Synthesis, characterization of some transition metal(II) complexes of acetone p-amino acetophenone salicyloyl hydrazone and their anti microbial activity

Abstract

Complexes of the type [M(apash)Cl] and [M(Hapash)(H2O)SO4], where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); Hapash = acetone p-amino acetophenone salicyloyl hydrazone have been synthesized and characterized by elemental analyses, molar conductance, magnetic moments, electronic, ESR and IR spectra, thermal studies (TGA & DTA) and X-ray diffraction studies. The ligand coordinates through two >C=N and a deprotonated enolate group in all the chloro complexes, whereas through two >C=N- and a >C=O group in all the sulfato complexes. The electronic spectra suggest a square planar geometry for Co(II), Ni(II) and Cu(II) chloride complexes and an octahedral geometry for the sulfate complexes. ESR data show an isotropic symmetry for [Cu(apash)Cl] and [Cu(Hapash)(H2O)SO4] in solid state. However, ESR spectra of both Cu(II) complexes indicate the presence of unpaired electron in d x2-y2. The X-ray diffraction parameters for [Co(apash)Cl] and [Cu(Hapash)(H2O)SO4] complexes correspond to a tetragonal and an orthorhombic crystal lattices, respectively. Thermal studies of [Co(apash)Cl] complex shows a multi-step decomposition pattern. Most of the complexes show better antifungal activity than the standard miconazole against a number of pathogenic fungi. The antibacterial activity of these complexes has been evaluated against E. coli and Clostridium sp. which shows a moderate activity.

Synthesis, characterization and biocidal activity of some transition metal(II) complexes with isatin salicylaldehyde acyldihydrazones

“…The minor shifted position of ν(C-N) bands in the metal complexes as compared to the ligands also support the non-involvement of the two amide >C=O groups in bonding. However, the other ν(C=O) band due to indole >C=O group is considerably shifted to lower frequency by 19-23 cm −1 in all ismdh complexes, indicating the participation of indole >C=O group in bonding with metal 35 . The disappearance of ν(C=O) of indole ring in all the isodh complexes suggests the enolization of indole ring >C=O group during complexation ( Table 6).…”

Oxidatively Locked [Co2L3]6+ Cylinders Derived from Bis(bidentate) 2-Pyridyl-1,2,3-triazole “Click” Ligands: Synthesis, Stability, and Antimicrobial Studies

“…Unfortunately, these experiments also indicated that the cobalt(III) cylinders are not active antimicrobial agents, and no inhibition of bacterial growth was observed over a range of concentrations, from 1024 µg·mL −1 to 1 µg·mL −1 . Given the stability of the [Co 2 (L pytrz ) 3 ](OTf) 6 cylinders in aqueous and pseudo-biological conditions and the activity of other triply stranded helicates [13,18], related dinuclear ruthenium(II) compounds [53,57], and cobalt(III) complexes [41,42], the observed lack of activity was initially surprising. However, a series of elegant papers from Keene and co-workers have shown that the charge of the metal complex is an important factor for obtaining active antimicrobial complexes.…”

“…Cobalt is a physiologically active metal that has key functions in many biological processes [37]. Because of this, more and more cobalt complexes are being explored for an extensive range of biological applications such as anti-inflammatory [38], antiviral [39], anticancer [40], and antimicrobial [41,42] agents amongst others [43]. Consequently, development of cobalt complexes could significantly enhance the arsenal of pharmaceutical drugs available to combat a wide variety of harmful diseases and reduce antibiotic resistance.…”

Synthesis, Characterization and Antimicrobial Activities of Hydrazone Ligands Derived from 2-(phenylamino)acetohydrazide and Their Metal Complexes

“…The interest in the study of hydrazone compounds and their metal complexes has recently been grown up due to their biological activities as antifungal, 1-3 antibacterial [1][2][3][4] anticonvulsant, 5 anti-inflammatory, 3 anti-malarial, 6 analgesic, 7 anti-platelets, 8 anti-tuberculosis, 9 anticancer, 10 and a treatment of leprosy and mental disorder diseases.…”

“…The spectral and elemental analyses indicated that, the hydrazone ligands behave as neutral bidentate (H 2 L 1-2 ), monobasic bidentate (HL [1][2] ) or monobasic tridentate ligands toward the metal ions, bonded with the metal ion via protonated or deprotonated phenolic hydroxyl oxygen atom, azomethine nitrogen atom or ketonic carbonyl oxygen atom.…”