S 98 Synthesis, spectral and electrochemical properties of pyrimidine-containing dyes as photosensitizers for dye-sensitized solar cells [Electronic resource] / E. V. Verbitskiy [и др.] // Dyes and Pigments. - 2014. - Vol.100. - С. 201-214. - Bibliogr. : p. 213-214 (37 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ORGANIC DYES -- PYRIMIDINE -- MICROWAVE-ASSISTED Аннотация: Six novel donor–π–acceptor organic dyes bearing a pyrimidine as the anchoring group have been obtained in good yields by combination of the microwave-assisted Suzuki cross-coupling and nucleophilic aromatic substitution of hydrogen reactions. Their absorption, photoluminescence and electrochemical properties were fully investigated in detail. The infrared spectra of dyes adsorbed on TiO2 indicate the formation of coordinate bonds between the pyrimidine ring of dyes and the Lewis acid sites (exposed Tin+ cations) of the TiO2 surface. This work demonstrates that the pyrimidine rings of dye sensitizers that form a coordinate bond with the Lewis acid site of a TiO2 surface are promising candidates as the electron-withdrawing anchoring group. The data from quantum calculations show that all of the dyes are potentially good photosensitizers for dye-sensitized solar cells \\\\expert2\\NBO\\Dyes and Pigments\\2014, v. 100, p.201-214.pdf |
S 98 Synthesis and optical properties of new photochromic systems based on 1,2-bis(2-methylbenzo[b]thien-3-yl) hexafluorocyclopentenes and 5,7-dihydro-1H-1,2,5,7,8-pentaaza-s-indacen-6-one or 1,7-dihydro-5-thia-1,2,7,8- tetraaza-s-indacen-6-one derivatives [Electronic resource] / M. M. Krayushkin, A. M. Bogacheva, A. N. Komogortsev, B. V. Lichitsky, A. A. Dudinov, K. S. Levchenko, O. I. Kobeleva, T. M. Valova, V. A. Barachevskii, V. N. Charushin // Journal of Sulfur Chemistry. - 2013. - Vol.34, №6. - С. 580-587. - Bibliogr. : p. 587 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): BIS(BENZOTHIENYL)HEXAFLUOROCYCLOPENTENES -- FLUORESCENT DYES -- PHOTOCHROMES Аннотация: New photochromic molecules based on 1,2-bis(2-methylbenzo[b]thien-3-yl) hexafluorocyclopentenes and fluorescent 5,7-dihydro-1H-1,2,5,7,8-pentaaza-s- indacen-6-one or 1,7-dihydro-5-thia-1,2,7,8-tetraaza-s-indacen-6-one derivatives were synthesized via nucleophilic substitution. Photochromic properties of the compounds and composite mixtures of fluorophores and photochrome were investigated \\\\expert2\\nbo\\Journal of Sulfur Chemistry\\2013. V. 34, N 6. P. 580-587.pdf |
5-(Methylidene)barbituric acid as a new anchor unit for dye-sensitized solar cells (DSSC) [Electronic resource] / R. A. Irgashev, G. A. Kim, G. L. Rusinov, V. N. Charushin // ARKIVOC. - 2014. - Vol. 2014, №5. - С. 123-131. - Bibliogr. : p. 131 (14 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ANCHOR GROUP -- BARBITURIC ACID -- CARBAZOLE Аннотация: Novel dyes bearing a 5-(methylidene)barbituric acid moiety as a new acceptor/anchor fragment were obtained and exhibited remarkable photophysical properties, according to a preliminary assessment of their sensitization activity as elements for dye-sensitized solar cells \\\\expert2\\nbo\\ARKIVOC\\2014, p.123-131.pdf |
S 98 Synthesis, Photophysical and Redox Properties of the D-pi-A Type Pyrimidine Dyes Bearing the 9-Phenyl-9H-Carbazole Moiety [Electronic resource] / E. V. Verbitskiy [и др.] // Journal of Fluorescence. - 2015. - Vol. 25, № 3. - С. 763-775. - Bibliogr. : p. 774-775 (51 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): PYRIMIDINES -- CARBAZOLE -- DYE-SENSITIZED SOLAR CELLS Аннотация: Novel donor-pi-acceptor dyes bearing the pyrimidine unit as an electron-withdrawing group have been synthesized by using combination of two processes, based on the microwave-assisted Suzuki cross-coupling reaction