| 摘要： |
Stereoregular polymerizations are of high importance, which disclosing the relationships between microstructures and physical properties of polymers. In this contribution, a series of iminopyridyl vanadium oxychloride complexesV1-V8(R = H, R-1= CH2Ph forV1; R = H, R-1= CHPh(2)forV2; R = H, R-1= octamyl forV3; R = H, R-1= Ph forV4; R = H, R-1= 4-OMe-C(6)H(4)forV5; R = H, R-1= 4-CF3-C(6)H(4)forV6; R = H, R-1= 2,4,6-Ph-3-C(6)H(2)forV7and R = Me, R-1= Ph forV8) have been prepared, and were investigated for their catalytic capacity of isoprene polymerization. A single crystal structure ofV7 ' was reported, which was reduced from V(v) to V(iv) in the oxidation state of vanadium central atom. The catalytic activity was up to 408 kg (mol V)(-1)hr(-1), whenV4was used. The catalystV6was found to be highly thermo-stable with excellent activity even at 100 degrees C. Most importantly, resultant polymers mainly possessedcis-1,4 units (up to 75%) with 25% side-chain 3,4 functional group, which is particularly important component to enhance the application of these synthetic rubbers. |
