The complexes [M (tptpy) 2](ClO4) 2 (M= Zn (II)(1), Cd (II)(2), and Cu (II)(3)); tptpy= 4′-[1, 1′: 4′, 1′′] terphenyl-4′′-yl-[2, 2′: 6′, 2′′] terpyridine= 4′-terphenylterpyridine) have been synthesized, structurally characterized by X-ray crystallography and subjected to preliminary luminescence studies. In the crystalline state, all the metal ions have an N6 coordination sphere of distorted octahedral geometry and the structures of the Zn (II) and ...