The cis/trans geometry of olefins is known to dramatically influence the thermal and mechanical properties of polyalkenamers. Yet, polymerization methods that efficiently control this parameter are scarce. Here we report the development of a stereoretentive acyclic diene metathesis polymerization that uses the reactivity of dithiolate Ru carbenes combined with cis monomers. These Ru catalysts exhibit exquisite retention of the cis geometry and tolerate many polar functional groups, enabling the synthesis of all-cis polyesters, polycarbonates, polyethers and polysulfites. The stereoretentive acyclic diene metathesis polymerization is also characterized by low catalyst loadings and tolerance towards trans impurities in the monomer batch, which should facilitate large-scale implementation. Modulation of the reaction temperature and time leads to an erosion of stereoretention, permitting a stereocontrolled synthesis of polyalkenamers with predictable cis:trans ratios. The impact of the stereochemistry of the repeating alkenes on the thermal properties is clearly demonstrated through differential scanning calorimetry and thermogravimetric analysis.

众所周知，烯烃的顺式/反式几何形状会极大地影响聚烯烃的热性能和机械性能。然而，有效控制该参数的聚合方法很少。在这里，我们报告了一种立体保留无环二烯复分解聚合的发展，该聚合利用二硫醇钌卡宾与顺式单体结合的反应性。这些Ru催化剂表现出对顺式几何形状的精确保留，并耐受许多极性官能团，从而能够合成全顺式聚酯、聚碳酸酯、聚醚和多亚硫酸盐。立体保留无环二烯复分解聚合还具有催化剂负载量低和对单体批次中反式杂质的耐受性的特点，这将有利于大规模实施。反应温度和时间的调节导致立体保留的侵蚀，从而允许具有可预测的顺式：反式比率的聚烯烃的立体控制合成。通过差示扫描量热法和热重分析清楚地证明了重复烯烃的立体化学对热性能的影响。