Computational Study of the Substituent Effects for the Spectroscopic Properties of Thiazolo[5,4‑d]thiazole Derivatives

Inspired by the structure and optical properties of N,N′-dialkylated/dibenzylated 2,5-bis­(4-pyridinium)­thiazolo­[5,4-d]­thiazole, we proposed a series of disubstituted thiazolo­[5,4-d]­thiazole derivatives as promising materials for multifunctional optoelectronic, electron transfer sensing, and other photochemical applications. Density functional theory study of the electronic structures and transition properties of those newly proposed molecules indicates that the electron-donating and electron-withdrawing groups introduced to the peripheral pyridyl ligands extend the distributions of molecular frontier orbitals, increase the electron density in thiazolo­[5,4-d]­thiazolea, and therefore lead to remarkable red-shifts of their absorption and emission peaks.