Chemiluminescence properties of luminol related o-hydroxybenzimidazole analogues: Experimental and DFT based approach to photophysical properties

Deshmukh, Mininath S.; Sekar, Nagaiyan

doi:10.1016/j.dyepig.2014.08.009

Cited by 10 publications

(8 citation statements)

References 42 publications

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“…We have employed the Density Functional Theory (DFT) and the Time-Dependent Density Functional Theory (TD-DFT) to study the ESIPT process for N E , O E and S E . These approaches have been widely used before to clarify fundamental aspects regarding the different structural and electronic states [ 13 , 59 , 65 , 73 , 74 , 75 , 76 , 77 ] as well as to study theoretically the intramolecular hydrogen bonding in the excited state for different compounds for whose ESIPT occurs [ 44 , 78 , 79 , 80 , 81 , 82 , 83 ].…”

Section: Methodsmentioning

confidence: 99%

Density Functional Theory Applied to Excited State Intramolecular Proton Transfer in Imidazole-, Oxazole-, and Thiazole-Based Systems

et al. 2018

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Excited state intramolecular proton transfer (ESIPT) is a photoinduced process strongly associated to hydrogen bonding within a molecular framework. In this manuscript, we computed potential energy data using Time Dependent Density Functional Theory (TDDFT) for triphenyl-substituted heterocycles, which evidenced an energetically favorable proton transfer on the excited state (i.e., ESIPT) but not on the ground state. Moreover, we describe how changes on heterocyclic functionalities, based on imidazole, oxazole, and thiazole systems, affect the ESIPT process that converts an enolic species to a ketonic one through photon-induced proton transfer. Structural and photophysical data were obtained theoretically by means of density functional theory (DFT) calculations and contrasted for the three heterocyclics. Different functionals were used, but B3LYP was the one that adequately predicted absorption data. It was observed that the intramolecular hydrogen bond is strengthened in the excited state, supporting the occurrence of ESIPT. Finally, it was observed that, with the formation of the excited state, there is a decrease in electronic density at the oxygen atom that acts as proton donor, while there is a substantial increase in the corresponding density at the nitrogen atom that serves as proton acceptor, thus, indicating that proton transfer is indeed favored after photon absorption.

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Section: Methodsmentioning

confidence: 99%

Density Functional Theory Applied to Excited State Intramolecular Proton Transfer in Imidazole-, Oxazole-, and Thiazole-Based Systems

et al. 2018

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“…Initially, dimethyl 1,3-diphenyl-1H-pyrazolo [3,4-b]pyridine-4,5-dicarboxylate 8 and diethyl 1,3-diphenyl-1H-pyrazolo [3,4-b]pyridine-4,5-dicarboxylate 9 were prepared by following our previously reported literature [24] from N,N-diisopropylamidinyl pyrazolylimine and chosen as the model substrate for this investigation on the construction of pyrazolopyridopyridazine diones 6a (Scheme 1). Compounds 8 and 9 were reacted with hydrazine hydrate at reflux in methanol or ethanol solution under the basic condition for 24-36 h [25,26]. However, all the efforts for the predominant formation of 6a were unsuccessful.…”

Section: Resultsmentioning

confidence: 99%

“…Additionally, the fluorescence intensity of 6j was significantly promoted about 2.3 times in comparison with compound 6a (Figure 5). Based on the result of the substituent study, we conceived that compound 6j was an effective substrate that possessed suitable conjugation conformation without the torsion effect to facilitate the photoluminescence properties [26]. For compounds 7a-i bearing the above various substituents, they provided the weak fluorescence intensity [45] and possessed the blue-shift phenomenon when compared with 7a, except for 7c with m-chloro group and 7h with p-CN group (Figure 6).…”

Section: Resultsmentioning

confidence: 99%

“…The crude desired products 6a-j were recrystallized in acetone/THF (1/4) solution to obtain the pure pyrazolopyridopyridazine diones 6a-j in 11-84% yields. The low solubility of the compounds 6a-j made the 13 C-NMR characterization of quaternary and carbonyl carbons of these substrates unclear [25,26].…”

