Poly(p-phenylene vinylene)s (PPVs), a staple of the conductive polymer family, consist of alternating alkene and phenyl groups in conjugation. The physical properties of this organic material are intimately linked to the cis/trans configuration of the alkene groups. While many synthetic methods afford PPVs with all-trans stereochemistry, very few deliver the all-cis congeners. We report herein a synthesis of all-cis PPVs with living characteristics via stereoretentive ring-opening metathesis polymerization (ROMP). Exquisite catalyst control allows for the preparation of homopolymers or diblock copolymers with perfect stereoselectivity, narrow dispersities, and predictable average molar masses. All-cis PPVs can then serve as light-responsive polymers through clean photoisomerization of the stilbenoid units.

中文翻译：

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立体保持开环复分解聚合获得具有活性特征的全顺式聚（对亚苯基亚乙烯基）

聚（对亚苯基亚乙烯基）（PPV）是导电聚合物家族的主要产品，由交替共轭的烯烃和苯基组成。这种有机材料的物理性质与烯烃基团的顺式/反式构型密切相关。虽然许多合成方法提供具有全反式立体化学的 PPV，但很少提供全顺式同源物。我们在此报告了通过立体保留开环复分解聚合（ROMP）合成具有活性特征的全顺式 PPV。精确的催化剂控制允许制备具有完美立体选择性、窄分散性和可预测平均摩尔质量的均聚物或二嵌段共聚物。然后，全顺式 PPV 可以通过二苯乙烯单元的清洁光异构化作为光响应聚合物。