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Novel Highly Active Niobium Catalysts for Ring Opening Metathesis Polymerization of Norbornene

โœ Scribed by Anna Maria Raspolli Galletti; Guido Pampaloni; Aldo D'Alessio; Yogesh Patil; Filippo Renili; Simone Giaiacopi

Publisher
John Wiley and Sons
Year
2009
Tongue
English
Weight
189 KB
Volume
30
Category
Article
ISSN
1022-1336

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โœฆ Synopsis

Abstract

Ringโ€opening metathesis polymerization (ROMP) of norbornene catalyzed by niobium(V) N,Nโ€dialkylcarbamates Nb(O~2~CNR~2~)~5~, Rโ€‰=โ€‰Et (1), Me (2) was studied in the presence of methylaluminoxane (MAO) as a cocatalyst. These novel catalytic systems resulted very active in chlorobenzene: 1 in the presence of methylaluminoxane catalyzes the ROMP of norbornene with the highest activity (29โ€‰000โ€‰kg of polymer/mol of catalystโ€‰ร—โ€‰hour) never reported up to now for niobium catalysts. The high productivity appears particularly attractive considering that these precursors are rather cheap and easy to synthesize and to handle. Polynorbornenes were characterized by FTโ€IR and NMR spectroscopies and by DSC calorimetry. A new FTโ€IR method for the swift determination of the cis/trans content of the polymer is presented.

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๐Ÿ“œ SIMILAR VOLUMES

Effect of Cocatalysts on the Catalytic A
Effect of Cocatalysts on the Catalytic Activities of Tantalum- and Niobium-Based Catalysts for Ring-Opening Metathesis Polymerization of Norbornene
โœ Yuushou Nakayama; Masaya Tanimoto; Takeshi Shiono ๐Ÿ“‚ Article ๐Ÿ“… 2007 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 128 KB

## Abstract A series of pentavalent tantalum and niobium complexes with aryloxy ligands was prepared, and their catalytic behavior for the ROMP of norbornene was studied in the presence of an alkylaluminum cocatalyst. Tantalum complexes **1**โ€“**4** showed very high activity for the ROMP of NBE in c