Section: Standard Procedures For Synthesis Of Pyrazolopyridopyridazine Diones 6a-jmentioning

confidence: 99%

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Selective Synthesis and Photoluminescence Study of Pyrazolopyridopyridazine Diones and N-Aminopyrazolopyrrolopyridine Diones

et al. 2020

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The newly designed luminol structures of pyrazolopyridopyridazine diones and N-aminopyrazolopyrrolopyridine diones were synthesized from versatile 1,3-diaryfuropyrazolopyridine-6,8-diones, 1,3-diarylpyrazolopyrrolopyridine-6,8-diones, or 1,3-diaryl-7-methylpyrazolopyrrolopyridine-6,8-diones with hydrazine monohydrate. Photoluminescent and solvatofluorism properties containing UV–Vis absorption, emission spectra, and quantum yield (Φf) study of pyrazolopyridopyridazine diones and N-aminopyrazolopyrrolopyridine diones were also studied. Generally, most of pyrazolopyrrolopyridine-6,8-diones 6 exhibited the significant fluorescence intensity and the substituent effect when compared with N-aminopyrazolopyrrolopyridine diones, particularly for 6c and 6j with a m-chloro group. Additionally, the fluorescence intensity of 6j was significantly promoted due to the suitable conjugation conformation. Based on the quantum yield (Φf) study, the value of compound 6j (0.140) with planar structural skeletal was similar to that of standard luminol (1, 0.175).

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“…[9][10][11][12][13][14][15][16][17] Such a broad exploration of ESIPT in applications depends on rationalizing the phenomenon on an experimental level and, equally important, through computational simulation techniques. 7,[18][19][20][21][22][23][24] In the process of understanding ESIPT, some studies were carried out to compare the properties of different benzazole derivatives (i.e., benzimidazole, benzoxazole, etc.) as proton acceptors, using appended phenols as donors.…”

Section: Introductionmentioning

confidence: 99%

Substitution by tert-butyl groups facilitates excited state proton transfer in hydroxylated triphenylimidazole frameworks more than it does for oxazole and thiazole analogs

Carvalho¹,

Coutinho-Neto²,

Bartoloni³

et al. 2020

Arkivoc

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Excited state intramolecular proton transfer (ESIPT) processes typically occur when photoexcited molecules relax via a tautomeric proton transfer event in the excited state, and it is known to depend on the properties of donor and acceptor groups. In this work, we employed ground state and Time Dependent Density Functional Theory aiming at studying the ESIPT viability on triphenyl-substituted heterocyclic (imidazole, oxazole, and thiazole) tert-butyl derivatives. For all compounds, the formation of a keto tautomer is favored once an excited state is generated from a ground state enol tautomer. The expected tert-butyl electron donor effect and enol form stabilization is verified in the ground state, but the opposite is observed for the excited state. We found that tert-butyl substituted compounds have reduced HOMO-LUMO gap, exhibit barrierless proton transfer in the excited state and stronger Hydrogen bond after light excitation.

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Chemiluminescence properties of luminol related o-hydroxybenzimidazole analogues: Experimental and DFT based approach to photophysical properties

Cited by 10 publications

References 42 publications

Density Functional Theory Applied to Excited State Intramolecular Proton Transfer in Imidazole-, Oxazole-, and Thiazole-Based Systems

Density Functional Theory Applied to Excited State Intramolecular Proton Transfer in Imidazole-, Oxazole-, and Thiazole-Based Systems

Selective Synthesis and Photoluminescence Study of Pyrazolopyridopyridazine Diones and N-Aminopyrazolopyrrolopyridine Diones

Substitution by tert-butyl groups facilitates excited state proton transfer in hydroxylated triphenylimidazole frameworks more than it does for oxazole and thiazole analogs

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