A Highly Efficient UV‐C Absorber Based on Theoretical and Experimental Studies

Abstract

Based on two published UV absorbing molecules 2-(5 0 -tert-butyl-2 0 -hydroxyl)benzotriazole (Tinuvin-PS) and hydroxybenzophenone (HBP), both having characteristic absorption capability, a refined UV absorber, 2-(3 0 -benzoyl-2 0 -hydroxy-5 0 -tert-butylphenyl)benzotriazole, has been synthesized. This new UV absorber exhibits a wider absorption range and better thermal stability compared to either Tinuvin-PS and HBP and a higher absorption efficiency in the UV-C range. Theoretical studies reveal that the UV-C absorption arises from the electron density transfer from the Tinuvin-PS moiety to the HBP moiety and the enhanced absorption efficiency is ascribed to the presence of the carbonyl's π system.

Azaindolizine proton cranes attached to 7-hydroxyquinoline and 3-hydroxypyridine: a comparative theoretical study

“…Among PT processes, excited-state intramolecular PT (ESIPT) [3][4][5][6] plays a substantial role in the design of fluorescent sensors, imaging agents and emitters, [7][8][9][10][11][12][13][14][15] as well as in the development of UV absorbers. [16][17][18][19][20][21] Depending on the distance that has to be overcome for the PT, from one side of the tautomeric compound to another, the process can be performed in a number of specific ways, assuming that the process is truly intramolecular. When direct intramolecular PT (IPT) takes place in the case of short-range intramolecular interactions via strong intramolecular hydrogen bonding (IHB), there are no concerns about steric factors, solvent or large reaction barrier.…”

“…Among PT processes, excited-state intramolecular PT (ESIPT) 3–6 plays a substantial role in the design of fluorescent sensors, imaging agents and emitters, 7–15 as well as in the development of UV absorbers. 16–21…”