DUAL FLUORESCENCE OF A 10-HYDROXYACRIDINEDIONE DERIVATIVE IN POLAR SOLVENTS

• Published in: Journal of applied spectroscopy Vol. 88; no. 5; pp. 929 - 934
• Main Authors: Bondarev, S.L, Pirko, A.N, Raichenok, T.F, Pilipovicha, A.S
• Format: Journal Article
• Language: English
• Published: Springer 01.11.2021
• Subjects: Acetonitrile; Analysis; Dimethylformamide; Fluorescence; Glycerin; Glycerol; Methanol
• ISSN: 0021-9037; 1573-8647
• DOI: 10.1007/s10812-021-01261-w

Stationary luminescence and pulse fluorometry methods were used to study the spectral-kinetic and photophysical properties of a 9-methyl-10-hydroxyacridine(1,8)dione derivative dye (9,10-ACD) in polar protic and aprotic solvents at 293 and 77 K. We are the first to report a new long-wavelength fluorescence band (LF, 670-710 nm) in both polar protic (methanol and ethanol) and aprotic solvents (N,N-dimethylformamide and dimethyl sulfoxide) at room temperature. This band is attributed to the high-lying singlet excited state (in the range 460-490 nm) responsible for the short-wavelength fluorescence band (SF). The LF is not found in low-polar (methylene chloride, polar aprotic (acetonitrile) and highly viscous protic solvents (glycerol) at 293 K as well as at 77 K in ethanol. This band arises as a result of deprotonation of a molecule in an excited state and emission of the resultant anion in the long-wavelength region. Analysis of the spectral and kinetic data for SF decay and the LF rise indicates a mechanism, in which the dye anion formation depends on the basicity of the polar solvent. Possible practical applications of this spectral effect in biology, medicine, and analytical chemistry are proposed.