Synthesis, Structure And Properties Of The Coordination Polymers Based On Benzotriazole-5-Carboxylate Ligand

Recently, the rational design and synthesis of coordination polymer has received rather considerable attention, not only stemming from their potential applications in gas absorption, separation, catalytic, ion exchange, molecular recognition, NLO materials, magnetic materials and molecular recognition. but also from their interesting variety of topologies. In this paper, we select benzotriazole-5-carboxylic acid as organic ligand. The reason is as follows: benzotriazole-5-carboxylic acids combine the advantages of both carboxyl and aromatic heterocyclic components and are able to link various metal ions through many kinds of coordination fashions. In this paper, six compounds were separated on the basis of solvothermal technique and structurally characterized by elemental analyses, IR, XRPD, TG and single crystal X-ray diffractions, magnetic properties and gas adsorption isotherm measurement of partial compounds have also studied and discussed. We have hydrothermally synthesized six compounds with benzotriazole-5-carboxylic acids:In the first chapter, the recent results of the work in the field of coordination polymers were reviewed. The structural type, property and application of some significance of compounds are also presented and summarized.In the second chapter, five Mn(II), Co(II) and Zn(II) compounds Mn₅(btac)₄(μ₃-OH)₂(EtOH)₂·DMF·3EtOH·3H₂O(1), Mn₅(btac)₄(μ₃-OH)₂(EtOH)₂·(bpt)·2H₂O(2), [Zn₃(OH)₂(btca)₂]·2DMF·H₂O(3) and [Co₃(OH)₂(btca)₂]·2DMF(4) were synthesized through solvothermal reactions of benzotriazole-5-carboxylic acids. Compound 1 is a 3D neutral framework featuring 1D porous channels constructed by {Mn-OH-Mn}_n chains and btac linkers. Magnetic studies show that 1 is a three-dimensional 3D metamagnet containing one-dimensional 1D {Mn-OH-Mn}_n ferrimagnetic chains. High-pressure H2 adsorption measurement at 77K reveals that activated 1, can absorb 0.99wt% H2 at 0.5atm and reaches a maximum of 1.03wt% at 5.5atm. Compound 2 exhibited an interesting 3D porous metal-organic framework constructed by pentanuclear Mn(II) subunits and btac bridges. Compound 3 and 4 are isostructural. The Co(II) and Zn(II) ions are bridged byμ3-OH groups to form extended {Zn₃(OH)₂}_n and {Co₃(OH)₂}_n chain. The extended {Zn₃(OH)₂}_n and {Co₃(OH)₂}_n chains are linked by btca ligands in theμ5 mode to furnish the 3D porous metal-organic framework.In the third chapter, we reacted benzotriazole-5-carboxylic acids with Zn(II) ion, then employed phen and tatp an auxiliary ligand, which feature two compounds, namely {[Zn(btca)(tatp)]·0.25H₂O}_n (5) and [Zn(btca)(phen)]_n(6). Complex 5 is a 2D wavelike layers which are further conneced by hydrogen-bonding interaction to form a 3D supramolecular. Complex 6 exhibits a 2D wavelike layer structure. The btca ligand linking two adjacent Zn(II) centers to form a one-dimensional a zigzag chain. In the extended structure, such chains are future linked to each other by bridging N atoms of btca, giving rise to an extended wave-like layer structure.In the fifth chapter, we have summarized the structures and properties of the six coordination polymers.