Novel enantiomorphic Pb-coordination polymers dictated by the corresponding chiral ligands, [Pb((R,R)-TBA)(H2O)]•1.7H2O and [Pb((S,S)-TBA)(H2O)]•1.7H2O [TBA=1,3,5-triazin-2(1H)-one-4,6-bis(alanyl)]

초록

New enantiomorphic Pb-based metal-organic coordination polymers, i.e., [Pb((R,R)-TBA)(H2O)]center dot 1.7H(2)O (R1) and [Pb((S,S)-TBA)(H2O)]center dot 1.7H(2)O (S1) (TBA = 1,3,5-triazin-2(1H)-one-4,6-bis(alanyl)), have been successfully synthesized through solvothermal reactions with the aid of carefully designed corresponding chiral ligands. Compounds R1 and S1 crystallizing in the chiral space group, P2(1)2(1)2(1), reveal infinite unidimensional (1D) chain structures consisting of highly distortive PbO7 polyhedra with lone pairs. Owing to the multiple hydrogen bonding interactions with adjacent TBA ligands, the overall structures of R1 and S1 reveal three-dimensional frameworks containing 1D channels along the a-axis. The title compounds exhibit high water and chemical stabilities in a wide pH range. The reported complexes not only reveal second-harmonic generation signals originating from the macroscopic noncentrosymmetric structures, but also show a selective adsorption of anionic organic dyes via a host-guest hydrogen bonding interaction. A detailed adsorption study of the chiral Pb complexes towards a complete removal of organic dyes and the effect of pH and particle size on the adsorption are discussed.

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