Russian Journal of Biological Physics and Chemisrty Russian Journal of Biological Physics and Chemisrty АКТУАЛЬНЫЕ ВОПРОСЫ БИОЛОГИЧЕСКОЙ ФИЗИКИ И ХИМИИ 2499-9962 83368 10.29039/rusjbpc.2023.0625 МОДЕЛИРОВАНИЕ В БИОФИЗИКЕ И БИОИНФОРМАТИКА MODELLING IN BIOPHYCIS AND BIOINFORMATISC МОДЕЛИРОВАНИЕ В БИОФИЗИКЕ И БИОИНФОРМАТИКА EXCITATIONS OF PYRONIN Y AND PYRONIN B DYES IN AQUEOUS SOLUTION: COMPARATIVE THEORETICAL ANALYSIS ВОЗБУЖДЕНИЕ КРАСИТЕЛЕЙ ПИРОНИНА Y И ПИРОНИНА В В ВОДНОМ РАСТВОРЕ: СРАВНИТЕЛЬНЫЙ ТЕОРЕТИЧЕСКИЙ АНАЛИЗ Леонтьева С. В. Leontieva S. V. tezidi@gmail.com Черноморское высшее военно-морское ордена Красной Звезды училище имени П.С. Нахимова Севастополь Россия Black Sea Higher Naval Orders of the Red Star School named after P.S. Nakhimov Sevastopol Russian Federation Севастопольский государственный университет Севастополь Россия Sevastopol State University Sevastopol Russian Federation 27 05 2024 27 05 2024 8 3 301 311 28 07 2023 https://rusjbpc.ru/en/nauka/article/83368/view

Чтобы выяснить влияние боковых групп на возбуждение ксантеновых красителей, пиронин Y (PY) и пиронин B (PB) были изучены методом DFT/TD-DFT. Результаты расчетов сравнивались между собой, а также с данными ранее исследованного красителя акридинового красного. Уровень теории O3LYP/6-31++G(d,p)/IEFPCM хорошо воспроизводил экспериментальные спектры водных растворов PY и PB. Согласно расчетам, коротковолновые плечи этих спектров обусловлены вибронными переходами. Боковые группы существенно влияют на набор вибронных переходов. Фотовозбуждение существенно изменяет интенсивность ИК-колебаний. Боковые группы этих ксантеновых красителей (аминодиметил/аминодиэтил) сильно влияют на колебания их хромофоров. HOMO покрывают боковые группы обоих красителей в большей степени, чем LUМО. Конфигурации обеих граничных орбиталей вокруг хромофоров идентичны для PY и PB. Дипольный момент молекул красителя в возбужденном состоянии оказался больше, чем в основном состоянии. В основном состоянии дипольный момент PB в 2,5 раза больше, чем у PY, а в возбужденных состояниях – в 1,7 раза меньше. Моменты перехода PY и PB практически идентичны друг другу. Проведен учет сайт-специфических взаимодействий растворенное вещество-растворитель в виде явного отнесения молекул воды, образующих прочные водородные связи с катионами красителей.

To elucidate the effect of side groups on the excitation of xanthene dyes, pyronin Y (PY) and pyronin B (PB) were studied by DFT/TD-DFT. The calculation results were compared with each other, as well as with the data for the acridine red dye previously studied. The O3LYP/6-31++G(d,p)/IEFPCM theory level reproduced well the experimental spectra of PY and PB aqueous solutions. According to calculations, the short-wavelength shoulders of these spectra are caused by vibronic transitions. The side groups significantly affect the set of vibronic transitions. The photoexcitation significantly changes the intensities of IR vibrations. The side groups of these xanthene dyes (aminodimethyl/aminodiethyl) strongly influence the vibrations of their chromophores. HOMOs cover the side groups of both dyes to a greater extent compared to LUMOs. The configurations of both frontier orbitals around the chromophores are identical for PY and PB. The dipole moment of the dye molecules in the excited state turned out to be greater than in the ground state. In the ground state, the dipole moment of the PB is 2.5 times greater than that of the PY, and in the excited states, it is 1.7 times less. The transition moments of PY and PB are almost identical to each other. Considering site-specific solute-solvent interactions in the form of an explicit assignment of water molecules that form strong hydrogen bonds with the dye cations was performed.

