Tris(2-pyridyl)phosphine oxide reacts with CuSCN to form a variety of luminescent complexes, depending
on the specified metal-to-ligand ratio and the solvent used, viz. mononuclear [Cu(N,N',N''-Py3P=O)(NCS)],
dinuclear (N,N'-Py3P=O)Cu(SCN,NCS)Cu[(N,N'-Py3P=O)], their co-crystal (2 : 1, correspondingly) and trinuclear {Cu(NCS)[SCNCu(N,N',N''-Py3P=O)]2}. In the solid state, these complexes feature red-orange emission upon UV photoexcitation. The reaction of tris(2-pyridyl)phosphine with CuSCN quantitatively produces an almost insoluble coordination polymer, [Cu(Py3P)NCS]n, which exhibits bright green emission. The synthesized compounds are the first members of the hitherto unknown family of Cu(I) thiocyanate complexes supported by tripodal ligands.