Assembly, Structures And Properties Of Coordination Polymers From Transition Metal With 3, 3', 4, 4'-Benzophenonetetracarboxylic Acid

The design and construction of metal-organic coordination polymers is of current interest in the fields of supramolecular chemistry and crystal engineering. A major reason for this interest is the promise of being able to generate new materials with intriguing architectures and potential applications in adsorption, gas storage, ion exchange, optical, biology activity, electronic and magnetic. How to obtain materials with prospective structures and function is the prime importance in crystal engineering. It demonstrates that using some specific assembly strategy and choosing suitable building blocks should be the key in constructing target materials. In this paper, with the aim of preparing novel materials with beautiful architecture and excellent physical properties, we select 3,3',4,4'-benzophenonetetracarboxylic acid (H₄bptc) as building blocks to construct coordination polymers under the intervention of various transition metal ions and auxiliary ligands guided by assembly principle of coordination polymer crystal engineering. The coordination behavior of the ligand completely and the role of solvent, metal ions, and different pH values to the produces has been discussed. Ten coordination polymers have been synthesized under slow diffusion method, slow evaporation and hydrothermal conditions and structurally characterized by Single-crystal X-ray diffractometer. They are listed as follows: {Cu(H₂bptc)(bpa)(μ₂-H₂O)}_n (1) {[Cu₃(Hbptc)₂(bpa)₃(H₂O)₈]·4H₂O}_n (2),{[Cu₂(bptc)(bpa)₂(H₂O)]·6.5H₂O}_n (3), {[Mn₂(bptc)(bpa)(μ₂-H₂O)(H₂O)₅]·H₂O}_n (4), {[Co₂(bptc)(bpe)(μ₂-H₂O)(H₂O)₅]·H₂O}_n (5), {[Mn₂(bptc)(bpe)(μ₂-H₂O)(H₂O)₅]·H₂O}_n (6), {[Cd₂(bptc)(Hdpa)₂(H₂O)₂]·2H₂O}_n (7) {[Ni(H₂bptc)(bpa)]H₂O}_n (8),{[Ag₃(Hbptc)(bpa)₂]·H₂0}_n (9) and [Ag₂(H₂bptc)(bpp)₂]_n (10). The structure of 1 displays a 3D open rhombic framework based on infinite metal-aqua chain. Compound 2 contains two different motifs: an cationic 1D chain of [Cu(bpa)(H₂O)₄]²⁺, and an anionic 2D network of [Cu₂(Hbptc)₂(bpa)₂(H₂O)₄]^2-. Compound 3, a microporous open-framework structure, presents an uncommon 3D, trinodal, 4-connected self-penetrating network. Compounds 4, 5 and 6 present the same arrangement and the free water molecules and coordinated water molecules form a cyclic centrosymmetric water hexamer which adopts a chair conformation by strong hydrogen-bonding interactions. 9 and 10 exhibit two kinds of ladder-like chains based on linear or T-shaped coordination environments of Ag(I). The IR spectra, elemental analysis, fluorescence spectra, and magnetic analysis for the compounds are discussed.