1615710-18-3Relevant articles and documents
Copolymerization of ethylene and methyl acrylate by cationic palladium catalysts that contain phosphine-diethyl phosphonate ancillary ligands
Contrella, Nathan D.,Sampson, Jessica R.,Jordan, Richard F.
, p. 3546 - 3555 (2014/08/05)
A series of benzo-linked phosphine-diethyl phosphonate (P-PO) and phosphine-bis(diethyl phosphonate) (P-(PO)2) ligands and the corresponding (P-PO)PdMe(2,6-lutidine)+ and (P-(PO) 2)PdMe(2,6-lutidine)+ complexes were synthesized. Cationic (P-PO)PdMe(2,6-lutidine)+ complexes are active for ethylene oligomerization/polymerization, with activities of 2 kg mol-1 h -1 for {κ2-1-PiPr2-2-P(O)(OEt) 2-5-Me-Ph}PdMe(2,6-lutidine)+ (3c), 125 kg mol -1 h-1 for {κ2-1-PPh2-2-P(O) (OEt)2-5-Me-Ph}PdMe(2,6-lutidine)+ (3a), and 1470 kg mol-1 h-1 for {κ2-1-P(2-OMe-Ph) 2-2-P(O)(OEt)2-Ph}PdMe(2,6-lutidine)+ (3b). The polyethylene is highly linear, with over 80% terminal unsaturation and low (230-1890 Da) molecular weight in all cases. 3b copolymerizes ethylene with methyl acrylate, exhibiting highly selective (95%) in-chain (rather than chain-end) acrylate incorporation. The P-(PO)2 catalyst {κ2-1-P(4-tBu-Ph)(2-P(O)(OEt)2-5-Me-Ph)- 2-P(O)(OEt)2-5-Me-Ph}PdMe(2,6-lutidine)+ (3d) is more active for ethylene homopolymerization (2640 kg mol-1 h -1), yielding linear, low-molecular-weight polymer (1280-1430 Da) with predominantly internal olefin placement. In ethylene/methyl acrylate copolymerization, 3d incorporates 2.6 mol % methyl acrylate, 60% of which is in-chain. Both 3b and 3d catalyze ethylene/acrylic acid copolymerization, albeit with low (-1 h-1) activities and acrylic acid incorporation up to 1.1 mol %.
