Mixed cobalt/gold clusters based on octahedral or prismatic Co6C skeletons

摘要

The reaction of AuCl(PPh3) in THF with [Co6C(CO)(15)](2-) 1 afforded [Co6C(CO)(15){AuPPh3}](-) 3, with a metal skeleton consisting of a Co6C trigonal prism capped by a AuPPh3 group. 3 incorporated a new AuPPh3+ fragment giving [Co6C(CO)(13){AuPPh3}(2)] 4. The crystal structure of 4 reveals that the metal skeleton consists of a cobalt octahedron with a face capped by an Au-2(PPh3)(2) unit. The reaction of AuCl(PPh3) with the anion [Co6C(CO)(13)](2-), 2 produced the octahedral cluster [Co6C(CO)(13){AuPPh3}](-) in which a face appears to be capped by a AuPPh3+ group according to the crystal structure determination. This compound reacts with an excess of AuPPh3+ to give 4, and produces 3 by reversible reaction with a mild stream of CO. The electrochemical behaviour of these species has been investigated by cyclic voltammetry and coulometry. [References: 38]