Lane Jakob D E, Shiels Gabrielle, Ramamurthi Parathan, Müllner Markus, Jolliffe Katrina A
School of Chemistry, The University of Sydney, NSW, 2006, Australia.
Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, NSW, 2006, Australia.
Macromol Rapid Commun. 2025 Apr;46(8):e2300406. doi: 10.1002/marc.202300406. Epub 2023 Oct 2.
A series of ethylene glycol-based squaramide-containing copolymers are synthesized via a post-polymerization functionalization strategy. Conversion of polymeric amines to squaramides is found to proceed in good yields, representing a versatile method of incorporating squaramides into polymers for anion recognition. Analysis of the polymers by UV-Vis and fluorescence spectroscopy revealed that anion binding takes place similarly to that of small-molecule squaramides. The presence of a fluorescent sensing group on polymer-bound squaramides allowed for a fluorescent sensing mechanism for anions that followed a similar trend in selectivity in aqueous DMSO solution, with selectivity observed for HPO , AcO and SO over other common anions tested. The anion response and selectivity towards anions is similar to that of analogous small-molecule squaramides, however polymeric squaramides exhibited a greater resistance to deprotonation by more basic anions, which is attributed to the closer proximity of individual squaramides on a macromolecule. The squaramide-containing polymers exhibited good water solubility, overcoming a common problem for anion sensors which are typically not sufficiently soluble in water to function in many required applications. Despite no anion binding being observed in water, this study represents a simple and effective method of creating fully water-soluble anion receptors which may be adapted to give improved binding affinity and selectivity depending on the anion binding moiety.
通过后聚合官能化策略合成了一系列含乙二醇基方酰胺的共聚物。发现将聚合胺转化为方酰胺的产率良好，这代表了一种将方酰胺引入聚合物以进行阴离子识别的通用方法。通过紫外可见光谱和荧光光谱对聚合物进行分析表明，阴离子结合的发生方式与小分子方酰胺类似。聚合物结合的方酰胺上存在荧光传感基团，使得在水-二甲基亚砜溶液中对阴离子的荧光传感机制在选择性上呈现相似趋势，观察到对HPO 、AcO 和SO 相对于其他测试的常见阴离子具有选择性。对阴离子的阴离子响应和选择性与类似的小分子方酰胺相似，然而聚合物方酰胺对碱性更强的阴离子去质子化表现出更大的抗性，这归因于大分子上单个方酰胺之间更近的距离。含方酰胺的聚合物表现出良好的水溶性，克服了阴离子传感器的一个常见问题，即它们通常在水中的溶解度不足以在许多所需应用中发挥作用。尽管在水中未观察到阴离子结合，但本研究代表了一种创建完全水溶性阴离子受体的简单有效方法，根据阴离子结合部分的不同，可能会有更高的结合亲和力和选择性。
