Second-Harmonic Generation and Photoluminescence Properties of Sn(II)- and Bi(III)-Based Lone Pair Cation-Pyridine Dicarboxylate Coordination Compounds.

Lone pair cation-based novel coordination compounds Sn[(pdc)(HO)] () and (Hbpy)[Bi(pdc)(Hpdc)]·5HO () (pdc = pyridine-2,6-dicarboxylate; bpy = 4,4'-bipyridine) were synthesized through mild hydrothermal reactions. While crystallizing in the polar space group, 2, exhibits a helical chain structure consisting of SnON distorted seesaws, 2,6-pdc linkers, and water molecules, crystallizing in the centrosymmetric (CS) space group, 1̅, reveals a pseudo-3D network composed of BiON polyhedra, 2,6-pdc ligands, Hbpy cations, and isolated HO molecules. The lone cations Sn and Bi in the title compounds are in a highly deformed polyhedral environment.