Series of Coordination Polymers Based on Different Carboxylates and a Tri(4-imidazolylphenyl)amine Ligand: Entangled Structures and Photoluminescence

Seven new coordination polymers, namely, [Cd(Tipa)(L1)2]·H2O (1), [Cd(Tipa)(L2)]·H2O (2), [Cd(Tipa)(L2)]·CH3OH·H2O (3), Cd(Tipa)(L3)(H2O) (4), [Mn(Tipa)(L2)]·H2O (5), [Ni2(Tipa)2(L4)(H2O)2]2·Cl4·4H2O (6), and [Ni2(Tipa)2(L5)(H2O)4]·(H4L5)·0.5H2O (7), where HL1 = benzoic acid, H2L2 = 5-NH2-1,3-benzenedicarboxylic acid, H2L3 = 2-(4-carboxybenzylamino)benzoic acid, H2L4 = 1,4-benzenedicarboxylic acid, H4L5 = 1,2,4,5-benzenetetracarboxylic acid, and Tipa = tri(4-imidazolylphenyl)amine, have been synthesized by varying the carboxylate anions and metal centers under hydrothermal conditions. Compound 1 shows a one-dimensional (1D) chain. Compounds 2 and 5 are isostructural and display (3,5)-connected (42·6)(42·67·8) topology. In the two compounds, the identical 2D networks entangle in highly rare parallel fashions to give fascinating 2D → 3D frameworks with polycatenation and polyrotaxane characters. Compound 3 displays a 2-fold interpenetrating 3D framework with (3,5)-connected (63)(65·85) topology. The structure of 4 is a 4-fold interpenetrating 3D (10,3)-b framework. 6 is an uncommon 4-fold interpenetrating 3D framework with (3,4)-connected (4·82)(4·85) topology. 7 exhibits an unprecedented 2D → 2D polyrotaxane layer with (3,4)-connected (42·6)(42·63·8) topology. The IR spectra, elemental analyses, and luminescent properties for the compounds were also investigated.