title: Rhodium-mediated stereoselective polymerization of "carbenes".
abstract: Unprecedented rhodium-catalyzed stereoselective polymerization of "carbenes" from ethyl diazoacetate (EDA) to give high molecular mass poly(ethyl 2-ylidene-acetate) is described. The mononuclear, neutral [(N,O-ligand)M(I)(cod)] (M = Rh, Ir) catalytic precursors for this reaction are characterized by (among others) single-crystal X-ray diffraction. These species mediate formation of a new type of polymers from EDA: carbon-chain polymers functionalized with a polar substituent at each carbon of the polymer backbone. The polymers are obtained as white powders with surprisingly sharp NMR resonances. Solution and solid state NMR data for these new polymers reveal a highly stereoregular polymer, with a high degree of crystallinity. The polymer is likely syndiotactic. Material properties are very different from those of atactic poly(diethyl fumarate) polymer obtained by radical polymerization of diethyl fumarate. Other diazoacetates are also polymerized. Further studies are underway to reveal possible applications of these new materials.
authors.affiliation: Institute for Molecules and Materials (IMM), Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
authors.forename: Dennis G H
authors.initials: DG
authors.lastname: Hetterscheid
authors.forename: Coen
authors.initials: C
authors.lastname: Hendriksen
authors.forename: Wojciech I
authors.initials: WI
authors.lastname: Dzik
authors.forename: Jan M M
authors.initials: JM
authors.lastname: Smits
authors.forename: Ernst R H
authors.initials: ER
authors.lastname: van Eck
authors.forename: Alan E
authors.initials: AE
authors.lastname: Rowan
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Busico
authors.forename: Michele
authors.initials: M
authors.lastname: Vacatello
authors.forename: Valeria
authors.initials: V
authors.lastname: Van Axel Castelli
authors.forename: Annalaura
authors.initials: A
authors.lastname: Segre
authors.forename: Erica
authors.initials: E
authors.lastname: Jellema
authors.forename: Tom G
authors.initials: TG
authors.lastname: Bloemberg
authors.forename: Bas
authors.initials: B
authors.lastname: de Bruin