Production of polyketone realizes the direct conversion of cost effective and abundant olefin and carbon monoxide (CO) monomers. However, copolymerization of ethylene with CO shows a high tendency for the formation of strictly alternating structures, and they feature a high melting temperature () of 260 °C that impedes the processing by using the conventional injection molding and extrusion. Nonalternating preference in such copolymerization is a very promising method to circumvent the processability issues. In this study, we present a series of phosphine-sulfonate Pd catalysts for nonalternating copolymerization of ethylene and CO, since rare study has investigated the electronic and steric nature systematically in such ligand platform in this field. The usage of dicyclohexyl substituents on phosphorus moiety exhibits unexpected nonalternating preference with up to 29.2 mol% extra ethylene incorporation, thus lowing the values to 162 °C. Notably, such alkyl substituted phosphine sulfonate Pd catalyst exhibits high thermally robust nature in this nonalternating copolymerization.

中文翻译：

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烷基膦发挥作用：用于乙烯与一氧化碳非交替共聚的高度稳健的膦磺酸钯 (II) 催化剂

聚酮的生产实现了成本有效且丰富的烯烃和一氧化碳（CO）单体的直接转化。然而，乙烯与CO的共聚显示出形成严格交替结构的高趋势，并且它们具有260℃的高熔融温度（），这阻碍了使用传统的注塑和挤出进行加工。这种共聚中的非交替偏好是一种非常有前途的解决加工性能问题的方法。在这项研究中，我们提出了一系列用于乙烯和CO非交替共聚的膦磺酸钯催化剂，因为很少有研究系统地研究该领域此类配体平台的电子和空间性质。在磷部分上使用二环己基取代基表现出意想不到的非交替偏好，额外引入高达 29.2 mol% 的乙烯，从而将值降低至 162 °C。值得注意的是，这种烷基取代的膦磺酸钯催化剂在这种非交替共聚中表现出高耐热性。