Combined Experimental and Computational Study of Intramolecular Charge Transfer In p-N,N-Dimethylamino-p′-cyano-diphenylacetylene

Fujiwara, Toru; Zgierski, Marek Z.; Lim, E. C.

doi:10.1021/jp109674t

Cited by 11 publications

(21 citation statements)

References 10 publications

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“…Note that neither DACN-DPA nor BODIPY derivatives bearing a dimethylaminophenyl group at the meso position exhibit such CT absorption feature at low energy. [60][61][62]67,68 Fluorescence Emission and Photophysical Properties. The fluorescence emission spectra of T-1 and T-2 were obtained upon excitation at 485 nm ( Figures S4 and S5 in the Supporting Information).…”

Section: Table 1 Experimental and Calculated λ Values (Nm) And Transmentioning

confidence: 99%

Tuning the Direction of Intramolecular Charge Transfer and the Nature of the Fluorescent State in a T-Shaped Molecular Dyad

et al. 2015

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Controlling photoinduced intramolecular charge transfer at the molecular scale is key to the development of molecular devices for nanooptoelectronics. Here, we describe the design, synthesis, electronic characterization, and photophysical properties of two electron donor-acceptor molecular systems that consist of tolane and BF2-containing curcuminoid chromophoric subunits connected in a T-shaped arrangement. The two π-conjugated segments intersect at the electron acceptor dioxaborine core. From steady-state electronic absorption and fluorescence emission, we find that the photophysics of the dialkylamino-substituted analogue is governed by the occurrence of two closely lying excited states. From DFT calculations, we show that excitation in either of these two states results in a distinct shift of the electron density, whether it occurs along the curcuminoid or tolane moiety. Femtosecond transient absorption spectroscopy confirmed these findings. As a consequence, the nature of the emitting state and the photophysical properties are strongly dependent on solvent polarity. Moreover, these characteristics can also be switched by protonation or complexation at the nitrogen atom of the amino group. These features set new approaches toward the construction of a three-terminal molecular system in which the lateral branch would transduce a change of electronic state and ultimately control charge transport in a molecular-scale device.

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Section: Table 1 Experimental and Calculated λ Values (Nm) And Transmentioning

confidence: 99%

Tuning the Direction of Intramolecular Charge Transfer and the Nature of the Fluorescent State in a T-Shaped Molecular Dyad

et al. 2015

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“…By further comparing these results with ICT-based aryl amines have been designed and synthesized for potential applications in chemical sensors, fluorescence probe, and the mimicry of photosynthesis in plants. 1,[4][5][6][7][8][9] However, the mechanism for the ICT is very versatile, even controversial in some systems. 1 There is a heated debate over molecular conformation change in the ICT process, the two dominant models being the twisted intramolecular charge transfer (TICT) and planar intramolecular charge transfer (PICT).…”

mentioning

confidence: 99%

Theoretical and experimental study on intramolecular charge-transfer in symmetric bi-1,3,4-oxadiazole derivatives

Wang¹,

Liu²,

Bai³

et al. 2015

Journal of Photochemistry and Photobiology A: Chemistry

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“…(3) The transient absorption spectra peaked around 500 nm at early dynamics can be assigned to the S n ← S 1 transition. (4) It is found that the formation of the PICT state is about 2 orders of magnitude faster in ACN (3.25 ps) compared to CHX (361 ps), revealing the solvent polarity dependence of the ICT state formation barrier . (5) The decay associated spectra of 978 ps obtained for DA1 in ACN reflect the absorption spectra of a twisted intramolecular charge separated state where 420 and 575 nm are assigned to benzonitrile anion and alkoxybenzene cation radical species, respectively.…”

Section: Discussionmentioning

confidence: 91%

“…(4) It is found that the formation of the PICT state is about 2 orders of magnitude faster in ACN (3.25 ps) compared to CHX (361 ps), revealing the solvent polarity dependence of the ICT state formation barrier. 49 (5) The decay associated spectra of 978 ps obtained for DA1 in ACN reflect the absorption spectra of a twisted intramolecular charge separated state where 420 and 575 nm are assigned to benzonitrile anion and alkoxybenzene cation radical species, respectively. (6) The band around 480 nm in the nanosecond transient absorption spectra is ascribed to the T n ← T 1 transition and stabilized in ACN compared to the CHX.…”

Section: Discussionmentioning

confidence: 99%

Direct Observation of Cascade of Photoinduced Ultrafast Intramolecular Charge Transfer Dynamics in Diphenyl Acetylene Derivatives: Via Solvation and Intramolecular Relaxation

Karunakaran

Das

2016

J. Phys. Chem. B

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Interaction of light with electron donor-acceptor π-conjugated systems leading to intramolecular charge transfer (ICT) plays an essential role in transformation of light energy. Here the cascade of photoinduced ICT processes is directly observed by investigating the excited state relaxation dynamics of cyano and mono/di methoxy substituted diphenyl acetylene derivatives using femtosecond pump-probe spectroscopy and nanosecond laser flash photolysis. The femtosecond transient absorption spectra of the chromophores upon ultrafast excitation reveal the dynamics of intermediates involved in transition from initially populated Frank-Condon state to local excited state (LE). It also provides the dynamic details of the transition from the LE to the charge transfer state yielding the formation of the radical ions. Finally, the charge transfer state decays to the triplet state by geminate charge recombination. The latter dynamics are observed in the nanosecond transient absorption spectra. It is found that excited state relaxation pathways are controlled by different stages of solvation and intramolecular relaxation depending on the solvent polarity. The twisted ICT state is more stabilized (978 ps) in acetonitrile than cyclohexane where major components of transient absorption originate from the S1 state.

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Combined Experimental and Computational Study of Intramolecular Charge Transfer In p-N,N-Dimethylamino-p′-cyano-diphenylacetylene

Cited by 11 publications

References 10 publications

Tuning the Direction of Intramolecular Charge Transfer and the Nature of the Fluorescent State in a T-Shaped Molecular Dyad

Tuning the Direction of Intramolecular Charge Transfer and the Nature of the Fluorescent State in a T-Shaped Molecular Dyad

Theoretical and experimental study on intramolecular charge-transfer in symmetric bi-1,3,4-oxadiazole derivatives

Direct Observation of Cascade of Photoinduced Ultrafast Intramolecular Charge Transfer Dynamics in Diphenyl Acetylene Derivatives: Via Solvation and Intramolecular Relaxation

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