Synthesis and anti-fungicidal activity of some transition metal complexes with benzimidazole dithiocarbamate ligand

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 72; no. 3; pp. 610 - 615
• Main Authors: Mohamed, Gehad G., Ibrahim, Nasser A., Attia, Hanaa A.E.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.04.2009
• Subjects: Antifungal Agents - chemical synthesis; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Antifungal Agents - standards; Benzimidazole ligand; Benzimidazoles - chemistry; Dithiocarbamate; Electric Conductivity; Fungi - drug effects; Inhibitory Concentration 50; Kinetics; Ligands; Magnetic moment; Magnetics; Microbial Sensitivity Tests; Molecular Structure; Soil borne fungi and WP formulation; Spectrophotometry, Infrared; Spectroscopy, Fourier Transform Infrared; Thermal analysis; Thermodynamics; Thermogravimetry; Transition Elements - chemical synthesis; Transition Elements - chemistry; Transition Elements - pharmacology; Transition metal complexes; Transition metal complexes; Soil borne fungi and WP formulation; IR; Dithiocarbamate; Thermal analysis; Benzimidazole ligand; Magnetic moment
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2008.10.051

Seven transition metal complexes of benzimidazole ligand (HL) are reported and characterized based on elemental analyses, IR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TGA and DTA). From the obtained data, the complexes were proposed to have the general formulae [MX 2(HL)(H 2O)]· yH 2O, where M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cr(III); X = Cl −, SO 4 2− and y = 0–4. The molar conductance data revealed that all the metal chelates were non-electrolytes. From the magnetic and solid reflectance spectra, it was found that the geometrical structure of these complexes is octahedral. The thermal behaviour of these chelates showed that the hydrated complexes loss water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. Fungicidal activity of the prepared complexes and free ligand was evaluated against three soil borne fungi. Data obtained showed the higher biological activity of the prepared complexes than the parent Schiff base ligand. Formulation of the most potent complex was carried out in the form of 25% WP. Fungicidal activity of the new formulation was evaluated and compared with the standard fungicide Pencycuron (Monceren 25% WP). In most cases, the new formulation possessed higher fungicidal activity than the standard fungicide under the laboratory conditions.