobalt carbonyls

Article abstract of DOI:10.1021/om00128a006

(Alkoxycarbonyl)cobalt tetracarbonyls (1) were synthesized from Co₂(CO)₈ in THF and from ICo(CO)₄ by the reaction with the corresponding alkali-metal alkoxides in saturated hydrocarbons using crown ethers as solid/liquid phase-transfer catalysts. Both 1 and, for the first time, [(aryloxy)carbonyl]cobalt tetracarbonyls (2) were obtained in a homogeneous system containing ICo(CO)₄ and alkali-metal alkoxides or phenoxides, respectively, in THF. Tertiary phosphine derivatives of 1 and 2 were also prepared. The formation of complexes 1 and 2 proceeds through the ionic intermediates [ICo(COOR)(CO)₃]^- which were characterized by their infrared spectra. Analogous ionic species [Co(COOR)₂(CO)₃]^- are formed from the reaction of complexes 1 and RO. [(Allyloxy)carbonyl]cobalt tetracarbonyl shows thermal decarboxylation at 20°C yielding (η³-C₃H₅)Co(CO)₃ and CO₂.