Novel highly active niobium catalysts for ring opening metathesis polymerization of norbornene

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

doi:10.1002/marc.200900248

Novel highly active niobium catalysts for ring opening metathesis polymerization of norbornene

Macromol Rapid Commun. 2009 Oct 19;30(20):1762-8. doi: 10.1002/marc.200900248. Epub 2009 Jul 27.

Authors

Anna Maria Raspolli Galletti¹, Guido Pampaloni, Aldo D'Alessio, Yogesh Patil, Filippo Renili, Simone Giaiacopi

Affiliation

¹ Dipartimento di Chimica e Chimica Industriale, University of Pisa, via Risorgimento 35, 56126 Pisa, Italy. roxy@dcci.unipi.it.

PMID: 21638451
DOI: 10.1002/marc.200900248

Abstract

Ring-opening metathesis polymerization (ROMP) of norbornene catalyzed by niobium(V) N,N-dialkylcarbamates Nb(O(2) CNR(2) )(5) , R = 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 (29 000 kg of polymer/mol of catalyst × 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 FT-IR and NMR spectroscopies and by DSC calorimetry. A new FT-IR method for the swift determination of the cis/trans content of the polymer is presented.