Understanding the photophysics of 4-nitro-1-hydroxy-2-naphthoic acid: A controlled excited state proton transfer

Sahoo, Dibakar; Adhikary, Tirtha Pratim; Chowdhury, Papia; Roy, Saonli; Chakravorti, S.

doi:10.1016/j.chemphys.2008.06.008

Cited by 15 publications

(11 citation statements)

References 43 publications

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“…But in plain water solution NHNA shows different peak in presence of a basic medium. 6 So the effects that we see here is purely a micellar effect.…”

Section: Effect Of Aggregates On the Emissionmentioning

confidence: 72%

“…Preparation of 1-hydroxy-4-nitro-2-naphthoic acid from 1hydroxy-2-naphthoic acid is described in elsewhere. 6 Sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTAB) and Tween 80 (TW 80) were used as received from Fluka or Aldrich Chemicals, USA. For measuring absorption and fluorescence spectra deionised water (Millipore) was used.…”

Section: Methodsmentioning

confidence: 99%

“…In ESIPT, a Stokes-shifted new emission band is observed due to transfer of a proton from acidic to basic moieties in the excited state. 5 In a previous paper 6 we demonstrated that when one nitro group is attached with 1-hydroxy naphthoic acid the excited state properties change dramatically in the form of intramolecular proton transfer (ESIPT) of 4-nitro-1-hydroxy naphthoic acid (NHNA) via preexisting hydrogen bond between adjacent proton donor and acceptor moieties of the molecule in the excited state. It was very interesting to find that different spectral characteristics of this molecule were very sensitive to the environment as with other ESIPT molecules.…”

Section: Introductionmentioning

confidence: 99%

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Influence of surfactants on the excited state photophysics of 4-nitro-1-hydroxy-2-naphthoic acid

Sahoo

Chakravorti

2010

Photochem Photobiol Sci

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This paper reports the changed dynamics of excited state proton transfer (ESPT) photophysics of 4-nitro-1-hydroxy-2-naphthoic acid (NHNA) in ionic and nonionic micelles, as revealed from time-resolved emission spectra (TRES) and time-resolved area normalized emission spectra (TRANES). Both the neutral and anionic bands of NHNA are enhanced and blue-shifted inside the micelles. Quenching of emission by metal Cu(2+) reveals that NHNA does not penetrate into the core of the micelles; rather it binds to the micelle/water interfacial region. The fast decay component is due to decay of normal species and the slow component is assigned to decay of anionic species. In all the micelles the decay time becomes longer by three times compared to that in water. The efficiency of formation of anionic state from the locally excited state gets enhanced in micellar media due to enhanced sojourn in the first excited state in increased viscous medium around NHNA. TRANES data also indicate that of the normal and anionic species in the aqueous phase the anionic species increases in the micelles as the time evolved.

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“…But in plain water solution NHNA shows different peak in presence of a basic medium. 6 So the effects that we see here is purely a micellar effect.…”

Section: Effect Of Aggregates On the Emissionmentioning

confidence: 72%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of surfactants on the excited state photophysics of 4-nitro-1-hydroxy-2-naphthoic acid

Sahoo

Chakravorti

2010

Photochem Photobiol Sci

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“…[19][20][21] On the other hand, however, activating RTP from ESIPT molecules is much less explored [22,23] while most photophysical studies focus on low-temperature phosphorescence properties. [24,25] Moreover, as these pioneering works explored the keto-form properties of ESIPT triplet emitters, molecular engineering pathways to harvest triplet energy from the enol tautomer is missing.…”

Section: Introductionmentioning

confidence: 99%

Metal‐Free Organic Triplet Emitters with On–Off Switchable Excited State Intramolecular Proton Transfer

Shao

Hao

Jiang

et al. 2022

Adv Funct Materials

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Metal‐free organic triplet emitters are an emerging class of organic semiconducting material. Among them, molecules with tunable emission responsive to environmental stimuli have shown great potential in solid‐state lighting, sensors, and anti‐counterfeiting systems. Here, a novel excited‐state intramolecular proton transfer (ESIPT) system is proposed showing the activation of thermally activated delayed fluorescence (TADF) or room‐temperature phosphorescence (RTP) simultaneously from both keto and enol tautomers. The prototype ESIPT triplet emitters exhibit up to 50% delayed emission quantum yield. Their enol–keto tautomerization can be switched by controlling the matrix acidity in doped polymer films. Taking advantage of these unique properties, “on‐off” switchable triplet emission systems controlled by acid vapor annealing, as well as photopatterning systems capable of generating facile and high‐contrast emissive patterns, are devised.

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“…The quantum yield was determined by using a secondary standard method with recrystallized NAPMD. The quantum yields of fluorescence were calculated using 4‐nitro‐1‐hydroxy‐2‐naphthoic acid ( ϕ ref = 0.08) in ethanol (20) as a standard according to following relation where OD′, A ′, n′ and OD, A , n represent the optical density at the excited wavelength, the integrated emission band area and the solvent refractive index of the standard and the sample, respectively (21). …”

mentioning

confidence: 99%

Charge Transfer in 1,8‐Naphthalimide: A Combined Theoretical and Experimental Approach

Manna

Chakravorti²

2010

Photochem & Photobiology

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Photophysics of 1,8-naphthalimide (NAPMD) in different solvents has been delineated in this paper. Theoretically calculated bond distance of N-H and C=O groups rule out any intramolecular proton transfer in the excited state. Concomitant increase in negative charge on O atom compared to N atom and dipole moment hints at possible intramolecular charge transfer. Progressive redshift with polarity of solvents in emission and absorption spectra also confirms the theoretical prediction. Weakening of N-H bond helps hydrogen abstraction and anion formation in water with decay time of 2.54 ns through intermolecular proton transfer. This was corroborated from the ground state photoexcitation of laboratory synthesized anion of NAPMD. Amide hydrolysis in higher pH and excess proton availability at low pH are responsible for anion emission quenching. A possible electron transfer diminishes phosphorescence at 77 K with changing pH.

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Understanding the photophysics of 4-nitro-1-hydroxy-2-naphthoic acid: A controlled excited state proton transfer

Cited by 15 publications

References 43 publications

Influence of surfactants on the excited state photophysics of 4-nitro-1-hydroxy-2-naphthoic acid

Influence of surfactants on the excited state photophysics of 4-nitro-1-hydroxy-2-naphthoic acid

Metal‐Free Organic Triplet Emitters with On–Off Switchable Excited State Intramolecular Proton Transfer

Charge Transfer in 1,8‐Naphthalimide: A Combined Theoretical and Experimental Approach

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