Spectroscopic characterization of some metal complexes derived from 4-acetylpyridine nicotinoylhydrazone

Abstract

Coordination compounds of Mn II , Cu II , Fe III and Zn II ions with 4-acetylpyridine nicotinoylhydrazone (4-APNH) were synthesized and characterized by elemental analyses, molar conductivity, magnetic moments, i.r., u.v./vis., m.s., 1 H-n.m.r. and thermal analyses. I.r. spectra show that the ligand can act either in the enol form as monovalent bidentate or in the keto form as neutral bidentate depending on the metal salt used. Octahedral structures are proposed for Fe complex and square -planar for the Cu complex, while tetrahedral structures were suggested for Zn and Mn complexes on the basis of magnetic and spectral evidences. Semi-empirical calculations ZINDO/1 have been used to study the molecular geometry and the harmonic vibrational spectra with the purpose to assist the experimental assignment of the complexes.

Synthesis, Spectroscopic and Antimicrobial Studies on Copper(II), Cobalt(II), Nickel(II) and Manganese(II) Complexes of N-(2-Ethylphenyl) N'-Picolinoyl Hydrazine

“…The mass spectrum clearly suggests existence of ligand in the hydrazones form. The electronic spectra of Mn(II) complex show three bands in the regions 485-491, 529-530 and 710-721 nm, which may be assigned to 6 A 1g → 4 T 1g , 6 A 1g → 4 T 2g (G) and 6 A 1g → 4 T 1g (D) transitions respectively suggesting octahedral environment around the Mn(II) ion 14,15 . The magnetic moment 4.88 is an additional evidence for an octahedral structure.…”

Synthesis, Characterization and Cytotoxic Activity of N-(5-indanyl(methylene)anthranilic acid(5-indanyl methylene)-hydrazide and Its Pt(II) Complex

“…Two tautomeric forms are suggested for the ligand, the Keto (Fig.1 A) and the enol ( due to ν (NH). The strong bands at 1662 and 1621 cm -1 are attributed to ν (C=O) and ν (CONH), respectively [20,21,22,23,24]. These bands confirm the presence of the free ligand in the keto form.…”

Spectral, optical, and cytotoxicity studies on N‐(2‐isonicotinoylhydrazine‐carbonothioyl)benzamide and its metal complexes

“…The infrared spectra of H 3 L, as KBr disk, showed sharp band at 3211 cm −1 with shoulders at 3243 and 3147 cm −1 assigned to ν(N 2 H), ν(N 4 H), and ν(N 1 H) vibrations, respectively. Moreover, three sharp bands appear at 1691, 1672, and 1640 cm −1 attributed to ν(C=O) Ph , ν(C=O) Py , and ν(C=N) Py vibrations, respectively. The spectrum displayed four bands in the range 1550‐1450 cm −1 due to amide II, amide III, thioamide I, and thioamide II (Figure ).…”