Showing papers by "Marc A. Hillmyer published in 1992"
TL;DR: The ring-opening metathesis polymerization (ROMP) of exo-N-methyl-7-oxabicyclo[2.2]-hept-5-ene-2,3-dicarboximide (1) was accomplished in aqueous solution under mild conditions using the simple ruthenium(II) coordination complex Ru(II)(H_2O)_6(tos)_2 (tos = p-toluenesulfonate) (2).
Abstract: The ring-opening metathesis polymerization (ROMP) of exo-N-methyl-7-oxabicyclo[2.2.1]-hept-5-ene-2,3-dicarboximide (1) was accomplished in aqueous solution under mild conditions using the simple ruthenium(II) coordination complex Ru^(II)(H_2O)_6(tos)_2 (tos = p-toluenesulfonate) (2). The polymerization yield was nearly quantitative. The resultant high molecular weight polymer (poly-1) exhibited a glass transition temperature (T_g) of 225 °C and was thermally stable up to 402 °C. The thermal and radiative stabilities of poly-1 were further investigated. Poly-1 was hydrogenated to yield its saturated analogue, which had a lower T_g (170 °C) but a higher temperature of decomposition (430 °C). Complex 2 was deactivated by coordination of free maleimides formed during the polymerization of carboximide-functionalized monomers capable of undergoing retro Diels-Alder chemistry. The scope of this polymerization was therefore limited to carboximide-functionalized monomers that are stable toward retro Diels-Alder reactions at the polymerization temperature. Both ruthenium (II)-1 and ruthenium(II)-N-methylmaleimide olefin complexes were identified.
86 citations
TL;DR: In this article, the reaction of terminal dibromoalkanes with S −2 on Al 2 O 3 has been examined, and the use of a solid support for the macrocyclization represents a viable alternate procedure to the more traditional high dilution technique in solution.
22 citations
Patent•
25 Nov 1992
TL;DR: In this paper, the authors proposed a step propagation, condensation type polymerization of acyclic dienes employing Lewis acid-free metal alkylidene complexes as catalysts.
Abstract: Novel polymerized dienes prepared by the step propagation, condensation type polymerization of acyclic dienes employing Lewis acid-free metal alkylidene complexes as catalysts.
7 citations