كليدواژه :
Organoclay , Schiff base chelates , Epoxidation , Pyllosilicate
چكيده فارسي :
Epoxides are intermediates to produce valuable chemicals Such as polymers, pharmaceuticals, food additives, dyestuffs and fragrance compounds which are commonly used in commercial scales [1]. Reduction, rearrangement or ring opening reactions of, epoxides with various nucleophiles convert, epoxides to diols, amino alcohols, allylic alcohols, ketones and polyether’s [2]. They are regularly manufactured by mild oxidation of alkenes which required the presence of metal based catalysts to coordinate and activate the oxidant for selective production of them [1, 3].
An amine-functionalized layered magnesium-phyllosilicate (AMP) was prepared using a direct alkaline co-polymerization method between magnesium chloride and 3-aminopropyltriethoxysilane. The surface of AMP was further reacted with aldehydes (salicylaldehyde) in order to form Schiff base chelating ligands with N-donor groups incorporated in the layer surface. After than the product was reacte with VO (acac) 2 and used them as Heterogeneous catalysts in epoxidation of some alkenes.
The optimal conditions for a yield of 95% include 20mg of catalyst, 2ml C2H4Cl2 as solvent and 0.4ml THBH as oxidant at 80 °c after 90 min.
The final products were thoroughly characterized by Fourier Transform Infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) along with Energy Dispersive X-ray (EDX) Spectroscopy, thermo gravimetric and differential thermal analysis (TG/DTA) and X-ray photoelectron spectroscopy (XPS).