Claude Granel

Bio: Claude Granel is an academic researcher from University of Liège. The author has contributed to research in topics: Radical polymerization & Polymerization. The author has an hindex of 3, co-authored 8 publications receiving 782 citations.

Controlled Radical Polymerization of Methacrylic Monomers in the Presence of a Bis(ortho-chelated) Arylnickel(II) Complex and Different Activated Alkyl Halides

Abstract: A novel class of homogeneous nickel(II) catalysts, i.e [Ni{o,o‘(CH2NMe2)2C6H3}Br], denoted as Ni(NCN‘)Br, is reported to mediate in the presence of activated alkyl halides, e.g., CCl4 or α-halocarbonyl compounds, a well-controlled radical polymerization of methacrylic monomers [methyl and n-butyl methacrylate), (MMA, n-BuMA)] at rather low temperatures (<100 °C). The number-average molecular weight of the polymer gradually increased with the monomer conversion and was inversely proportional to the initiator concentration of alkyl halides. The molecular weight distribution (MWD) remained very narrow during the whole course of the polymerization (MWD < 1.3). All the experimental data including a successful block copolymerization (n-BuMA-b-MMA) experiment were in agreement with a living polymerization process, and remarkably enough, poly(methyl methacrylate) (PMMA) with molecular weight up to at least 105 g/mol was synthesized in a controlled fashion. Increased thermal stability of the PMMA is a further indi...

Controlled radical polymerization of methyl methacrylate initiated by an alkyl halide in the presence of the Wilkinson catalyst

Abstract: It is found that although the Wilkinson catalyst is less efficient than the Sawamoto and Matyjaszewski systems in terms of polymerization kinetics, it allows MMA to be polymerized in a living manner at a temperature as low as 60°C and in the absence of any Lewis acid

Atom Transfer Radical Polymerization of Methyl Methacrylate in Water-Borne System

Abstract: The controlled/living polymerization of methyl methacrylate was carried out by atom transfer radical polymerization (ATRP) in a water-borne system. Both the direct and reverse processes were perfor...

Controlled polymerization and copolymerization process of (meth)acrylic and vinylic monomers and products therefrom

Abstract: Method for controlled radical (co)polymerisation of (meth)acrylic and/or vinyl monomers in bulk, solution, emulsion or suspension at temperatures which can go as low as 0 degrees C comprises (co)polymerisation of at least one of said monomers in presence of initiating system consisting of radical generating compound, and at least one catalyst consisting of metal complex with ligand of type AC6H2(CH2NR1R2)2-2,6-R3-4U (I); in which R1, R2 = 1-4C alkyl, or phenyl, or form cyclic amine with N atom to which they are attached, or two R2 groups form polymethylene bridge; and R3 = H, alkyl, benzyl or functional electron donor/acceptor. Also claimed are polymers made by said method.

Polymerization and copolymerization of (meth)acrylic and vinyl monomers under control, and polymerization products

Abstract: PROBLEM TO BE SOLVED: To provide a method for radical polymerization or copolymerization which not only enables the control of molecular weight distribution of polymer chains, but also can be performed at a low temperature, in an aqueous medium, and on an industrial scale. SOLUTION: This is a method for radical polymerization or copolymerization of a (meth)acrylic and/or vinyl monomer under control, which comprises polymerizing or copolymerizing at least one said monomer in bulk, in solution, in emulsion or in suspension, at a temperature which may be 0 deg.C at the lowest, in the presence of a catalyst system comprising a radical generator and a metal complex compound containing the following ligand: [4-R -2,6-(CH2 NR R )2 C6 H2 ] wherein R and R may be the same or different, and, each of R and R represents a branched or non-branched 1-4C alkyl group or a phenyl group, or R and R form a cyclic amine together with a nitrogen atom bonded thereto, or R and R together form a polymethylene bridge, and R represents a hydrogen atom, an alkyl group, a benzyl group, an electron-donating functional group or an electron-withdrawing functional group.

Supported gold nanoparticles as catalysts for organic reactions

Abstract: This critical review is intended to attract the interest of organic chemists and researchers on green and sustainable chemistry on the catalytic activity of supported gold nanoparticles in organic transformations. In the general part of this critical review, emphasis is given to the different procedures to form supported gold nanoparticles and to the importance of the support cooperating in the catalysis. Also the convergence of homogeneous and heterogeneous catalysis in the study of gold nanoparticles has been discussed. The core part of this review is constituted by sections in which the reactions catalyzed by supported gold nanoparticles are described. Special emphasis is made on the unique ability of gold catalysts to promote additions to multiple C–C bonds, benzannulations and alcohol oxidation by oxygen (282 references).

Platinum Group Organometallics Based on “Pincer” Complexes: Sensors, Switches, and Catalysts

Abstract: Since the first reports in the late 1970s on transition metal complexes contain- ing pincer-type ligands—named after the particular coordination mode of these ligands—these systems have at- tracted increasing interest owing to the unusual properties of the metal centers imparted by the pincer ligand. Typical- ly, such a ligand comprises an anionic aryl ring which is ortho,ortho-disubsti- tuted with heteroatom substituents, for example, CH2NR2 ,C H 2PR2 or CH2SR, which generally coordinate to the met- al center, and therefore support the MC s bond. This commonly results in a terdentate and meridional coordina- tion mode consisting of two metalla- cycles which share the MC bond. Detailed studies of the formation and the properties of a large variety of pincers containing platinum group metal complexes have provided direct access to both a fundamental under- standing of a variety of reactions in organometallic chemistry and to a range of new applications of these complexes. The discovery of alkane dehydrogenation catalysts, the mecha- nistic elucidation of fundamental transformations (for example, CC bond activation), the construction of the first metallodendrimers for sustain- able homogeneous catalysis, and the engineering of crystalline switches for materials processing represent only a few of the many highlights which have emanated from these numerous inves- tigations. This review discusses the synthetic methodologies that are cur- rently available for the preparation of platinum group metal complexes con- taining pincer ligands and especially emphasizes different applications that have been realized in materials science such as the development and engineer- ing of sensors, switches, and catalysts.