Three New Zn(Ⅱ) Coordination Compounds Based on the in-situ Formed Tetrazolate Ligand: Syntheses,Crystal Structures and Luminescence Properties

Reactions of 2-(2-benzoimidazolyl)acetonitrile and Na N3 with Zn SO4 or Zn Cl2 in the presence of nicotinic acid in the mixture of Et OH/H2 O afforded a mononuclear compound [Zn(L1)2](1) and a 1-D polymer [Zn(L1)Cl]n(2), respectively(L1 = 5-[(benzoimidazolyl)methyl]-1H-tetrazolate). However, in the similar condition except that imidazole was added instead of nicotinic acid, the reaction afforded a 1-D compound [Zn(L1)2]n(3) featuring triply helical chains via the π-π stacking of ligands. They are characterized by elemental analysis and IR, and their structures have been determined by X-ray crystallography. Thermal stability of these compounds was measured by TGA and their luminescent properties were investigated at room temperature.