- New zirconocenes with 4,5,6,7-tetrahydroindene ligands. Synthesis and catalytic activity in the polymerization of ethylene and copolymerization of ethylene with hex-1-ene
-
A series of symmetric and nonsymmetric tetrahydroindenyl zirconium complexes was obtained by the reaction of ZrCl4 or (CpTMS)ZrCl3 with lithium salts of the corresponding tetrahydroindenes. Activated with methylalumoxane, these complexes exhibit high activity in polymerization of ethylene (up to 6.8?106 g PE (mol Zr h)–1), as well as in copolymerization of ethylene and hex-1-ene (up to 8.6?106 g PE (mol Zr h)–1).
- Asachenko,Bush,Smirnov, A. Yu.,Morozov,Dzhevakov,Kim,Cho,Lee,Lee,Cho,Lee,Nechaev
-
p. 1580 - 1585
(2017/03/01)
-
- The effect of phenyl substituents on the activity of some zirconocene photoinitiators
-
In this paper we report the synthesis of several unbridged zirconocenes, 1a-c, 2 and 5, each bearing a phenyl substituent in the 2-position of the cyclopentadienyl ring. We also report their photochemical behaviour and we compare the results with those obtained with the corresponding unsubstituted metallocenes 3a-c and 4. Study of their electronic spectra and EPR/spin trapping experiments showed photogeneration of ligand- and zirconium-centred radicals, thus making these complexes suitable as photoinitiators for radical polymerisation processes. The substitution of the hydrogen atom in the 2-position with a phenyl group had positive effects both on the absorption coefficients, improving the light absorption efficiency, and on the reaction yields of tert-butyl acrylate polymerisation. These results can be explained in terms of the combined effects of greater persistence of the radical in solution and/or increased efficiency of the radical in initiating the polymerisation process. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Polo, Eleonora,Barbieri, Andrea,Traverso, Orazio
-
p. 324 - 330
(2007/10/03)
-
- Electronic effects of bis(2-aryl-4,5,6,7-tetrahydroindenyl)titanocene dichlorides on the catalytic epoxidation of trans-3-hexene
-
The catalytic epoxidation of trans-3-hexene with electronically different bis(2-aryl-4,5,6,7-tetrahydroindenyl)titanium dichloride complexes in the presence of stoichiometric tert-butylhydroperoxide has been studied.The results show that both electron don
- Halterman, Ronald L.,Ramsey, Timothy M.
-
p. 175 - 180
(2007/10/02)
-