Synthesis, Crystal Structure, and Photoluminescence of Coordination Polymers with Mixed Ligands and Diverse Topologies

This work presents systematic investigation on reactions of zinc(II) salts with a rigid tripodal ligand in the presence of different benzenedicarboxylic acids. Seven new coordination polymers [Zn(tib)(1,3-BDC)]center dot H2O (1), [Zn-2(tib)(1,3-BDC)(2)-(H2O)]center dot 2H(2)O (2), [Zn-2(tib)(1,2-BDC)Cl-2] (3), [Zn-4(tib)(2)(1,2-BDC)(4)]center dot 2H(2)O (4), [(Zn-2(tib)(2)(1,2-BDC)](NO3)(2) (5), [Zn-2(tib)(2)(1,2-BDC)]I-2 (6), and [Zn-3(tib)(2)(4-BPA)Cl-4]center dot 2H(2)O (7) [tib = 1,3,5-tris(1-imidazolyl)benzene, 1,3-BDC2- = 1,3-benzenedicarboxylate, 1,2-BDC2- = 1,2-benzenedicarboxylate, 4-BPA(2-) = 4-bromo-1,2-benzenedicarboxylate] were obtained, and they were characterized by single crystal X-ray diffraction, IR, thermogravimetric and elemental analyses. Complexes 1, 4, and 7 are two-dimensional (2D) networks containing infinite one-dimensional (1D) Zn(II)-tib chains linked together by auxiliary dicarboxylate ligands. Complexes 2 with 2-fold interpenetration and 3 are three-dimensional (3D) frameworks containing infinite 2D networks pillared by 1,2-BDC2- ligands, while 5 and 6 feature unusual 3D supramolecular architectures with 4.8(2) networks linked by 1,2-BDC2- ligands. The results showed that the dicarboxylate auxiliary ligands and the counteranions have a great influence on the structure of the complexes. The luminescence properties of 1-7 in the solid state were studied.