Document Detail


Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP.
MedLine Citation:
PMID:  20625541     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
We report on the block copolymerization of two structurally different norbornene monomers (+/-)-endo,exo-bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid dimethylester (7), and (+/-)-endo,exo-bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid bis(1-oxyl-2,2,6,6-tetramethyl-piperidin-4-yl) ester (9) using ruthenium based Grubbs' type initiators [(PCy(3))(2)Cl(2)Ru(benzylidene)] G1 (PCy(3) = tricyclohexylphosphine), [(H(2)IMes)(PCy(3))Cl(2)Ru(benzylidene)] G2 (H(2)IMes = 1,3-bis(mesityl)-2-imidazolidinylidene), [(H(2)IMes)(py)(2)Cl(2)Ru(benzylidene)] G3 (py = pyridine or 3-bromopyridine) and Umicore type initiators [(PCy(3))(2)Cl(2)Ru(3-phenylinden-1-ylidene)] U1 (PCy(3 )= tricyclohexylphosphine), [(H(2)IMes)(PCy(3))Cl(2)Ru(3-phenylinden-1-ylidene)] U2 (H(2)IMes = 1,3-bis(mesityl)-2-imidazolidinylidene), [(H(2)IMes)(py)Cl(2)Ru(3-phenylinden-1-ylidene)] U3 (py = pyridine or 3-bromopyridine) via ring opening polymerization (ROMP). The crossover reaction and the polymerization kinetics were investigated using matrix assisted laser desorption ionization mass spectroscopy (MALDI-TOF) and nuclear magnetic resonance (NMR), respectively. MALDI showed that there was a complete crossover reaction after the addition of 25 equivalents of the second monomer. NMR investigation showed that U3 gave a faster rate of polymerization in comparison to U1. The synthesis of block copolymers with molecular weights up to M(n) = 31 000 g/mol with low polydispersities (M(w)/M(n) = 1.2) is reported.
Authors:
Olubummo Adekunle; Susanne Tanner; Wolfgang H Binder
Publication Detail:
Type:  Journal Article     Date:  2010-06-01
Journal Detail:
Title:  Beilstein journal of organic chemistry     Volume:  6     ISSN:  1860-5397     ISO Abbreviation:  Beilstein J Org Chem     Publication Date:  2010  
Date Detail:
Created Date:  2010-07-13     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101250746     Medline TA:  Beilstein J Org Chem     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  59     Citation Subset:  -    
Affiliation:
Institute of Chemistry, Faculty of Natural Sciences II (Chemistry and Physics), Martin-Luther University, Halle-Wittenberg, von Danckelmannplatz 4, D-06120 Halle, Germany.
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