Cadmium(II) coordination polymers constructed from a bis-functionalized ligand 4′-(3-carboxyphenyl)-2,2′:6′,2″-terpyridine: Synthesis, structure and luminescence

Abstract

Five new cadmium(II) coordination polymers [Cd2(L)2Cl2]n·nH2O (1), [Cd(L)Cl(H2O)]n·n[Cd(HL)Cl2]·nH2O (2), [Cd3(L)(1,4-bdc)2.5]n·4nH2O (3), [Cd2(L)(HL)(1,3,5-btc)]n·2nH2O (4), [Cd2(L)2(SO4)]n·2nH2O (5) (HL=4′-(3-carboxyphenyl)-2,2′:6′,2″-terpyridine, H2(1,4-bdc)=benzene-1,4-dicarboxylic acid, H3(1,3,5-btc)=benzene-1,3,5-tricarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, and single crystal X-ray diffraction. Compounds 1 and 2 present a 1D chain structure, and further linked by the π–π interaction to form a 2D layer. Compound 3 features a new (3,3,9)-connected 3D network built up by [Cd3(COO)4] clusters with the point symbol of {3·42}{32·46·59·615·73·8}{43}. Compound 4 exhibits a 2D layer structure with binuclear eight-membered rings, which demonstrates a new 3-nodal (3,3,4)-connected topological network with the point symbol of {52·62·92}{52·6}4. Compound 5 displays an achiral 2D layer based on 1D left- and right-handed helical chains and contains dinuclear [Cd2(SO4)] clusters, which shows a 4-connected sql network with the point symbol of {44·62}. Additionally, the thermal stabilities and luminescent properties of 1–5 were investigated.