Reactions of diarsines with bi- and tri-metallic carbonyl complexes containing cobalt

Reaction of the diarsines As2R4 (R=Me or Ph) with alkyne-bridged dicobalt h exacarbonyl complexes leads to products with bridging (AsR2)(2)O ligands an d to the production of simple AsR3 substituted complexes; alkylidyne tricob alt nonacarbonyl complexes exhibit parallel reactivity with As2R4. Thermoly sis of the complex [Co-2(mu-PhCCPh){mu-(AsMe2)(2)O}(CO)(4)] gives the tetra -substituted complex, [Co-2(mu-PhCCPh){mu-(AsMe2)(2)O}(2)(CO)(2)]. Reaction of the heterometallic complex [(OC)(3)Co{mu-C-2(CO2Me)(2)}MoCp(CO)(2)] wit h As2Ph4 affords [{(HO)Ph2As}(OC)(2)Co{mu-C-2(CO2Me)(2)}MoCp(CO)(2)], suppo rting the suggestion of a possible hydrolytic mechanism for the formation o f the (AsR2)(2)O bridged complexes.