Organoiron compounds derived from the indium ‘carbene analogues’, [In{N(Ar)C(Me)}2CH] (Ar = dipp = 2,6-iPr2C6H3; = Mes = 2,4,6-Me3C6H2)

Abstract

Oxidative insertion of the In(I) ‘carbene analogues’, [In{N(Dipp)C(Me)}₂CH] (Ar = Dipp = 2,6-ⁱPr₂C₆H₃; Ar = Mes = 2,4,6-Me₃C₆H₂) into the Fe–I bond of [CpFe(CO)₂I] occurred cleanly and under mild conditions to yield the In(III) compounds [CH{(CH₃)₂CN-2,6-ⁱPr₂C₆H₃}₂In(I)FeCp(CO)₂] and [CH{(CH₃)₂CN-2,4,6-Me₃C₆H₃}₂In(I)FeCp(CO)₂], which have been fully characterised in solution and the solid state. Attempts to abstract the iodide anion from [CH{(CH₃)₂CN-2,6-ⁱPr₂C₆H₃}₂In(I)FeCp(CO)₂] to form cationic species containing a coordinated indium diyl were unsuccessful and resulted in a complex mixture of products from which two ionic species were isolated. Neither cation was found to contain indium by X-ray crystallographic analysis. These observations were indicative of ill-defined decomposition pathways as have been noted by previous workers. A further attempt to form a cationic iron species containing a coordinated [In{N(Dipp)C(Me)}₂CH] fragment resulted in oxidation of the iron centre from Fe(II) to Fe(III), with deposition of indium metal, and the isolation of a cationic Fe(III) β-diketiminate complex.