929284-68-4Relevant academic research and scientific papers
Novel highly active binuclear neutral nickel and palladium complexes as precatalysts for norbornene polymerization
Hu, Tao,Li, Yan-Guo,Li, Yue-Sheng,Hu, Ning-Hai
, p. 155 - 164 (2008/10/09)
A series of binuclear neutral nickel and palladium complexes [(XC6H2CH{double bond, long}NC6H3-iPr2)MRL]2 4b-f (X = NO2, M = Ni, R = Ph, L = PPh3, 4b; X = H, M = Pd, R = Me, L = PPh3, 4c; X = H, M = Pd, R = Me, L = Py, 4d; X = NO2, M = Pd, R = Me, L = PPh3, 4e; X = NO2, M = Pd, R = Me, L = Py, 4f) and [(C10H7CH{double bond, long}NC6H3-iPr2)MRL]2 8a-c (M = Ni, R = Ph, L = PPh3, 8a; M = Pd, R = Me, L = PPh3, 8b; M = Pd, R = Me, L = Py, 8c) have been synthesized and characterized. The structures of complexes 4e and 8b have also been confirmed by X-ray crystallographic analysis. With modified methylaluminoxane (MMAO) as cocatalysts, these complexes and complex [(C6H3CH{double bond, long}NC6H3-iPr2)NiPh(PPh3)]2 4a are capable of catalyzing the addition polymerization of norbornene (NBE) with the high activity up to 2.3 × 108 g PNBE/(molM h). The structure of complexes affects considerably catalytic activity towards norbornene polymerization. The polymers obtained with nickel complexes are soluble, while those obtained with palladium complexes are insoluble. Palladium complexes 4c, 4e and 8b bearing PPh3 ligands exhibit much higher activities than the corresponding complexes 4d, 4f and 8c bearing pyridine ligands under the same conditions.