and nucleophilic aromatic substitution of hydrogen. Spectral properties of the obtained dyes in six aprotic solvents of various polarities have been studied by ultraviolet-visible and fluorescence spectroscopy. In contrast to the absorption spectra, fluorescence emission spectra displayed a strong dependence from their solvent polarities. The nature of the observed long wavelength maxima has been elucidated by means of quantum chemical calculations. The electrochemical properties of these dyes have been investigated by using cyclic voltammetry, while their photovoltaic performance was evaluated by a device fabrication study. The experimental and calculation data show that all of the dyes can be regarded as potentially good photosensitizers for dye-sensitized solar cells. \\\\expert2\\nbo\\Journal of Fluorescence\\2015, v.25, p.763-775.pdf |
A 10 A facile and convenient synthesis and photovoltaic characterization of novel thieno[2,3-b]indole dyes for dye-sensitized solar cells [Electronic resource] / R. A. Irgashev, A. A. Karmatsky, S. Kozyukhin, V. K. Ivanov, A. Sadovnikov, V. V. Kozik // Synthetic Metals. - 2015. - Vol. 199. - С. 152-158. - Bibliogr. : p. 158 (28 ref/) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): THIENO[2,3-b]INDOLE -- DYES -- THIOPHENE Аннотация: Two novel dyes IK-1,2 bearing the 8-alkyl-8H-thieno[2,3-b]indole unit as an electron-donating part of the push-pull system have been designed and prepared, as promising sensitizers for solar cells. The key steps of the synthesis involve the crotonic condensation of 1-alkylisatins with 2-acetylthiophene, followed by reduction of the C=C double bond and further cyclization through the Paal-Knorr reaction with the Lawesson reagent, thus leading to the formation of 2-(thien-2-yl) substituted thieno[2,3-b] indole derivatives. The optical and electrochemical properties of these dye's have been investigated by using spectrophotometry and cyclic voltammetry respectively, while their photovoltaic performance was evaluated by a device fabricatien study. The DSSCs based on IK-1 and IK-2 have demonstrated an efficiency of eta = 0.37% (FF = 73%) and eta = 0.7g% (FF = 69%) under 100 mW cm(-2) simulated AM 1.5G solar irradiation, respectively. \\\\expert2\\nbo\\Synthetic Mеtals\\2015, V.199, p. 152-158.pdf |
D 47 Detection of nitroaromatic explosives by new D-π-A sensing fluorophores on the basis of the pyrimidine scaffold [Electronic resource] / E. V. Verbitskiy, A. A. Baranova, K. I. Ludovik, M. Z. Shafikov, K. O. Khokhlov, E. M. Cheprakova, G. L. Rusinov, O. N. Chupakhin, V. N. Charushin // Analytical and Bioanalytical Chemistry. - 2016. - Ahead of Print Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): NITROAROMATIC EXPLOSIVES -- PYRIMIDINE SCAFFOLD Аннотация: A series of D-π-A- type dyes based on pyrimidines, bearing various thiophene linkers, have been studied as sensing fluorophores. Fluorescence studies have demonstrated that the emission of all derivs. is sensitive to the presence of nitroarom. explosives, such as 2,4,6-trinitrophenol (PA), 2,4,6-trinitrotoluene (TNT), and 2,4-dinitrotoluene (DNT), in their acetonitrile solns. The detection limits of fluorophores to PA, TNT, and DNT proved to be in the range from 5.83 × 10-6 to 2.38 × 10-7 mol/L, 1.70 × 10-4 to 8.40 × 10-6 mol/L, and 8.39 × 10-5 to 6.87 × 10-6 mol/L, resp. The theor. investigation into the quenching mechanism in the presence of fluorophore has been performed. All compds. have shown a good efficiency as sensor materials when tested as elements of the original device < \\\\expert2\\nbo\\Analytical and Bioanalytical Chemistry\\2016, Ahead Print.pdf |
