Novel cyclic olefin copolymer (COC) with high glass transition temperature, good mechanical performance, high transparency, and excellent film forming ability has been achieved in this work by effective copolymerization of ethylene and exo-1,4,4a,9,9a,10-hexahydro-9,10(1′,2′)-benzeno-l,4-methanoanthracene (HBMN). This bulky cyclic olefin comonomer can be simply prepared in good yield via Diels−Alder reaction. By utilizing constrained geometry catalyst (CGC) activated with Al( i Bu) 3 /[Ph 3 C][B(C 6 F 5 ) 4 ], ethylene/HBMN copolymer can be obtained with excellent production, high molecular weight, and a wide range of HBMN incorporation. 13 C NMR (DEPT) spectra reveal alternating ethylene−HBMN sequence can be detected at high HBMN incorporation. The glass transition temperature (T g ) of resulted copolymer enhances with increasing HBMN incorporation. A high T g up to 207.0°C is attainable at low comonomer incorporation of 30.4 mol %, which is 61°C higher than that of commercial norbornene (NB)-derived COC (54 mol %). The tensile test indicates that the ethylene/HBMN copolymer has good mechanical performance which is more flexible than ethylene/NB copolymer and the previously reported COC even at a higher T g level.

Vanadium(III) complexes bearing tridentate salicylaldiminato ligands (2a-f) [OC 6 H 4 CHdNL]-VCl 2 (THF) (L ) CH 2 CH 2 OMe, 2a; CH 2 CH 2 NMe 2 , 2b; CH 2 C 5 H 4 N, 2c; 8-C 9 H 6 N (quinoline), 2d; 2-MeSC 6 H 4 , 2e; 2-Ph 2 PC 6 H 4 , 2f) and tridentate β-enaminoketonato ligands [OC 6 H 8 CHdN-2-Ph 2 PC 6 H 4 ]VCl 2 (THF) (2g) and [O(Ph)CdCHCHdN-2-Ph 2 PC 6 H 4 ]VCl 2 (THF) (2h) were prepared from VCl 3 (THF) 3 by treating with 1.0 equiv of the deprotonated ligands in tetrahydrofuran (THF). These complexes were characterized by FTIR and mass spectrometry as well as elemental analysis. Structures of complexes 2e, 2f, and 2h were further confirmed by X-ray crystallographic analysis. These complexes were investigated as catalysts for olefin polymerization in the presence of organoaluminum compounds. On activation with Et 2 AlCl, complexes 2a-h exhibited high catalytic activities toward ethylene polymerization (up to 20.64 kg PE/mmol V • h • bar) even at high temperature, suggesting these catalysts possess high thermal stability. Moreover, high molecular weight polymers with unimodal molecular weight distribution can be obtained, indicating the single site behavior of these catalysts. The copolymerizations of ethylene and norbornene or 1-hexene with catalysts 2a-h were also explored in the presence of Et 2 AlCl, which led to high molecular weight poly(ethylene-co-1-hexene)s (M w up to 138 000) and poly(ethyleneco-norbornene)s (M w up to 164 000). 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 Al/V molar ratio, comonomer feed concentration, and polymerization reaction temperature.