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Homo‐ and Copolymerization of Aromatic Diynes by Ruthenium/Acid‐Promoted (RAP) Catalysis
Author(s) -
Pasquini Chiara,
Fratoddi Ilaria,
Bassetti Mauro
Publication year - 2009
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200900748
Subject(s) - chemistry , copolymer , ruthenium , moiety , polymer chemistry , catalysis , conjugated system , fluorene , polyfluorene , polymer , dimer , acetic acid , polymerization , dextrin , yield (engineering) , organic chemistry , materials science , starch , metallurgy
9,9‐Bis(2′‐ethylhexyl)‐2,7‐diethynylfluorene ( 1 ) or 1‐(2′‐ethylhexyloxy)‐2,5‐diethynyl‐4‐methoxybenzene ( 2 ) react in the presence of the [{RuCl(μ‐Cl)( p ‐cymene)}] 2 /AcOH catalytic system to yield the corresponding poly(aryleneethynylenevinylene) π‐conjugated homopolymers, featuring the areneenyne repeat unit (Ar–C≡C–CH=CH–) and characterized by high regio‐ and stereoselectivity [( E ) > 93 %]. The copolymerization of 1 and 2 affords poly‐( E )‐FL‐ethynylenevinylene‐ co ‐( E )‐MEH‐ethynylenevinylene [FL = fluorene; MEH = 1‐(2′‐ethylhexyloxy)‐4‐methoxybenzene], as the first example of a random copolymer derived from the polyaddition process of aromatic diynes. The catalytic system of this atom‐economic polyaddition process is formed in situ from the commercially available ruthenium dimer and acetic acid and promotes the C–C coupling at room temperature. The branched 2‐ethylhexyl chains in the arene moiety assist the formation of polymers with degrees of polymerization in the range of 9–20 repeat units. The optical properties of the new polymers were studied in chloroform solution and in film and compared to those of the main classes poly(arylenevinylene) and poly(aryleneethynylene) conjugated polymers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)