Dedicated to Professor Rosalinda Contreras on the occasion of her 60th anniversary AbstractThe 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- (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.