N 52 New 2H-[1,2,3]triazolo[4,5-e][1,2,4]triazolo[1,5-a]pyrimidine derivatives as luminescent fluorophores for detection of nitroaromatic explosives [Electronic resource] / E. V. Verbitskiy, E. B. Gorbunov, A. A. Baranova, K. I. Ludovik, K. O. Khokhlov, E. M. Cheprakova, G. A. Kim, G. L. Rusinov, O. N. Chupakhin, V. N. Charushin // Tetrahedron. - 2016. - Vol. 72, № 32. - С. 4954-4961 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CARBAZOLE -- NITROAROMATIC EXPLOSIVES -- TRIPHENYLAMINE Аннотация: A number of D-pi-A type dyes on the basis of new 2H[1,2,3]triazolo[4,5-e][1,2,4]triazolo[1,5-a]pyrimidines, bearing various electron-donating carbazole and triphenylamine fragments, have been studied as sensing fluorophores. Fluorescence studies have demonstrated that emission spectra of these compounds in acetonitrile are sensitive to the presence of nitroaromatic explosives, such as 2,4-dinitroanisole (DNAN), picric acid (PA), styphnic acid (SA), 1,3,5-triethoxy-2,4,6-trinitrobenzene (TETNB), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT) and nitrobenzene (NB). Detection limits of fluorophores for DNAN, PA, SA, TETNB, DNT and TNT proved to be in the range from 4.82x10(-1) to 2.96x10(-3) mol/L, 2.10x10(-3) to 5.98x10(-5) mol/L, 1.26x10(-1) to 2.02x10(-4) mol/L, 1.58 x 10(-1) to 1.62x10(-3) mol/L, 1.26x10(-1) to 5.61x10(-4) mol/L and 9.01x10(-2) to 2.77x10(-3) mol/L, respectively. Selective fluorescence quenching response, including a sharp color change under UV irradiation (especially for PA, SA and DNT), makes these compounds promising fluorescence chemosensors for nitroaromatic explosives \\\\expert2\\NBO\\Tetrahedron\\2016, v. 72 , p. 4954-4961.pdf |
N 52 New 4,5-di(hetero)arylpyrimidines as sensing elements for detection of nitroaromatic explosives in vapor phase / E. V. Verbitskiy, A. A. Baranova, K. I. Lugovik, K. O. Khokhlov, E. M. Cheprakova, M. Z. Shafikov, G. L. Rusinov, O. N. Chupakhin, V. N. Charushin // Dyes and Pigments. - 2016. - Vol. 137. - С. 360-371. - Bibliogr. : p. 370-371 (50 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 4,5-DI(HETERO)ARYLPYRIMIDINES -- NITROAROMATIC EXPLOSIVES -- VAPOR PHASE Аннотация: A series of D–π–A–π–D type dyes based on pyrimidines, bearing thiophene linkers, have been studied as sensing fluorophores. Fluorescence studies have demonstrated that the emission of all derivatives is sensitive to the presence of 2,4,6-trinitrotoluene (TNT) and other nitroaromatic compounds (NACs), in their acetonitrile solutions. The detection limits of fluorophores to NACs proved to be in the range from 10−4 to 10−6 mol/L. The time-resolved fluorescence measurements and theoretical investigation into the quenching mechanism in the presence of fluorophore has been performed. The two types of sensor prototypes for handheld sniffer «Nitroscan» (Plant «Promautomatika», Ekaterinburg, Russia) on the basis of non-woven dry wipe and spunlace non-woven fabric with various quantities of the most sensitive fluorophore have been fabricated. The reusable, reversible and sensitive response of the designed prototypes to NACs enables one to qualify these compounds as promising fluorescent sensory materials for detection of NACs. \\\\expert2\\nbo\\Dyes and Pigments\\2016, v. 137, p.360-371.pdf |
S 98 Synthesis and properties of new π-conjugated imidazole/carbazole structures / R. A. Irgashev, N. A. Kazin, N. I. Makarova, I. V. Dorogan, V. V. Malov, A. R. Tameev, G. L. Rusinov, A. V. Metelitsa, V. I. Minkin, V. N. Charushin // Dyes and Pigments. - 2017. - Vol. 141. - P512-520 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): IMIDAZOLES -- CARBAZOLES -- ABSORPTION SPECTRA -- PHOTOLUMINESCENCE -- TDDFT CALCULATIONS -- CHARGE MOBILITY Аннотация: New 3-(1H-imidazol-2-yl)-9H-carbazoles and 6,6′-di(1H-imidazol-2-yl)-9H,9′H-3,3′-bicarbazoles have been prepared, starting from 