 TD-DFT вибронные переходы водный раствор пиронин Y пиронин Б спектр поглощения TD-DFT vibronic transitions aqueous solution pyronin Y pyronin B absorption spectrum

Wright P. Xanth ene Dyes in Kirk-Othmer. Encyclopedia of Chemical Technology, 2000. Wright P. Xanth ene Dyes in Kirk-Othmer. Encyclopedia of Chemical Technology, 2000. Kurnick N.B. Methyl green-pyronin; basis of selective staining of nucleic acids. J. Gen. Physiol., 1950, vol. 33, pp. 243-264. Kurnick N.B. Methyl green-pyronin; basis of selective staining of nucleic acids. J. Gen. Physiol., 1950, vol. 33, pp. 243-264. Darzynkiewicz Z., Kapuscinski J., Traganos F., Crissman H.A. Application of Pyronin Y(G) in Cytochemistry of Nucleic Acidsl. Cytometry, 1987, vol. 8, pp. 138-145. Darzynkiewicz Z., Kapuscinski J., Traganos F., Crissman H.A. Application of Pyronin Y(G) in Cytochemistry of Nucleic Acidsl. Cytometry, 1987, vol. 8, pp. 138-145. Tomov T.C. Pyronin G as a fluorescent probe for quantitative determination of the membrane potential of mitochondria. J. Biochem. Biophys. Methods, 1986, vol.13, pp. 29-38. Tomov T.C. Pyronin G as a fluorescent probe for quantitative determination of the membrane potential of mitochondria. J. Biochem. Biophys. Methods, 1986, vol.13, pp. 29-38. Essawy A.A., Attia M.S. Novel application of pyronin Y fluorophore as high sensitive optical sensor of glucose in human serum. Talanta, 2013, vol. 107, p. 18-24. Essawy A.A., Attia M.S. Novel application of pyronin Y fluorophore as high sensitive optical sensor of glucose in human serum. Talanta, 2013, vol. 107, p. 18-24. Balraju P., Janu Y., Roy M.S., Sharma G.D. Dye Sensitized Solar Cell Based On Pyronin G Dye and TiO2. AIP Conf. Proc., 2008, vol. 1004, pp. 135-140. Balraju P., Janu Y., Roy M.S., Sharma G.D. Dye Sensitized Solar Cell Based On Pyronin G Dye and TiO2. AIP Conf. Proc., 2008, vol. 1004, pp. 135-140. Balraju P., Suresh P., Kumar M., Roy M.S., Sharma G.D. Effect of counter electrode, thickness and sintering temperature of TiO2 electrode and TBP addition in electrolyte on photovoltaic performance of dye sensitized solar cell using pyronine G (PYR) dye. J. Photochem. Photobiol. A, 2009, vol. 206, pp. 53-63. Balraju P., Suresh P., Kumar M., Roy M.S., Sharma G.D. Effect of counter electrode, thickness and sintering temperature of TiO2 electrode and TBP addition in electrolyte on photovoltaic performance of dye sensitized solar cell using pyronine G (PYR) dye. J. Photochem. Photobiol. A, 2009, vol. 206, pp. 53-63. Muller W., Crothers D.M. Interactions of Heteroaromatic Compounds with Nucleic Acids. 1. The Influence of Heteroatoms and Polarizability on the Base Specificity of Intercalating Ligands. Eur. J. Biochem., 1975, vol. 54, pp. 267-277. Muller W., Crothers D.M. Interactions of Heteroaromatic Compounds with Nucleic Acids. 1. The Influence of Heteroatoms and Polarizability on the Base Specificity of Intercalating Ligands. Eur. J. Biochem., 1975, vol. 54, pp. 267-277. Kapuscinski J. Interactions of Nucleic Acids with Fluorescent Dyes: Spectral Properties of Condensed Complexes. J. Histochem. Cytochem., 1990, vol. 38, pp. 1323-1329. Kapuscinski J. Interactions of Nucleic Acids with Fluorescent Dyes: Spectral Properties of Condensed Complexes. J. Histochem. Cytochem., 1990, vol. 38, pp. 1323-1329. Kapuscinski J., Darzynkiewicz Z. Interactions of Pyronin Y(G) With Nucleic Acids. Cytometry, 1987, vol. 8, pp. 129-137. Kapuscinski J., Darzynkiewicz Z. Interactions of Pyronin Y(G) With Nucleic Acids. Cytometry, 1987, vol. 8, pp. 129-137. Salci A., Toprak M. Spectroscopic investigations on the binding of