Photophysical study of 6-amino-3-methyl-4-(4-nitrophenyl)-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile and estimation of ground-state and singlet excited-state dipole moments by solvatochromic approaches

A semi-empirical determination of ground and excited state dipole moments of zinc phthalocyanine (ZnPc) from solvatochromic shifts is hereby presented. The ratio of the excited- and ground-state dipole moments of ZnPc ( ) was estimated by a combination of the Bakshiev and the Kawski-Chamma-Viallet’s equations, while the difference in the excited- and ground-state dipole moments (Dm) was estimated usingthe molecular-microscopic solvent polarity parameters ( ), alongside the Stokes’ shifts (Dῡ) in the various solvents. The dipole moment of ZnPc is significantly higher in the excited singlet state (me = 3.12 D) than in the ground state (mg = 1.50 D). Obviously charge separation is greater in the excited state of ZnPc than in its ground state.

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Estimating the Ground and Excited State Dipole Moments of Levofloxacin and Norfloxacin Drugs Using Solvatochromic Effects and Computational Work

Journal of Spectroscopy ◽

10.1155/2021/7214182 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Kinfe Woldegiorges ◽

Abebe Belay ◽

Alemu Kebede ◽

Tamirat Abebe

Keyword(s):

Excited State ◽

Ground State ◽

Dipole Moments ◽

Bacterial Species ◽

Emission Spectra ◽

Solvent Polarity ◽

Electron Charge Density ◽

Nonpolar Solvents ◽

Computational Work ◽

Excited State Dipole Moments

Levofloxacin (LVF) and norfloxacin (NRF) are a group of fluoroquinolone antibiotics, broad spectrum used to treat various infections caused by many bacterial species. The drugs contain functional groups which control the type and degree of interaction with different solvents. In this research, the ground and excited state dipole moments of LVF and NRF drugs were estimated using solvatochromic effects and computational work. The dipole moments were estimated from absorption and emission spectra in polar and nonpolar solvents using Bakhshiev’s, Kawski–Chamma–Viallet, Lippert–Mataga, and Reichardt models. The results indicated the emission spectra are more strongly affected by solvent polarity than the absorption spectra. The calculated excited state dipole moment is larger than that of the ground state, indicating that the probe compounds are significantly more polarized in the excited state than in the ground state. From computational work, the HOMO-LUMO energy band gap, the dipole moments, electron charge density distribution, and oscillator strength were determined using the semiempirical MP6 method, DFT-B3LYP-6-31G, and DFT-B3LYP-3-21G employing Gaussian 09 software. In general, larger dipole moments were obtained by computation rather than from experiments due to the absence of solvent effects.

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A combined experimental and computational investigation of solvatochromism of nonpolar laser dyes: Evaluation of ground and singlet excited-state dipole moments

Journal of Molecular Liquids ◽

10.1016/j.molliq.2017.08.078 ◽

2017 ◽

Vol 244 ◽

pp. 453-463 ◽

Cited By ~ 6

Author(s):

G.H. Pujar ◽

M.N. Wari ◽

B. Steffi ◽

H. Varsha ◽

B. Kavita ◽

...

Keyword(s):

Excited State ◽

Dipole Moments ◽

Laser Dyes ◽

Singlet Excited State ◽

Computational Investigation ◽

Excited State Dipole Moments

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Ground-and Excited-State Dipole Moments of 6-Propionyl-2-(dimethylamino)naphthalene Determined from Solvatochromic Shifts

Zeitschrift für Naturforschung A ◽

10.1515/zna-1999-6-706 ◽

1999 ◽

Vol 54 (6-7) ◽

pp. 379-381 ◽

Cited By ~ 17

Author(s):

A. Kawski

Keyword(s):

Dipole Moment ◽

Excited State ◽

Ground State ◽

Singlet State ◽

Fluorescence Probe ◽

Dipole Moments ◽

Free Molecule ◽

Excited Singlet ◽

Solvatochromic Shifts ◽

Excited State Dipole Moments

Abstract The dipole moments in the ground-and excited-state of the fluorescence probe 6-propionyl-2-(dim-ethylamino)naphthalene (PRODAN) are determined from solvatochromic shifts to μe = 2.1 D and μg = 6.4 D. These values concern the free molecule. In the first excited singlet state the dipole moment is only 3 times greater than in the ground state.

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