Investigation on the mechanism of ESIPT of 2-hydroxy-1-naphthaldehyde-(4-pyridinecarboxylic)-hydrazone and detection of Al3+ ion

2019 ◽  
Vol 97 (7) ◽  
pp. 721-725 ◽  
Author(s):  
Songsong Liu ◽  
Jie Pan ◽  
Dongmei Wei ◽  
Jihua Xu ◽  
Yong Zhou ◽  
...  
Keyword(s):  
Excited State ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Intramolecular Proton Transfer ◽  
Absorption And Fluorescence Spectra ◽  
Molecular Configuration ◽  
Photo Induced Electron Transfer ◽  
Reduced Density Gradient ◽  
State Changes ◽  
Reduced Density

The sensing mechanism of 2-hydroxy-1-naphthaldehyde-(4-pyridinecarboxylic)-hydrazone for Al3+ is investigated based on the excited-state intramolecular proton transfer (ESIPT) and photo-induced electron transfer (PET) processes. Absorption and fluorescence spectra are calculated, which are consistent with experimental results. By analyzing the major bond parameters, infrared vibrational spectra as well as frontier molecular orbitals, it can be concluded that the hydrogen bond is enhanced in the first singlet excited state (S1), which can also be visualized by the reduced density gradient function. Potential energy curves are also scanned, which can elucidate that the ESIPT process is more likely to occur in the S1 state. Changes in molecular configuration and intensity of fluorescence emission confirmed that the ESIPT and PET processes are forbidden in the presence of Al3+.

EFFECT OF SOLVENT ON NONLINEAR REFRACTIVE INDEX OF 2-(2′-HYDROXYPHENYL) BENZOXAZOLE

2003 ◽  
Vol 12 (03) ◽  
pp. 385-391
Author(s):  
GUILAN ZHANG ◽  
FEIBING XIONG ◽  
BAO ZHANG ◽  
GUOQING TANG ◽  
WENJU CHEN ◽  
...  
Keyword(s):  
Refractive Index ◽  
Excited State ◽  
Proton Transfer ◽  
Dimethyl Sulfoxide ◽  
Nonlinear Refractive Index ◽  
Fluorescence Spectra ◽  
Incident Light ◽  
Intramolecular Proton Transfer ◽  
Absorption And Fluorescence Spectra ◽  
Effect Of Solvent

Nonlinear refractive indexes n2 of 2-(2′-hydroxyphenyl) benzoxazole (HBO) in three species of solvent (cyclohexane, ethanol and dimethyl sulfoxide) have been determined by using the Z-scan technique. The experimental results show that the n2 of HBO is strongly dependent on the polarity of the solvent. Through the study on the absorption and fluorescence spectra of HBO in different solvents, we regard that the principal origin of the nonlinear refractive index of HBO is not the thermal effect because of absorption of incident light but the excited state intramolecular proton transfer of HBO under the incident light.

scholarly journals Spectral Properties of Hybrid of Rhodamine (6G) Dyes Doped Epoxy Resin Dissolved in Chloroform

2019 ◽  
Vol 16 (3(Suppl.)) ◽  
pp. 0764 ◽  
Author(s):  
Al-Hamdani Et al.
Keyword(s):  
Epoxy Resin ◽  
Quantum Efficiency ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Rhodamine 6G ◽  
Energy Gap ◽  
Radiative Lifetime ◽  
Stokes Shift ◽  
Fluorescence Emission ◽  
Absorption And Fluorescence Spectra

            The research is dealing with the absorption and fluorescence spectra for the hybrid of  an Epoxy Resin doped with organic dye Rhodamine (R6G) of different concentrations (5*10-6, 5*10-5, 1*10-5, 1*10-4, 5*10-4) Mol/ℓ at room temperature. The Quantum efficiency Qfm, the rate of fluorescence emission Kfm (s-1), the non-radiative lifetime τfm (s), fluorescence lifetime τf and the Stokes shift were calculated. Also the energy gap (Eg) for each dye concentration was evaluated. The results showed that the maximum quantum efficiency 62 % and maximum stokes shift 96 nm was obtained in dye concentration 5*10-6 and 1*10-4. The energy gap ranges between 1.066 eV to 1.128 eV depending proportionally on the dye concentrations.

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