Pyronin Y to human serum albumin. J. Biomol. Struct. Dyn., 2017, vol. 35, pp. 8-16. Salci A., Toprak M. Spectroscopic investigations on the binding of Pyronin Y to human serum albumin. J. Biomol. Struct. Dyn., 2017, vol. 35, pp. 8-16. Bordello J., Reija B., Al-Soufi W., Novo M. Host-Assisted Guest Self-Assembly: Enhancement of the Dimerization of Pyronines Y and B by γ-Cyclodextrin. ChemPhysChem, 2009, vol. 10, pp. 931-939. Bordello J., Reija B., Al-Soufi W., Novo M. Host-Assisted Guest Self-Assembly: Enhancement of the Dimerization of Pyronines Y and B by γ-Cyclodextrin. ChemPhysChem, 2009, vol. 10, pp. 931-939. Grauer Z., Grauer G.L., Avnir D., Yariv S. Metachromasy in Clay Minerals. Sorption of Pyronin Y by Montmorillonite and Laponite. J. Chem. Soc., Faraday Trans., 1987, vol 83, pp. 1685-1701. Grauer Z., Grauer G.L., Avnir D., Yariv S. Metachromasy in Clay Minerals. Sorption of Pyronin Y by Montmorillonite and Laponite. J. Chem. Soc., Faraday Trans., 1987, vol 83, pp. 1685-1701. Senol A.M., Metin O., Acar M., Onganer Y., Meral K. The interaction of fluorescent Pyronin Y molecules with monodisperse silver nanoparticles in chloroform. J. Mol. Structure, 2016, vol. 1103, pp. 212-216. Senol A.M., Metin O., Acar M., Onganer Y., Meral K. The interaction of fluorescent Pyronin Y molecules with monodisperse silver nanoparticles in chloroform. J. Mol. Structure, 2016, vol. 1103, pp. 212-216. Arik M., Onganer Y. Molecular excitons of Pyronin B and Pyronin Y in colloidal silica suspension. Chem. Phys. Lett., 2003, vol. 375, pp. 126-133. Arik M., Onganer Y. Molecular excitons of Pyronin B and Pyronin Y in colloidal silica suspension. Chem. Phys. Lett., 2003, vol. 375, pp. 126-133. Senol A.M., Metin O., Onganer Y. A facile route for the preparation of silver nanoparticles-graphene oxide nanocomposites and their interactions with pyronin Y dye molecules. Dyes Pigments, 2019, vol. 162, pp. 926-933. Senol A.M., Metin O., Onganer Y. A facile route for the preparation of silver nanoparticles-graphene oxide nanocomposites and their interactions with pyronin Y dye molecules. Dyes Pigments, 2019, vol. 162, pp. 926-933. Gianneschi L.P., Kurucsev T. Derivation and Interpretation of the Spectra of Aggregates. Part 3.-Prediction Analytical Study of the Spectrum of Pyronine Y in Aqueous Solution. J. Chem. Soc., 1974, vol. 70, pp. 1334-1342. Gianneschi L.P., Kurucsev T. Derivation and Interpretation of the Spectra of Aggregates. Part 3.-Prediction Analytical Study of the Spectrum of Pyronine Y in Aqueous Solution. J. Chem. Soc., 1974, vol. 70, pp. 1334-1342. Gianneschi L.P., Cant A., Kurucsev T. Derivation and interpretation of the spectra of aggregates. J. Chem. Soc., 1977, vol. 73, pp. 664-668. Gianneschi L.P., Cant A., Kurucsev T. Derivation and interpretation of the spectra of aggregates. J. Chem. Soc., 1977, vol. 73, pp. 664-668. Lee B.G., Kim K.J. Spectroscopic Characterization on the Aggregation Behavior of Pyronin G with Tetraphenylborate anion. Anal. Sci. Technol., 1995, vol. 8, pp. 47-53. Lee B.G., Kim K.J. Spectroscopic Characterization on the Aggregation Behavior of Pyronin G with Tetraphenylborate anion. Anal. Sci. Technol., 1995, vol. 8, pp. 47-53. Epelde-Elezcano N., Martinez-Martinez V., Duque-Redondo E., Temino I., Manzano H., López-Arbeloa I. Strategies for modulating the luminescence properties of pyronin Y dye-clay films: an experimental and theoretical study. Phys. Chem. Chem. Phys., 2016, vol. 18, pp. 8730-8738. Epelde-Elezcano N., Martinez-Martinez V., Duque-Redondo E., Temino I., Manzano H., López-Arbeloa I. Strategies for modulating the