A new oxidovanadium(IV) complex containing an O, N-bidentate Schiff base ligand: Synthesis, characterization, crystal structure determination, thermal study and catalytic activity for an oxidative bromination reaction

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• 作者：Gholamhossein Grivani ; Vida Tahmasebi ; Aliakbar Dehno Khalaji
• 关键词：Oxidovanadium(IV) ; Schiff base ; Crystal structure ; Oxidative bromination ; V2O5 nanoparticle ; TG
• 刊名：Polyhedron
• 出版年：28 January, 2014
• 年：2014
• 卷：68
• 期：Complete
• 页码：144-150
• 全文大小：1035 K

文摘

A new oxidovanadium(IV) schiff base complex (1) containing an ethyl bromide pendant group was synthesized by the reaction of the related bidentate O, N-Schiff base ligand and VO(acac)₂ in a 2:1 ratio in methanol, under reflux conditions. The Schiff base ligand and its vanadyl Schiff base complex were characterized by ¹H NMR and FT-IR spectra, and CHN analysis. The crystal structure of 1 was also determined by single crystal X-ray analysis. The vanadium center in this structure has a distorted tetragonal pyramidal N₂O₃ coordination sphere. The Schiff base ligand HL acts as a bidentate ligand by coordinating via the nitrogen atom of the imine group and the oxygen atom of the phenolic group, thereby forming a six-membered chelating ring. There are some non-classical inter- and intra-molecular hydrogen bonds of the type C-H鈰疧 and C-H鈰疊r in 1. The catalytic activity of 1 was studied for the oxidative bromination of 2-nitrophenol as a model substrate. Different reaction parameters were studied in this reaction and the oxidative bromination of some organic compounds by a catalytic amount of 1 showed that it was an effective and selective catalyst under optimal conditions. Thermogravimeric analysis of 1 showed that it decomposed in two stages. In addition, complex 1 thermally decomposed in air at 660 掳C and the XRD pattern of the obtained solid showed the formation of V₂O₅ nanoparticles with an average size of 57 nm.