Synthesis of bis-(acyl, carbamoyl or alkoxycarbonyl) iron monomer or dimer complexes by reaction of oxalyl chloride with various tetracarbonyl ferrates: {Fe[C(O)R](CO) 4} −

Abstract

The reaction of oxalyl chloride with various tetracarbonyl ferrates bearing a carbonylated organic ligand induces the formation of bis substituted monomers Fe[C(O)R] 2(CO) 4 or dimers {Fe[C(O)R](CO) 4} 2 and of bis-[μ,η 2-C(O)R]Fe 2(CO) 6 bridged dimers. The orientation of the reaction depends on the nature of the organic ligand of the ferrates. Thus carbamoyls or alkoxycarbonyls ferrates bearing mobile R groups are found to induce the formation of bis substituted monomers while bulky alkoxycarbonyl ligands afford non-bridged dimers. Acyls and bulky carbamoyls give rise to dimers bearing bridging acyls or carbamoyls. The mechanisms of formation of these different complexes and the possible thermal interconversions of these compounds are investigated.