SYNTHESIS, CHARACTERIZATION, AND COORDINATION CHEMISTRY OF LONG CHAIN<i>n</i>-ALKYLDIPHENYLPHOSPHINE LIGANDS

Davies, Julian A.; Mierzwiak, James G.; Syed, R.

doi:10.1080/00958978808078445

Cited by 12 publications

(6 citation statements)

References 58 publications

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“…Furthermore, the ∼1:1 PPh 2 and −CH 3 chain end resonance ratio implies that a phosphine moiety terminates each polymer chain. For comparison, the 1 H, 13 C, and 31 P NMR spectra of the model product 1-eicosyldiphenylphosphine oxide ( 2 ; Figure a) are in good agreement with the polymer spectral assignments.…”

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confidence: 53%

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes

Kawaoka

Marks

2004

J. Am. Chem. Soc.

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Organolanthanide-mediated hydrophosphination and ethylene polymerization are coupled in a catalytic cycle to produce diphenylphosphine-terminated polyethylenes. The resulting polymers were characterized by 1H, 13C, and 31P NMR, GPC, and DSC and compared spectroscopically to the model compound, 1-eicosyldiphenylphosphine oxide. High activities (107 g polymer/(mol Ln.atm ethylene.h)) and narrow polydispersities were observed in the polymerization/chain transfer process. Polyethylene molecular weights were found to be inversely proportional to diphenylphosphine concentration, supporting a chain transfer mechanism. The present discovery represents the first case in which an electron-rich phosphine functions efficiently as a chain transfer agent in a single-site fn/d0-mediated olefin polymerization process.

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confidence: 53%

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes

Kawaoka

Marks

2004

J. Am. Chem. Soc.

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“…In step 2 of Scheme , nucleophilic substitution of the bromide with the diphenylphosphide afforded the final product R 2 PyP as an oxygen-sensitive viscous oil (R = Me, 2b ; i Pr, 2c ) or waxy solid (R = H, 2a ; Ph, 2d ) in approximately 80% yield. The 31 P{ 1 H} NMR (C 6 D 6 ) spectra of the final products show a singlet in the region −20 to −22 ppm, which is typical for alkyldiarylphosphines …”

Section: Resultsmentioning

confidence: 99%

“…The 31 P{ 1 H} NMR (C 6 D 6 ) spectra of the final products show a singlet in the region -20 to -22 ppm, which is typical for alkyldiarylphosphines. 58 Synthesis of Cationic Iridium and Rhodium Complexes with R 2 PyP and 1,5-Cyclooctadiene as Co-ligands, [M(R 2 PyP)-(COD)]BPh 4 (M ) Rh, Ir). Cationic metal complexes of the general formula [M(R 2 PyP)(COD)]BPh 4 (R ) H, Me, iPr, Ph, M ) Ir, 3a-3d and M ) Rh, 4a-4d) were synthesized by the addition of a methanol solution of the ligand to a methanol suspension/solution of the [M(µ-Cl)(COD)] 2 (M ) Rh, Ir) metal precursor at room temperature (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

Rhodium(I) and Iridium(I) Complexes with Bidentate Phosphine−Pyrazolyl Ligands: Highly Efficient Catalysts for the Hydroamination Reaction

et al. 2007

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A range of rhodium(I) and iridium(I) complexes containing bidentate phosphine-pyrazolyl ligands of general formulas [M(R 2 PyP)(COD)]BPh 4 (R ) Me, iPr, Ph, M ) Ir, 3b-3d and M ) Rh, 4b-4d), [Ir(R 2 PyP)(CO) 2 ]BPh 4 (R ) Me, iPr, 5b,5c), and [M(R 2 PyP)(CO)Cl] (R ) Me, iPr, Ph, M ) Ir, 6b-6d and M ) Rh, 7b-7d) were successfully synthesized. A number of these complexes and their analogues with unsubstituted ligands are extremely active as catalysts for the intramolecular hydroamination of alkynes. The air-stable cationic iridium complexes containing 1,5-cyclooctadiene, COD, as co-ligands, [Ir(R 2 PyP)(COD)]BPh 4 (R ) H, Me, iPr, and Ph, 3a-3d), are efficient as catalysts for the cyclization of 4-pentyn-1-amine (8) to 2-methyl-1-pyrroline (9) with the turnover rate at 50% conversion (N t ) of up to 3100 h -1 , at 60°C. The cationic iridium complexes containing carbonyl co-ligands, [Ir(R 2 PyP)(CO) 2 ]-BPh 4 (R ) H, Me, iPr, 5a-5c), are moderately effective in catalyzing this reaction, and the neutral complexes [M(R 2 PyP)(CO)Cl] (M ) Ir, 6a Ir, 7a) are ineffective. Generally, an increase in steric bulk of the substituent R near the nitrogen donor leads to an improvement in catalytic performance of the resulting metal complexes.

