Schiff Base Derivatives in Zinc(II) and Cadmium(II) Complexation with the closo-Dodecaborate Anion

Abstract

A series of Schiff base derivatives, namely N-(4-methoxyphenyl)-1-(1-methylbenzimidazol-2-yl)methanimine (L1), 4-methoxy-N-[(1-methylbenzimidazol-2-yl)methyl]aniline (L2), and 2-[(E)-(1-propylbenzimidazol-2-yl)iminomethyl]phenol (L3), were synthesized. These compounds feature different linker groups, including –CH=N–, –CH2–NH–, and –N=CH–, respectively. During the process of zinc(II) and cadmium(II) complexation in the presence of the closo-dodecaborate [B12H12]2– anion, it was observed that ligand L3 underwent degradation. Consequently, two compounds were isolated, [Zn(Bz-NH2)2(CH3COO)2] and (HBz-NH2)2[B12H12]∙2CH3CN, both containing 1-propyl-2-aminobenzimidazole (Bz-NH2), which is a degraded fragment of the ligand. Several new zinc(II) and cadmium(II) coordination compounds were synthesized and characterized using various physicochemical analysis methods, including elemental analysis, IR, and UV spectroscopy. Additionally, X-ray diffraction and Hirshfeld surface analysis were performed for compounds [Cd(L2)2(CH3CN)(H2O)][B12H12], [Zn(Bz-NH2)2(CH3COO)2], and (HBz-NH2)2[B12H12]∙2CH3CN, as well as for ligand L2.