Hydrothermal Synthesis, Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH2]2+·[SbCl5]2-}2

A new supramolecular compound, {2-(2-pyridyl)benzimidazoleH2]2 ·SbCl5]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylic acid and SbCl3 in 1:1 HCl solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetric analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/c, with a = 16.0397(13), b = 14.3189(12), c = 15.6370(13) (A), β = 105.8980(10)°, V = 3454.0(5) (A)3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3, μ = 2.366 mm-1, S = 1.010, F(000) = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3 ion and five adjacent chloride ions. Every four coordination anions of SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb…C1.Moreover,the compund adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-(2-pyridy1)benzimidazole divalent cations.The title compound also shows godd fluorescent behaviors.