Copolymerization of carbon monoxide with ethene catalyzed by palladium(II) complexes of 1,3-bis(diphenylphosphino)propane ligands bearing different substituents on the carbon backbone

Claudio Bianchini, Hon Man Lee, Andrea Meli, Simonetta Moneti, Francesco Vizza, Marco Fontani, Piero Zanello

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

In this work are described the synthesis of several new dppp-like ligands (dppp = 1,3-bis(diphenylphosphino)propane) bearing different substituents on the carbon backbone and of their palladium(II) complexes with acetate or trifluoroacetate coligands (L). The complexes exhibit the general formula Pd(P-P)(L)2 and have been experimental conditions that are comparable to those reported in the relevant monoxide in MeOH under experimental conditions that are comparable to those reported in the relevant literature and patents for dppp-based Pd(II) copolymerization catalysts. It has been found that the introduction of alkyl substituents in the 2-position of the carbon backbone of dppp does not significantly improve the performance of the corresponding catalyst precursors (highest productivity value 6.2 kg of copolymer (g of Pd h)-1 vs 5.4 kg of copolymer (g of Pd h)-1 for Pd(dppp)(L)2). In contrast, the productivity increases remarkably when methyl groups are introduced in both 1-positions of the diphosphine ligand, particularly with R,S (S,R) stereochemistry as in meso-CH2(CH3CHPPh2)2 (productivity of 8.0 kg of copolymer (g of Pd h)-1). On the basis of NMR and cyclic voltammetric studies of the catalyst precursors, it is suggested that the increased productivity provided by the C1-substituted ligands is both electronic and steric in nature. In situ high-pressure NMR experiments in sapphire tubes equipped with Ti alloy valves showed that the only phosphorus-containing species visible on the NMR time scale in effective copolymerization conditions are Pd(II) complexes with the formula Pd(diphosphine)X2 (X = p-toluene-sulfonate, trifluoroacetate, or MeOH). It has been proposed that these Pd(II) complexes act as a reservoir of [Pd(diphosphine)]2+ moieties which may either be delivered into the catalysis cycle by action of various reagents (MeOH, H+, H2O, H2) or be withdrawn after the termination step and watched over deactivation paths.

Original languageEnglish
Pages (from-to)4183-4193
Number of pages11
JournalMacromolecules
Volume32
Issue number13
DOIs
Publication statusPublished - 1999 Jun 29

Fingerprint

Bearings (structural)
Palladium
Carbon Monoxide
Propane
Carbon monoxide
Copolymerization
Carbon
Productivity
Ligands
Trifluoroacetic Acid
Copolymers
Nuclear magnetic resonance
Catalysts
Stereochemistry
Aluminum Oxide
Sapphire
Phosphorus
Catalysis
Toluene
Acetates

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Bianchini, Claudio ; Lee, Hon Man ; Meli, Andrea ; Moneti, Simonetta ; Vizza, Francesco ; Fontani, Marco ; Zanello, Piero. / Copolymerization of carbon monoxide with ethene catalyzed by palladium(II) complexes of 1,3-bis(diphenylphosphino)propane ligands bearing different substituents on the carbon backbone. In: Macromolecules. 1999 ; Vol. 32, No. 13. pp. 4183-4193.
@article{38ee185b212d4d2eb7b4fb3897b3e7d3,
title = "Copolymerization of carbon monoxide with ethene catalyzed by palladium(II) complexes of 1,3-bis(diphenylphosphino)propane ligands bearing different substituents on the carbon backbone",
abstract = "In this work are described the synthesis of several new dppp-like ligands (dppp = 1,3-bis(diphenylphosphino)propane) bearing different substituents on the carbon backbone and of their palladium(II) complexes with acetate or trifluoroacetate coligands (L). The complexes exhibit the general formula Pd(P-P)(L)2 and have been experimental conditions that are comparable to those reported in the relevant monoxide in MeOH under experimental conditions that are comparable to those reported in the relevant literature and patents for dppp-based Pd(II) copolymerization catalysts. It has been found that the introduction of alkyl substituents in the 2-position of the carbon backbone of dppp does not significantly improve the performance of the corresponding catalyst precursors (highest productivity value 6.2 kg of copolymer (g of Pd h)-1 vs 5.4 kg of copolymer (g of Pd h)-1 for Pd(dppp)(L)2). In contrast, the productivity increases remarkably when methyl groups are introduced in both 1-positions of the diphosphine ligand, particularly with R,S (S,R) stereochemistry as in meso-CH2(CH3CHPPh2)2 (productivity of 8.0 kg of copolymer (g of Pd h)-1). On the basis of NMR and cyclic voltammetric studies of the catalyst precursors, it is suggested that the increased productivity provided by the C1-substituted ligands is both electronic and steric in nature. In situ high-pressure NMR experiments in sapphire tubes equipped with Ti alloy valves showed that the only phosphorus-containing species visible on the NMR time scale in effective copolymerization conditions are Pd(II) complexes with the formula Pd(diphosphine)X2 (X = p-toluene-sulfonate, trifluoroacetate, or MeOH). It has been proposed that these Pd(II) complexes act as a reservoir of [Pd(diphosphine)]2+ moieties which may either be delivered into the catalysis cycle by action of various reagents (MeOH, H+, H2O, H2) or be withdrawn after the termination step and watched over deactivation paths.",
author = "Claudio Bianchini and Lee, {Hon Man} and Andrea Meli and Simonetta Moneti and Francesco Vizza and Marco Fontani and Piero Zanello",
year = "1999",
month = "6",
day = "29",
doi = "10.1021/ma990045o",
language = "English",
volume = "32",
pages = "4183--4193",
journal = "Macromolecules",
issn = "0024-9297",
publisher = "American Chemical Society",
number = "13",

}

Copolymerization of carbon monoxide with ethene catalyzed by palladium(II) complexes of 1,3-bis(diphenylphosphino)propane ligands bearing different substituents on the carbon backbone. / Bianchini, Claudio; Lee, Hon Man; Meli, Andrea; Moneti, Simonetta; Vizza, Francesco; Fontani, Marco; Zanello, Piero.

In: Macromolecules, Vol. 32, No. 13, 29.06.1999, p. 4183-4193.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Copolymerization of carbon monoxide with ethene catalyzed by palladium(II) complexes of 1,3-bis(diphenylphosphino)propane ligands bearing different substituents on the carbon backbone

AU - Bianchini, Claudio

AU - Lee, Hon Man

AU - Meli, Andrea

AU - Moneti, Simonetta

AU - Vizza, Francesco

AU - Fontani, Marco

AU - Zanello, Piero

PY - 1999/6/29

Y1 - 1999/6/29

N2 - In this work are described the synthesis of several new dppp-like ligands (dppp = 1,3-bis(diphenylphosphino)propane) bearing different substituents on the carbon backbone and of their palladium(II) complexes with acetate or trifluoroacetate coligands (L). The complexes exhibit the general formula Pd(P-P)(L)2 and have been experimental conditions that are comparable to those reported in the relevant monoxide in MeOH under experimental conditions that are comparable to those reported in the relevant literature and patents for dppp-based Pd(II) copolymerization catalysts. It has been found that the introduction of alkyl substituents in the 2-position of the carbon backbone of dppp does not significantly improve the performance of the corresponding catalyst precursors (highest productivity value 6.2 kg of copolymer (g of Pd h)-1 vs 5.4 kg of copolymer (g of Pd h)-1 for Pd(dppp)(L)2). In contrast, the productivity increases remarkably when methyl groups are introduced in both 1-positions of the diphosphine ligand, particularly with R,S (S,R) stereochemistry as in meso-CH2(CH3CHPPh2)2 (productivity of 8.0 kg of copolymer (g of Pd h)-1). On the basis of NMR and cyclic voltammetric studies of the catalyst precursors, it is suggested that the increased productivity provided by the C1-substituted ligands is both electronic and steric in nature. In situ high-pressure NMR experiments in sapphire tubes equipped with Ti alloy valves showed that the only phosphorus-containing species visible on the NMR time scale in effective copolymerization conditions are Pd(II) complexes with the formula Pd(diphosphine)X2 (X = p-toluene-sulfonate, trifluoroacetate, or MeOH). It has been proposed that these Pd(II) complexes act as a reservoir of [Pd(diphosphine)]2+ moieties which may either be delivered into the catalysis cycle by action of various reagents (MeOH, H+, H2O, H2) or be withdrawn after the termination step and watched over deactivation paths.

AB - In this work are described the synthesis of several new dppp-like ligands (dppp = 1,3-bis(diphenylphosphino)propane) bearing different substituents on the carbon backbone and of their palladium(II) complexes with acetate or trifluoroacetate coligands (L). The complexes exhibit the general formula Pd(P-P)(L)2 and have been experimental conditions that are comparable to those reported in the relevant monoxide in MeOH under experimental conditions that are comparable to those reported in the relevant literature and patents for dppp-based Pd(II) copolymerization catalysts. It has been found that the introduction of alkyl substituents in the 2-position of the carbon backbone of dppp does not significantly improve the performance of the corresponding catalyst precursors (highest productivity value 6.2 kg of copolymer (g of Pd h)-1 vs 5.4 kg of copolymer (g of Pd h)-1 for Pd(dppp)(L)2). In contrast, the productivity increases remarkably when methyl groups are introduced in both 1-positions of the diphosphine ligand, particularly with R,S (S,R) stereochemistry as in meso-CH2(CH3CHPPh2)2 (productivity of 8.0 kg of copolymer (g of Pd h)-1). On the basis of NMR and cyclic voltammetric studies of the catalyst precursors, it is suggested that the increased productivity provided by the C1-substituted ligands is both electronic and steric in nature. In situ high-pressure NMR experiments in sapphire tubes equipped with Ti alloy valves showed that the only phosphorus-containing species visible on the NMR time scale in effective copolymerization conditions are Pd(II) complexes with the formula Pd(diphosphine)X2 (X = p-toluene-sulfonate, trifluoroacetate, or MeOH). It has been proposed that these Pd(II) complexes act as a reservoir of [Pd(diphosphine)]2+ moieties which may either be delivered into the catalysis cycle by action of various reagents (MeOH, H+, H2O, H2) or be withdrawn after the termination step and watched over deactivation paths.

UR - http://www.scopus.com/inward/record.url?scp=0344614668&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0344614668&partnerID=8YFLogxK

U2 - 10.1021/ma990045o

DO - 10.1021/ma990045o

M3 - Article

AN - SCOPUS:0344614668

VL - 32

SP - 4183

EP - 4193

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 13

ER -