Journal ArticleDOI
Carbon monoxide-ethylene copolymerisation catalysed by [PdCl2(dppp)] in methanol-water or in acetic acid-water as solvents (dppp = 1,3-bis(diphenylphosphine)propane)
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In this article, it was shown that the catalytic activity of [PdCl2(dppp) is strongly dependent on the content of H2O. In the absence of acid, it is inactive, though it does not decompose to palladium metal.Abstract:
The complex [PdCl2(dppp)] catalyses the copolymerisation of CO–ethylene when employed in a mixture of methanol and water as solvent. In the absence of H2O, it is inactive and at the end of the experiment, formation of metallic palladium has been noted. A sharp increase in the activity occurs at a water concentration above 5%, to reach a maximum of 4100 g copolymer/(g Pd h) by increasing the content of H2O up to 20% (mol/mol). In AcOH as solvent the catalytic activity of [PdCl2(dppp)] is also strongly dependent on the content of H2O. In the absence of H2O it is inactive, though it does not decompose to palladium metal. Upon addition of H2O, it turns into a highly active system and the catalytic activity passes through a maximum of ca. 28 000 h−1 when the molar ratio H2O/AcOH=55%. The 13 C NMR spectra show that the polymer chain is perfectly alternated. Polyketones obtained in MeOH–H2O (molecular weight ca. 6.5×103 g/mol) are of three types, differing for the nature of end-groups H(CH2CH2CO)nOMe, MeOCO(CH2CH2CO)nOMe and H(CH2CH2CO)nCH2CH3. In AcOH–H2O, only one type of polyketone forms having ketonic end-groups (average molecular weight ca. 2.7×104 g/mol). On the basis of these experimental evidences, a mechanism for their formation is proposed. It is also proposed that the main role of H2O is that of forming an active Pd–H species which would start the catalysis upon interaction with CO through a reaction closely related to the water gas shift reaction (WGSR) (during the catalysis there is formation of CO2 in significant amounts). It is also proposed that the main role of acid is that of stabilizing Pd–H active species preventing their deprotonation to inactive species.read more
Citations
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Journal ArticleDOI
Alternating and Non-Alternating Pd-Catalysed Co- and Terpolymerisation of Carbon Monoxide and Alkenes
TL;DR: The co-and terpolymerization of carbon monoxide and alkenes is usually catalysed by palladium complexes, and the properties of the produced polyketones can be finely tuned by an appropriate choice of catalyst and olefinic monomer as mentioned in this paper.
Journal ArticleDOI
Theoretical analysis of factors controlling the nonalternating CO/C(2)H(4) copolymerization.
TL;DR: The selectivity toward a nonalternating distribution of both comonomers appears to be mainly a result of a strong destabilization of the Pd-acyl complex, consistent with the energy changes obtained for the real catalyst model.
Journal ArticleDOI
Carbonylation of ethene catalysed by Pd(II)-phosphine complexes.
Gianni Cavinato,Luigi Toniolo +1 more
TL;DR: It is shown that the steric bulk plays a major role in directing the selectivity of the very active and selective catalysis to methyl propanoate, including the mechanism of the catalytic cycles with diphosphine- and monoph phosphine-catalysts.
Journal ArticleDOI
CO-ethylene copolymerization reactions in different reaction media catalyzed by palladium(II) complexes with chelating diphosphines bearing ortho-methoxy-substituted aryl groups
Claudio Bianchini,Andrea Meli,Werner Oberhauser,Anna M. Segarra,Carmen Claver,Eduardo J. Garcia Suarez +5 more
TL;DR: In this paper, neutral and bis-cationic palladium(II) complexes with 1,2-bis(di(2-methoxyphenyl)phosphino)ethane (o-MeO-dppe) and 1,3-bis (di( 2methylphosphinosophosphino)-propane (dppp) have been synthesized and employed to catalyze the CO-ethylene copolymerization reaction in either protic or aprotic solvents.
Journal ArticleDOI
Polyketone polymer: a new support for direct enzyme immobilization.
Enzo Agostinelli,Francesca Belli,G. Tempera,Anna Mura,Giovanni Floris,Luigi Toniolo,Andrea Vavasori,S Fabris,Federico Momo,Roberto Stevanato +9 more
TL;DR: Polyketone polymer, obtained by copolymerization of ethene and carbon monoxide, is utilized for immobilization of three different enzymes, one peroxidase from horseradish (HRP) and two amine oxidases, from bovine serum (BSAO) and lentil seedlings (LSAO).
References
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Journal ArticleDOI
Palladium-Catalyzed Alternating Copolymerization of Alkenes and Carbon Monoxide.
Eite Drent,Peter H. M. Budzelaar +1 more
Journal ArticleDOI
Efficient palladium catalysts for the copolymerization of carbon monoxide with olefins to produce perfectly alternating polyketones
TL;DR: In this paper, a homogeneous palladium catalyst system was developed for the production of perfectly alternating copolymers of carbon monoxide with ethylene, where C 3 units randomly replace ethylene units along the chain.
Journal ArticleDOI
Mechanistic aspects of metal-catalyzed alternating copolymerization of olefins with carbon monoxide
TL;DR: The metal-catalyzed copolymerization procedure has several noteworthy advantages over the other two as discussed by the authors, such as it occurs at significantly lower pressures and at or below ambient temperature, and the resultant polymers have a strictly alternating structure and high molecular weights.
Journal ArticleDOI
Alternating copolymerization of carbon monoxide and olefins by single-site metal catalysis
Claudio Bianchini,Andrea Meli +1 more
TL;DR: The alternating copolymerization of carbon monoxide and olefins is a reaction that transition metal complexes, generally containing palladium, catalyze in different phase variation systems as discussed by the authors.
Journal ArticleDOI
Alcoholysis of acylpalladium(II) complexes relevant to the alternating copolymerization of ethene and carbon monoxide and the alkoxycarbonylation of alkenes: the importance of Cis-coordinating phosphines.
Piet W. N. M. van Leeuwen,Martin Alexander Zuideveld,Bert H. G. Swennenhuis,Zoraida Freixa,Paul C. J. Kamer,Kees Goubitz,Jan Fraanje,Martin Lutz,Anthony L. Spek +8 more
TL;DR: It is concluded that ester elimination from acylpalladium complexes with alcohols requires cis geometry of the acyl group and coordinating alcohol.
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