Influence of Phenyl Substitution Position on the Physical Properties of Diazachrysenes

ABSTRACT Aryl‐substituted 4,10‐diazachrysenes were synthesized to investigate the influence of substitution positions on their fundamental physical properties. A crystallographic analysis revealed that 3,9‐diphenyl diazachrysene ( 3,9‐DiPh ) adopts a planar geometry, whereas 5,11‐diphenyl derivative ( 5,11‐DiPh ) exhibits a distorted framework because of steric repulsion between the phenyl groups and diazachrysene core. Photophysical studies have shown that 3,9‐DiPh exhibits red‐shifted photoluminescence compared to the parent diazachrysene, whereas 5,11‐DiPh is non‐emissive. Furthermore, introducing substituents such as – n Bu, and –F on the phenyl rings at the 3 and 9 positions slightly modulated the absorption and emission profiles depending on the electronic nature of the substituents. These findings provide fundamental insights into the structure–property relationships of diazachrysene derivatives and offer guidance for future molecular design.