luminescence properties of pyronin Y dye-clay films: an experimental and theoretical study. Phys. Chem. Chem. Phys., 2016, vol. 18, pp. 8730-8738. Meral K., Yilmaz N., Kaya M., Tabak A., Onganer Y. The molecular aggregation of pyronin Y in natural bentonite clay suspension. J. Luminesc., 2011, vol. 131, pp. 2121-2127. Meral K., Yilmaz N., Kaya M., Tabak A., Onganer Y. The molecular aggregation of pyronin Y in natural bentonite clay suspension. J. Luminesc., 2011, vol. 131, pp. 2121-2127. Sinoforoglu M., Gur B., Arik M., Onganer Y., Meral K. Graphene oxide sheets as a template for dye assembly: graphene oxide sheets induce H-aggregates of pyronin (Y) dye. RSC Adv., 2013, vol.3, pp. 11832-11838. Sinoforoglu M., Gur B., Arik M., Onganer Y., Meral K. Graphene oxide sheets as a template for dye assembly: graphene oxide sheets induce H-aggregates of pyronin (Y) dye. RSC Adv., 2013, vol.3, pp. 11832-11838. Fujiki K.O.N., Iwanaga C., Koizumi M. Some spectral studies of the aqueous solution of pyronine G. Bull. Chem. Soc. Jpn, 1962, vol. 35, pp. 185-193. Fujiki K.O.N., Iwanaga C., Koizumi M. Some spectral studies of the aqueous solution of pyronine G. Bull. Chem. Soc. Jpn, 1962, vol. 35, pp. 185-193. Arik M., Meral K., Onganer Y. Effect of surfactants on the aggregation of pyronin B and pyronin Y in aqueous solution. J. Luminesc., 2009, vol.129, pp. 599-604. Arik M., Meral K., Onganer Y. Effect of surfactants on the aggregation of pyronin B and pyronin Y in aqueous solution. J. Luminesc., 2009, vol.129, pp. 599-604. Arik M., Kassa S.B., Onganer Y. Molecular aggregates of pyronin dyes with polyelectrolyte polystyrene sulfonate (PSS) in aqueous solution. J. Photochem. Photobiol. A, 2020, vol. 391, p. 112309. Arik M., Kassa S.B., Onganer Y. Molecular aggregates of pyronin dyes with polyelectrolyte polystyrene sulfonate (PSS) in aqueous solution. J. Photochem. Photobiol. A, 2020, vol. 391, p. 112309. Meral K., Erbil H.Y., Onganer Y. A spectroscopic study of water-soluble pyronin B and pyronin Y in Langmuir-Blodgett films mixed with stearic acid. Appl. Surf. Sci., 2011, vol. 258, pp. 1605-1612. Meral K., Erbil H.Y., Onganer Y. A spectroscopic study of water-soluble pyronin B and pyronin Y in Langmuir-Blodgett films mixed with stearic acid. Appl. Surf. Sci., 2011, vol. 258, pp. 1605-1612. Zhang X.-F., Zhang J., Lu X. The Fluorescence Properties of Three Rhodamine Dye Analogues: Acridine Red, Pyronin Y and Pyronin B. J. Fluoresc., 2015, vol. 25, pp. 1151-1158. Zhang X.-F., Zhang J., Lu X. The Fluorescence Properties of Three Rhodamine Dye Analogues: Acridine Red, Pyronin Y and Pyronin B. J. Fluoresc., 2015, vol. 25, pp. 1151-1158. Baraka M.E., Deumie M., Viallet P., Lampidis T.J. Fluorimetric studies of solutions of pyronin dyes: equilibrium constants in water and partition coefficients in organic-solvent-water systems. J. Photochem. Photobiol. A, 1991, vol. 56, pp. 295-311. Baraka M.E., Deumie M., Viallet P., Lampidis T.J. Fluorimetric studies of solutions of pyronin dyes: equilibrium constants in water and partition coefficients in organic-solvent-water systems. J. Photochem. Photobiol. A, 1991, vol. 56, pp. 295-311. Celebi N., Arik M., Onganer Y. Analysis of fluorescence quenching of pyronin B and pyronin Y by molecular oxygen in aqueous solution. J. Luminesc., 2007, vol. 126, pp. 103-108. Celebi N., Arik M., Onganer Y. Analysis of fluorescence quenching of pyronin B and pyronin Y by molecular oxygen in aqueous solution. J. Luminesc., 2007, vol. 126, pp. 103-108. Rowe P.B. Spectrophotometry of dyes 1. Methyl green. 