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

Abstract

Reaction of the diarsines As₂R₄ (R = Me or Ph) with alkyne-bridged dicobalt hexacarbonyl complexes leads to products with bridging (AsR₂)₂O ligands and to the production of simple AsR₃ substituted complexes; alkylidyne tricobalt nonacarbonyl complexes exhibit parallel reactivity with As₂R₄. Thermolysis of the complex [Co₂(μ-PhCCPh){μ-(AsMe₂)₂O}(CO)₄] gives the tetra-substituted complex, [Co₂(μ-PhCCPh){μ-(AsMe₂)₂O}₂(CO)₂]. Reaction of the heterometallic complex [(OC)₃Co{μ-C₂(CO₂Me)₂}MoCp(CO)₂] with As₂Ph₄ affords [{(HO)Ph₂As}(OC)₂Co{μ-C₂(CO₂Me)₂}MoCp(CO)₂], supporting the suggestion of a possible hydrolytic mechanism for the formation of the (AsR₂)₂O bridged complexes.