Mononuclear gold(I) acetylide complexes with carbonyl moiety: Synthesis, characterization, and tunable emission energy

•A series of mononuclear gold(I) acetylide complexes bearing carbonyl group, 1–4, have been synthesized.•The emission origin of complexes 1–4 comes from the 3(ππ*) excited states of the acetylide ligands.•The emission energies of complexes 1–4 can be tuned by changing the substituents R on the acetylide ligands.