161660-68-0Relevant academic research and scientific papers
Geometrically distorted and redox-active organometallic iridium complexes containing biphenyl-2,2′-diyl
Lu, Zheng,Jun, Chul-Ho,De Gala, Susan R.,Sigalas, Michael P.,Eisenstein, Odile,Crabtree, Robert H.
, p. 1168 - 1175 (1995)
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 PPh3 to give [Ir(PPh3)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(PMe3)3-(biph)Cl] can be oxidized quasi-reversibly to an Ir(IV) species. Oxidation with NOBF4 gives the unusual Ir(IV) boryl compound [Ir(PMe3)3(biphBF)Cl]+, which has been isolated and structurally characterized. Extended Hückel (EHT) calculations suggest that the easy oxidation of the {Ir(biph)} system is associated with the presence of a high-lying Ir dyz orbital. The {Ir(biph)} fragment is remarkably stable; only Br2 is able to cleave the Ir-C bonds.
