Fluorescence quenching in bichromophoric systems with nonconjugated chromophores: 5-substituted derivatives of l,3,5-triaryl-2-pyrazoline

Дорошенко, А. О.; Skripkina, V. T.; Schershukov, V. M.; Ponomaryov, O. A.

doi:10.1007/bf02760504

Cited by 10 publications

(4 citation statements)

References 13 publications

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“…Thus, in all the solvents, emission is due to an allowed charge-transfer transition S 1 (CT) → S 0 . These observations are in agreement with those reported by other research groups for 1,3-di- and 1,3,5-triaryl-Δ 2 -pyrazolines. ,,,− The negligible spectroscopic effect of various 5- p donor substituents is even observed for the bulky crown ether groups and gives further evidence for the rigidity of the “Δ 2 -pyrazoline bridge” and the prearrangement of 1-, 3-, and 5-substituents in a conformation preventing sizable orbital overlap.…”

Section: Resultssupporting

confidence: 91%

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ²-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

Rurack¹,

Bricks²,

Schulz³

et al. 2000

J. Phys. Chem. A

103

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The spectroscopic properties of 1-phenyl-3-benzothiazol-2-yl-5-(4-R-phenyl)-∆ 2 -pyrazolines are strongly dependent on both the electronic nature of the substituent R and solvent polarity. As revealed by spectroscopic studies as a function of solvent polarity as well as temperature, for electron-rich amino donor substituents in polar solvents, deactivation of the strongly emissive charge transfer (CT) state of the basic 1-phenyl-3benzothiazol-2-yl-∆ 2 -pyrazoline chromophore has to compete with a fast intramolecular electron transfer (ET) quenching reaction. In the case of the dimethylamino derivative (R ) DMA), the rate constant of ET in acetonitrile was determined to k et ) 3 × 10 10 s -1 . This ET process can be utilized for metal ion sensing by introducing nitrogen containing aza crown ether receptor units to the 4-position of the 5-phenyl group. The spectroscopically determined ET rates of the 5-(N-alkyl)anilino substituents, a DMA, a tetrathia-(AT 4 15C5), and a tetraoxa-monoaza-15-crown-5 (A15C5) group, correlate with electrochemical data and increase in the order AT 4 15C5 < A15C5 < DMA. The metal ion sensing abilities of the two crowned derivatives are presented, and the different signaling mechanisms include binding to the crown ether in the 4-R-position, chelate formation in the 3-benzothiazol-2-yl-∆ 2 -pyrazoline moiety, and electrophotochemical detection. Furthermore, the rigid "pseudo spiro" geometry of the molecules, which holds the three substituents of the central ∆ 2 -pyrazoline ring in a fixed prearrangement, was confirmed by X-ray structure analysis.

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Section: Resultssupporting

confidence: 91%

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ²-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

Rurack¹,

Bricks²,

Schulz³

et al. 2000

J. Phys. Chem. A

103

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“…Quantum calculations of the excited states of 4а showed a cross-linked excited state located just a few hundred of сm -1 higher than its singlet excited state. An energy difference of 1000 сm -1 for similar states would quench fluorescence almost entirely (Doroshenko et al, 1997b). The dissipation of electronic energy without effective emission in the 4а-g series was the result of processes similar to those described above; for example, the rapid pace of the molecule to the triplet state, with consequent dissipation of energy as heat.…”

Section: Fluorescence and Intersystem Crossingmentioning

confidence: 78%

1,3,5-Triaryl 2-Pyrazolines With 8-Hydroxyquinolinic Substituent: Syntheses, Photophysical Properties, and Biological Activity

