Study of the Coordination Modes of Hybrid NNCp Cyclopentadienyl/Scorpionate Ligands in Ir Compounds

A new coordination mode for the hybrid scorpionate/cyclopentadienyl ligand bpzcp, [bpzcp = 2,2-bis (3,5-dimethylpyrazol-1-yl)-1,1-diphenylethylcyclopentadienyl] is observed in iridium complexes. The reaction of the lithium precursor, [Li(bpzcp)(THF)], with a range of [IrCl(diene)](2) compounds leads to an unprecedented binding mode of the hybrid scorpionate/cyclopentadienyl ligand as eta(5)-Cp-coordinated and the formation of Ir(I) derivatives [Ir(eta Cp5--bpzcp)(eta(4)-cod)] (1), [Ir(eta(5)-Cp-bpzcp){eta(4)-CH2=C(Me)-C(Me)=CH2}] (2), [Ir(eta(5)-Cp-bpzcp)(eta(2)-coe)(2)] (3), and [Ir(eta(5)-Cp-bpzcp)(eta(2)-CH2=CH2)(2)] (4). The Ir(I) complex 4 reacts with CO or bromine to afford the compound [Ir(eta(5)-Cp-bpzcp)(CO)(2)] (5) and the 18e(-) Ir(III) complex [Ir(kappa-N-eta(5)-cp-bpzcpBr(2))Br-2] (6), respectively. Reaction of the iridium compounds (2-4) with CuI or [PdCl2(CH3CN)(2)] yields the heterobimetallic iridium-copper or iridium-palladium complexes [Ir(eta(5)-Cp-bpzcp) {eta(4)-CH2=C(Me)C(Me)=CH2} (mu-bPzcp){CuI(kappa(2)-NN-bpzcp)}] (7), [Ir(eta(5)-Cp-bpzcp) (eta(2)-coe)(2)} (mu-bpzcp){CuI(kappa(2)-NN-bpzcp)}] (8), [Ir(eta(5)-Cp-bpzcp) (eta(2)-CH2=CH2)(2)}(mu-bpzcp){CuI(kappa(2)-NN-bpzcp}] (9), [Ir(eta-CP-bPzcP)-(coe)(2)}(mu-bpzcp){PdCl2(kappa(2)-NN-bpzcp)}] (10), and [Ir(eta(5)-Cp-bpzcp)(eta(2)-CH2=CH2)(2)(mu-bPzcP){PdCl2(kappa(2)-NN-bpzcp)}] (11). All products were characterized by spectroscopic methods and the X-ray crystal structures of 1, 2, 3, 4, and 6 were also established.