(Coumarin‐4‐yl)methyl (c4m) and p‐hydroxyphenacyl (pHP)‐based compounds are well known for their highly efficient photoreactions, but often show limited solubility in aqueous media. To circumvent this, we synthesized and characterized the two new c4m and pHP‐based photoacid generators (PAGs), 7‐[bis(carboxymethyl)amino]‐4‐(acetoxymethyl)coumarin (c4m‐ac) and p‐hydroxyphenacyl‐2,5,8,11‐tetraoxatridecan‐13‐oate (pHP‐t), and determined their solubilities, stabilities and photolysis in aqueous media. The two compounds showed high solubilities in water of 2.77 mmol L⁻¹±0.07 mmol L⁻¹ (c4m‐ac) and 124.66 mmol L⁻¹±2.1 mmol L⁻¹ (pHP‐t). In basic conditions at pH 9, solubility increased for c4m‐ac to 646.46 mmol L⁻¹±0.63 mmol L⁻¹, for pHP‐t it decreased to 34.68 mmol L⁻¹±0.62 mmol L⁻¹. Photochemical properties of the two PAGs, such as the absorption maxima, the maximum molar absorption coefficients and the quantum yields, were found to be strongly pH‐dependent. Both PAGs showed high stabilities s_24h ≥95 % in water for 24 h, but decreasing stability with increasing pH value due to hydrolysis. The present study contributes to a clearer insight into the synthesis, solubilities, stabilities, and photolysis of c4m and pHP‐based PAGs for further photochemical applications when high PAG concentrations are required, such as in polymeric foaming.

中文翻译：

---

在水性介质中具有高溶解度的基于香豆素-4-烷基甲基和对羟基苯甲酰基的光产酸剂：合成，稳定性和光解作用

（香豆素-4-基）甲基（c4m）和对羟基苯甲酰（p HP）基化合物因其高效的光反应而闻名，但通常在水性介质中的溶解度有限。为了避免这种情况，我们合成并表征了两种基于c4m和p HP的新型光酸产生剂（PAG），即7- [双（羧甲基）氨基] -4-（乙酰氧基甲基）香豆素（c4m-ac）和p-羟基苯酰基-2 ，5,8,11-四氧杂癸酸酯-13-酸酯（p HP-t），并确定它们在水性介质中的溶解度，稳定性和光解作用。两种化合物在水中的溶解度高，分别为2.77 mmol L ^-1 ±0.07 mmol L ^-1（c4m‐ac）和124.66 mmol L ^-1 ±2.1 mmol L ^-1（p HP-t）。在碱性条件下，pH为9时，c4mac的溶解度增加至646.46 mmol L ^-1 ±0.63 mmol L ^-1，而对于p HP‐t则降低至34.68 mmol L ^-1 ±0.62 mmol L ^-1。发现两个PAG的光化学特性（例如最大吸收值，最大摩尔吸收系数和量子产率）与pH密切相关。两种PAG均在水中24h≥95％时显示_24h的高稳定性，但由于水解而随着pH值的增加而降低了稳定性。本研究有助于更清楚地了解c4m和p的合成，溶解度，稳定性和光解作用当需要高PAG浓度时，例如在聚合物发泡中，基于HP的PAG可以用于进一步的光化学应用。