These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
2 files

Photoacid Generators Activated Through Sequential Two-Photon Excitation: 1-Sulfonatoxy-2-alkoxyanthraquinone Derivatives

submitted on 12.01.2021, 19:47 and posted on 13.01.2021, 12:44 by Andrea Zeppuhar, Steven Wolf, Daniel Falvey
Two sulfonate ester derivatives of anthraquinone, 1-tosyloxy-2-methoxy-9,10-anthraquinone (1a) and 1-trifluoromethylsulfonoxy-2-methoxy-9,10-anthraquinone (1b) were prepared and their ability to produce strong acids upon photoexcitation was examined. It is shown that these compounds generate acid with a yield that increases with light intensity when the applied photon dose is held constant. Additional experiments show that the rate of acid generation increases 4 fold when visible light (532 nm) laser pulses are combined with ultraviolet (355 nm) compared with ultraviolet alone. Continuous wave diode laser photolysis also effects acid generation with a rate that depends quadratically on the light intensity. Density functional theory calculations, laser flash photolysis, and chemical trapping experiments support a mechanism whereby an initially formed triplet state (T1) is excited to a higher triplet state which in turn undergoes homolysis of the RS(O2)–OAr bond. Secondary reactions of the initially formed sulfonyl radicals produce strong acids. It is demonstrated that high intensity photolysis of either 1a or 1b can initiate cationic polymerization of ethyl vinyl ether.


ACS PRF 60034-ND4


Email Address of Submitting Author


University of Maryland, College Park MD



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest.