Spectroscopy of Lumazine and Alloxazine in the Binary DMSO-Water Mixture

presentation, poster

English

The absorption and emission spectra were investigated for four molecules – lumazine and its cyanated derivativeand alloxazine and its fluorinated derivative, with dimethyl sulfoxide (DMSO) serving as the primary solvent. To modulate the spectroscopic properties, water was progressively added to the DMSO. Interesting effects were found, especially in the case of the cyanated derivative, where the addition of water results in a uniform blue shift. Further intriguing results were found for the samples containing 65 % of water and 35 % of DMSO. In this case, a notable decrease in absorption and emission intensities was registered, even larger than the water quenching observed in other cases. This is likely related to the formation of DMSO∙2H2O trimers that has been documented in this case. A similar behavior has been found for acetonitrile mixtures in the past, and a possible use for probing microenvironments of solvent immediately surrounding an analyte has been suggested. Finally, water solubility is greatly enhanced by the substitution of polar groups, making it easier to penetrate cell membranes than the larger flavins, which have been used for fluorescence imaging of living cells. Therefore, these molecules could find broader use for example in in vitro imaging. The spectroscopic properties of studied molecules were calculated using the density functional theory in the implicit DMSO solvent model and with explicit water molecules.

Lumazine, Flavins, Vertical Excited States, Fluorescence, Bio-inspired Material, Tautomerisation

TRUKSA, J.; KRATOCHVÍL, M.; RICHTÁR, J.; IVANOVÁ, L.; WEITER, M.; KRAJČOVIČ, J., LUKEŠ, V.

2. 10. 2023

Universitá degli studi di Bari Aldo Moro

Bari, Itálie

1

https://www.ecme2023.eu/book-of-abstract/