2. Pyronin. Stain Tech., 1953, vol. 28, pp. 265-273. Rowe P.B. Spectrophotometry of dyes 1. Methyl green. 2. Pyronin. Stain Tech., 1953, vol. 28, pp. 265-273. Beser B.M., Onganer Y., Arik M. Photophysics and photodynamics of Pyronin Y in n‐alcohols. J. Luminesc., 2018, vol. 33, pp. 1394-1400. Beser B.M., Onganer Y., Arik M. Photophysics and photodynamics of Pyronin Y in n‐alcohols. J. Luminesc., 2018, vol. 33, pp. 1394-1400. Jakobsen P., Lyon H., Treppendahl S. Spectrophotometric characteristics and assay of pure pyronin Y. Histochemistry, 1984, vol 81, pp. 99-101. Jakobsen P., Lyon H., Treppendahl S. Spectrophotometric characteristics and assay of pure pyronin Y. Histochemistry, 1984, vol 81, pp. 99-101. Gur B., Meral K. The effect of poly (vinyl alcohol) on the photophysical properties of pyronin dyes in aqueous solution: A spectroscopic study. Spectrochim. Acta A, 2013 vol. 101, pp. 306-313. Gur B., Meral K. The effect of poly (vinyl alcohol) on the photophysical properties of pyronin dyes in aqueous solution: A spectroscopic study. Spectrochim. Acta A, 2013 vol. 101, pp. 306-313. Savarese M., Aliberti A., De Santo I., Battista E., Causa F., Netti P.A, Rega N. Fluorescence Lifetimes and Quantum Yields of Rhodamine Derivatives: New Insights from Theory and Experiment. J. Phys. Chem. A, 2012, vol. 116, pp. 7491-7497. Savarese M., Aliberti A., De Santo I., Battista E., Causa F., Netti P.A, Rega N. Fluorescence Lifetimes and Quantum Yields of Rhodamine Derivatives: New Insights from Theory and Experiment. J. Phys. Chem. A, 2012, vol. 116, pp. 7491-7497. Zhou P. Why the lowest electronic excitations of rhodamines are overestimated by time-dependent density functional theory. Int. J. Quantum Chem, 2018, p. 25780. Zhou P. Why the lowest electronic excitations of rhodamines are overestimated by time-dependent density functional theory. Int. J. Quantum Chem, 2018, p. 25780. Kulesza A.J., Titov E., Daly S., Wlodarczyk R., Megow J., Saalfrank P., Choi C.M., MacAleese L., Antoine R., Dugourd P. Excited States of Xanthene Analogues: Photofragmentation and Calculations by CC2 and Time-Dependent Density Functional Theory. ChemPhysChem, 2016, vol. 17, pp. 3129-3138. Kulesza A.J., Titov E., Daly S., Wlodarczyk R., Megow J., Saalfrank P., Choi C.M., MacAleese L., Antoine R., Dugourd P. Excited States of Xanthene Analogues: Photofragmentation and Calculations by CC2 and Time-Dependent Density Functional Theory. ChemPhysChem, 2016, vol. 17, pp. 3129-3138. Cossi M., Rega N., Scalmani G., Barone V. Energies, structures, and electronic properties of molecules in solution with the C-PCM solvation model. J. Comput. Chem., 2003, vol. 24, pp. 669-681. Cossi M., Rega N., Scalmani G., Barone V. Energies, structures, and electronic properties of molecules in solution with the C-PCM solvation model. J. Comput. Chem., 2003, vol. 24, pp. 669-681. Adamo C., Jacquemin D. The calculations of excited-state properties with Time-Dependent Density Functional Theory. Chem. Soc. Rev., 2013, vol. 42, pp. 845-856. Adamo C., Jacquemin D. The calculations of excited-state properties with Time-Dependent Density Functional Theory. Chem. Soc. Rev., 2013, vol. 42, pp. 845-856. Charaf-Eddin A., Planchat A., Mennucci B., Adamo C., Jacquemin D. Choosing a Functional for Computing Absorption and Fluorescence Band Shapes with TD-DFT. J. Chem. Theory Comput., 2013, vol. 9 pp. 2749-2760. Charaf-Eddin A., Planchat A., Mennucci B., Adamo C., Jacquemin D. Choosing a Functional for Computing Absorption and Fluorescence Band Shapes with TD-DFT. J. Chem. Theory Comput., 2013, vol. 9 pp. 2749-2760. Kostjukov V.V. Vibronic absorption spectra and