서강대학교

초록/요약

Two types of novel enantiomorphic coordination polymers (CPs), i.e., [Pb(TBA)(H2O)] and [Ln2(TBA)2(HTBA)2(H2O)2]·7H2O (TBA = 1,3,5-triazin-2(1H)-one-4,6-bis(alanyl)), have been synthesized by solvothermal reactions. The crystal structures were determined through single crystal X-ray diffraction. Pb-MOCPs and Ln-MOCPs crystallized in the chiral space group, P212121 and C2, respectively. Whereas compounds Pb(R) and Pb(S) reveal unidimensional (1D) infinite chain composed of highly distortive PbO7 polyhedra, compounds Ln(R) and Ln(S) exhibit three-dimensional (3D) supramolecular frameworks consist of Ln(1)O8 and Ln(2)O10 polyhedra. Both of the title compounds exhibit solid-state circular dichroism (CD) signals with the aid of carefully designed corresponding chiral ligands. The reported complexes reveal second-harmonic generation (SHG) signals originating from the macroscopic NCS structures. Powder SHG measurements reveal that compounds Pb(S) and La(S) are type-1 phase matchable and exhibit SHG efficiencies of approximately 5 and 7 times that of α-SiO2, respectively. Especially, Pb complexes not only reveal high stability in various solvents in a wide range of acidity, 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.