A series of trinuclear copper(I) acetylide complexes with carbonyl moiety, [Cu 3 (μ-dppm) 3 (μ 3 -η 1 -CCC(O)R) 2 ](ClO 4 ) (R = H (1), CH 3 (2), OCH 3 (3), NH 2 (4), NEt 2 (5)) (dppm = bis(diphenylphosphino)methane), have been synthesized and characterized. The crystal structures of [Cu 3 (μ-dppm) 3 (μ 3 -η 1 -CCC(O)CH 3 ) 2 ](ClO 4 ) (2) and [Cu 3 (μ-dppm) 3 (μ 3 -η 1 -CCC(O)NH 2 ) 2 ](ClO 4 ) (4) were determined by X-ray diffraction. The photophysical properties of complexes 1−5 have been studied. Complexes 1−5 show luminescence both in the solid state and in acetonitrile solution at 298 K, and their emission energies are in the order: 5 > 4 > 3 > 2 > 1. Density function theory (DFT) calculations at the hybrid Perdew, Burke, and Ernzerhof functional (PBE1PBE) level were performed on model complex 1 to elucidate the emission origin of complexes 1−5.