M. Ravindranathan

Bio: M. Ravindranathan is an academic researcher. The author has contributed to research in topics: Catalysis & Ethylene. The author has an hindex of 13, co-authored 21 publications receiving 520 citations.

Catalytic oxidation by polymer-supported copper(II)-L-valine complexes

Abstract: Anchoring of an amino acid l -valine on cross-linked styrene–divinyl benzene was carried out in presence of a base. Reaction of cupric acetate with the polymeric ligand resulted in chelate formation with Cu(II) ion. The immobilized Cu(II) catalysts were characterized by elemental analyses, IR, UV-Vis, SEM, ESR and thermal analysis. Physico-chemical properties like surface area, apparent bulk density, pore volume, etc. have been determined. The supported Cu(II) complexes behave as versatile catalysts in the oxidation of various substrates such as benzyl alcohol, cyclohexanol and styrene in presence of t -butyl hydroperoxide as oxidant. The effect of reaction conditions on conversion and selectivity to products has been studied in detail. Preliminary kinetic experiments reveal that the Cu(II) complexes attached to polymer matrix can be recycled about four times with no major loss in activity.

Synthesis of lower olefins from methanol and subsequent conversion of ethylene to higher olefins via oligomerisation

Abstract: Catalytic conversion of methanol to hydrocarbons with the special emphasis on lower olefins (ethylene and propylene) was carried out using 12-heteropoly acids of W and Mo and P or Si and salts of 12-heteropoly acids. Amongst the metal salts of tungstophosphoric acid, cesium salt exhibited better activity and selectivity for the formation of ethylene and propylene. The maximum selectivity for C2–C4 olefins was 60.7%. Physico-chemical characterization of the catalysts has been made by FTIR spectroscopy, XRD, DTA, acidity by n-butyl amine titration and surface area. Acidity and surface area of the catalysts influence the activity and selectivity for the olefins. Oligomerization of ethylene to higher olefins was carried out in liquid phase using TiCl4–Et3Al2Cl3, TiCl4–Et2AlCl, TiCl4–Et3Al and Ti(OBu)4–Et3Al2Cl3 catalyst systems. Among the catalysts tried, TiCl4 and Ti(OBu)4 based catalysts showed better activity and selectivity to alpha olefins in the range C4–C14. For vapour phase, HZSM-5, nickel salt supported on SAPO-5 molecular sieve, ZSM-5 and γ-alumina, heteropoly acid supported on ZSM-5 and potassium salt of tungstophosphoric acid were tested. The maximum selectivity of C4–C6 olefins was 10.0 wt.% with HZSM-5 catalyst with a Si/Al ratio of 100. The selectivity for higher olefins was less than that obtained by liquid phase oligomerization of ethylene.

Hydration of 3-cyanopyridine to nicotinamide over MnO2 catalyst

Abstract: A simple and an eco-friendly process for the hydration of 3-cyanopyridine to nicotinamide in the presence of manganese dioxide catalyst has been described. The reaction is conducted at moderate temperature with the reaction times of 5–8 h using an aqueous solution of 3-cyanopyridine. The effect of various reaction parameters on the yield of nicotinamide was studied. In most instances, nearly quantitative yields of amides are obtained without any by-products. The IR and ESCA findings of the catalysts are correlated with the catalytic activity.

Catalysts for Production of Lower Olefins from Synthesis Gas: A Review

Abstract: C2 to C4 olefins are traditionally produced from steam cracking of naphtha. The necessity for alternative production routes for these major commodity chemicals via non-oil-based processes has driven research in past times during the oil crises. Currently, there is a renewed interest in producing lower olefins from alternative feedstocks such as coal, natural gas, or biomass, in view of high oil prices, environmental regulations, and strategies to gain independence from oil imports. This review describes the major routes for the production of lower olefins from synthesis gas with an emphasis on a direct or single step process, the so-called FTO or Fischer–Tropsch to olefins process. The different catalysts for FTO are outlined and compared, and the key issues and requirements for future developments are highlighted. Iron-based catalysts are prevailing for FTO, and reproducible lower olefin selectivities of 50 wt % of hydrocarbons produced have been realized at CO conversions higher than 70% for 60 to 1000 ...

Asymmetric Hydrovinylation Reaction

Abstract: Carbon-carbon bond-forming reactions are among the most important types of bond constructions in organic chemistry. Yet, the paucity of methods for the stereoselective incorporation of abundantly available carbon feedstocks such as CO, CO2, HCN, or simple olefins to prochiral substrates is one of the major limitations in this area.1 Ideally, from a manufacturing perspective, these reactions should proceed near ambient conditions under the influence of a catalyst capable of delivering very high turnover frequencies (number of moles of product/mole of catalyst/unit time) and high regioand stereoselectivities. In addition to the obvious economic benefits, such reactions would also enrich our repertoire of environmentally benign chemical processes. One potentially important class of such reactions is the [Ni+-H]-catalyzed oligomerization of olefins, which forms the basis of the dimersol technology (olefin dimerization, eq 1)2 and the shell higher olefin process (SHOP, eq 2).3 These two immensely successful commercial processes showcase the rewards of modern organometallic research, especially of the role of catalyst tuning to achieve highly selective carbon-carbon bond-forming reactions. The catalytic dimerization of propene proceeds with an astonishingly high rate of over 625 000 [propene][Ni]-1 [h]-1) for the precatalyst, [η-(allyl)Ni(PR3)] [RAlX3], making this one of the best homogeneously catalyzed reactions known.4 Applications of this chemistry for the synthesis of fine chemicals have been the subject of much research ever since its initial discovery. Dr. RajanBabu had his early education in India at Kerala University and the Indian Institute of Technology, Madras. He obtained a Ph.D. degree from the Ohio State University in 1978 working with Professor Harold Shechter, and was a postdoctoral fellow at Harvard University with the late Professor R. B. Woodward. He then joined the research staff of DuPont Central Research and Development, becoming a Research Fellow in 1993. He returned to Ohio State as a Professor of Chemistry in 1995. His primary research interests are in applications of organometallic reagents for stereoselective synthesis, asymmetric catalysis, free radical chemistry, and organic chemistry in aqueous medium. 2845 Chem. Rev. 2003, 103, 2845−2860