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Titolo:
Protonation of the heterocyclic Cp-anion equivalent [pyrrolyl-B(C6F5)(3)]Li - Formation of a useful neutral Bronsted acid for the generation of homogeneous metallocene Ziegler catalysts
Autore:
Kehr, G; Roesmann, R; Frohlich, R; Holst, C; Erker, G;
Indirizzi:
Univ Munster, Inst Organ Chem, D-48149 Munster, Germany Univ Munster Munster Germany D-48149 rgan Chem, D-48149 Munster, Germany
Titolo Testata:
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
fascicolo: 2, , anno: 2001,
pagine: 535 - 538
SICI:
1434-1948(200102):2<535:POTHCE>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
OLEFIN POLYMERIZATION; COORDINATION CHEMISTRY; TRIS(PENTAFLUOROPHENYL)BORANE; COMPLEXES; CYCLOPENTADIENYL; FLUOROCARBONS; ZIRCONIUM; TITANIUM;
Keywords:
protonations; heterocycles; homogeneous catalysis; bronsted acids; zirconium;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
35
Recensione:
Indirizzi per estratti:
Indirizzo: Erker, G Univ Munster, Inst Organ Chem, Corrensstr 40, D-48149 Munster, Germany Univ Munster Corrensstr 40 Munster Germany D-48149 ster, Germany
Citazione:
G. Kehr et al., "Protonation of the heterocyclic Cp-anion equivalent [pyrrolyl-B(C6F5)(3)]Li - Formation of a useful neutral Bronsted acid for the generation of homogeneous metallocene Ziegler catalysts", EUR J INORG, (2), 2001, pp. 535-538

Abstract

N-pyrrolyllithium (1) adds to B(C6F5)(3) to yield [(C4H4N)B(C6F5)(3)]Li (3) The corresponding monoetherate (3 . OEt2) was characterized by X-ray diffraction and shows an eta (5) coordination of the pyrrolyl moiety to the Lithium cation. Treatment of 3 with HCl in ether leads to H+ addition at a pyrrolyl a-position to yield the neutral dipolar Bronsted acid system [(C4H5N)B(C6F5)(3)] (4) The reagent 4 can be used to protonate Cp2Zr(CH3)(3) to yield [Cp2Zr(CH3)(+)(C4H4N)B(C6F5)(3)(-)] (6) and methane. H+ transfer from 4 to (butadiene)-zirconocene results in the formation of the (pi -allyl)metallocene salt [(C4H7)ZrCp2+(C4H4N)B(C6F5)(3)(-)] (8). In analogous reactions.the neutral Bronsted acid was employed as a protonating activator component for the generation of homogeneous Ziegler catalysts derived from a variety of (butadiene)or (dimethyl)ansa-metallocenes. The systems generated by treatment with 4 show comparable activities in ethene or propene polymerization reactions as conventionally generated Group 4 metallocene Ziegler catalysts.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 12:06:13