An anti-quinoid structure in dual fluorescence of fluozazene molecule and solvent effect of intramolecular charge transfer

He, Rongxing; Li, Xiangyuan

doi:10.1016/j.chemphys.2006.12.016

Cited by 12 publications

(2 citation statements)

References 65 publications

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“…As a result, the quinoid and antiquinoid structures have different energies. In fluorazene 55 or pyrrolobenzonitrile, 54 for example, the antiquinoid (AQ) minima are more stable that the Q ones, while in di-tert-butylaminobenzonitrile the opposite is true. 23 In the case of DMABN, the CT-AQ state is higher in energy than the CT-Q one, so its involvement in the processes studied is not probable and it has not been further considered.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Insight into the Mechanisms of Luminescence of Aminobenzonitrile and Dimethylaminobenzonitrile in Polar Solvents. An ab Initio Study

2015

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The dual fluorescence of 4-(dimethylamino)benzonitrile (DMABN) has been intensively studied in the last decades, but surprisingly there is not any detailed theoretical study of its photochemistry in polar solvents. In this work, we rationalize the different luminescent behavior of 4-aminobenzonitrile (ABN) and DMABN in acetonitrile by a computational study developed at the CASSCF/CASPT2 level and using the Polarized Continuum Model to reproduce the solvent environment. We present here the critical geometries, energies, and connections between the potential energy surfaces of the low-lying excited states: the locally excited state (LE) and several intramolecular charge transfer states (ICT). The computational results show that the topology of the potential energy surfaces (PES) does not change substantially when the effect of a polar solvent is included, in comparison with the gas phase. For DMABN, though, polar solvents stabilize preferentially the ICT states in such a way that the different interplay with the LE state induces strong qualitative changes in the photochemistry of this compound. Specifically, the planar ICT (PICT) species located on the S2 surface in the gas phase is, in acetonitrile, located on the S1 surface. that is, at the geometry of the PICT minimum, the LE state is higher in energy than the ICT. Now LE and PICT minima are practically degenerate and, given that both correspond to first excited state species, emission can take place from both of them. However, the twisted ICT (TICT) species is still the most favored thermodynamically so it is expected that this species would be preferentially populated. On the other hand, for ABN the equilibrium lies in favor of LE, as the TICT species was found at a much higher energy with a low reaction barrier toward LE. This explains why dual fluorescence cannot be observed in ABN, even in polar solvents.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Insight into the Mechanisms of Luminescence of Aminobenzonitrile and Dimethylaminobenzonitrile in Polar Solvents. An ab Initio Study

2015

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“…[13][14][15][16]. Among these, the ESPT performing dynamic role in determining the photophysical and photo-chemical properties of organic molecules, which usually shows dual uorescence behaviour [17,18]. The PET mechanism was used to describe the hydrogen bonding, in which enhancing or quenching corresponds to red or blue shifts in the absorption spectra [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

TD-DFT investigation on anion recognition mechanism of anthraldehyde-based fluorescent thiosemicarbazone derivatives

Basheer

Gandhaveeti

2022

J Mol Model

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The mechanism of host-guest interaction of receptors towards uoride ion has been investigated using computational methods. To distinguish the effect of aromaticity in host-guest interaction, we investigated unsubstituted (ATSC) and phenyl substituted (APTSC) anthracene thiosemicarbazones towards different ions. In the ground state of receptor-uoride complex, the added uoride ion made hydrogen bond through N−H … F … H−N. Whereas, the intramolecular hydrogen bonding was through F−H … N in the excited state of receptor-uoride complex. Experimental absorption and emission spectra were well reproduced by the calculated vertical excitation energies. The transition state (TS) calculations were performed to understand the thermodynamic features and mechanism of host-guest interaction. The natural bond orbital analyses show the second perturbation energy for donor-acceptor interaction of Fwith hydrogen is more than 300 kcal/mol at the excited state of receptor-uoride complex, which indicates the strong single bond between uoride and hydrogen atom. The PES scan con rms that deprotonation took place at the excited state of receptor-uoride complex. The results indicate that the excited-state proton transfer (ESPT) process from N-H group nearby the anthracene moiety. The APTSC is better chemosensor than ATSC. This infer that the aromaticity will increase the e ciency of uorescence receptor towards uoride ion.

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Theoretical study of electronic properties of organic photovoltaic materials

et al. 2008

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It has been proved that fullerene derivatives, in which an oligophenylenevinylene (OPV) group is attached to C(60), present an interesting photophysical phenomenon and can be incorporated into photovoltaic cells. In these systems, the OPV acts as electron donor upon excitation, and then fullerene absorbs photoexcited electrons. These new organic semiconductor materials offer the prospect of lower manufacturing costs and they present several advantages: easy fabrication, large area, flexible and light weight devices when compared with inorganic counter parts. In the present theoretical study, oligomeric chains of p-phenylenevinylene (n-PPV, n = 3-8 units) and C(60)-OPV hybrids have been studied by density functional theory (DFT). Electronic properties such as electronic absorption and emission spectra were calculated in order to determinate how the increment of spectroscopic units affects their electronic behavior. These properties were carried out with time dependent-density functional theory (TD-DFT) and ZINDO semiempirical method. The theoretical calculations of the structural properties of n-PPV and fullerene-OPV hybrids were obtained using PBE1PBE/6-31G and ONIOM two-layered version, respectively. All calculations were done with Gaussian 03W program package.

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An anti-quinoid structure in dual fluorescence of fluozazene molecule and solvent effect of intramolecular charge transfer

Cited by 12 publications

References 65 publications

Insight into the Mechanisms of Luminescence of Aminobenzonitrile and Dimethylaminobenzonitrile in Polar Solvents. An ab Initio Study

Insight into the Mechanisms of Luminescence of Aminobenzonitrile and Dimethylaminobenzonitrile in Polar Solvents. An ab Initio Study

TD-DFT investigation on anion recognition mechanism of anthraldehyde-based fluorescent thiosemicarbazone derivatives

Theoretical study of electronic properties of organic photovoltaic materials

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