Geometrically Distorted and Redox-Active Organometallic Iridium Complexes Containing Biphenyl-2,2'-diyl
摘要:
C-C bond cleavage of biphenylene by an Ir(I) complex via an oxidation addition generates the biph (=biphenyl-2,2'-diyl) ligand. The resulting compound is treated with PPh(3) to give [Ir(PPh(3))(2)(biph)Cl], having a 16 e five-coordinate structure lying between Y and T geometries, being closer to a Y, which is rationalized on theoretical grounds. The complex [Ir(PMe(3))(3)-(biph)Cl] can be oxidized quasi-reversibly to an Ir(TV) species. Oxidation with NOBF4 gives the unusual Ir(IV) boryl compound [Ir(PMe(3))(3)(biphBF)Cl](+), which has been isolated and structurally characterized. Extended Huckel (EHT) calculations suggest that the easy oxidation of the {Ir(biph)} system is associated with the presence of a high-lying Ir d(yz) orbital. The {Ir(biph)} fragment is remarkably stable; only Br-2 is able to cleave the Ir-C bonds.
Geometrically Distorted and Redox-Active Organometallic Iridium Complexes Containing Biphenyl-2,2'-diyl
摘要:
C-C bond cleavage of biphenylene by an Ir(I) complex via an oxidation addition generates the biph (=biphenyl-2,2'-diyl) ligand. The resulting compound is treated with PPh(3) to give [Ir(PPh(3))(2)(biph)Cl], having a 16 e five-coordinate structure lying between Y and T geometries, being closer to a Y, which is rationalized on theoretical grounds. The complex [Ir(PMe(3))(3)-(biph)Cl] can be oxidized quasi-reversibly to an Ir(TV) species. Oxidation with NOBF4 gives the unusual Ir(IV) boryl compound [Ir(PMe(3))(3)(biphBF)Cl](+), which has been isolated and structurally characterized. Extended Huckel (EHT) calculations suggest that the easy oxidation of the {Ir(biph)} system is associated with the presence of a high-lying Ir d(yz) orbital. The {Ir(biph)} fragment is remarkably stable; only Br-2 is able to cleave the Ir-C bonds.