Polymerization of <i>tert</i>‐butylacetylene catalyzed by the bromides of molybdenum (III) and tungsten(V)

Okano, Yoshimichi; Masuda, Toshio; Higashimura, Toshinobu

doi:10.1002/pola.1987.080250421

Cited by 8 publications

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References 8 publications

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“…Materials. The monomer was prepared by the AlBr 3 -catalyzed addition of tert -butyl bromide to vinyl bromide, followed by dehydrobromination with KOH . The crude product was distilled twice from CaH 2 before use.…”

Section: Methodsmentioning

confidence: 99%

Stereospecific Polymerization of tert-Butylacetylene by Molybdenum Catalysts. Effect of Acid-Catalyzed Geometric Isomerization

et al. 1996

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Stereospecificity of the polymerization of tert-butylacetylene by Mo-based catalysts was investigated. The polymer obtained by the MoOCl4−n-Bu4Sn system just after complete monomer consumption had an all-cis structure. However, the stereoregularity decreased when the polymerization was allowed to stand further. These findings indicate that, though the propagation reaction proceeds stereospecifically, the geometric isomerization of polymer lowers stereoregularity. This isomerization was catalyzed by several acids as well as by polymerization catalysts and, hence, is an acid-catalyzed reaction. Highly stereoregular polymer could be obtained by accelerating polymerization (by use of cocatalysts) and/or by decelerating isomerization (by use of cocatalysts, poor solvents of the polymer, or the less acidic Mo(CO)6-based catalyst and by polymerization at low temperatures).

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Section: Methodsmentioning

confidence: 99%