Marrugo-González¹,

Orlov²,

Fernandez‐Maestre³

2015

PTQ

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1,3,5-triaryl-2-pyrazolines are organic luminophores with arylic radicals that show a wide biological activity and are used as liquid scintillators and electro-optic materials. Experimental. Eleven 2-pyrazolines were synthesized from phenylhidrazine and chalcones of the 8-hydroxyquinoline series: 3-(8-hydroxyquinolin-5-yl)-1-(3-R)-phenylprop-2-enone and 1-(8-hydroxyquinolin-5-yl)-3--(3-R)-phenylprop-2-enone, where R = H, CH3, OCH3, N(CH3)2, Cl, Br, and NO2. The structures were confirmed by elemental analysis, IR, 1H-NMR, and electronic spectroscopy. Results and discussion. The 1- and 3-aryl substituents of the pyrazoline ring produced shifts to shorter or longer wavelengths, in absorbance and fluorescence. The electron acceptor hydroxyquinolinic fragment influenced the absorption and luminescence spectra; the possible cause of low quantum yields in pyrazolines (1-phenyl-3-(4-R phenyl)-5-(8-hydroxyquinolinil-5)-2-pyrazoline) may be the specific intramolecular fluorescence quenching in bicromophores, characteristic of 5-acceptor substituted pyrazolines, and, in series (1-phenyl-5-(4-R phenyl)-3-(8-hydroxyquinolinil-5)-2-pyrazoline) of excited-state intramolecular proton transfer (ESIPT) reactions, and the increasing donor-acceptor intramolecular interaction of their excited molecules; Density functional calculations (method PM6) were used to probe the electronic structure and energy ordering of the emissive and the electron-transfer states; PM6 results agreed with the experimental data. 1-phenyl-3-(4-R phenyl)-5-(8-hydroxyquinolinil-5)-2-pyrazoline showed fungistatic and fungicide activities. Additionally, all our pyrazolines showed wide theoretical biological activities.

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“…Here we do not consider the last possibility, because in such a case 5-aryl moiety is out of conjugation with the main chromophoric fragment of the molecule, 1,3-diaryl-2-pyrazoline. In most cases substituents in position 5 of pyrazoline cycle have no effect on fluorescent characteristics at all, however, several publications reported dramatic decreasing of fluorescence quantum yields in case of introducing into position 5 electron-withdrawing groups or polycyclic aromatic moieties like anthracene [37][38][39][40].…”

Section: Introductionmentioning

confidence: 99%

1,5-Diaryl-3-Benzimidazolyl-2-Pyrazolines and Pyrazoles – Novel Fluorescent Dyes of Pyrazoline Family

Kotlyar¹,

Orlov²,

Grygorovych³

et al. 2017

Chemical Series

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A series of novel aryl derivatives of 2-pyrazoline bearing 2-benzimidazolyl moiety was synthesized via condensation of corresponding chalcones with phenyl hydrazine. Pyrazoles on their background were obtained by the optimized oxidation procedure with manganese dioxide in benzene. Fluorescent characteristics of the title compounds were determined for their solutions in acetonitrile. Quantum-chemical modeling of molecular structure, UV/Vis spectra, electron density redistribution and structural relaxation at electronic excitation resulting in high fluorescence Stokes shifts were conducted as well.

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Fluorescence quenching in bichromophoric systems with nonconjugated chromophores: 5-substituted derivatives of l,3,5-triaryl-2-pyrazoline

Cited by 10 publications

References 13 publications

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ²-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ²-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

1,3,5-Triaryl 2-Pyrazolines With 8-Hydroxyquinolinic Substituent: Syntheses, Photophysical Properties, and Biological Activity

1,5-Diaryl-3-Benzimidazolyl-2-Pyrazolines and Pyrazoles – Novel Fluorescent Dyes of Pyrazoline Family

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Fluorescence quenching in bichromophoric systems with nonconjugated chromophores: 5-substituted derivatives of l,3,5-triaryl-2-pyrazoline

Cited by 10 publications

References 13 publications

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ2-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ2-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

1,3,5-Triaryl 2-Pyrazolines With 8-Hydroxyquinolinic Substituent: Syntheses, Photophysical Properties, and Biological Activity

1,5-Diaryl-3-Benzimidazolyl-2-Pyrazolines and Pyrazoles – Novel Fluorescent Dyes of Pyrazoline Family

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Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ²-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties

Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ²-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties