Catalytic activity of cationic diphospalladium(II) complexes in the alkene/CO copolymerization in organic solvents and water in dependence on the length of the alkyl chain at the phosphine ligands

Lindner, Ekkehard; Schmid, Markus; Wald, Joachim; Queisser, Joachim; Geprägs, Michael; Wegner, Peter; Nachtigal, C.

doi:10.1016/s0022-328x(00)00154-6

Cited by 60 publications

(56 citation statements)

References 46 publications

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“…Acetone and CH 2 Cl 2 were dried with CaH 2 and then distilled. Literature procedures were used to prepare the following compounds: 1,3-bis(diisopropylphosphanyl)propane (dippp), [43] 1,2-bis(diisopropylphosphanyl)ethane (dippe), 1,2-bis(dicyclohexylphosphanyl)ethane (dcype), [44] 1,1Ј-bis(diphenylphosphanyl)ferrocene (dippf), [45] [38] and [Mo(CO) 4 (NO)(ClAlCl 3 ). [47] Other reagents were purchased and used without further purification.…”

Section: Methodsmentioning

confidence: 99%

Molybdenum Nitrosyl Complexes and Their Application in Catalytic Imine Hydrogenation Reactions

2010

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The reaction between [Mo(CO)4(NO)(ClAlCl3)] and the sterically hindered diphosphanes (P∩P) 1,3‐bis(diisopropylphosphanyl)propane (dippp, a), 1,2‐bis(diisopropylphosphanyl)ethane (dippe, b), 1,1′‐bis(diisopropylphosphanyl)ferrocene (dippf, c) and 1,2‐bis(dicyclohexylphosphanyl)ethane (dcype, d) produced the chlorides [Mo(P∩P)(CO)2(NO)Cl] (1a–1d), which were transformed into the corresponding hydrides [Mo(P∩P)(CO)2(NO)H] (2a–2d) by reaction with LiBH4 in Et3N at room temperature. The molybdenum–THF complex [Mo(dippp)(CO)2(NO)(THF)][BArF4] [3a; ArF = 3,5‐(CF3)2C6H3], obtained by the reaction of 2a with [H(Et2O)2][BArF4], was exemplarily tested in the hydrogenation of the imine PhCH=N(α‐naphthyl). Replacement of the [BArF4]– counterion by the more stable [B(C6F5)4]– anion greatly increased the catalytic activity. The use of in situ mixtures of the hydrides 2a–2d and [H(Et2O)2][B(C6F5)4] improved the hydrogenation activity. The hydride 2b in combination with [H(Et2O)2][B(C6F5)4] exhibited the highest TOF value of 123 h–1 in the reduction of PhCH=N(α‐naphthyl). The hydrogenation of the imines PhCH=NPh, p‐ClC6H4CH=NPh, p‐ClC6H4CH=N‐p‐C6H4Cl, PhCH=NCH(Ph)2 and PhCH=NMes showed TOF values of 34, 74, 41, 18 and 84 h–1 at room temperatureand a H2 pressure of 30 bar. A mechanism for the ionic hydrogenation with “proton‐before‐hydride transfer” is anticipated.

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Section: Methodsmentioning

confidence: 99%

Molybdenum Nitrosyl Complexes and Their Application in Catalytic Imine Hydrogenation Reactions

2010

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“…Also the activity of water-soluble catalysts based on the hydrophilic bidentate phosphines is significantly influenced by the nature of the anion [22][23][24][25][26][27][28].…”

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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“…These are mainly obtained by sulfonation of the diphosphine ligands (ca. 7 kg PK/(gPd·h) [22][23][24][25][26][27][28]), but also by fitting the phosphorus atoms with hydroxyl alkyl groups [29,30], or generally by using tenside phosphorus ligands [31].…”

Section: Introductionmentioning

confidence: 99%

The Catalytic Copolymerization of Ethene with Carbon Monoxide Efficiently Carried out in Water-Dichloromethane-Sodium Dodecylsulfate Emulsion

Vavasori¹,

Ronchin²,

Quartarone³

et al. 2013

MRC

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Catalytic activity of cationic diphospalladium(II) complexes in the alkene/CO copolymerization in organic solvents and water in dependence on the length of the alkyl chain at the phosphine ligands

Cited by 60 publications

References 46 publications

Molybdenum Nitrosyl Complexes and Their Application in Catalytic Imine Hydrogenation Reactions

Molybdenum Nitrosyl Complexes and Their Application in Catalytic Imine Hydrogenation Reactions

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

The Catalytic Copolymerization of Ethene with Carbon Monoxide Efficiently Carried out in Water-Dichloromethane-Sodium Dodecylsulfate Emulsion

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