RT info:eu-repo/semantics/article
T1 Dinuclear dialkoxo-bridged cyclopentadienylsiloxo titanium complexes
A1 Postigo Galindo, Lorena
A1 Sánchez-Nieves Fernández, Javier
A1 Royo Gracia, Pascual
A1 González Mosquera, Marta Elena
K1 Cyclopentadienylsiloxo titanium
K1 Ciencia
K1 Química inorgánica
K1 Science
K1 Chemistry, inorganic
AB The dinuclear dialkoxo-bridged complexes [(TiCl)2(μ-O2L)(μ-{(η5-C5Me4SiMeO)2(μ-O)})] (O2L = 1,2-O2C2H41a, 1,2-O2C6H41b, 1,2-(OCH2)2C6H41c, O2SiPh21d) were obtained by reaction of [(TiCl2)2(μ-{(η5-C5Me4SiMeO)2(μ-O)})] (A) with the corresponding dilithium salt (1a) or diol (1b, 1c, 1d). Alkylation of 1a and 1b with ClRMg afforded [(TiR)2(μ-O2L)(μ-{(η5-C5Me4SiMeO)2(μ-O)})] (O2L = 1,2-O2C2H4, R = Me 2a, Bz 3a; O2L = 1,2-O2C6H4, R = Me 2b, Bz 3b). Addition of four equiv. of LiOiPr to A afforded [{Ti(OiPr)2}2(μ-{(η5-C5Me4SiMeO)2(μ-O)})] (4). Reaction of 1a with Al(C6F5)3 produced the elimination of the dialkoxo ligand to give [{TiCl(C6F5)}2(μ-{(η5-C5Me4SiMeO)2(μ-O)})] (5), whereas the same reaction of 1b with Al(C6F5)3 produced the oxo-alane adduct [(TiCl)2(μ-O2L)(μ-{(η5-C5Me4SiMeO)2(μ-O·Al{C6F5}3)})] (O2L = 1,2-O2C6H46) which was further transformed to give a mixture of 5 and [(TiCl){Ti(C6F5)}(μ-O2L)(μ-{(η5-C5Me4SiMeO)2(μ-O)})] (O2L = 1,2-O2C6H47). One benzyl group of complexes 3 was abstracted with E(C6F5)3 (E = B, Al) to give the monoionic compounds [Ti(TiBz)(μ-O2L)(μ-{(η5-C5Me4SiMeO)2(μ-O)})][BzE(C6F5)3] (O2L = 1,2-O2C2H4, E = B 8B, Al 8Al; O2L = 1,2-O2C6H4, E = B 9B), although 8Al was unstable in CD2Cl2 evolving to a mixture of compounds where [(TiBz)2(μ-Cl)(μ-{(η5-C5Me4SiMeO)2(μ-O)})][BzAl(C6F5)3] (10) was identified, and compound 9B was also unstable at ambient temperature. Polymerization of ε-caprolactone was only achieved with the tetraalkoxo compound 4. All of these complexes were characterized by NMR spectroscopy and 1a, 1b and 7 by X-ray diffraction studies.
PB Royal Society of Chemistry
SN 1477-9226
YR 2009
FD 2009
LK http://hdl.handle.net/10017/4168
UL http://hdl.handle.net/10017/4168
LA eng
DS MINDS@UW
RD 18-abr-2024