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

Abstract

A new unsymmetrical tridentate NNS Schiff base ligand, 2-(2-nitrophenylthio)-N-((pyridine-2-yl) methylene)benzenamine (L), and its Mn(II), Ni(II), Cu(II), and Zn(II) complexes were synthesized. These compounds were characterized by different physicochemical and spectroscopic techniques. The molecular structure of [NiL 2 ](ClO 4 ) 2 was determined by single-crystal X-ray diffraction. In this complex, two ligands coordinate through azomethine-N, pyridine-N, and thioether-S, forming a mononuclear 6-coordinate distorted octahedral geometry about a nickel.

Oxotitanium(IV) complexes of some bis‐unsymmetric Schiff bases: Synthesis, structural elucidation and biomedical applications

“…For the present systems, the FT-IR spectra of the ligands and metal complexes provided information about their formation in respect to the presence and coordination of the ligands. [12] The bands observed for the present complexes in the range 1301-1330 cm −1 have been assigned to υC─O. A band at 1610-1620 cm −1 assigned to the υC═N stretching frequency in the spectra of free Schiff bases was shifted to a lower frequency ranging from 20 to 30 cm −1 in all complexes.…”

“…[2,13] Another band near 1621 cm −1 indicates the presence of υC═O group found for both ligands and complexes which was shifted to a lower frequency due to coordination of oxygen with central metal atom. [6,12] The some physical properties and FT-IR spectral bands of the prepared ligands and complexes are summarized in Table 1. The bands appearing at 1320-1365 cm −1 have been assigned to the υC─N mode.…”

“…[12,24] Generally for transition metal complexes, which are insoluble in aqueous medium, conductance data are obtained in non-aqueous solvents. Mainly data are used in obtaining information about the nature of complexes in solution.…”

“…[3,4] The study of metal complexes of Schiff bases is also increasing because of their anticancer, antitumor, antimicrobial, antifungal, herbicidal and antibiotic properties. [12] Fasina et al studied the synthesis, characterization and biological activity of unsymmetric N 2 O 2 Schiff bases obtained from the condensation of o-phenylenediamine with various salicylaldehydes. [12] Fasina et al studied the synthesis, characterization and biological activity of unsymmetric N 2 O 2 Schiff bases obtained from the condensation of o-phenylenediamine with various salicylaldehydes.…”

“…[5][6][7][8][9][10][11] An unsymmetric tridentate Schiff base ligand, 2-(2-nitrophenylthio)-N-((pyridine-2-yl) methylene)benzenamine, and its Mn(II), Ni(II), Cu(II) and Zn(II) complexes were synthesized and characterized using various physicochemical and spectroscopic techniques and crystal X-ray diffraction. [12] Fasina et al studied the synthesis, characterization and biological activity of unsymmetric N 2 O 2 Schiff bases obtained from the condensation of o-phenylenediamine with various salicylaldehydes. [13] A novel Schiff base, Z-3-((2-((E)-(2hydroxynaphthyl)methylene)amino)-5-nitrophenylimino) -1,3-dihydroindin-2-one, was synthesized from the condensation of 2-hydroxy-1-naphthaldehyde and isatin with 4-nitro-o-phenylenediamine.…”