Photoreactivity of (2,9-dimethyl-1,10-phenanthroline) copper(I) borohydride

Abstract

The complex (dmp)Cu I(BH 4) with dmp=2,9-dimethyl-1,10-phenanthroline displays a long-wavelength absorption at λ max =465 nm which is assigned to a BH 4 −→dmp ligand-to-ligand charge transfer (LLCT) transition. In the solid state the LLCT state is emissive (λ max =626 nm) . In non-coordinating solvents such as CH 2Cl 2,CHCl 3 or toluene the complex undergoes a photoredox decomposition leading to the generation of metallic copper. At λ irr =436 nm ( dmp) Cu I ( BH 4) disappears with φ=1.2×10 −3.