Study On Functional Coordination Complexes Based On V-shaped Tetracarboxylate Ligand

The design and construction of metal-organic coordination polymers is of current interest in the fields of supramolecular chemistry and crystal engineering. Major reasons for this interest stem from their intriguing variety of topologies and structural diversity,such as helixes and diamonded nets, and because of their potential applications as functional materials,such as heterogeneous catalysis, molecular recognition, magnetism, gas storage, ion exchange, nonlinear optics, and electrical conductivity. Although many coordination polymers with unusual structures have been constructed depending on the self-assembly, the exploration for preparing functional coordination polymers still remains a challenge. The prime importance in crystal engineering is how to obtain materials with prospective structures and function by choosing and designing suitable building blocks and using some specific assembly strategy. This is also one of the most challenging research domains nowadays. Therefore, in further designing coordination polymers possessing interesting structural motifs and properties, the elaboration of organic ligands, the choice of metal ions and the controlling of reaction conditions are of significant importance.In this paper, with the aim of preparing novel materials with beautiful architecture and excellent physical properties, we select V-shaped 3,3',4,4'-diphenylsulfonetetra carboxylic acid as building blocks to construct coordination polymers with selected transition metal ions guided by assembly principle of coordination polymer crystal engineering. We study on the coordination behavior (such as coordination abilities, coordination modes and the structures of complexes) of the ligand completely, and research the possible influence factors to the produces under different reaction condition. Seven coordination polymers have been synthesized under hydrothermal conditions and others and structurally characterized by Single-crystal X-ray diffractometer. They are listed as follows: [Ni₂(Hdstc)(phen)₂·5H₂O] (1), [Mn₂(Hdstc)(phen)₂·5H₂O] (2), [Co (H₂dstc)(trpy)·H₂O] (3), [Co₂(dstc)(phen)₂·4H₂O]·2H₂O (4), [Mn₂(dstc)(2,2'-bipy)₂·3H₂O]·H₂O (5), [Mn₂(dstc)(phen)₂·3H₂O]·H₂O (6), [Mn₂(dstc)(bpe)₂·2H₂O]·2H₂O (7). 1 and 2 are isostructural and show a binuclear structure; while 3 and 4 exhibit different topological 1D chain structures; 5 and 6 are similar 2D networks. By auxiliary exo-bidentate bipyridyl ligand of bpe, 7 exhibits 4-connected topology 3D frameworks. The elemental analysis, and magnetic analysis for the compounds are discussed.