9-ethyl-9H-carbazole-3-carbaldehyde or 9,9′-diethyl-9H,9′H-[3,3′-bicarbazole]-6,6′-dicarbaldehyde through their reactions with 4-methoxyaniline or 4-fluoroaniline, benzil or 2,2′-thenil [1,2-di(thien-2,2′-yl) glyoxal] and ammonium acetate on reflux in glacial acetic acid. The obtained compounds have been shown to demonstrate an effective fluorescence in the blue spectral region, exhibiting quantum yields in the range of 0.08–0.51, depending on their molecular structure and solvent polarity. The nature of the observed absorption spectra has been elucidated by the TDDFT calculations. |
N 52 New 4,5-di(hetero)arylpyrimidines as sensing elements for detection of nitroaromatic explosives in vapor phase / E. V. Verbitskiy, A. A. Baranova, K. I. Lugovik, K. O. Khokhlov, E. M. Cheprakova, M. Z. Shafikov, G. L. Rusinov, O. N. Chupakhin, V. N. Charushin // Dyes and Pigments. - 2017. - Vol. 137. - P360-371 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): FLUORESCENCE QUENCHING -- NITROAROMATIC EXPLOSIVES -- TRIPHENYLAMINES -- CARBAZOLES -- PYRIMIDINES Аннотация: A series of D–π–A–π–D type dyes based on pyrimidines, bearing thiophene linkers, have been studied as sensing fluorophores. Fluorescence studies have demonstrated that the emission of all derivatives is sensitive to the presence of 2,4,6-trinitrotoluene (TNT) and other nitroaromatic compounds (NACs), in their acetonitrile solutions. The detection limits of fluorophores to NACs proved to be in the range from 10−4 to 10−6 mol/L. The time-resolved fluorescence measurements and theoretical investigation into the quenching mechanism in the presence of fluorophore has been performed. The two types of sensor prototypes for handheld sniffer «Nitroscan» (Plant «Promautomatika», Ekaterinburg, Russia) on the basis of non-woven dry wipe and spunlace non-woven fabric with various quantities of the most sensitive fluorophore have been fabricated. The reusable, reversible and sensitive response of the designed prototypes to NACs enables one to qualify these compounds as promising fluorescent sensory materials for detection of NACs. |
N 89 Novel push-pull thieno[2,3-b]indole-based dyes for efficient dye-sensitized solar cells (DSSCs) / R. A. Irgashev, A. A. Karmatsky, G. A. Kim, G. L. Rusinov, V. N. Charushin, A. A. Sadovnikov, V. K. Ivanov, S. A. Kozyukhin, V. V. Emets, V. A. Grinberg // Arkivoc. - 2017. - Vol. 4. - P34-50 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): DYE-SENSITIZED SOLAR CELLS -- ELECTRON-RICH HETEROCYCLES -- METAL-FREE DYES -- PHOTOVOLTAIC PROPERTIES -- PUSH-PULL STRUCTURE -- THIENO[2,3-B]INDOLE Аннотация: New metal-free sensitizers (IK 3-6), based on the thieno[2,3-b]indole ring system, bearing various aliphatic substituents at the nitrogen atom (electron-donating part), several thiophene units (π-bridge linker) and 2-cyanoacrylic acid (the electron-accepting and anchoring group) have been synthesized for application in dye-sensitized solar cells (DSSCs). The relationship between the IK dye structure and efficiency of the corresponding DSSC has been elucidated. Power conversion efficiency (PCE) up to 6.3% (short-circuit photocurrent density (JSC) 19.0 mA cm-2, open-circuit voltage (VOC) 0.59 V, and fill factor (FF) 56.4%) were obtained for the DSSC, based on 2-cyano-3-{5-[8-(2-ethylhexyl)-8H-thieno[2,3-b]indol-2-yl]thiophen-2-yl}acrylic acid (IK 3), which proved to be a highly synthetic available compound, under simulated AM 1.5 G irradiation (100 mW cm-2), thus indicating that thieno[2,3-b]indole-based organic dyes are perspective candidates for DSSCs. \\\\Expert2\\NBO\\ARKIVOC\\2017 v.4 p.34-50.pdf |
