Stationary and time-resolved spectra of 2,2′:5′,2″-terthiophene

Yang, Aiping; Hughes, Stephen; Kuroda, Masami; Shiraishi, Yotaro; Kobayashi, Takayoshi

doi:10.1016/s0009-2614(97)01216-5

Cited by 24 publications

(22 citation statements)

References 25 publications

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“…[2][3][4][5] In accordance with this observation and our identification of E 0-0 with E α 0 , we found that E α 0 is accurately described by the function E α 0 (n) ≈ (3.58/n + 1.91) eV. Good agreement with the experiment can be directly inferred from Fig.…”

Section: A Comparison With Experimental Spectrasupporting

confidence: 89%

On-the-fly ab initio semiclassical dynamics: Identifying degrees of freedom essential for emission spectra of oligothiophenes

Wehrle

Šulc

Vaníček

2014

The Journal of Chemical Physics

104

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Articles you may be interested inVibrationally resolved spectra provide a stringent test of the accuracy of theoretical calculations. We combine the thawed Gaussian approximation (TGA) with an on-the-fly ab initio (OTF-AI) scheme to calculate the vibrationally resolved emission spectra of oligothiophenes with up to five rings. The efficiency of the OTF-AI-TGA permits treating all vibrational degrees of freedom on an equal footing even in pentathiophene with 105 vibrational degrees of freedom, thus obviating the need for the global harmonic approximation, popular for large systems. Besides reproducing almost perfectly the experimental emission spectra, in order to provide a deeper insight into the associated physical and chemical processes, we also develop a novel systematic approach to assess the importance and coupling between individual vibrational degrees of freedom during the dynamics. This allows us to explain how the vibrational line shapes of the oligothiophenes change with increasing number of rings. Furthermore, we observe the dynamical interplay between the quinoid and aromatic characters of individual rings in the oligothiophene chain during the dynamics and confirm that the quinoid character prevails in the center of the chain. © 2014 AIP Publishing LLC.

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Section: A Comparison With Experimental Spectrasupporting

confidence: 89%

On-the-fly ab initio semiclassical dynamics: Identifying degrees of freedom essential for emission spectra of oligothiophenes

Wehrle

Šulc

Vaníček

2014

The Journal of Chemical Physics

104

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“…The 0–0 band origin has been measured at 3.08 eV for solid solutions of terthiophene in n ‐decane at low temperatures 7. A similar value, 3.15 eV, has been determined in solution at room temperature using the second derivative of the absorption spectrum 55. The C 2 v CASSCF/cc‐pVDZ‐optimised geometry for the 1 1 B 2 state (Figure 1) was used here to compute the 0–0 transition energy and the vertical emission energy.…”

Section: Resultsmentioning

confidence: 79%

A Theoretical Study on the Low‐Lying Excited States of 2,2′:5′,2′′‐Terthiophene and 2,2′:5′,2′′:5′′,2′′′‐Quaterthiophene

2005

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The nature and properties of the low-lying singlet and triplet valence excited states of 2,2':5',2''-terthiophene (terthiophene) and 2,2':5',2'':5'',2'''-quaterthiophene (tetrathiophene) are discussed on the basis of high-level ab initio computations. The spectroscopic features determined experimentally for short alpha-oligothiophenes are rationalised on theoretical grounds. Special attention is devoted to the nonradiative decay process through intersystem crossing (ISC) from the singlet to the triplet manifold, which is known to be relatively less efficient in tetrathiophene. Along the geometry relaxation of the S1 state of terthiophene, the S1 and T2 states become degenerate, which leads to a favourable situation for the occurrence of ISC. The parallel process is expected to be less favoured in tetrathiophene because of the less efficient spin-orbit coupling and the increase of the S1-T2 energy gap.

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“…The intensity of the up conversion signal (I SIGNAL ) for parallel and vertical polarization of the pumping beam (P PUMP ) is given by the relationships: [1][2][3][4] ( )…”

Section: Theoretical Aspects -Resultsmentioning

confidence: 99%

“…Exciton dynamics and trapping in Jaggregates of carbocyanine dyes M A Drobizhev, M N Sapozhnikov, I G Scheblykin et al Time-resolved spectroscopy of oligothiophenes using the femtosecond fluorescence upconversion technique 1…”

Section: Related Contentmentioning

confidence: 99%

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Time-resolved spectroscopy of oligothiophenes using the femtosecond fluorescence upconversion technique

Anestopoulos

Fakis

Polyzos

et al. 2005

J. Phys.: Conf. Ser.

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Time-resolved spectroscopy of oligothiophenes using the femtosecond fluorescence upconversion technique Abstract. In the present work the electronic properties of two oligothiophenes were experimentally studied through the time-resolved fluorescence spectroscopy up-conversion technique. The effect of the substituent at the end of the main chain on the excited state dynamics was investigated. The excited state decay time (τ fl ), the reorientation time of the emission dipole (τ or ), the initial fluorescence anisotropy (r 0 ) and the time-dependence of the fluorescence anisotropy r(t) were measured. The results showed that the molecule with the bigger dipole moment has smaller excited state decay time. The other coefficients are almost the same for the two materials because of their similar chemical structure. Also, the angle (α) between the absorption and emission dipoles, µ a and µ e respectively, was calculated through the anisotropy and found to be 29 o . This is attributed to the different geometry of the molecule in its ground and excited state. IntroductionThe research in ultra fast phenomena has been intensified during the last decades. These phenomena have to do with the chemical reactions (breakage of the chemical bonds, molecules orientation, transfer energy etc) as well as the behavior of the electrons and nuclei in the molecules. For the study of such phenomena the temporal resolution of the modern electronic systems is inadequate. Thus, new techniques, based on the femtosecond laser pulses, have already developed. The time resolved fluorescence spectroscopy, in femtosecond regime, is based on the frequency mixed phenomenon and presents the best temporal resolution to-date. This technique gives the possibility of measuring the lifetime of the excited state, as well as the temporal evolution of the fluorescence spectrum of a material.In the present work the above-mentioned technique is applied for the experimental study of two oligothiophenes for a better understanding of their structure and electronics properties. The influence of the change of the substituent, been located at the edge of the main chain, on their excited state dynamics is investigated. The excited state decay time (τ fl ), the reorientation time of the emission dipole (τ or ) and the initial fluorescence anisotropy (r 0 ) in directions perpendicular and parallel to the excitation dipole were measured for both materials. The angle (α) between the absorption µa and emission µe dipoles was calculated through anisotropy.

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Stationary and time-resolved spectra of 2,2′:5′,2″-terthiophene

Cited by 24 publications

References 25 publications

On-the-fly ab initio semiclassical dynamics: Identifying degrees of freedom essential for emission spectra of oligothiophenes

On-the-fly ab initio semiclassical dynamics: Identifying degrees of freedom essential for emission spectra of oligothiophenes

A Theoretical Study on the Low‐Lying Excited States of 2,2′:5′,2′′‐Terthiophene and 2,2′:5′,2′′:5′′,2′′′‐Quaterthiophene

Time-resolved spectroscopy of oligothiophenes using the femtosecond fluorescence upconversion technique

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