Efficient Self‐Contained Photoacid Generator System Based on Photochromic Terarylenes

Abstract

A series of highly sensitive neutral photoacid generators (PAGs) based on photochromic terarylenes was prepared. Like the example presented herein, these compounds show a subsequent thermal elimination of a Brønsted acid after a light-triggered 6π-electrocyclization, concomitant with the hexatriene aromatization. A novel type of molecular systems was developed, in which one thiazolyl moiety was replaced by a thienyl group. Depending on the solvents and on the nature of the acid source, the quantum yield (QY) for acid generation could reach up to 0.6. Comparative studies on the acid source clearly showed that aromatic leaving groups tend to extinguish the molecular system photoefficiency. A second type was also prepared, in which the nature of the hetero-aromatic rings were identical to our previous example, but their sequence was modified. Therefore, a second level of improvement was achieved in nonpolar solvents, pushing the QY value up to 0.7. Finally, we demonstrated the mesylic acid-releasing PAG as a photocatalyst in a chemically amplified positive resist system.

Photoinduced 6π-Electrocyclization of a 1,3,5-Hexatriene System Containing an Allomaltol Fragment

“…Thus, tosylated oxazol-2­(3 H )-one 18a can be considered as a photoacid generator (PAG). Note that PAGs are widely used in various fields of science and technology, including microlithographic imaging with photoresists, photocuring, and rapid prototyping (3D printing), in which PAGs are employed as a phototrigger of cationic polymerization . The proposed method can also be extended to the photogeneration of various carboxylic acids.…”

Switching the Mallory Reaction to Synthesis of Naphthalenes, Benzannulated Heterocycles, and Their Derivatives

“…Note that not only the compound with a methyl group but also the diarylethene with a methoxy group as a blocking substituent underwent this reaction. This is very unusual because normally methanol (or other low molecular weight compounds) is eliminated in such cases, as it was reported, for example, for related diarylethenes 35 …”

Using a visible light-triggered pH switch to activate nanozymes for antibacterial treatment

“…To overcome this problem, we introduced a photoacid generator (PAG) to a nanozyme/H 2 O 2 antibacterial system. PAGs, as photoinduced acid sources, 12 attract widely attention due to their wide applications in photolithography, polymerization, and stimuli-responsive systems. 13 Especially, PAGs possess the ability to induce proton dissociation under light irradiation, thus changing pH of an aqueous solution.…”