J Phys Chem A 2012 Jul 10;116(28):7474-90. Epub 2012 Jul 10.
Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.
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Phys Chem Chem Phys 2015 Jul;17(28):18729-41
Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b, 61-614 Poznań, Poland.
The photophysical properties of 5-deazaalloxazine and 1,3-dimethyl-5-deazalloxazine at different pH values were characterized using absorption spectra, fluorescence emission spectra, fluorescence excitation spectra, synchronous fluorescence spectra and total fluorescence spectra. Their ionised and/or neutral forms were discussed in comparison with those obtained for other derivatives of 5-deazaalloxazine and/or 5-deazaisoalloxazine. Steady-state and time-resolved techniques were used to study the protonation/deprotonation equilibria between cationic and neutral forms of both compounds and between neutral and monoanionic forms of 5-deazalloxazine, as well as between monoanionic forms of this compound and its dianion. Read More
Photochem Photobiol 2011 May-Jun;87(3):524-33. Epub 2010 Nov 19.
Fakultät für Physik, Universität Regensburg, Regensburg, Germany.
The spectroscopic behavior of lumichrome (7,8-dimethyl-alloxazine, LC) in aqueous solutions in a pH range from -1.08 to 14.6 is studied. Read More
J Phys Chem A 2006 Apr;110(14):4638-48
Faculty of Commodity Science, Poznań University of Economics, al. Niepodleglości 10, 60-967 Poznań, Poland.
Quantum chemical density functional theory (DFT) calculations and spectral data were employed to investigate the possibility of the excited-state double proton transfer (ESDPT) in lumichrome crystals. The calculations in a lumichrome dimer predict a transfer of a proton in the first excited state, leading to a cation-anion pair. The presently reported X-ray structure of 1,3-dimethyllumichrome and its complex solid-state luminescence indicate that also in this molecule intermolecular hydrogen bonds might be involved in the photophysics. Read More
J Phys Chem B 2011 Mar 18;115(10):2424-35. Epub 2011 Feb 18.
Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Departamento de Quimica Fisica, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N. 45071 Toledo, Spain.
We report on photophysical studies of lumichrome (Lc) in water at different pHs, and interacting with the human serum albumin (HSA) protein and β-cyclodextrin (β-CD) in neutral aqueous solutions. We used steady-state and picosecond time-resolved emission spectroscopy to investigate the structural changes of Lc at the ground and excited states, as well as the rotational dynamics of the complexes with HSA and β-CD. In neutral water, the predominant neutral alloxazine-type structure of Lc coexists with a small population of the anionic form. Read More