Multiple relaxation pathways in photoexcited dimethylaminonitro- and dimethylaminocyano-stilbenes

Lapouyade, R.; Kuhn, Alexander; Létard, Jean‐François; Rettig, Wolfgang

doi:10.1016/0009-2614(93)80075-z

Cited by 134 publications

(180 citation statements)

References 44 publications

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“…The fluorescence decay pattern ͑rise time plus emission-wavelength-dependent contribution of the long-lived component͒ seen for the CZD4SNC2 dendrimer is typical of two-component ͑dual͒ fluorescence. [11][12][13]16,17 The presence of a blue shoulder at about 485 nm in the steady-state fluorescence spectrum shown in Fig. 2 also supports this dual fluorescence model.…”

Section: Methodssupporting

confidence: 54%

“…The fluorescence maximum in different solvents showed a solvatochromic shift in accordance with the solvent polarity while the appearance of shoulder could be indicative of dual fluorescence. [11][12][13] For fast fluorescence kinetic measurements we apply the femtosecond fluorescence upconversion technique for time resolved detection of the luminescence. 14 The optical arrangement for the upconversion experiments was described previously.…”

Section: Methodsmentioning

confidence: 99%

“…Generally, dual ͑multiple͒ fluorescence could be associated with either solvent rearrangement 16,18 or photoinduced solute conformational changes. 11,13,17 It might also be suggested that the long-lived decay and the rise-time components could be connected with the formation of aggregates such as excimers or exciplexes. Note that the existence of excimerlike interactions was invoked to explain the fast excited-state dynamics of another type of dendrimer macromolecule bases on phenylene building blocks.…”

Section: Methodsmentioning

confidence: 99%

“…The TICT states are associated with a twisting of various single and double bonds in the molecule. 11 Therefore, the stabilization dynamics of the intramolecular charge-transfer state should reflect the balance between intramolecular energy relaxation and solvent reorganization. The dynamics is expected to be rather complex.…”

Section: Shown Inmentioning

confidence: 99%

“…However, the experimental proof of one or other theoretical models for NAS photophysics relied mainly on the concepts of fluorescence quantum yield and mean excited-state decay time. 11,12 At the same time, measurements with a femtosecond time resolution performed for related donor-acceptor dimethylaminocyanostilbene showed complicated dynamics with a rise-time component and several decay time components, which obviously could not be described in terms of a simple decay time concept. However, no time-resolved fluorescence measurement with femtosecond time resolution has been published for nitroaminostilbene derivatives.…”

Section: Shown Inmentioning

confidence: 99%

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Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

et al. 2000

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The ultrafast intrinsic dynamics of an organic dendrimer in solution and in a thin film is reported using fluorescence upconversion spectroscopy. Femtosecond decay is detected at higher emission energies, while at lower energies a fluorescence rise time (ϳ3 ps͒ was observed that is dependent on the solvent's polarity. A strong excitation energy dependence of the decay pattern was also observed. Different synthetic functional groups that comprise the macromolecular dendrimer structure were investigated. The mechanism, which describes the complex dynamics in the dendrimer system, was found to be associated with the excitation of the attached chromophore nitroaminostilbene. These results indicate the absence of excited-state interactions of functional groups within the dendrimer macromolecule. A model, which includes the existence of an intermediate nonradiative state, is proposed to describe the complex ultrafast fluorescence dynamics in the dendrimer system.

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Section: Methodssupporting

confidence: 54%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Shown Inmentioning

confidence: 99%

Section: Shown Inmentioning

confidence: 99%

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Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

et al. 2000

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Study of the intramolecular charge-transfer (ICT) process in 4-dimethylamino-4′- nitrostilbene by picosecond time-resolved CARS

Oberlé

Abraham

Jonusauskas

et al. 2000

J. Raman Spectrosc.

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The intramolecular charge-transfer (ICT) process of 4-dimethylamino-4 -nitrostilbene (DNS) in solution was studied by pump-probe and transient CARS experiments with a 1 ps time resolution. Whereas pump-probe experiments give good evidence for the formation of an ICT state in polar solvents, CARS experiments support structural changes associated with the ICT process. In acetonitrile, a 37 cm −1 downshift of the NO 2 stretching mode can be explained by a structural change located on the acceptor NO 2 group and assigned to conformational relaxation of the ICT state. In toluene, such behavior is not observed correlated with the absence of ICT state stabilization in non-polar solvents.

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Cis‐TransPhotoisomerization of Stilbenes and Stilbene‐Like Molecules

Görner¹,

Kuhn²

1994

Advances in Photochemistry

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Multiple relaxation pathways in photoexcited dimethylaminonitro- and dimethylaminocyano-stilbenes

Cited by 134 publications

References 44 publications

Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

Study of the intramolecular charge-transfer (ICT) process in 4-dimethylamino-4′- nitrostilbene by picosecond time-resolved CARS

Cis‐TransPhotoisomerization of Stilbenes and Stilbene‐Like Molecules

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