Syntheses, structures and physical properties of two zinc(II) coordination polymers with 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene and 1,3,5-benzenetricarboxylate

Two novel coordination polymers, formulated as Zn2(titmb)(BTC)Cl (1) and Zn3(titmb)(BTC)2(H2O) (2), have been prepared by reactions of 1,3,5-tris(1-imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (titmb) and 1,3,5-benzene-tricarboxylic acid (H3BTC) with corresponding Zn(II) salts, respectively. Complex 1 has an interesting three-dimensional (3D) (3,6)-connected framework by self-penetration of two sets of (10,3)-a nets, while complex 2 exhibits an unprecedented 3D 5-nodal (3,6)-connected network with a Schäfli symbol of (4.102)(4.6.8)(42.64.88.10)(6.102)(6.82). The results revealed that the coordinated ligands play subtle and important roles in determining the structure of the complexes. Luminescent properties of two complexes and ferroelectric properties of 2 are discussed in detail.