A polymer-supported Pd(II) species has been prepared by means of an oxidative addition reaction between Pd(PPh3)4 and chloromethylated crosslinked polystyrene. This catalyst has been used for the hydrogenation of alkenes and alkynes under mild conditions. Quantitative studies on the rates of hydrogenation of selected substrates are reported with the mechanisms being discussed. Data on the high recycling efficiency of the catalyst as well as solvent effects on the reaction are presented. Comparisons of the catalyst with earlier reported Pd(II) species supported on polystyrene have been made. © 1985.

Venkatanarayana Mahadevan

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Hydrogenation of alkenes and alkynes catalyzed by polymer-bound palladium(II) complexes

Journal of Catalysis

A polymer-supported palladium-imidazole catalyst was used to catalyze the hydrogenation of various olefins under mild conditions. The rate of hydrogenation was studied. The effects of factors such as substrate concentration, catalyst concentration, partial pressure of hydrogen and temperature on initial rate of reaction of selected olefins were investigated. A mechanism for the reaction was proposed from the rate equation. The effects of the solvent and structure of the olefin on the rate of hydrogenation were investigated. The catalyst showed good reusability without any leaching of metal from the support. The homologous analog of the polymer-supported catalyst could not be used as catalyst for the hydrogenation of olefins in methanol because there was precipitation of the metal during reaction. © 2011 Dalian Institute of Chemical Physics, the Chinese Academy of Sciences.

Fulltext

Chinese Journal of Catalysis

Hydrogenation of olefins catalyzed by polymer-supported palladium-imidazole

The synthesis and characterisation of copolymers containing tertiary nitrogen to which Cu(I) or Cu(II) species are anchored is described. The anchored species function as catalysts for the oxidation of 2,6-xylenol by O2 under basic conditions. The kinetics of these oxidations have been followed by monitoring oxygen uptake as a function of pH, temperature, reactant concentrations, oxygen partial pressure and catalyst loading. A suitable mechanism is proposed to account for the kinetics as well as the formation of the product, diphenoquinone. Recycling efficiencies of the catalysts are found to be good. © 1997 Published by Elsevier Science Ltd. All rights reserved.

Polymer

The oxidation of 2,6-xylenol catalysed by polymer supported copper complexes

Palladium(II) acetate has been anchored onto a copolymer support containing pyridyl and carboxyl groups. XPS studies showed the Pd 3d binding energies for the recovered catalyst to be less by 1 eV after being used in hydrogenation studies. However, x-ray studies and a chemical test based on KCN treatment failed to reveal any palladium oxide or palladium metal formation in the recovered catalyst. It is presumed that an acetate ligand is lost during hydrogenation, which could be the reason for the lowering of the palladium 3d binding energies in the recovered catalyst. Results of investigations of the hydrogenation of olefins and selectivity of the catalyst toward the hydrogenation of dienes and alkynes are presented. The loss of palladium due to leaching under the reaction conditions employed was found to be very low (< 1 %/cycle). © 1993, Taylor & Francis Group, LLC. All rights reserved.

Journal of Macromolecular Science, Part A

Characterization of a polymer-bound palladium acetate catalyst and studies on the selective hydrogenation of dienes and alkynes

Palladium acetate anchored to a copolymer containing pyridyl and carboxyl groups has been employed as a catalyst for the hydrogenation of azo and nitro groups under 1 atm hydrogen pressure and 30°C. The selective hydrogenation of azobenzene using a polymer-bound palladium catalyst is reported for the first time. Kinetic data on the hydrogenation of azo-benzene are also presented. © 1991.

Reactive Polymers

Polymer-bound palladium acetate as a catalyst for the reduction of nitro and azo groups

Inorganica Chimica Acta

Cyanobenzylpalladium(H) complexes. Synthesis and spectroscopic properties

Journal of the Chemical Society A: Inorganic, Physical, Theoretical

The preparation and properties of tris(triphenylphosphine)halogenorhodium(I) and some reactions thereof including catalytic homogeneous hydrogenation of olefins and acetylenes and their derivatives

Journal	Journal of Catalysis
ISSN	00219517
Open Access	No