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Titolo:
PALLADIUM(II)-CATALYZED OLEFIN ADDITION POLYMERIZATIONS OF 3,3-DIALKYL-SUBSTITUTED CYCLOPROPENES
Autore:
RUSH S; REINMUTH A; RISSE W;
Indirizzi:
NATL UNIV IRELAND UNIV COLL DUBLIN,DEPT CHEM DUBLIN 4 IRELAND NATL UNIV IRELAND UNIV COLL DUBLIN,DEPT CHEM DUBLIN 4 IRELAND
Titolo Testata:
Macromolecules
fascicolo: 24, volume: 30, anno: 1997,
pagine: 7375 - 7385
SICI:
0024-9297(1997)30:24<7375:POAPO3>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
MONOXIDE ALTERNATING COPOLYMERIZATION; CARBON-MONOXIDE; NORBORNENE DERIVATIVES; PALLADIUM(0) CATALYSTS; ALKYLIDENE COMPLEXES; MECHANISTIC ASPECTS; ETHYLENE; PROPENE; STEREOCHEMISTRY; POLY(1-OXO-2-PHENYLTRIMETHYLENE);
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
83
Recensione:
Indirizzi per estratti:
Citazione:
S. Rush et al., "PALLADIUM(II)-CATALYZED OLEFIN ADDITION POLYMERIZATIONS OF 3,3-DIALKYL-SUBSTITUTED CYCLOPROPENES", Macromolecules, 30(24), 1997, pp. 7375-7385

Abstract

Ionic (4-allyl)palladium complexes containing bidentate 2,2'-bipyridyl, sparteine and C-2-symmetric bisoxazoline ligands and weakly coordinating anions catalyze the addition polymerization of 3,3-dialkylcyclopropenes. Poly(3,3-dimethylcyclopropene), poly(3-ethyl-3-methylcyclopropene) and poly(3-n-pentyl-3-methylcyclopropene) with molecular weightsM-n(GPC) above 10 000 are formed which are nearly exclusively composed of triangular repeating units. In contrast, partial ring-opening occurs during polymerizations with ionic palladium tetrakis(nitrile) complexes [Pd(RCN)(4)][BF4](2) which contain relatively labile nitrile ligands. The latter reactions lead to polymers which contain approximately 50% ring-opened unsaturated repeating units. The polymerizations carried out in the presence of the C-2-symmetric phenyl-substituted bisoxazoline ligand and with the (-)-sparteine-based catalyst lead to partially stereoregular polymers which contain a slight excess of meso units. Assignment of C-13 NMR spectra was aided with a quatercyclopropyl model compound composed of exclusively racemic units. The polycyclopropenes are partially crystalline and show a relatively good short term thermal stability with TGA investigations indicating onset of thermallyinduced weight loss above 280 degrees C.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/12/20 alle ore 07:08:44