In Situ Monitoring of a Heterogeneous Palladium-Based Polyketone Catalyst

Mul, Wilhelmus P.; Oosterbeek, Heiko; Beitel, G.; Kramer, G.J.; Drent, Eite

doi:10.1002/(sici)1521-3773(20000515)39:10<1848::aid-anie1848>3.0.co;2-8

Cited by 68 publications

(73 citation statements)

References 6 publications

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“…Concerning the acid, not only the solubility of the monomers increases with increasing its concentration, but also a higher concentration of active Pd-H + species may be accomplished because the acid may prevent the deprotonation of the hydride with formation of hydride-deficient formally-Pd(I) species of the type [(dapp)(-H)(-CO)Pd(dapp)] 2+ or [(dapp)(-CO) 2 Pd(dapp)] 2+ , which ultimately may lead to the formation of inactive Pd(0) [1,3]. In addition, the acid may destabilize the ␤-and ␥-chelate rings through protonation at the oxygen atoms of the rings which have been proposed to be resting states in the incorporation of the monomers into the growing chain [26].…”

Section: Resultsmentioning

confidence: 99%

Influence of the operating conditions on the catalytic activity of [PdCl2(dapp)] in the CO–ethene copolymerization in the H2O–CH3COOH as a solvent (dapp=1,3-bis(di(2-methoxyphenyl)phosphino)propane)

Vavasori

Dall’Acqua

Cavinato

et al. 2010

Journal of Molecular Catalysis A: Chemical

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a b s t r a c tThe influence on the productivity of [PdCl 2 (dapp)] in H 2 O-CH 3 COOH in the CO-ethene copolymerization and on the LVN of the copolymer of the following reaction parameters has been studied: (i) composition of the H 2 O-CH 3 COOH reaction medium; (ii) temperature; (iii) CO/ethene ratio at a given total pressure; (iv) total pressure at fixed ratio CO/ethene = 1/1; (v) CO or ethene partial pressure at a given pressure of one monomer; (vi) reaction time. High molecular weight PKs are obtained under high pressure with the monomers in the ratio 1/1 at relatively low temperature and with a H 2 O/CH 3 COOH 40-50% with productivity ranging from 4 to 20 kg PK(g Pd h) −1 . The relation between productivity and LVN has been discussed in the light of the key steps of the catalytic cycle.

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Section: Resultsmentioning

confidence: 99%

Influence of the operating conditions on the catalytic activity of [PdCl2(dapp)] in the CO–ethene copolymerization in the H2O–CH3COOH as a solvent (dapp=1,3-bis(di(2-methoxyphenyl)phosphino)propane)

Vavasori

Dall’Acqua

Cavinato

et al. 2010

Journal of Molecular Catalysis A: Chemical

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“…DEK forms when the insertion of a second molecule of ethene into the Pd-acyl bond occurs with formation of a Pd-alkylacyl intermediate, followed by protonolysis [12][13][14]. If the Pd-alkylacyl intermediate undergoes successive multiple sequential insertions of CO and ethene the process of chain growing proceeds through the intermediate formation of b-and c-chelates till termination occurs with formation of cooligomers or of PK [1][2][3]15]. Termination occurs via alcoholysis or protonolysis.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Cavinato

Vavasori

Toniolo

et al. 2005

Inorganica Chimica Acta

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The title complex has been synthesized by first reacting dppp with Pd(AcO) 2 in acetone and then with NaHSO 4 in water. It has been characterized by IR, NMR and X-ray diffraction studies. The 31 P NMR spectrum in DMSO shows a singlet at 16.62 ppm indicating that the two P atoms are equivalent and that the sulfate anion is weakly coordinating. The X-ray structure shows that the Pd atom is surrounded in an almost regular square planar environment by the two P atoms and by two O atoms of the sulfate anion and that the neutral complex is accompanied by a water molecule of crystallization. The Pd-P distances (2.217(1) and 2.233(1)) and the P-Pd-P angle (90.78(3)°) are close to those found in other complexes where the chelating diphosphine is the same. Also the Pd-O distances and the O-Pd-O bond angle are comparable to those of other relevant chelating ligands.In MeOH, the title complex, in combination with H 2 SO 4 , catalyses the CO-ethene copolymerization. The productivity reaches a maximum upon increasing the H 2 SO 4 /Pd ratio up to ca. 470 (7650 g of polyketone/g Pd h at 90°C and 45 atm, CO/ethene 1/1). The viscosity of the polyketone passes through a maximum of 0.95 dL/g in m-cresol when the above ratio is ca. 100. It has been proposed that acid promotes the copolymerization process by destabilizing the b-and c-chelates intermediates involved in chain growing process, thus favoring the insertion of the monomers. At relatively high acid concentration the lowering of productivity and viscosity suggests that the sulfate anion competes with the monomers for the coordination to the metal center.In H 2 O-CH 3 COOH as a solvent the productivity strongly depends on the H 2 O/CH 3 COOH ratio, as it passes through a maximum of 12 000 g polymer/g Pd h in the presence of ca. 60% of H 2 O. The productivity is significantly lower than that found when the acetate and chloride analogues are used (27 000 g polyketone/g Pd AE h). Thus, it is likely that the sulfate anion assists significantly the copolymerization process even though the concentration of CH 3 COOH/CH 3 COO À is much preponderant.

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“…[10,37,38] Accordingly, for the system containing 1,3-bis(diphenylphosphino)propane, both alkyl and acyl intermediates correspond to resting states of the catalyst. [39] Therefore, for the development of efficient catalytic systems, the composition of the monomers must be studied, which leads to the terpolymer composition of actual interest. …”

Section: Resultsmentioning

confidence: 99%

Enantioselective Alternating Terpolymerization of Propene and Ethene with Carbon Monoxide

Sesto

Bronco

Gindro

et al. 2001

Macromol. Chem. Phys.

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In Situ Monitoring of a Heterogeneous Palladium-Based Polyketone Catalyst

Cited by 68 publications

References 6 publications

Influence of the operating conditions on the catalytic activity of [PdCl2(dapp)] in the CO–ethene copolymerization in the H2O–CH3COOH as a solvent (dapp=1,3-bis(di(2-methoxyphenyl)phosphino)propane)

Influence of the operating conditions on the catalytic activity of [PdCl2(dapp)] in the CO–ethene copolymerization in the H2O–CH3COOH as a solvent (dapp=1,3-bis(di(2-methoxyphenyl)phosphino)propane)

Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Enantioselective Alternating Terpolymerization of Propene and Ethene with Carbon Monoxide

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