Structural, spectroscopic, luminescence sensing and TD–DFT theoretical studies of a CuP2N-type complex

Luminescent cuprous complexes are an important class of coordination compounds due to their relative abundance, low cost and ability to display excellent luminescence. The title heteroleptic cuprous complex, [2,2'-bis(diphenylphosphanyl)-1,1'-binaphthyl-κ2P,P'](2-phenylpyridine-κN)copper(I) hexafluoridophosphate, rac-[Cu(C44H32P2)(C11H9N)]PF6, conventionally abbreviated rac-[Cu(BINAP)(2-PhPy)]PF6 (I), where BINAP and 2-PhPy represent 2,2'-bis(diphenylphosphanyl)-1,1'-binaphthyl and 2-phenylpyridine, respectively, is described. In this complex, the asymmetric unit consists of a hexafluoridophosphate anion and a heteroleptic cuprous complex cation, in which the cuprous centre in a CuP2N coordination triangle is coordinated by two P atoms from the BINAP ligand and by one N atom from the 2-PhPy ligand. Time-dependent density functional theory (TD-DFT) calculations show that the UV-Vis absorption of I should be attributed to ligand-to-ligand charge transfer (LLCT) characteristic excited states. It was also found that the paper-based film of this complex exhibited obvious luminescence light-up sensing for pyridine.