Photoisomerization Dynamics and Spectroscopy of the Polymethine Dye DTCI

Paolo, Roberto E. Di; Scaffardi, Lucia; Duchowicz, Ricardo; Bilmes, Gabriel Mario

doi:10.1021/j100038a008

Cited by 48 publications

(65 citation statements)

References 5 publications

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“…On the other hand, the less viscous and highly polar solvents provide TTBC a freedom to rotate and vibrate which can be the possible sources of the non-radiative transitions. These observations are in concert with the other cyanine dyes [1][2][3][4][5][6][7][8][9][10].…”

Section: Resultssupporting

confidence: 65%

“…The non-radiative rate constant can be represented as a sum of the rates associated with internal conversion, photoisomerization, intersystem crossing and specific solvent effects. There is a consensus in the literature [1][2][3][4][5][6][7][8][9][10][35][36][37][38][39][40][41] on the nature of nonradiative transitions: internal conversion and photoisomerisation are the major deactivation pathways of the excited singlet state of cyanines. This consensus is based on observations such as extremely low intersystem crossing quantum yields [35][36][37] and as very short fluorescence lifetimes of cyanine dyes in low viscosity solvents [37][38][39][40][41].…”

Section: Resultsmentioning

confidence: 99%

“…The pronounced dominance of viscosity suggests that the photoisomerization and internal conversions are the dominant non-radiative events in the excited states of TTBC. It is well known that a change in the twisting angle around a carbon-carbon bond of the polymethine chain for cyanines causes photoisomerisation [1][2][3][4][5][6][7][8][9][10].…”

Section: Resultsmentioning

confidence: 99%

“…The photophysics and photochemistry of cyanine dyes have been studied extensively [1][2][3][4][5][6][7][8][9][10]. It has been demonstrated that photoisomerisation and internal conversion, in general, participate in the deactivation of the excited state, and the restriction of these processes enhances fluorescence efficiency of cyanine dyes.…”

Section: Introductionmentioning

confidence: 99%

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Steady state and picosecond time-resolved photophysics of a benzimidazolocarbocyanine dye

Özçelik

2002

Journal of Luminescence

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We report the steady-state and the excited state properties of 1, 3, 1 0 , 3 0 -tetraethyl-5, 6, 5 0 , 6 0 -tetrachlorobenzimidazolocarbocyanine iodide (TTBC) in various solvents. The magnitude of the Stokes shift and the average transition energy proves that the structure of the fluorescent state should be very similar to that of the ground-state structure. The fluorescence lifetimes and quantum yields indicate that non-radiative processes are collectively much more effective than the radiative processes. It is therefore suggested that the non-radiative processes, which are driven by the medium around the TTBC molecule control the excited state dynamics. r

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Section: Resultssupporting

confidence: 65%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Steady state and picosecond time-resolved photophysics of a benzimidazolocarbocyanine dye

Özçelik

2002

Journal of Luminescence

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“…It could be attributed to fluorescence of a monocis isomer, since the occurrence of this conformation has already been proven for meso-unsubstituted dyes. 31, 35 The small relative amplitude of this component explains why it is not observed in the 1 H NMR data or the steady-state absorption and fluorescence spectra nor in the fluorescence quantum yield. This fast-decaying component might, however, also be attributed to a number of other possible processes, such as internal vibrational reorganization (IVR), vibrational relaxation, solvent relaxation, or singlet annihilation.…”

Section: Table 5: Data Retrieved From the Reference Convoluted Fits Omentioning

confidence: 99%

The Influence of Meso-Substitution on the Photophysical Behavior of Some Thiacarbocyanine Dyes in Dilute Solution

et al. 2001

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Fluorescence upconversion experiments were performed on monomer solutions of a number of structurally similar thiacarbocyanine dyes. The results from these time-resolved experiments combined with the data obtained from steady-state absorption and emission and 1 H NMR spectra allowed us to assign the components with different decay times to distinct isomers of the thiacarbocyanine dye molecules. Furthermore, it was possible to relate the substitution pattern of the dye molecules to their photophysical properties. For all mesosubstituted dyes, a short-lived component of either 3.5 or 5.7 ps could be assigned to a mono-cis conformation of the thiacarbocyanines. This component emits at longer wavelengths. A second component ranging from 15 to 71 ps and emitting at shorter wavelengths was attributed to the all-trans conformation of the mesosubstituted trimethine dyes. Time-resolved emission spectra revealed in a very clear and direct way the evolution of the contribution of the two conformations to the spectra. The size and/or solvation of the N,N′-substituents have a parallel influence on the decay time of the fast and the slow decaying component. Besides the N,N′-substituents also the meso-substituent has an influence on the decay time and amplitude of the longer-lived component.

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Confinement of Dyes inside Boron Nitride Nanotubes: Photostable and Shifted Fluorescence down to the Near Infrared

et al. 2020

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Fluorescence is ubiquitous in life science and used in many fields of research ranging from ecology to medicine. Among the most common fluorogenic compounds, dyes are being exploited in bioimaging for their outstanding optical properties from UV down to the near IR (NIR). However, dye molecules are often toxic to living organisms and photodegradable, which limits the time window for in vivo experiments. Here, it is demonstrated that organic dye molecules are passivated and photostable when they are encapsulated inside a boron nitride nanotube (dyes@BNNT). The results show that the BNNTs drive an aggregation of the encapsulated dyes, which induces a redshifted fluorescence from visible to NIR‐II. The fluorescence remains strong and stable, exempt of bleaching and blinking, over a time scale longer than that of free dyes by more than 104. This passivation also reduces the toxicity of the dyes and induces exceptional chemical robustness, even in harsh conditions. These properties are highlighted in bioimaging where the dyes@BNNT nanohybrids are used as fluorescent nanoprobes for in vivo monitoring of Daphnia Pulex microorganisms and for diffusion tracking on human hepatoblastoma cells with two‐photon imaging.

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Photoisomerization Dynamics and Spectroscopy of the Polymethine Dye DTCI

Cited by 48 publications

References 5 publications

Steady state and picosecond time-resolved photophysics of a benzimidazolocarbocyanine dye

Steady state and picosecond time-resolved photophysics of a benzimidazolocarbocyanine dye

The Influence of Meso-Substitution on the Photophysical Behavior of Some Thiacarbocyanine Dyes in Dilute Solution

Confinement of Dyes inside Boron Nitride Nanotubes: Photostable and Shifted Fluorescence down to the Near Infrared

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