The fluorescence of all-trans diphenyl polyenes

Birks, J. B.; Tripathi, G. N. R.; Lumb, M. D.

doi:10.1016/0301-0104(78)87128-6

Cited by 80 publications

(37 citation statements)

References 18 publications

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“…The lack of a mirror image between these spectra is due to the electronic states involved once the absorption corresponds to S o -S 2 * transition and the emission corresponds to S 1 * -S o transition. 12,13 In the presence of large amounts of water in ethanol and in DMSO, the absorption spectra of DPH changed as illustrated in Figure 2 (water/ethanol system as an example). However, these changes for [DPH] = 5.0 × 10 -6 mol L -1 at 30 °C are observed only above 54% water in ethanol and 46% water in DMSO.…”

Section: Resultsmentioning

confidence: 99%

“…20 Although hydrogen bonding or even polar-polar interactions are not recognizable for DPH, some authors have reported experimental and theoretical ground state benzene-water weak structures in which the aromatic rings would act as hydrogen bond acceptors. 23 For DPH, as reported, 10 the S 2 * electronic state ( 1 B u * ) of DPH is assigned as more "ionic" symmetry and there is a S 2 * -S 1 * coupling that changes the "purity" of both states, 12 which may turn the S 1 * state more "ionic", so that more sensible to interactions.…”

Section: Resultsmentioning

confidence: 99%

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Unusual 1,6-diphenyl-1,3,5-hexatriene (DPH) spectrophotometric behavior in water/ethanol and water/DMSO mixtures

Gracetto

Batistela

Santos

et al. 2010

J. Braz. Chem. Soc.

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O espectro de absorção de DPH, em concentração fixa, não varia com o teor de água em solvente orgânico. Tem-se a banda de monômeros igual àquela em etanol puro. A absorção não muda até o limite de 54 e 46% de água em etanol e DMSO, respectivamente, para [DPH] = 5,0 × 10 -6 mol L -1 a 30 °C. Entretanto, em misturas com água muito abaixo desses conteúdos críticos, observou-se um decaimento intenso de fluorescência enquanto a absorção manteve-se constante. Propõe-se que moléculas de água atuam como supressores dos estados excitados e a constante de supressão de Stern-Volmer através de intensidade relativas, resultou em 7,4 × 10 -2 (água/etanol) e 2,6 × 10 -2 L mol -1 (água/DMSO). Os tempos de vida do DPH na ausência e presença do supressor forneceram constantes de 7,1 × 10 -2 L mol -1 em água/etanol, indicando supressão dinâmica. Em investigações de ambientes com esta sonda, este processo deve ser considerado tendo em vista o risco de erros de interpretação.The absorption spectra of DPH at fixed concentration do not change with water content in organic solvents. It exhibits monomer bands, such as those obtained in ethanol. The absorption did not change for solutions up to 54 and 46% of water in ethanol and DMSO, respectively, for [DPH] = 5.0 × 10 -6 mol L -1 at 30 °C. However, at the same experimental conditions, a gradual sharp decay of the DPH fluorescence is observed. It is proposed that water molecules below these water concentration limits act as quenchers of the excited states of DPH. Stern-Volmer quenching constants by intensities measurements are 7.4 × 10 -2 (water/ethanol) and 2.6 × 10 -2 L mol -1 (water/DMSO). DPH lifetime measurements in the absence and presence of water resulted in 7.1 × 10 -2 L mol -1 in water/ethanol, which pointed out that the process is a dynamic quenching by water molecules. For experiments using DPH as probe, this process can affect data, leading to misunderstanding interpretation.Keywords: diphenylhexatriene, DPH, DPH fluorescence, dynamic quenching, lifetime 3,, which is used as a fluorescence probe, has a rod-like structure that absorbs and emits light with a high quantum efficiency, although it is not a large conjugative p-electron system. Introduction 1,2The spectrophotometric properties of DPH are very sensitive to the experimental conditions, which allows using this compound and its derivatives as environmental probes in colloidal systems to determine the critical micellar concentration of surfactants 3 and in biological cell membranes. 4,5 The measurement of the fluorescence anisotropy of DPH is extensively used for membranes, particularly in studies of microviscosities, 6 due to the non-polar characteristic, the low water solubility, and the suitable geometric design, which maintains the molecule aligned parallel to the phospholipids chains of the membranes. 7 Although the DPH molecule remains inserted in the membrane layer, it stays in contact with water molecules. 2,5The majority of DPH spectrophotometric studies on electronic transitions are performed in organic solven...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Unusual 1,6-diphenyl-1,3,5-hexatriene (DPH) spectrophotometric behavior in water/ethanol and water/DMSO mixtures

