Chromogenesis of a black fluoran dye: Theoretical and spectral studies

Fluoran dyes are widely used as chromogenic reagents in thermochromic and photochromic materials due to their intrinsic halochromic properties. However, theoretical and spectral reports on fluoran-based chromic materials are still rare. This paper investigates the chromogenic mechanism of a black fluoran dye 2-(2,4Dimethylphenylamino)-3-methyl-6-diethylaminofluoran (B-15) through spectral experiments and theoretical calculations. Computational chemistry was employed to optimize the geometry of B-15 and validate a chromogenic mechanism. The proposed chromogenic structure of B-15 was further verified by infrared spectra. The chromogenic performances of B-15 by four kinds of color developers were quantitatively analyzed using spectrometric methods. The study comprehensively examines the chromogenic mechanism of fluoran dyes and provides a valuable reference for practical chromogenic systems based on fluoran dyes.

Automated summary

This study investigates the chromogenic mechanism of a black fluoran dye through spectral experiments and theoretical calculations. The proposed chromogenic structure was verified using infrared spectra and the dye's performance was analyzed quantitatively with spectrometric methods. The research offers valuable insights into the chromogenic mechanism of fluoran dyes and serves as a reference for practical applications.