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“…Synthesis of 1-Eicosyldiphenylphosphine Oxide (2). In a 100 mL Schlenk flask, 12 mL of 0.5 M KPPh 2 in THF (6.0 mmol) was added dropwise to 2.1 g (5.8 mmol) of 1-bromoeicosane in 40 mL of dry THF. The orange-red KPPh 2 solution turned colorless upon addition to the 1-bromoeicosane solution.…”

Section: Methodsmentioning

confidence: 99%

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes. Scope and Mechanism

Kawaoka¹,

Marks

2005

J. Am. Chem. Soc.

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Primary and secondary phosphines are investigated as chain-transfer agents for organolanthanide-mediated olefin polymerization. Ethylene polymerizations were carried out with [Cp'(2)LnH](2) and Cp'(2)LnCH(SiMe(3))(2) (Cp' = eta(5)-Me(5)C(5); Ln = La, Sm, Y, Lu) precatalysts in the presence of dicyclohexyl-, diisobutyl-, diethyl-, diphenyl-, cyclohexyl-, and phenylphosphine. In the presence of secondary phosphines, high polymerization activities (up to 10(7) g of polymer/(mol of Ln.atm ethylene.h)) and narrow product polymer polydispersities are observed. For lanthanocene-mediated ethylene polymerizations, the phosphine chain-transfer efficiency correlates with the rate of Ln-CH(SiMe(3))(2) protonolysis by the same phosphines and follows the trend H(2)PPh >> H(2)PCy > HPPh(2) > HPEt(2) approximately HP(i)()Bu(2) > HPCy(2). Under the conditions investigated, dicyclohexylphosphine is not an efficient chain-transfer agent for Cp'(2)LaPCy(2)- and Cp'(2)YPCy(2)-mediated ethylene polymerizations. Diisobutylphosphine and diethylphosphine are efficient chain-transfer agents for Cp'(2)La-mediated polymerizations; however, phosphine chain transfer does not appear to be competitive with other chain-transfer pathways in Cp'(2)Y-mediated polymerizations involving diisobutylphosphine. Regardless of the lanthanide metal, diphenylphosphine is an efficient chain-transfer agent for ethylene polymerization. Polymerizations conducted in the presence of primary phosphines produce only low-molecular-weight products. Thus, Cp'(2)Y-mediated ethylene polymerizations conducted in the presence of phenylphosphine and cyclohexylphosphine produce low-molecular-weight phenylphosphine- and cyclohexylphosphine-capped oligomers, respectively. For Cp'(2)YPPh(2)-mediated ethylene polymerizations, a linear relationship is observed between M(n) and [diphenylphosphine](-)(1), consistent with a phosphine protonolytic chain-transfer mechanism.

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SYNTHESIS, CHARACTERIZATION, AND COORDINATION CHEMISTRY OF LONG CHAINn-ALKYLDIPHENYLPHOSPHINE LIGANDS

Cited by 12 publications

References 58 publications

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes

Rhodium(I) and Iridium(I) Complexes with Bidentate Phosphine−Pyrazolyl Ligands: Highly Efficient Catalysts for the Hydroamination Reaction

Organolanthanide-Catalyzed Synthesis of Phosphine-Terminated Polyethylenes. Scope and Mechanism

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