Synthesis and characterization of linear 1,4-diazine-triphenylamine–based selective chemosensors for recognition of nitroaromatic compounds and aliphatic amines / E. V. Verbitskiy, Y. A. Kvashnin, E. F. Zhilina [et al.] // Dyes and pigments. - 2020. - Vol. 178. - P108344 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ALIPHATIC AMINES -- FLUORESCENCE QUENCHING -- NITROAROMATIC COMPOUNDS -- PYRAZINE -- QUINOXALINE -- SOLVATOCHROMISM Аннотация: Novel 1,4-diazine-based dyes of the D–π–A type, possessing triphenylamine as an electron-donating group, have been developed. Fluorescence studies have demonstrated that emission of these fluorophores is sensitive towards different nitroaromatic compounds and aliphatic amines, both in solutions and in a vapor phase. Moreover, these compounds can be considered as “naked-eye” fluorescent probes for solution polarity because they possess pronounced solvatochromic properties. Therefore, these compounds have to be regarded as potential multifunctional chemosensors for monitoring hazardous organic substances. |
Design of fluorescent sensors based on azaheterocyclic push-pull systems towards nitroaromatic explosives and related compounds: a review / E. V. Verbitskiy, G. L. Rusinov, O. N. Chupakhin, V. N. Charushin // Dyes and pigments. - 2020. - Vol. 180. - P108414 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): NITROAROMATIC EXPLOSIVES -- FLUORESCENCE QUENCHING -- PYRIDINES -- PYRAZINE -- PYRIMIDINES -- TRIAZINES Аннотация: Highly sensitive and selective detection of nitro containing high energy organic compounds such as picric acid (PA), 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT) has become a challenging task due to concerns over national security, criminal investigations and environment protections. Among various known detection methods, fluorescence sensors have gained special attention in recent time. The family of fluorescent sensors based on push-pull systems that incorporate nitrogen heterocycles as an electron-withdrawing group have a growing interest due to their high sensitivity, selectivity and easy tuning. The fluorescent sensors discussed in this review are classified and organized according to used azaheterocyclic scaffold, their functionality and their ability to detect of nitroaromatics by fluorescence quenching. |
Substituted 2-(2-hydroxyphenyl)–3H-quinazolin-4-ones and their difluoroboron complexes: Synthesis and photophysical properties / T. N. Moshkina, E. V. Nosova, V. N. Charushin [et al.] // Spectrochimica acta part A: molecular and biomolecular spectroscopy. - 2021. - Vol. 252. - P119497 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ESIPT -- FLUORESCENCE -- O-LIGAND -- BF2-COMPLEX2-(2-HYDROXYPHENYL)–3H-QUINAZOLIN-4-ONES Аннотация: 2-(2-Hydroxyphenyl)–3H-quinazolin-4-ones with diverse substituents at phenol ring and their six-membered difluoroboron complexes have been synthesized via few-stage approach. The photophysical properties of target compounds have been investigated in two solvents as well as in the solid state. The nature of substituents and substitution point in the phenol moiety of ligands and resulting BF2-complexes on the photophysical properties of dyes have been explored. The complex bearing two t-Bu groups proved to be the most emissive in solid state, whereas its 5-methoxy and 4-diethylamino counterparts possess strong emission in toluene solution. The dyes exhibited large Stokes shifts which was attributed to excited state intramolecular proton transfer (ESIPT). Additionally, fluorescence of quinazolinones in the mixture of THF/water was studied. All ligands demonstrated emission enhancement with increase of water fraction which was due to aggregation induced emission. |
