Coumarin‐4‐ylmethyl‐ and p‐hydroxyphenacyl‐based photoacid generators with high solubility in aqueous media: synthesis, stability and photolysis

  • (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.

Download full text files

Export metadata

Metadaten
Author:Karishma K. Adatia, Thomas Halbritter, Matiss Reinfelds, Andre Michele, Michael Tran, Sabine Laschat, Alexander HeckelORCiDGND, Günter E. M. Tovar, Alexander Southan
URN:urn:nbn:de:hebis:30:3-565054
DOI:https://doi.org/10.1002/cptc.201900258
ISSN:2367-0932
Parent Title (German):ChemPhotoChem
Publisher:Wiley-VCH GmbH
Place of publication:Weinheim
Document Type:Article
Language:English
Date of Publication (online):2019/12/16
Date of first Publication:2019/12/16
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2020/10/29
Tag:coumarin-4-ylmethyl; p-hydroxyphenacyl; photoacid generator; photolysis; stability; water solubility
Volume:4.2020
Issue:3
Page Number:11
First Page:207
Last Page:217
HeBIS-PPN:471418595
Institutes:Biochemie, Chemie und Pharmazie / Biochemie und Chemie
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 4.0