Excited state intramolecular single proton transfer mechanism of pigment yellow 101 in solid state: Experiment and DFT calculation

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 217; pp. 93 - 100
• Main Authors: Shen, Shen, Liu, Xian, Sun, Jianqi, Wang, Mingda, Jiang, Zhengjun, Xia, Guomin, Wang, Hongming
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.06.2019
• Subjects: Aromatic aldehyde azines; DFT calculation; Excited-state intramolecular proton transfer; P. Y. 101; Polymorphs; DFT calculation; Aromatic aldehyde azines; Polymorphs; Excited-state intramolecular proton transfer; P. Y. 101
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2019.03.076

To investigate fluorescence mechanism of Pigment Yellow 101 (P. Y. 101) in solid state, three aromatic aldehyde azines (1–3) including P. Y. 101 have been synthesized and compared with each other. Results indicated that P. Y. 101 prepared by solvothermal method is actually the mixture of two polymorphs, whose molecular packing mode can be transformed into each other by recrystallizing or external stimuli such as pressure and grinding. The ESIPT properties of 1–3 were investigated by DFT/TD-DFT calculations and time-correlated single photon counting (TCSPC) technique. Both experimental and theoretical results revealed that the dual fluorescence properties of P. Y. 101 in solid state are ascribed to the excited-state intramolecular single proton transfer fluorescence emissions of two structurally different polymorphs rather than the results of the sequential or concerted excited-state intramolecular double proton transfers, which provide a potential valuable tool for developing multistimuli-responsive luminescent materials. [Display omitted] •Fluorescence mechanism of pigment yellow 101 in solid state was unveiled by experiments and theoretical calculations.•Dual emissions of pigment yellow 101 in solid state are ascribed to the two structurally different polymorphs.•External stimuli such as pressure, grinding can afford discrepant solid state fluorescence emissions of pigment yellow 101.