Hydrothermal synthesis and characterization of a new inorganic-organic hybrid compound AMP[ZnCl3] (AMP = 2-aminomethylpyridinium)

A novel organic-inorganic hybrid complex (2-NH₂CH₂C₅H₄N)ZnCl₃] has been hydrothermally synthesized and characterized by single crystal X-ray diffraction, thermal analysis and spectroscopic studies. The compound crystallizes in the triclinic system, space group , a = 7.5339(9), b = 7.589(2), c = 9.365(2) Å, α = 104.55(2)°, β = 97.22(1)°, γ = 87.88(2)°, V = 513.6(2), Z = 2. In the title compound the 2-aminomethylpyridine acts as a ligand covalently linked to Zn(II) cation to form a slightly distorted ZnCl₃N tetrahedral environment. Each Zn(C₆H₈N₂)Cl₃] unit is connected to one neighbor by a pair of hydrogen bonds between the apical chlorides and amine hydrogen atoms and to the other by a couple of π-π stacking interactions between the aromatic rings of the coordinated ligands forming a novel one-dimensional chain-like arrangement. The title complex is the first one that contains both coordinated and hydrogen bonded 2-aminomethylpyridine. Solid state ¹³C and ¹⁵N CP-MAS-NMR spectroscopies are in agreement with the X-ray structure. Ab initio calculations allow the attribution of carbons and nitrogen to the independent crystallographic sites. The Raman spectroscopy confirmed the presence of Zn-Cl and Zn-N bonds.