TY  - JOUR
A1  - Adatia, Karishma K.
A1  - Halbritter, Thomas
A1  - Reinfelds, Matiss
A1  - Michele, Andre
A1  - Tran, Michael
A1  - Laschat, Sabine
A1  - Heckel, Alexander
A1  - Tovar, Günter E. M.
A1  - Southan, Alexander
T1  - Coumarin‐4‐ylmethyl‐ and p‐hydroxyphenacyl‐based photoacid generators with high solubility in aqueous media: synthesis, stability and photolysis
T2  - ChemPhotoChem
N2  - (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 s24h ≥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.
KW  - coumarin-4-ylmethyl
KW  - photoacid generator
KW  - p-hydroxyphenacyl
KW  - photolysis
KW  - stability
KW  - water solubility
Y1  - 2019
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/56505
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-565054
SN  - 2367-0932
VL  - 4.2020
IS  - 3
SP  - 207
EP  - 217
PB  - Wiley-VCH GmbH
CY  - Weinheim
ER  -