Realizing Ultrafine Color Tuning of Organic Electronics Materials by Electronic State Informatics

Organic electrochromic (EC) materials enabling energy-efficient
smart windows, human-friendly displays, and highly transparent medical
lenses are key for a future society. However, developing organic EC
molecules that change from transparent to pure magenta, one of the
three primary colors, had been impossible through simple quantum chemical
calculations and experiments alone, as it requires sophisticated spectral
optimization involving multiple electronic transitions in neutral
and radical states. In this study, we successfully identified structures
exhibiting colorless-to-pure-magenta switching from 1.2 million triphenylamine
derivatives using electronic state descriptors easily obtained from
semiempirical molecular orbital calculations with qualitative accuracy.
Subsequent organic synthesis and spectroelectrochemical experiments
proved that the identified candidate molecules achieve the desired
functionality.