Graphene Oxide Supported Oxovanadium (IV) Complex for Catalytic Peroxidative Epoxidation of Styrene: An Eye‐Catching Impact of Solvent. (22nd January 2020)

• Record Type: Journal Article
• Authors: Vithalani, Ravi; Patel, Dikin S.; Modi, Chetan K.; Sharma, Vaishali; Jha, Prafulla K.
• Is Part Of: Applied organometallic chemistry. Volume 34:Number 4(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-22
• Subjects: density functional theory -- GO supported heterogeneous catalyst -- peroxidative epoxidation of styrene -- solvent effect; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.5500
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : Graphene oxide (GO) supported transition metal complexes are apprised as sturdy and everlasting heterogeneous catalysts. GO surface was functionalized with 3‐triethoxysilylpropylamine (TSPA) and this amino functionalized GO (A‐ f ‐GO) nanocomposite with vanadyl Schiff base complex (VO‐ f ‐GO) was prepared and to give credence of its potentiality, it was chosen for the selective epoxidation of styrene using environmentally benign 30% H2 O2 to styrene oxide (SO). To evade the detrimental exposure of " inborn " water, a selective high boiling and potent hygroscopic solvent, ethylene glycol was chosen to make this transformation productively successful. With the assistance of theoretical studies, we have probed the effect of H2 O2 on to structural properties, binding mechanism and electronic properties of the catalyst and substrate. Adsorption energy (Ead ), energy band gap (Eg ) and HOMO‐LUMO were also calculated. Based on DFT calculations, resonance Raman and U V /Vis studies, we confirmed the formation of metal‐peroxo species and propose the plausible catalytic pathway. The influence of the diverse experimental parameters, like substrate to oxidant mole ratio, catalyst concentration, type of solvents, solvent amount, time, temperature and oxidant were tested. A clear relationship was found between different reaction parameters like solvent amount, oxidant, catalyst concentration and temperature etc. and product distribution. This heterogeneous catalyst yielded styrene oxide as nearly the sole product (selectivity = 98.7%) with a conversion value of 99.2% in the oxidation of styrene with hydrogen peroxide in ethylene glycol. Abstract : Graphene oxide‐based oxovanadium complex via ligand spacer as a heterogeneous catalyst was inspected over the selective peroxidative oxidation of styrene using 30% hydrogen peroxide as an environmentally benign oxidant and ethylene glycol as a potent hygroscopic solvent to avoid the adverse effect of "inborn" water. It shows an excellent 99.2% conversion of styrene with superior 98.7% styrene oxide selectivity.