excited states of acridine red dye in aqueous solution: TD-DFT/DFT study. Z. fur Natur. A, 2022, vol. 77, pp. 207-215. Kostjukov V.V. Vibronic absorption spectra and excited states of acridine red dye in aqueous solution: TD-DFT/DFT study. Z. fur Natur. A, 2022, vol. 77, pp. 207-215. Alia J.D., Flack J.A. Unspecified verticality of Franck-Condon transitions, absorption and emission spectra of cyanine dyes, and a classically inspired approximation. RSC Adv., 2020, vol. 10, pp. 43153-43167. Alia J.D., Flack J.A. Unspecified verticality of Franck-Condon transitions, absorption and emission spectra of cyanine dyes, and a classically inspired approximation. RSC Adv., 2020, vol. 10, pp. 43153-43167. Tomasi J., Mennucci B., Cammi R. Quantum mechanical continuum solvation models. Chem. Rev., 2005, vol. 105, pp. 2999-3093. Tomasi J., Mennucci B., Cammi R. Quantum mechanical continuum solvation models. Chem. Rev., 2005, vol. 105, pp. 2999-3093. Baiardi A., Bloino J., Barone V. General Time Dependent Approach to Vibronic Spectroscopy Including Franck-Condon, Herzberg-Teller, and Duschinsky Effects. J. Chem. Theory Comput., 2013, vol. 9, pp. 4097-4115. Baiardi A., Bloino J., Barone V. General Time Dependent Approach to Vibronic Spectroscopy Including Franck-Condon, Herzberg-Teller, and Duschinsky Effects. J. Chem. Theory Comput., 2013, vol. 9, pp. 4097-4115. Frisch M.J. et al. Gaussian 16, Revision C.01, Inc., Wallingford CT, 2016. Frisch M.J. et al. Gaussian 16, Revision C.01, Inc., Wallingford CT, 2016. Condon E.U. Nuclear motions associated with electron transitions in diatomic molecules. Phys. Rev., 1928, vol. 32, pp. 858-872. Condon E.U. Nuclear motions associated with electron transitions in diatomic molecules. Phys. Rev., 1928, vol. 32, pp. 858-872. Scalmani G., Frisch M.J., Mennucci B., Tomasi J., Cammi R., Barone V. Geometries and properties of excited states in the gas phase and in solution: Theory and application of a time-dependent density functional theory polarizable continuum model. J. Chem. Phys., 2006, vol. 124, p. 94107. Scalmani G., Frisch M.J., Mennucci B., Tomasi J., Cammi R., Barone V. Geometries and properties of excited states in the gas phase and in solution: Theory and application of a time-dependent density functional theory polarizable continuum model. J. Chem. Phys., 2006, vol. 124, p. 94107. Reed A.E., Curtiss L.A., Weinhold F. Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint. Chem. Rev., 1988, vol. 88, pp. 899-926. Reed A.E., Curtiss L.A., Weinhold F. Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint. Chem. Rev., 1988, vol. 88, pp. 899-926. Dennington R., Keith T.A., Millam J.M. GaussView, Version 6.1, Semichem Inc., Shawnee Mission KS, 2016. Dennington R., Keith T.A., Millam J.M. GaussView, Version 6.1, Semichem Inc., Shawnee Mission KS, 2016. Reichardt C. Solvatochromic Dyes as Solvent Polarity Indicators. Chem. Rev., 1994, vol. 94, pp. 2319-2358. Reichardt C. Solvatochromic Dyes as Solvent Polarity Indicators. Chem. Rev., 1994, vol. 94, pp. 2319-2358. Zhao G.J., Han K.L. Effects of hydrogen bonding on tuning photochemistry: Concerted hydrogen‐bond strengthening and weakening. ChemPhysChem, 2008, vol. 9, pp. 1842-1846. Zhao G.J., Han K.L. Effects of hydrogen bonding on tuning photochemistry: Concerted hydrogen‐bond strengthening and weakening. ChemPhysChem, 2008, vol. 9, pp. 1842-1846. Zhao G.-J., Han K.-L. Hydrogen Bonding in the Electronic Excited State. Acc. Chem. Res., 2012, vol. 45, pp. 404-413. Zhao G.-J., Han K.-L. Hydrogen Bonding in the Electronic Excited State. Acc. Chem. Res., 2012, vol. 45, pp. 404-413.