Ethynylation of [1,2,4]triazolo[1,5-a]pyrimidinesusing substituted ethynylmagnesium bromides / N. A. Rasputin, N. S. Demina, E. F. Zhilina [и др.] // ChemistrySelect. - 2021. - Vol. 6, № 21. - С. 5167-5172 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A series of [1,2,4]triazolo[1,5-a]pyrimidine-cored push-pull compounds, bearing ethynyl moieties, was effectively prepared using transition-metal-free strategy involving the direct C−H functionalization of [1,2,4]triazolo[1,5-a]pyrimidine scaffold with the Grignard-Iocich reagents (ethynylmagnesium bromides). The basic optical and electrochemical properties of the synthesized derivatives were studied and gave grounds to consider the obtained compounds as promising UV dyes with high quantum yields. |
Synthesis of new water-soluble polyarene-substituted naphtho[1,2-d]oxazole-based fluorophores as fluorescent dyes and biological photosensitizers / N. V. Slovesnova, A. S. Minin, O. S. Taniya [et al.] // Dyes and Pigments. - 2022. - Vol. 204. - Ст. 110410 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
Fluoroaromatic 2H-imidazole-based push-pull fluorophores: Synthesis, theoretical studies, and application opportunities as probes for sensing the pH in saliva / T. D. Moseev, M. V. Varaksin, E. A. Virlova [et al.] // Dyes and Pigments. - 2022. - Vol. 202. - Ст. 110251 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
(A)symmetric chromophores based on cyano and fluorine-substituted 2,3-bis(5-arylthiophen-2-yl)quinoxalines: Synthesis, photophysical properties and application prospects / T. N. Moshkina, E. V. Nosova, A. E. Kopotilova [et al.] // Dyes and Pigments. - 2022. - Vol. 204. - Ст. 110434 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
Abnormal push-pull benzo[4,5]imidazo[1,2-a][1,2,3]triazolo[4,5-e]pyrimidine fluorophores in planarized intramolecular charge transfer (PLICT) state: Synthesis, photophysical studies and theoretical calculations / O. S. Taniya, V. V. Fedotov, L. K. Sadieva [et al.] // Dyes and Pigments. - 2022. - Vol. 204. - Ст. 110405 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The combination of excellent luminescence with high solvent polarity effect and aggregation induced emission (AIE) is an ideal combination for creating fluorophores/probes with high microenvironmental sensitivity. However, many push-pull chromophores of the D−A type in common intramolecular charge transfer (ICT) state with a significant solvatochromic effect and AIE activity, have poor luminescent properties. Herein, to overcome this problem by using reactions of nucleophilic aromatic hydrogen substitution (SNH), we have designed a series of novel 4-heteroaryl-substituted 2-aryl-2H-benzo[4,5]imidazo[1,2-a][1,2,3]triazolo[4,5-e]pyrimidine fluorophores possessing a planarized intramolecular charge transfer (PLICT) state. All these fluorophores exhibited high luminescence quantum yields (up to 60%) and large Stokes shift values of up to 7459 cm−1. Among them, the fluorophore 4h was found to exhibit the most pronounced positive solvatochromic effect and the probe 4f exhibited the most pronounced aggregation induced emission characteristics. This AIE behavior was further confirmed by means of time-resolved fluorescence lifetime measurements as well as DFT-assisted geometry optimization studies. In the presence of trifluoroacetic acid (TFA) compound 4h exhibited a well-pronounced acidochromism via visible color change from yellow-green to orange which returned to the original yellow-green solution after the addition of triethylamine (TEA). The Stern-Volmer constant for the probe 4h towards TFA was 38 M−1. Finally, for the compounds 4f, g, h theoretical calculations in the ground and excited states in different solvents were carried out to confirm the PLICT process. Based on all above the herein reported PLICT fluorophores 4a-h can be successfully applied as biological probes and optical switches. |