Gracetto

Batistela

Santos

et al. 2010

J. Braz. Chem. Soc.

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show abstract

“…In particular, the phenyl substituted polyenes have received specific attention because they fluoresce and that made them attractive systems for investigation with technics such as two-photon absorption spectroscopy -3 and lifetime measurements with single photon techniques, [4][5][6][7] both requiring reasonable fluorescence quantum yields.…”

Section: Introductionmentioning

confidence: 99%

“…This conclusion allowed to explain previous discrepancies between observations and calculations, particularly that between the measured radiative lifetime and the calculated lifetime using the Strickler Berg relation. 4 Moreover one photon spectroscopy in solutions, at room temperature, has shown that, owing to the small energy gap between Ag and Bu levels, the latter is also thermally repopulated. 8'9 At the opposite limit of short chains (n 1), state S* was given symmetry Bu in the case of t-stilbene.…”

Section: Introductionmentioning

confidence: 99%

Picosecond Photophysics of1,4‐Diphenyl‐butadiene inCondensed Phase. SolventAssisted Electronic LevelInversion

1985

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“…[1,[8][9][10] The combination of a low isomerization rate in the S 1 state and the dipole forbiddenness of its radiative relaxation to the electronic ground state is also consistent with the long intrinsic fluorescence lifetime of 13.3 ns in hydrocarbon solutions. [14] Moreover, the long lifetime of the 2 1 A g state and the strong nonadiabatic coupling in the neighborhood of the conical intersection with the optically bright 1 1 B u state offer a conclusive explanation for the experimentally observed delayed fluorescence on the blue edge of the emission band. This transition has been attributed to delayed emission from the S 2 state due to thermal repopulation of the 1 1 B u potential, [15,16] in qualitative agreement with our model.…”

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confidence: 96%

On the Photophysics of 1,6‐Diphenyl‐1,3,5‐Hexatriene Isomers and Rotamers

et al. 2011

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Herein, the low-lying electronic states of various isomers and rotamers of 1,6-diphenyl-1,3,5-hexatriene (DPH) are studied by a combination of density functional theory and multireference configuration interaction. Starting from the all-trans nuclear arrangement, trans-cis isomerization pathways in the electronic ground state and in the first excited triplet state were determined. Further, spin-orbit coupling calculations were carried out at selected points where singlet-triplet energy gaps are small. The calculations reveal that the primarily excited, optically bright 1(1)B(u) state undergoes a curve crossing with the optically dark multiconfigurational 2(1)A(g) state upon geometry relaxation in the excited state. The strong vibronic coupling of the two singlets in the neighborhood of the conical intersection provides a conclusive explanation for the experimentally observed fast equilibration of the states and the appearance of delayed fluorescence. With regard to the trans-cis isomerization of the central CC bond, the perpendicular conformation is found to represent a maximum on the energy profile not only of the electronic ground state, but also of the low-lying excited states. The lack of a strong driving force along the torsional coordinate explains the low tendency of DPH for isomerization. Finally, the results of our spin-orbit coupling calculations suggest that the intramolecular formation of DPH molecules in the T(1)(1(3)B(u)) state proceeds from the 1(1)B(u) state and involves intermediately the T(2)(1(3)A(g)) state.

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The fluorescence of all-trans diphenyl polyenes

Cited by 80 publications

References 18 publications

Unusual 1,6-diphenyl-1,3,5-hexatriene (DPH) spectrophotometric behavior in water/ethanol and water/DMSO mixtures

Unusual 1,6-diphenyl-1,3,5-hexatriene (DPH) spectrophotometric behavior in water/ethanol and water/DMSO mixtures

Picosecond Photophysics of1,4‐Diphenyl‐butadiene inCondensed Phase. SolventAssisted Electronic LevelInversion

On the Photophysics of 1,6‐Diphenyl‐1,3,5‐Hexatriene Isomers and Rotamers

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