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Abstract
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Methyl hydrazinocarboxylate, also known as methyl carbazate, is an important intermediate in many fields like coordination chemistry, analytical chemistry, synthetic organic chemistry and biological studies [1]. This compound has been widely used in the production of medicines, pesticides, fine chemical petroleum derivatives [2] and is one of the intermediates for preparing energetic materials [3]. The terminal N atom of the hydrazine group and the O atom from the carbonyl group provide lone pair electrons which make methyl carbazate a good chelating ligand [4]. From a view point of coordination chemistry methyl hydrazinocarboxylate is N,O-chelating ligand which has good potential to form several hydrogen bonding interactions. In this work, we report synthesis, characterization, structure and catalytic activity of two oxovanadium(V) complexes obtained from methyl hydrazinocarboxylate based ligands. In this research, two Schiff base ligands were synthesized from the reaction of methyl hydrazinocarboxylate with 2-hydroxybenzaldehyde or 2-hydroxy-3-methoxybenzaldehyde. These ligands were characterized by elemental analyses and spectroscopic (NMR, IR, UV-Vis) methods. Oxovanadium (V) complexes were synthesized by the reaction of bis (acetylacetonato) oxovanadium(IV) with mentioned ligands in methanol solvent. The obtained complexes were characterized by elemental analyses and spectroscopic methods. These complexes were used as catalyst in the oxidation of olefins by H2O2 as an oxidant. The effect of some important parameters like temperature, solvent and molar ratios of reagents in catalytic reaction was studied. The results of catalytic reactions indicated that these complexes are highly active catalysts in the clean epoxidation of olefins by aqueous hydrogen peroxide.
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