Electronic and photophysical properties of 2-(2′-hydroxyphenyl)benzoxazole and its derivatives enhancing in the excited-state intramolecular proton transfer processes: A TD-DFT study on substitution effect

Daengngern, Rathawat; Kungwan, Nawee

doi:10.1016/j.jlumin.2015.06.001

Cited by 24 publications

(11 citation statements)

References 52 publications

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“…This structural change results in a localization of the HOMO and LUMO in the ESIPT state, which results in a reduced overlap between ground and ES wavefunction and consequently leads to a small oscillator strength associated with the radiative decay. 28 In addition, according to the energy-gap law, 29 the nonradiative decay rate constants are expected to significantly increase upon bathochromically shifting the electronic transition. Therefore, a new design of an ESIPT-capable skeleton that does not rely on the keto–enol tautomerism is required to attain an intense emission in the NIR region based on the ESIPT mechanism.…”

Section: Introductionmentioning

confidence: 99%

Near infrared two-photon-excited and -emissive dyes based on a strapped excited-state intramolecular proton-transfer (ESIPT) scaffold

et al. 2018

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Section: Introductionmentioning

confidence: 99%

Near infrared two-photon-excited and -emissive dyes based on a strapped excited-state intramolecular proton-transfer (ESIPT) scaffold

et al. 2018

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“…Among all ESIPT fluorophore, the HBX (i. e. HBI, HBO, and HBT) fluorophores are extensively investigated with both experimental and theoretical methods. [48,[64][65][66][67][68] The photophysical properties of HBX derivatives can be tuned by altering the substituents, [66,69] temperature [70,71] and environmental changes. [72] HBO and HBT derivatives both these compounds are almost similar but they have different ESIPT dynamics.…”

Section: Esipt Phenomenonmentioning

confidence: 99%

“…The most common ESIPT fluorophore are derivatives of benzophenones, flavones, quinolones, quinoxalines, anthraquinone, benzotriazoles, N‐salicylideneanilines, 2‐(2’‐hydroxyphenyl) benzimidazole (HBI), 2‐(2’‐hydroxyphenyl) benzoxazole (HBO) and 2‐(2’‐hydroxyphenyl) benzothiazole (HBT) (see Figure ). Among all ESIPT fluorophore, the HBX (i. e. HBI, HBO, and HBT) fluorophores are extensively investigated with both experimental and theoretical methods …”

Section: Introductionmentioning

confidence: 99%

Towards NIR‐Active Hydroxybenzazole (HBX)‐Based ESIPT Motifs: A Recent Research Trend

2020

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In this review, we have explored the synthetic strategies adopted for designing the hydroxybenzazoles (imidazole, oxazole, and thiazole) i. e. HBX derivatives which show emission in red and NIR region. Further, we have examined the effect of different substituents i. e. either directly attached or with extended conjugation on a phenolic ring/ phenyl ring of heterocycles to achieve a red to NIR shift in emission. Finally, we have investigated the applications and computational methodologies adopted for red to NIR emitting dyes. In the future, this review will help to design, synthesized and examine the applications of new derivatives of HBX which will show emission in red to NIR region.

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“…To future investigate the chance of PT process, the S 0 state energy curve (GS-PECs) and the S 1 state potential energy curves (ES-PECs) of all molecules along PT process coordinate were scanned by constraining optimizations with fixed the covalent (O1−H1) bond distance at a series of values. This approach was used in the previous studies and shown to be reliable in providing qualitative energetic pathways for PT process [62,[66][67][68][69][70]. In addition, to obtain the thermodynamic information, the ESIPT reaction energies were calculated from the S 1 state optimization of keto forms of all molecules.…”

Section: Static Calculationsmentioning

confidence: 99%

“…Solving Newton's equation of nuclear motion was achieved by the Velocity-Verlet algorithm [22]. The Born-Oppenheimer energies and gradients were obtained at each time step by mean of the TD-B3LYP method, which has been tested and used in dynamic simulations in previous studies [60][61][62][66][67][68]75]. All trajectories for each complex were simulated with a time step of 1 fs with the maximal duration of 500 fs, which is long enough to cover the pre-and post-PT regimes.…”

Section: Dynamics Simulationsmentioning

confidence: 99%

Heteroatom substitution effect on electronic structures, photophysical properties, and excited-state intramolecular proton transfer processes of 3-hydroxyflavone and its analogues: A TD-DFT study

Sukpattanacharoen

Salaeh

Promarak

et al. 2019

Journal of Molecular Structure

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The effects of the electron-donating capacity altered by heteroatom substituents on the electronic structures, photophysical properties, and excited-state intramolecular proton transfer (ESIPT) processes of 3HX analogues (3HF, 3HQ, 3HTF, and 3HSO where X = O, NH, S, and SO 2 , respectively) have been investigated by both static calculations and dynamic simulations using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods at B3LYP/TZVP level for ground state (S 0 ) and excited-state (S 1 ), respectively. The static results indicate that the intramolecular hydrogen bonds of all molecules are strengthened in the S 1 , confirmed by the red-shift of IR vibrational spectra and the topology analysis. Heteroatom substitutions cause the red-shift on enol absorption and keto emission spectra of 3HX with relatively larger Stoke shift corresponding to their HOMO−LUMO gaps compared with that of 3HF. Frontier molecular orbitals (MOs) show that upon the photoexcitation, the charge redistribution between the proton donor and proton acceptor groups have induced the ESIPT process. Moreover, the potential energy curves (PECs) of proton transfer (PT) processes of all molecules reveal that the PT processes of all molecules are most likely to proceed in the S 1 state because of low barriers and exothermic reaction. The chance of ESIPT for all molecules is in this order: 3HSO > 3HTF > 3HF > 3HQ. The results of dynamic simulations confirm that the ESIPT processes of all molecules easily occur with the ultrafast time scale (48, 55, 60, 70 fs for 3HSO, 3HTF, 3HF, and 3HQ, respectively). Furthermore, the PT time is anti-correlated with the electronegativity of heteroatoms in 3HX, supported by Mulliken analysis. The ESIPT process of 3HSO is the fastest among 3HX in accordance with its highest intramolecular hydrogen bond strength, lowest PT barrier, and highest exothermic reaction. Nevertheless, after the ESIPT is complete, the twisted structure of 3HSO has initiated the conical intersection, leading to no keto emission observed in the experiment.

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Electronic and photophysical properties of 2-(2′-hydroxyphenyl)benzoxazole and its derivatives enhancing in the excited-state intramolecular proton transfer processes: A TD-DFT study on substitution effect

Cited by 24 publications

References 52 publications

Near infrared two-photon-excited and -emissive dyes based on a strapped excited-state intramolecular proton-transfer (ESIPT) scaffold

Near infrared two-photon-excited and -emissive dyes based on a strapped excited-state intramolecular proton-transfer (ESIPT) scaffold

Towards NIR‐Active Hydroxybenzazole (HBX)‐Based ESIPT Motifs: A Recent Research Trend

Heteroatom substitution effect on electronic structures, photophysical properties, and excited-state intramolecular proton transfer processes of 3-hydroxyflavone and its analogues: A TD-DFT study

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