Efficiency Tuning of UVA/UVB Absorbance through Control over the Intramolecular Hydrogen Bonding of Triazine Derivatives

Abstract

We systematically designed triaryl-1,3,5-triazine (TATZ) derivatives based on 2-(4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine through inner and outer hydroxyl (OH) group substitution and analyzed their structures and electronic transitions in order to design a new UV absorber type with anti-UVA and UVB functionality. In this work, we show that UV absorption efficiency can be controlled through inner and outer OH substitution between 320-400 nm (UVA) and 280-320 nm (UVB) due to their effect on the HOMO levels of TATZ. Consequently, we propose an optimal combination of inner or outer OH substituted TATZ derivatives as novel UVA/UVB absorbers. Additionally, we elucidated the relationship between the structural parameters of intramolecular hydrogen bonding (IMHB) and the UV absorption properties of TATZ derivatives using natural bond orbital (NBO) analysis. This work shows that first principle theory-aided design can be used to develop highly efficient UV absorbers.