Synthesis and characterization of four new unsymmetrical potentially pentadentate Schiff base ligands and related Zn(II) and Cd(II) complexes

Abstract

KEYWORDSTwo thioether diamines 2-(2-aminoethylthio)aniline and 2-(3-aminopropylthio)aniline have been prepared employing a new procedure by reaction of 2-aminothiophenol and N-(2-bromoethyl)phthalimide or N-(3-bromopropyl)phthalimide, respectively. Then two new potentially pentadentate (N2O2S) Schiff base ligands derived from direct condensation between two maintained diamines and 2-hydroxybenzaldehyde or 5-bromo-2-hydroxy benzaldehyde were synthesized. Also, Zn(II) and Cd(II) complexes of Schiff base ligands have been prepared. These compounds have been characterized by physico-chemical and spectroscopic methods.

Synthesis, characterization, biological activity, and corrosion inhibition in acid medium of unsymmetrical tetradentate N2O2 Schiff base complexes

“…Unsymmetrical Schiff base ligands with N, O, and S donors have been able to provide diverse possibilities in the structure and chemical properties, and these complexes are the most abundant and dominate the field. The presence of both hard and soft donor atoms in one ligand increases the coordination ability toward hard as well as soft metals . The interest in the coordination chemistry of tridentate unsymmetrical Schiff base ligands with NOS donating sites has increased because of their capability of forming stable complexes of four, five, and six coordination and because they show a broad range of antifungal, antibacterial, and anticancer properties .…”

“…The presence of both hard and soft donor atoms in one ligand increases the coordination ability toward hard as well as soft metals. [8][9][10][11] The interest in the coordination chemistry of tridentate unsymmetrical Schiff base ligands with NOS donating sites has increased because of their capability of forming stable complexes of four, five, and six coordination [12,13] and because they show a broad range of antifungal, [14] antibacterial, [15] and anticancer properties. [16] Tridentate NOS donor unsymmetrical Schiff base ligands have been able to form 1:1 and/or 1:2 complexes.…”

Synthesis and Characterization of a New Unsymmetrical Potentially Pentadentate Schiff Base Ligand and Related Complexes with Manganese(II), Nickel(II), Copper(II), Zinc(II) and Cadmium(II)

“…The mixture was refluxed for 8 h and then filtered hot. 9 The filtrate was reduced to dryness by rotary evaporation. The resulting product was dissolved in ethanol (40 mL) and thiophene-2-carbaldehyde (5.6 g, 50 mmol) was added.…”

“…8 Most of these unsymmetrical ligands and related complexes are Schiff bases obtained by the condensation of different types of amines with various ketones and aldehydes, and many of these in turn are multidentate ligands. 5,[9][10][11][12][13] Unsymmetrical linear pentadentate Schiff base ligands that have N 3 S 2 donors or have thiophene and pyridine groups in their structure are very rare.…”

Synthesis and Characterization of Metal Complexes of a New Unsymmetrical Tridentate NNS Schiff Base Ligand: X‐ray Crystal Structure Determination of Nickel(II) Complex

“…The synthesis of these complexes is an important area of study with implications in bioinorganic chemistry, catalysis, and medical chemistry . Also, unsymmetrical Schiff base ligands with N and S donors have been able to provide diverse possibilities in structure and chemical properties, and these complexes are the most abundant in and dominate the field …”