Living metathesis polymerization of substituted acetylenes by MoOCl4–Et2Zn–EtOH and MoOCl4–n-BuLi systems

✍ Scribed by Toshio Masuda; Shigetaka Hayano; Eiji Iwawaki; Ryoji Nomura

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 202 KB
• Volume: 133
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(98)00098-3

✦ Synopsis

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. Several organometallic compounds were examined as second catalyst components cocatalysts of the MoOCl -cocata-4

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. lyst -EtOH system with the motivation of development of novel catalysts for the living polymerization of substituted acetylenes. Catalyst systems such as MoOCl -Et Zn-EtOH and MoOCl -n-BuLi have proven to be very effective for the 4 2 4 Ž living polymerization of substituted acetylenes. Suitable mole ratios of the catalyst components MoOCl :Et Zn:EtOHs 4 2 . 1:1:3 and MoOCl :n-BuLis 1:1 made it possible to achieve living polymerization of substituted acetylenes including 4 Ž . Ž . o-trifluoromethyl phenylacetylene, o-trimethylsilyl phenylacetylene, o-isopropylphenylacetylene, and 1-chloro-1-octyne.

Use of anisole instead of toluene as solvent remarkably improved the living nature of polymerization to provide polymers Ž . with extremely narrow molecular weight distributions 1.03-1.14 in quantitative yields. Sequential living polymerization of two monomers by these catalyst systems produced block copolymers with low polydispersities without the formation of homopolymers.