Viscosity effect on the rate of back electron transfer within a short-lived exciplex

Vauthey, Eric; Phillips, David

doi:10.1016/0301-0104(90)85056-3

Cited by 22 publications

(11 citation statements)

References 22 publications

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“…A negative Δ G PET in all the solvents for the NGQD–DEA pair confirmed PET as the reason behind the observed luminescence quenching. Additionally, we calculated the driving force for the back electron transfer process (Δ G BET ) utilizing the values of E 00 and Δ G PET according to the following formula , The obtained values are tabulated in Table .…”

Section: Resultsmentioning

confidence: 99%

“…Vauthey et al demonstrated that the BET dynamics within an exciplex (CIP) depends on the rate of the conformational changes in viscous nonpolar solvents, viz., decalin . However, if the back electron transfer is from the solvent-separated ion pairs (SSIPs), the equations in the exciplex model can be modified, keeping in mind the fact that conformational changes can occur provided the SSIPs have already diffused toward each other.…”

Section: Resultsmentioning

confidence: 99%

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Diffusion of Solvent-Separated Ion Pairs Controls Back Electron Transfer Rate in Graphene Quantum Dots

et al. 2018

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In the present study, the stability of the photogenerated, solvent-separated charged states of graphene quantum dots (GQDs) in the presence of N,N-diethylaniline (DEA) has been evaluated in a series of organic solvents. The results indicate that the rate constant for back electron transfer (k BET) from GQD radical anion to DEA radical cation is diffusion-controlled. As a result of the diffusion-controlled back electron transfer (BET), k BET exhibits an inverse exponential relation to (a) the viscosity coefficient (η) of the solvent and (b) the average radius of the graphene quantum dots. An analytical expression for the diffusion-controlled back electron transfer rate constant has been formulated. The dependence of k BET on the diffusion of solvent-separated ion pairs has been evaluated for the first time for quantum dot systems and the results provide an efficient method for enhancing the lifetime of the photogenerated charge-separated states from graphene quantum dots. The present findings can potentially improve the performance of GQD-based photovoltaic and optoelectronic devices.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Diffusion of Solvent-Separated Ion Pairs Controls Back Electron Transfer Rate in Graphene Quantum Dots

et al. 2018

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“…29 (1) where, E 0 (D Additionally, we calculated the driving force for the back electron transfer process ( G BET ) viz. −1.95 eV utilizing the value of E 00 and G PET according to the following formula: 30,31 G BET = −E 00 − G PET (2) In order to observe the formation of the charge separated states via PET, nanosecond laser flash photolysis experiments were carried out.…”

Section: Calculation Of the Free Energy Change Associated With Forwarmentioning

confidence: 99%

Photoinduced electron transfer processes of (E)-9-(4-nitrostyryl)anthracene in non-polar solvent medium: generation of long-lived charge-separated states $$^{\S }$$ §

2018

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In the present study, photoinduced electron transfer (PET) dynamics between N,N-diethylaniline (DEA) and (E)-9-(4-nitrostyryl)anthracene (An-NO 2 ) in a non-polar solvent medium {methylcyclohexane (MCH)}, has been investigated. The rate constant of back electron transfer (k BET ) for the An-NO 2 -DEA pair was ∼ 3.8 × 10 5 s −1 which is ca. 2 orders of magnitude less compared to the anthracene (An)-DEA (control) system. The results indicate that long-lived charge separated species can be generated using the design strategy used herein by achieving resonance stabilization of the excited state (acceptor) radical via conjugation.

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“…Earliest work involved the measurement of time-resolved resonance Raman spectra of transients on the nanosecond timescale [81][82][83]; subsequently, this was extended to picosecond resonance Raman [84][85][86] and then the development of an instrument (PIRATE) at the Rutherford Appleton Laboratories, Oxford, on which picosecond Raman, infrared and transient absorption measurements could be made [87] (figure 10).…”

Section: Time-resolved Vibrational Spectroscopymentioning

confidence: 99%

A lifetime in photochemistry; some ultrafast measurements on singlet states

Phillips¹

2016

Proc. R. Soc. A.

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We describe here the development of time-correlated single-photon counting techniques from the early use of spark discharge lamps as light sources through to the use of femtosecond mode-locked lasers through the personal work of the author. We used laser-excited fluorescence in studies on energy migration and rotational relaxation in synthetic polymer solutions, in biological probe molecules and in supersonic jet expansions. Time-correlated single-photon counting was the first method used in early fluorescence lifetime imaging microscopy (FLIM), and we outline the development of this powerful technique, with a comparison of techniques including wide-field microscopy. We employed these modern forms of FLIM to study single biological cells, and applied FLIM also to gain an understanding the distribution in tissue, and fates of photosensitizer molecules used in photodynamic therapy. We also describe the uses and instrumental design of laser systems for the study of ultrafast time-resolved vibrational spectroscopy.

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Viscosity effect on the rate of back electron transfer within a short-lived exciplex

Cited by 22 publications

References 22 publications

Diffusion of Solvent-Separated Ion Pairs Controls Back Electron Transfer Rate in Graphene Quantum Dots

Diffusion of Solvent-Separated Ion Pairs Controls Back Electron Transfer Rate in Graphene Quantum Dots

Photoinduced electron transfer processes of (E)-9-(4-nitrostyryl)anthracene in non-polar solvent medium: generation of long-lived charge-separated states $$^{\S }$$ §

A lifetime in photochemistry; some ultrafast measurements on singlet states

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