Poly(alkyl ethylene phosphonate)s with different alkyl side chains exhibit significant differences in their degradation behavior. Three novel 2-alkyl-2-oxo-1,3,2-dioxaphospholanes, cyclic monomers for the ring-opening polymerization (ROP) toward poly(alkyl alkylene phosphonate)s, were synthesized by robust two- or three-step protocols in reasonable yields and high purity. The polymerization was promoted by the organocatalysts 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and proceeded with high control over molecular weight and narrow molecular weight distributions (Đ < 1.2) up to full conversion. These polymers with methyl, ethyl, and isopropyl side chains are perfectly soluble in water (up to 25 mg mL^–1) without a temperature-dependent phase separation. They showed no toxicity against HeLa cells after 24 h of incubation at any tested concentration. Polymers with butyl side chains exhibit decreased solubility and concentration-dependent cloud point temperatures and show toxicity against HeLa cells at concentrations above 25 μg mL^–1. The polymers showed no acetylcholinesterase inhibition. All polymers exhibited significantly different degradation times under both neutral as well as basic conditions (variation of the alkyl side chain allowed stabilities from 8 h up to 6 days).

中文翻译：

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水解度可调节的定义明确且水溶性的聚（膦酸烷基酯）库

具有不同烷基侧链的聚（烷基亚乙基膦酸酯）在其降解行为方面显示出显着差异。通过稳健的两步或三步规程合成了3种新颖的2-烷基-2-氧代1,3,2-二氧杂膦酸根酯（面向聚（烷基亚烷基膦酸酯）的开环聚合（ROP）的环状单体。产量合理，纯度高。有机催化剂1,8-二氮杂双环[5.4.0]十一碳-7-烯（DBU）和1,5,7-三氮杂双环[4.4.0] dec-5-烯（TBD）促进了聚合反应，控制分子量和窄分子量分布（Đ <1.2）直至完全转化。这些具有甲基，乙基和异丙基侧链的聚合物可完美溶于水（最高25 mg mL ^–1），而无需进行与温度相关的相分离。在任何测试浓度下孵育24小时后，它们均未显示出对HeLa细胞的毒性。具有丁基侧链的聚合物在浓度高于25μgmL ^–1时，溶解度和浓度依赖的浊点温度降低，并且对HeLa细胞具有毒性。该聚合物没有显示出乙酰胆碱酯酶抑制作用。在中性和碱性条件下，所有聚合物均表现出明显不同的降解时间（烷基侧链的变化允许8h至6天的稳定性）。