Syntheses, crystal structures and properties of six coordination compounds with flexible dps ligand

Six new compounds: [M(dps)(dca)2]∞ (1, M = Cd; 2, M = Fe), [Cu(dps)(dca)2(CH3OH)2]∞ (3), [M(dps)2(SCN)2(H2O)2]∞ (4, M = Cd; 5, M = Fe), [Cu(dps)4(SCN)2]∞ (6), (dps = 4,4′-dipyridyl sulfide, dca = dicyanamide) were synthesized, characterized by FT-IR, element analysis and TG. Their structures were determined by single crystal X-ray diffraction. According to the structure analysis, compounds 1 and 2 are three-dimensional microporous frameworks constructed by Cu–dps–Cu and Cu–dca–Cu bridges; compound 3 shows a zigzag chain constructed by a Cu–dps–Cu bridge; compounds 4 and 5 show double-stranded chains constructed by a Cu–(dps)2–Cu bridge while thiocyanate anions act as terminal groups; compound 6 is a mononuclear compound. Moreover, compound 1 shows visible yellow luminescence under UV light irradiation and such phenomenon is mainly attributed to inter-ligand transitions.

Graphical abstractAs a flexible ligand, 4,4′-dipyridyl sulfide was reacted with Fe(II), Cd(II) and Cu(II) metal ions to afford six different coordination polymers. These complexes show diverse coordination modes and structural architectures.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Six novel compounds bearing dps ligand were reported. ► Those compounds exhibit diverse structural architectures due to center ion and counteranion. ► Compound 1 shows visible yellow luminescence.