Benzophenothiazine and benzophenoxazine photosensitizers for triarylsulfonium salt cationic photoinitiators

Abstract

An investigation of the photosensitization of triarylsulfonium salts at wavelengths greater than 400 nm was carried out with phenothiazine and phenoxazine compounds possessing extended benzenoid conjugation. Accordingly, three isomeric benzophenothiazines and 12H-benzo[b]phenoxazine were prepared and employed for the photosensitization of several different types of triarylsulfonium salts. These compounds display a tail absorption that extends at least to 450 nm, making them useful for conducting photopolymerizations using long wavelength emission sources. The photosensitized vinyl and ring-opening polymerizations of a number of monomers were conducted and the results are reported in this communication. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: [3820][3821][3822][3823][3824][3825][3826][3827][3828][3829] 2008

“Kick-Starting” oxetane photopolymerizations

“…Considering the high sensitivity of the current “kick‐started” oxetane systems, it was of interest to demonstrate that these materials can be photosensitized to long wavelength UV and visible radiation. Recently, phenothiazines and benzoxazines were reported to be efficient photosensitizers for the photolysis of triarylsulfonium salts . Accordingly, two sample 4:1 molar mixtures of POX and LDO containing 1 mol % SOC‐10 were prepared.…”

Phenyl Benzo[b]phenothiazine as a Visible Light Photoredox Catalyst for Metal‐Free Atom Transfer Radical Polymerization

“…In this Communication we expand the scope of photoinduced metal‐free ATRP by utilizing phenyl benzo[ b ]phenothiazine (Ph‐benzoPTZ) as a visible light activated photoredox catalyst to promote ATRP of methacrylate monomers under LED irradiation. Due to more extended conjugation, with respect to Ph‐PTZ, the Ph‐benzoPTZ photocatalyst exhibits a stronger absorption in the visible light region, around 400 nm . In this area Ph‐PTZ is transparent and shows a very weak absorption.…”

Major adverse limb events and wound healing following infrapopliteal artery stent implantation in patients with critical limb ischemia: The XCELL trial

“…Therefore, the development of long wavelength light absorbing photosensitizers has become an important subject. Hitherto, curcumin,22 carbazole derivatives,23 benzophenothiazine and benzophenooxazine,24 dithienothiophene,25 and quinoxaline derivatives26, 27 were reported to work as efficient photosensitizers for PCPs.…”