A.S. Kanmani

Bio: A.S. Kanmani is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Cyclohexene & Perchlorate. The author has an hindex of 2, co-authored 2 publications receiving 31 citations.

Selective oxidation of alkenes catalysed by ruthenium(II) complexes containing coordinated perchlorate

Abstract: Ruthenium(II) perchlorate complexes, [Ru(dppm)3(ClO4)]ClO4 1, [Ru(dppe)3(ClO4)]ClO4 2, and [Ru(dpae)3(ClO4)]ClO4 3, catalyse the selective homogeneous oxidation of alkenes with TBHP and H2O2 as oxidizing agents. Oxidation of cyclohexene with TBHP gave 2-cyclohexene-1-ol, 2-cyclohexenone and 1-(tert-butylperoxy)-2-cyclohexene. The homogeneous liquid phase oxidation of cyclohexene with TBHP shows appreciable solvent effect. Styrene on oxidation with TBHP gave benzaldehyde as the major product and styrene oxide as the minor product. Oxidation with H2O2 is radical-initiated and gives low conversion to products. TBHP and H2O2 are compared for their oxidizing ability and TBHP is more effective than H2O2 as an oxidizing agent. Linear and long chain alkenes are not efficiently oxidized. Cyclooctene and trans-stilbene are oxidized to the corresponding epoxides.

Catalytic oxidation of alkenes with ruthenium(II) perchlorate complexes

Abstract: Ruthenium(11) perchlorate complexes,.Ru(dppm)3(Cl04)]Cl04, 1, Ru(dppe)3(Cl04)]Cl04, 2, [Ru(dpae)3(Cl04)]Cl04, 3, catalyse the oxidation of cyclohexene in the presence of cumene hydroperoxide (CHP) under homogeneous liquid phase. The products of oxidation are 2-cyclohexen-I-ol and 2-cyclohexenone. Linear alkenes like 1-heptene and 1-octene are not efficiently oxidised under these conditions. Solvent influences the rate of oxidation considerably. N-methylmorpholine-N-oxide (NMO) and CHP are compared for their oxidising ability.

Ruthenium(II) complexes with 2,6-pyridyl-diimine ligands: synthesis, characterization and catalytic activity in epoxidation reactions

Abstract: Reaction of [RuCl 2 ( p -cymene)] 2 with the tridentate N - N ′- N ligands, 2,6-pyridyl-diimines, led to substitution of p -cymene. The resulting complexes, believed to be coordinatively unsaturated, exhibit efficient activity for the epoxidation of cyclohexene in the presence of iodosobenzene (PhIO): the complexes formed initially take up donor molecules such as acetonitrile to achieve hexacoordination. The molecular structure for one of these, (acetonitrile){2,6-bis[1-(4-methoxyphenylimino)ethyl]pyridine}dichlororuthenium(II), 2 , has been determined by X-ray diffraction. The immediate coordination sphere is a distorted octahedron with trans chloride atoms and a short Ru–N(py) (1.906 A) bond.

Preparation of highly ordered Fe-SBA-15 by physical-vapor-infiltration and their application to liquid phase selective oxidation of styrene

Abstract: A simple physical-vapor-infiltration (PVI) method was applied to prepare highly ordered Fe-containing mesoporous silica SBA-15. The loading amount of Fe in SBA-15 was very high (up to 24 mol%) and can be tuned by using different PVI time. The liquid phase selective oxidation of styrene with H 2 O 2 has been used to characterize their catalytic properties, the major product is benzaldehyde and the minor is styrene oxide. Independent of the Fe contents and the heat treatment temperature, the selectivity for benzaldehyde in the reaction at a mild temperature of 50 °C are all above 91%. At elevated temperature of 70 °C, the conversion rate of styrene increases beyond 36% and more significantly the selectivity for benzaldehyde can reach as high as 99%. Comparatively, another two different schemes (simple wet impregnation and incorporation using silane coupling agent) have been also applied to synthesize Fe-containing SBA-15 samples. Under the same condition, the styrene conversion on these two samples are both very low with minor product of phenylacetaldehyde and other styrene oxides.

Immobilization of chromium complexes in zeolite Y obtained from biosorbents: Synthesis, characterization and catalytic behaviour

Abstract: The goal of this study is the preparation of new heterogeneous catalytic materials to be used in oxidation reactions under mild conditions through the valuation of heavy metals in wastewater. The samples used in the immobilization of chromium complexes were prepared from a dichromate solution of 100 mgCr L � 1 . The zeolite CrNaY was prepared from a robust biosorption system consisting of a bacterial biofilm, Arthrobacter viscosus, supported on zeolite NaY. The biofilm performs the reduction of Cr(VI) to Cr(III) and this cation is retained in the zeolite by ion exchange. The immobilization of chromium complexes with heterocyclic ligands in the supercages of Y zeolite was performed by the in situ synthesis with three different ligands, 3-methoxy-6-chloropyridazine (A), 3-piperidino-6-chloropyridazine (B) and 1-(2pyridylazo)-2-naphthol (C). A sample loaded with Cr from a liquid solution with the same initial concentration was prepared as a reference through the traditional direct ion-exchange method and coordinated with ligand (A). The resulting catalysts were fully characterized by different techniques (FTIR, XRD, TGA, SEM, Raman, cyclic voltammetric studies and chemical analysis) and the results confirmed that the Cr complexes were immobilized in supercages of NaY. Catalytic studies were performed in liquid phase for the cyclohexene oxidation, at 40 8C, using tert-butyl hydroperoxide (TBHP) as the oxidizing agent. All the prepared catalysts exhibited catalytic activity for the oxidation reaction.