Synthesis, physico-chemical and antimicrobial screening studies of some transition metal complexes with O:O donor ligands

Abstract

The solid complexes of Mn II , Fe III , Co II , Ni II and Cu II with 3-(3-furan-2yl-acryloyl)-6-methyl-pyran-2,4-dione(L 1 ) and 3-(3-thiophene-2yl-acryloyl)-6-methyl-pyran-2,4-dione (L 2 ) have been synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic, i.r., P-n.m.r., u.v.-vis, X-ray diffraction and antimicrobial study. From the analytical and spectral data, the stoichiometry of the complexes has been found to be 1:2 (metal:ligand). I.r. spectral data suggest that the ligand behaves as a dibasic bidentate ligand with O:O donor sequence towards metal ions. The physico-chemical data suggests distorted octahedral geometry for Cu II complexes and octahedral geometry for all other complexes. The X-ray diffraction suggests an Orthorhombic crystal system for the Cu II complex and Monoclinic crystal system for Co II and Ni II complexes of ligand L 1 . The ligands and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli, and the fungicidal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum.

Synthesis, molecular structure analyses and DFT studies on new asymmetrical azines based Schiff bases

“…However, the absorption bands appearing at 1183 and 1175 cm -1 are assigned to the υ (N-N) [58,59] stretching for three compounds. The bands due to carbonyl υ (C=O) were found at 1674 cm -1 for II and III [60].…”

Synthesis, characterization of metal complexes of dehydroacetic-1,8-naphthaleimine. Study their effect on the larval mortality of Parasarcophaga aegyptiaca salem

“…It appeared as an attractive ligand for complexation and had been shown to possess modest antibacterial and antifungal properties [2,3]. Its transition metal complexes were also reported in the literature [4][5][6]. The current ligand differs from the former ligand in its structure and having two arms of the corresponding imine of the dehydroacetic acid, hence our approach is to maximize the reactivity.…”

Synthesis, spectral, thermal and biological studies of transition metal complexes of 4-hydroxy-3-[3-(4-hydroxyphenyl)-acryloyl]-6-methyl-pyran-2-one

“…30 The complex did not remain stable at higher temperatures and exhibited a slow second step decomposition in the temperature range 360-950 °C with a mass loss of 42 % (calcd. The TG curve of the Mn(II) complex showed a rapid first step decomposition between 240-350 °C with 48 % mass loss (calcd.…”

“…This has stimulated enormous interest in the synthesis of transition metal complexes with oxygen and nitrogen donor groups, due to the wide range of pharmacological activities of such compounds. [16][17][18][19] The aim of this work was to: i) synthesize and characterize the solid complexes of a ligand containing a carbonyl group directly linked to the α,β-unsaturated system derived from 3-acetyl-6-methyl-2H-pyran-2,4(3H)-dione (dehydroacetic acid) and 4-hydroxybenzaldehyde with Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) and ii) to investigate their antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), and their fungicidal activity towards Aspergillus flavus, Curvularia lunata and Penicillium notatum fungi. Chalcones are important compounds because of their contribution to human health and their multiple biological effects.…”