Structural and photophysical study on heterobimetallic complexes with d8-d10 interactions supported by carborane ligands: Theoretical analysis of the emissive behaviour

Article abstract of DOI:10.1002/chem.201303735

Heterobimetallic complexes of formula [M{(PPh₂) ₂C₂B₉H₁₀}(S₂C ₂B₁₀H₁₀)M'(PPh₃)] (M=Pd, Pt; M'=Au, Ag, Cu) and [Ni{(PPh₂)₂C₂B₉H ₁₀}(S₂C₂B₁₀H₁₀) Au(PPh₃)] were obtained from the reaction of [M{(PPh ₂)₂C₂B₁₀H₁₀}(S ₂C₂B₁₀H₁₀)] (M=Pd, Pt) with [M'(PPh₃)]⁺ (M'=Au, Ag, Cu) or by one-pot synthesis from [(SH)₂C₂B₁₀H₁₀], (PPh ₂)₂C₂B₁₀H₁₀, NiCl ₂×6 H₂O, and [Au(PPh₃)]⁺. They display d⁸-d¹⁰ intermetallic interactions and emit red light in the solid state at 77aK. Theoretical studies on [M{(PPh ₂)₂C₂B₉H₁₀}(S ₂C₂B₁₀H₁₀)Au(PPh₃)] (M=Pd, Pt, Ni) attribute the luminescence to ligand (thiolate, L)-to- P₂-M-S₂ (ML') charge-transfer (LML'CT) transitions for M=Pt and to metal (M)-to- P₂-M-S ₂ (ML') charge-transfer (MML′CT) transitions for M=Ni, Pd. A family of red emitters of formula [M{(PPh₂)₂C ₂B₉H₁₀}(S₂C₂B ₁₀H₁₀)M′(PPh₃)] (M=Pd, Pt; M′=Au, Ag, Cu) and [Ni{(PPh₂)₂C₂B₉H ₁₀}(S₂C₂B₁₀H₁₀) Au(PPh₃)] (see figure) was synthesised. Theoretical studies on [M{(PPh₂)₂C₂B₉H₁₀}(S ₂C₂B₁₀H₁₀)Au(PPh₃)] (M=Pd, Pt, Ni) attribute the luminescence to ligand (thiolate, L)-to- P₂-M-S₂ group (ML′) charge-transfer (LML′CT) transitions for M=Pt and to metal (M)-to- P₂-M-S₂ group (ML′) charge-transfer (MML′CT) transitions for M=Ni, Pd.