Synthesis of a Novel Benzimidazole Moiety-Appended Schiff Base Derivative: Fluorescence and Chemosensor Study

Abstract

In this study, we synthesized a novel benzimidazole-based Schiff base; (E)-4,4'-methylenebis(2-((E)-(((1H-benzo[d]imidazol-2-yl)methyl)imino)methyl)phenol) (3) was synthesized bythe condensation of 5,5'-methylenebis(2-hydroxybenzaldehyde) (1) and (1H-benzo[d]imidazol-2-yl)methanamine.HCl salt (2). This Schiff base derivative was reported for the first time and fullycharacterized by common spectroscopic techniques. Absorption and fluorescence spectroscopy wererecorded to determine the sensing ability of 3 towards metal ions. Selectivity to Zn2+ ion among studiedother cations was detected. The crystal structure of 2, C8H13Cl2N3O, has been determined by single crystalX-ray diffraction method. The crystal structure of the title compound, $C8H11N32+2(Cl-)H2O$, consists of anorganic 1H-benzoimidazol-3-ium (C8H11N32+) cation, an inorganic 2(Cl-) anion and one water (H2O)molecule. In the cation of studied compound, C8H11N32+, the benzimidazole ring is almost planar with amaximum deviation of -0.012 (3) Å. The molecule crystallized in the monoclinic structure and the spacegroup P21/c. The crystalline stacking structure is stabilized by intramolecular N–H···Cl, N–H···O, theintermolecular N–H···Cl hydrogen bond interactions connection the molecules into a two dimensionalnetwork and between anions and the water molecules. π-π interaction between benzimidazole rings[centroid–centroid lengths = 3.4642 (2) Å, 3.5309 (2) Å and 3.5527 (2) Å] may further stabilize thestructure.