Ground- and excited-state prototropic tautomerism in anils of aromatic α-hydroxy aldehydes studied by electronic absorption, fluorescence and1H and13C NMR spectroscopies and semi-empirical calculations

1995 ◽  
Vol 8 (11) ◽  
pp. 713-720 ◽  
Author(s):  
Sergio H. Alarcón ◽  
Alejandro C. Olivieri ◽  
Raquel M. Cravero ◽  
Guillermo Labadie ◽  
Manuel González-Sierra
Keyword(s):  
Excited State ◽  
Electronic Absorption ◽  
Prototropic Tautomerism ◽  
Hydroxy Aldehydes ◽  
Semi Empirical

Excited-state localization and energy transfer in pyrene core dendrimers with fluorene/carbazole as the dendrons and acetylene as the linkages

2016 ◽  
Vol 18 (5) ◽  
pp. 4134-4143 ◽  
Author(s):  
Linyin Yan ◽  
Yan Wan ◽  
Andong Xia ◽  
Sheng Hien Lin ◽  
Ran Huang
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Theoretical Model ◽  
Empirical Methods ◽  
Multi Scale ◽  
Td Dft ◽  
Semi Empirical

Multi-scale theoretical model and spectra simulation for dendrimers combining TD-DFT/DFT and semi-empirical methods.

The electronic absorption spectrum of NHD

1979 ◽  
Vol 57 (5) ◽  
pp. 761-766 ◽  
Author(s):  
D. A. Ramsay ◽  
F.D. Wayne
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Electronic Absorption Spectrum ◽  
Electronic Absorption ◽  
Rotational Constants ◽  
Axis Switching

Rotational assignments are given for about 350 lines in the (0,9,0)–(0,0,0), (0,10,0)–(0,0,0), and (0,11,0)–(0,0,0) bands in the electronic absorption spectrum of NHD. The Σ and Δ sub-bands have been identified for the bands with ν2′ odd and the Π sub-band for the band with ν2′ even.Ground state rotational and spin–rotational constants have been determined. The principal constants in reciprocal centimetres are: A = 20.1162(32), B = 8.1114(16), C = 5.6681(16), εaa = −0.2324(51),εbb = −0.0373ε, εcc = −0.0019ε, where the error limits are 1σ. Term values are tabulated for both the ground and excited state levels.Several 'axis-switching' branches have been identified in agreement with the predictions of Hougen and Watson.

Experimental Determination of Dipole Moments of Some Benzamide Derivatives

1998 ◽  
Vol 53 (8) ◽  
pp. 684-688
Author(s):  
J. Heidt ◽  
J. R. Heidt ◽  
M. Raciniewskab
Keyword(s):  
Excited State ◽  
Experimental Determination ◽  
Gas Phase ◽  
Electronic Absorption ◽  
Dipole Moments ◽  
Absorption Bands ◽  
Excited State Dipole Moments ◽  
Benzamide Derivatives

Abstract The excited state dipole moments of some benzamide derivatives are determined. The method of solvent induced shifts of electronic absorption bands in comparison with their positions in the gas phase is used. Some regular trends revealed in the obtained data are discussed. The present results are compared with those available in the literature.

scholarly journals A semi-empirical estimation of ground and excited state dipole moments of zinc phthalocyanine from solvatochromic shift data

2018 ◽  
Vol 6 (2) ◽  
pp. 190
Author(s):  
Abimbola Ogunsipe
Keyword(s):  
Excited State ◽  
Ground State ◽  
Dipole Moments ◽  
Solvent Polarity ◽  
Zinc Phthalocyanine ◽  
Empirical Estimation ◽  
Solvatochromic Shift ◽  
Excited State Dipole Moments ◽  
Semi Empirical ◽  
Ground State Dipole Moments

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.  

Electronic absorption spectrum and π-electronic structure of cryptocyanine

1980 ◽  
Vol 45 (2) ◽  
pp. 307-320 ◽  
Author(s):  
Miloš Titz ◽  
Antonín Novák ◽  
Viktor Řehák
Keyword(s):  
Absorption Spectrum ◽  
Electronic Structure ◽  
Dipole Moment ◽  
Excited State ◽  
Absorption Band ◽  
Electronic Absorption ◽  
Quantum Chemical ◽  
Fluorescence Excitation ◽  
Real Geometry ◽  
Optimum Model

Absorption, fluorescence excitation and APF spectra of cryptocyanine have been measured. Dipole moment of the respective S1 excited state has been estimated from shifts of the marked maximum of the first absorption band in various solvents. On the basis of quantum-chemical calculations carried out by the PPP method in the approximation of quasi-real geometry we have received the optimum model of π-electronic structure of the cryptocyanine molecule and therefrom the theoretical electronic singlet spectrum inclusive character of the S0 - S1 transition.

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