Oxidative addition of a B—B bond by an iridium(I) complex: molecular structure of mer-cis-[Ir(PMe3)3Cl(Bcat)2]

Abstract
The B—B bond in B2Cat2 (cat = 1,2-O2C6H4) is readily activated by [Ir(PMe3)3Cl(COE)] (COE = η2-cyclooctene) (1) to yield a novel iridium(III) bis(boryl) complex mer-cis-[Ir(PMe3)3Cl(Bcat)2] (2). This complex is the first structurally characterized iridium bis(boryl) compound, and is the first metal bis(boryl) complex for which two distinct boryl group environments are observed in solution. Colourless crystals of 2 are monoclinic, P21/n, with unit cell dimensions a = 8.9638(7) Å, b = 32.197(2) Å, c = 9.3980(7) Å, and β = 90.385(2)°. Key words: iridium, boron, diboron, boryl, oxidative addition, X-ray structure, trimethylphosphine.