Abstract: A mononuclear Cu(I) complex Cu(Hbmp)(BINAP)(ClO₄) (1) was synthesized by using starting materials involving Cu(CH₃CN)₄(ClO₄), 1, 1'-binaphthal-2, 2'-bisdiphenylphosphine (BINAP) and 2-(2-benzimidazolyl)-6-methylpyridine (Hbmp), and its structure and photophysical properties were investigated. As revealed by X-ray single-crystal diffraction, complex 1 exhibits a distorted tetrahedral geometry, where the Cu(I) ion coordinates with two N atoms of Hbmp and two P atoms of BINAP. Complex 1 has a weak low-energy broad absorption peaking at 340~450 nm, which is attributable to metal-to-ligand charge transfer (MLCT) transitions from Cu(I) to Hbmp. Complex 1 exhibits good photoluminescence properties in both solution and solid states.