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

Abstract

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)]·H2O (1), [Zn2(tib)(1,3-BDC)2(H2O)]·2H2O (2), [Zn2(tib)(1,2-BDC)Cl2] (3), [Zn4(tib)2(1,2-BDC)4]·2H2O (4), [Zn2(tib)2(1,2-BDC)](NO3)2 (5), [Zn2(tib)2(1,2-BDC)]I2 (6), and [Zn3(tib)2(4-BPA)Cl4]·2H2O (7) [tib = 1,3,5-tris(1-imidazolyl)benzene, 1,3-BDC2− = 1,3-benzenedicarboxylate, 1,2-BDC2− = 1,2-benzenedicarboxylate, 4-BPA2− = 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 4.82 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.