N-(salicylidene)nitrosophenylglycine Schiff base as NOOO-donor towards transition metal ions

Abstract

A new tetradentate NOOO-donor ligand, N-(salicylidene)nitrosophenylglycine (H 2 snpg) has been designed, synthesized and structurally characterized. Copper(II), nickel(II), cobalt(II), manganese(II) and zinc(II) complexes of H 2 snpg have been prepared for the first time. The authenticities of the ligand and its metal complexes have been established on the basis of elemental analyses, molar conductance measurements, magnetic properties, spectral (i.r., 1 H-n.m.r., u.v.-vis. and mass) studies. The i.r. spectral studies of all the complexes exhibit a similar feature about the ligating nature of the ligand to the metal ions and revealed that the ligand has coordinated through the carbonyl oxygen, azomethine nitrogen, nitroso oxygen and deprotonated hydroxyl oxygen. The molar conductance data suggest them to be non-electrolytes. The antimicrobial activity of all the compounds was studied against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger and Candida albicans. All the complexes have shown a moderate to high fungal activity compared to the ligand.

Synthesis and characterization of transition metal complexes of N′-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)methylene]thiophene-2-carbohydrazide

“…This finding indicates that the two complexes are tetragonally distorted and the states are connected with spin orbit coupling. This situation leads to short relaxation times, where absorption is difficult to observe [42,44,45]. The ESR spectrum of the solid iron(III) complex [FeLCl 2 (H 2 O)] Á 2H 2 O at room temperature showed three bands at 1.9, 3.2, and 5.8.…”

Copper(II) complexes of coumarin-derived Schiff bases and their anti-Candida activity

“…In more recent years there have been numerous reports highlighting the significant biological activity of Cu(II) Schiff base complexes [40][41][42][43][44][45][46]. Patil et al detailed the preparation of Co(II), Ni(II) and Cu(II) complexes with 1,2,4-triazole-derived coumarin Schiff bases and assessed their biological activity [47].…”

Synthesis, spectral characterization, electrochemistry and catalytic activities of Cu(II) complexes of bifunctional tridentate Schiff bases containing ONO donors

“…The behaviour of the > C N bond is strongly dependent on the structure of the amine moiety, which in turn controls the efficiency of the conjugation and may incorporate structural elements able to modulate the steric crowding around the coordination. [1] This class of ligands is flexible in terms of both size and charge. [2] Schiff base complexes of transition metals [3] having O and N donor atoms have shown an exponential increase as inorganic catalysts for various organic transformations.…”