Synthesis, Crystal Structure and Antimicrobial Activity of a Linear Trinuclear Nickel(II) Complex with Schiff Base Ligand

Cui-Lin Zhang,Xiao-Yang Qiu,Shu-Juan Liu

doi:10.17344/acsi.2019.5019

Abstract

A new linear trinuclear Schiff base nickel(II) complex, [NiNiL(α2-α1:α1-OAc)(OH2)2]·H2O, where L is the dianionic form of N,N'-bis(5-chloro-2-hydroxybenzylidene)-1,3-propanediamine (H2L), was synthesized and characterized by elemental analyses, IR spectroscopy, and X-ray single-crystal determination. There are three bridges across the Ni-Ni atom pairs, involving two phenolate O atoms of a Schiff base ligand, and an O-C-O moiety of a α2-α1:α1-OAc group. The Ni atoms have octahedral coordination. The acetate bridges linking the central and terminal nickel atoms are mutually trans. The adjacent NiαααNi distances are 3.047(1) α. The complex was evaluated for its antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and antifungal (Candida albicans and Aspergillus niger) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method.

Highlights

Schiff bases are biological active compounds bearing the –N=CH– functional groups, which can be prepared by the condensation reactions of carbonyl-containing compounds with primary amines
The Schiff base ligand H2L was readily prepared by the condensation reaction of 5-chlorosalicylaldehyde with 1,3-propanediamine in 2:1 molar ratio
The present complex was prepared by the reaction of the Schiff base ligand with nickel acetate in a 2:3 molar ratio under ambient condition

Summary

Introduction

Schiff bases are biological active compounds bearing the –N=CH– functional groups, which can be prepared by the condensation reactions of carbonyl-containing compounds with primary amines. The compounds have been attracted considerable attention for their wide range of biological activities, such as antibacterial,[1] antifungal,[2] antitumor,[3] anti-inflammatory,[4] and cytotoxic.[5] Metal-organic complexes containing Schiff bases and bridging ligands are of current interest because of their interesting molecular topologies as well as the fact that they may be designed with specific functionalities.[6] Among the bridging groups, acetate anion is highly flexible, and can coordinate to metal atoms in a variety of coordination modes such as monodentate, chelating, bidentate bridging, monoatomic bridging, and chelating bridging (Scheme 1).[7] Bis-Schiff bases. Elemental analysis found: C, 43.77; H, 3.98; N, 5.27%, C38H40Cl4N4Ni3O11 calcd: C, 43.61; H, 3.85; N, 5.35%

1. General Methods and Materials

Results and Discussion

Conclusion