Ultraviolet light-emitting CdII complexes: synthesis and property studies

Abstract

Four ultraviolet light-emitting CdII complexes, [CdL1(H2O)]n (1), [CdL1(bpy)(H2O)2]n (2), [CdL2(H2O)]n (3), and [CdL2(bpy)(H2O)2]n (4), where L1 = 3,3′-(4-phenyl-4H-1,2,4-triazole-3,5-diyl)dibenzoate, L2 = 3,3′-(4-(4-fluorophenyl)-4H-1,2,4triazole-3,5-diyl)dibenzoate, and bpy = 2,2′-bipyridine, were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, powder scattering spectra, and infrared spectra. 1–4 possess excellent thermal stability with decomposition temperature of ca. 340 °C. Their powder samples mainly give luminescent spectra at 350, 339, 351, and 339 nm, respectively, which should be attributed to the ligand-centered π* → π transfer transitions. Additionally, 1–4 have weak emission bands at 400–500 nm, which are tentatively attributed to the triplet ligand to ligand charge transfer transitions.