摘要
Vanadium（III） complexes bearing thiophenol-phosphine ligands （2a-2b） （2-R-6-PPh2-C6H2S） VC12（THF）2 （2a： R = H; 2b： R = MeaSi） were prepared from VCla（THF）3 by treating with 1.0 equiv of the ligand in tetrahydrofuran in the presence of excess triethylamine. The two complexes were characterized by FTIR and mass spectra as well as elemental analyses. On activation with Et2AIC1, these complexes exhibited high catalytic activities （up to 22.1 kg PE/（mmolv.h.bar）） even at high temperature （70 ℃）, and produced high molecular weight polymers with unimodal molecular weight distributions, indicating the polymerization took place in a single-site nature. This result may be attributed to benefits of introduction of second-row donor atoms for adjusting charge density of the vanadium centers. In addition, these complexes also exhibited high catalytic activities for ethylene/1-hexene copolymerization. Catalytic activity, comonomer incorporation and polymer molecular weight can be controlled in a wide range by the variation of catalyst structure and the reaction parameters such as A1/V molar ratio, comonomer feed concentration and polymerization reaction temperature.
Vanadium（III） complexes bearing thiophenol-phosphine ligands （2a-2b） （2-R-6-PPh2-C6H2S） VC12（THF）2 （2a： R = H; 2b： R = MeaSi） were prepared from VCla（THF）3 by treating with 1.0 equiv of the ligand in tetrahydrofuran in the presence of excess triethylamine. The two complexes were characterized by FTIR and mass spectra as well as elemental analyses. On activation with Et2AIC1, these complexes exhibited high catalytic activities （up to 22.1 kg PE/（mmolv.h.bar）） even at high temperature （70 ℃）, and produced high molecular weight polymers with unimodal molecular weight distributions, indicating the polymerization took place in a single-site nature. This result may be attributed to benefits of introduction of second-row donor atoms for adjusting charge density of the vanadium centers. In addition, these complexes also exhibited high catalytic activities for ethylene/1-hexene copolymerization. Catalytic activity, comonomer incorporation and polymer molecular weight can be controlled in a wide range by the variation of catalyst structure and the reaction parameters such as A1/V molar ratio, comonomer feed concentration and polymerization reaction temperature.
基金
supported by the National Natural Science Foundation of China (No. 21234006)
