Photoredox reactivity of copper(II)-3,5-diisopropylsalicylate induced by ligand-to-metal charge transfer excitation of the copper-phenolate chromophore

Abstract

The electronic spectrum of Cu II(dps) 2 in CH 3CN with dps=3,5-diisopropylsalicylate shows a ligand field absorption at λ max=711 nm ( ε=140 M −1 cm −1), and a phenolate to Cu(II) ligand-to-metal charge transfer (LMCT) band at λ max=428 nm ( ε=950). LMCT excitation of Cu II(dps) 2 leads to the reduction of Cu(II) to Cu(I). Copper(II) disappears with φ=2.8×10 −3 at λ irr=436 nm.