Synthesis, characterization, and antibacterial activity of two zinc(II) complexes with Schiff bases from halogenated salicylaldehyde and amantadine

Abstract

By a condensation reaction of halogenated salicylaldehyde and amantadine, two new Schiff base ligands (HL1 and HL2) were synthesized, respectively. A followed mixture of the ligands and zinc(II) chloride in the presence of NaOH in an alcoholic medium brought out two novel complexes (ZnL21) (I) and (ZnL22 (II). These two complexes were characterized by the means of melting point, elemental analysis, IR, UV-Vis, 1H NMR, molar conductance and single-crystal X-ray diffraction analysis. X-ray diffraction analysis reveals that I crystallizes in monoclinic system, P21/c space group, a = 9.7812(5), b = 25.6198(12), c = 27.7381(18) A, β = 105.881(4), F(000) = 1416, R1 = 0.0731, wR2 = 0.1147; II crystallizes in orthorhombic system, Pbca space group, a = 11.1717(10), b = 20.5888(15), c = 27.7381(18) A, F(000) = 2976, R1 = 0.1341, wR2 = 0.1410. Both in I and II, the central zinc(II) atom is four-coordinated via two nitrogen atoms and two oxygen atoms from the corresponding Schiff base ligands, forming a distorted tetrahedral geometry.