Dicationic ruthenium(II) complexes containing bridged eta(1):eta(6)-phosphinoarene ligands for the ring-opening metathesis polymerization

Citation
A. Abele et al., Dicationic ruthenium(II) complexes containing bridged eta(1):eta(6)-phosphinoarene ligands for the ring-opening metathesis polymerization, J MOL CAT A, 160(1), 2000, pp. 23-33
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
ISSN journal
1381-1169 → ACNP
Volume
160
Issue
1
Year of publication
2000
Pages
23 - 33
Database
ISI
SICI code
1381-1169(20001023)160:1<23:DRCCBE>2.0.ZU;2-1
Abstract
Tertiary phosphines with pendant arenes R2PR' (R = Cy, Ph; R' = CH2CH2Ph or CH2CHPh2) (1-4) were synthesized and converted to the corresponding chelat ing ruthenium(II) complexes [RuCl2(eta(1):eta(6)-R2PR')] (1a-4a). Halide ex change yielded [RuI2(eta(1):eta(6)-R2PR')] (1b,3b), which were structurally characterized by single crystal X-ray diffraction. The systems (la,2a,4a) were activated for ROMP of norbornene by addition of a diazo compound (trim ethylsilyldiazomethane) and AgBF4 (A), by a diazo compound alone (B) or by a combination of the sodium salt NaB(Ar-f)(4)(Ar-f = 3,5-(CF3)(2)C6H3) and methanol (C). The influence of the thereby created differing number of acce ssible coordination sites on the polymerization activity and the polymer mi crostructure (cis/trans ratio) was investigated. The nucleophilicity of the counter ion was found to play a crucial role in terms of catalytic activit y. (C) 2000 Elsevier Science B.V. All rights reserved.