Synthesis of Zn compounds derived from 1H-benzimidazole-2-ylmethanamine

The influence of the pH on the synthesis of Zn(II) complexes derived from 1H-benzimidazol-2- ylmethanamine (HL) has been investigated with X-ray crystallography, FAB mass spectrometry, NMR, infrared and Raman spectroscopy. The crystal structures of (1H-benzimidazol-2- ylmethanamine)tetrachlorozincate(2-) dihydrogen [H3LZnCl4] (2), (1H-benzimidazol-2- ylmethanamine-?n 3 )trichlorozincate(1-) hydrogen hydrate [H2LZnCl3]H2O (3), (1Hbenzimidazol-2-ylmethanamine-? 2 N 2 ,N 3 )dichlorozinc(II) [HLZnCl2] (4) and Bis[1Hbenzimidazol-2-ylmethanamine-k 2 N 2 ,N 3 ]chlorozinc(II) chloride hydrate [(HL)2ZnCl]ClH2O (5) are reported. Compounds 2-4 exhibit a distorted tetrahedral environment around the metal center. Complex 5 has distorted trigonal bipyramidal geometry. The crystalline structures of 2-5 show the presence of strong intermolecular hydrogen bond interactions that produces graph sets with pseudo-macrocyclic network. The NMR studies show the dynamic behavior of compounds 3-5 due to break-formation phenomena of N?Zn bonds.