Femtosecond Excited State Studies of the Two-Center Three-Electron Bond Driven Twisted Internal Charge Transfer Dynamics in 1,8-Bis(dimethylamino)naphthalene

The excited state photophysical properties of the 1,3,5-triarylpyrazolines 1–4 were studied in methanol and 1:1 (v/v) methanol–water, as well as 1:4 (v/v) methanol–water and water by fluorescence spectroscopy. The molecules 2–4 incorporate a “receptor1-fluorophore-spacer-receptor2” format while 1 is a reference compound based on a “fluorophore-receptor1” design. The molecular probes operate according to photoinduced electron transfer (PET) and internal charge transfer (ICT) processes. At basic and neutral pHs, 2–4 are essentially nonfluorescent due to PET from the electron-donating dimethylamino moiety appended on the 5-phenyl ring to the excited state of the 1,3,5-triarylpyrazoline fluorophore. At proton concentrations of 10−3 mol/L, the dimethylamino unit is protonated resulting in a strong blue fluorescence about 460 nm with significant quantum yields up to 0.54. At acid concentrations above 10−2 mol/L, fluorescence quenching is observed by an ICT mechanism due to protonation of the pyrazoline chromophore. Symmetrical off-on-off fluorescence–pH profiles are observed, spanning six log units with a narrow on window within three pH units. Hence, 2–4 are novel examples of ternary photonic pH sensing molecular devices.

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Excited State Localization and Delocalization of Internal Charge Transfer in Branched Push−Pull Chromophores Studied by Single-Molecule Spectroscopy

Journal of the American Chemical Society ◽

10.1021/ja901268h ◽

2009 ◽

Vol 131 (16) ◽

pp. 5742-5743 ◽

Cited By ~ 20

Author(s):

Damir Aumiler ◽

Sufan Wang ◽

Xudong Chen ◽

Andong Xia

Keyword(s):

Excited State ◽

Charge Transfer ◽

Single Molecule ◽

Single Molecule Spectroscopy ◽

Internal Charge Transfer ◽

Internal Charge

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Highly selective colorimetric fluorescence sensor for Cu2+: cation-induced ‘switching on’ of fluorescence due to excited state internal charge transfer in the red/near-infrared region of emission spectra

Tetrahedron Letters ◽

10.1016/j.tetlet.2010.08.048 ◽

2010 ◽

Vol 51 (42) ◽

pp. 5563-5566 ◽

Cited By ~ 63

Author(s):

Shyamaprosad Goswami ◽

Debabrata Sen ◽

Nirmal Kumar Das ◽

Giridhari Hazra

Keyword(s):

Excited State ◽

Charge Transfer ◽

Near Infrared ◽

Emission Spectra ◽

Infrared Region ◽

Fluorescence Sensor ◽

Near Infrared Region ◽

Internal Charge Transfer ◽

Internal Charge

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Excited state and charge transfer dynamics in gas phase molecule of CH3NH3PbI3: first-principles study

Journal of Molecular Modeling ◽

10.1007/s00894-020-04635-7 ◽

2021 ◽

Vol 27 (2) ◽

Author(s):

Nitika ◽

Shiv Kumar Dixit ◽

Haider Abbas

Keyword(s):

Excited State ◽

Charge Transfer ◽

Gas Phase ◽

First Principles ◽

First Principles Study ◽

Charge Transfer Dynamics

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A benzothiazole-based fluorescence turn-on sensor for copper(II)

10.21203/rs.3.rs-381861/v1 ◽

2021 ◽

Author(s):

Gyeongjin Kim ◽

Donghwan Choi ◽

Cheal Kim

Keyword(s):

Charge Transfer ◽

Limit Of Detection ◽

Theoretical Calculations ◽

Enhanced Fluorescence ◽

Turn On ◽

Fluorescent Response ◽

Chelation Enhanced Fluorescence ◽

Fluorescence Turn On ◽

Internal Charge Transfer ◽

Internal Charge

Abstract A new benzothiazole-based chemosensor BTN (1-((Z)-(((E)-3-methylbenzo[d]thiazol-2(3H)-ylidene)hydrazono)methyl)naphthalen-2-ol) was synthesized for the detection of Cu2+. BTN could detect Cu2+ with “off-on” fluorescent response from colorless to yellow irrespective of presence of other cations. Limit of detection for Cu2+ was determined to be 3.3 µM. Binding ratio of BTN and Cu2+ turned out to be a 1:1 with the analysis of Job plot and ESI-MS. Sensing feature of Cu2+ by BTN was explained with theoretical calculations, which might be owing to internal charge transfer and chelation-enhanced fluorescence processes.

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