Elaborating and regulating ESIPT associated with solvent polarity for the novel 2-(benzo[d]thiazol-2-yl)-4-(9H-diphenylamino-9-yl)phenol fluorophore

A New Series of D1‐A‐D2‐type ESIPT‐TICT‐AIE Active Orange‐to‐red Emissive Unsymmetrical Azines: Their All‐throughout Mechanochemical Synthesis and Exploration of Photophysical Properties

“…However, it can be seen that in the S 1 state, the energy barrier is reduced as the OÀ H distance increases which facilitates the excited state intramolecular proton transfer phenomenon. [53,54] As already discussed in the DFT section, the electron density is mostly localized on the benzothiazole group or the diphenyl methylene group in the HOMO and on the phenyl-azine linkage in the LUMO in most of the dyes, particularly in the case of 6 k. This indicates that the system behaves as a donor 1 -acceptordonor 2 unit and thus the intramolecular charge transfer from HOMO to LUMO is possible. Also, the presence of the extended conjugation in the system and the electron flow over the azine linkage from the HOMO to the LUMO is responsible for the shift in the emission wavelengths of the corresponding dyes.…”