Effect of positional substitution of methyl group on the fluorescence properties of quinolinium ion

• Published in: Journal of luminescence Vol. 132; no. 8; pp. 2151 - 2154
• Main Authors: Rautela, R., Joshi, H.C., Joshi, N.K., Tewari, N., Pant, S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2012; Elsevier
• Subjects: Atomic and molecular physics; Deactivation; Decay; Exact sciences and technology; Fluorescence; Fluorescence and phosphorescence spectra; Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion); Intersystem crossing; Luminescence; Methylquinolines; Modulation; Molecular properties and interactions with photons; Physics; Spectra; Methylquinolines; Intersystem crossing; Methyl group; Modulation; Quinoline derivatives; Fluorescence; Absorption spectra; Chemical substitution; Nonradiative transitions; Luminescence decay
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2012.03.037

In the present study we have investigated the effect of methyl substitution at various positions on the spectral and decay behavior of some quinolinium ions. The spectra reveal marked differences when methyl group is present at 7th and 8th positions. The non-radiative deactivation is also considerably affected by the substituent position. The results are explained by considering the modulation (decrease as compared to the unsubstituted quinolinium) in nonradiative rate (intersystem crossing) due to substitution. ► The effect of methyl substitution at various positions on the spectral and decay behavior of quinolinium ion has been studied. ► The spectra reveal marked differences when methyl group is present at 7th and 8th positions. ► The results are explained by considering the modulation in nonradiative deactivation due to intersystem crossing.