Spectroscopic Studies on Some Benzenethiols

1972 ◽  
Vol 26 (2) ◽  
pp. 270-277 ◽  
Author(s):  
R. H. Abu-Eittah ◽  
R. H. Hilal
Keyword(s):  
Charge Transfer ◽  
Oscillator Strength ◽  
Electronic Absorption ◽  
Intramolecular Charge Transfer ◽  
Electronic Absorption Spectra ◽  
Transition Probability ◽  
Spectroscopic Studies ◽  
Different Types ◽  
Charge Transfer Transitions ◽  
Derivatives Of

The electronic absorption spectra of some derivatives of benzenethiol were studied in the visible-ultraviolet regions in a number of solvents. Solvent effects on the position of band maxima helped in identifying the different types of transitions obtained, namely n → π*, π → π*, and intramolecular charge transfer transitions. Energies of the charge transfer bands were computed theoretically and agreed well with the experimental results. Transition probability coefficients and oscillator strength were calculated for the different transitions. Numerical values of the oscillator strength helped to differentiate between the various types of transitions.

Spectroscopic Studies of Some Drugs of Toxicological Interest. Part II. p-Aminobenzoic Acid Drugs

1969 ◽  
Vol 23 (3) ◽  
pp. 254-256 ◽  
Author(s):  
A. Mustafa ◽  
R. Abu-Eittah ◽  
S. Elgendi
Keyword(s):  
Charge Transfer ◽  
Benzoic Acid ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Intramolecular Charge Transfer ◽  
Electronic Absorption Spectra ◽  
Spectroscopic Studies ◽  
Aminobenzoic Acid ◽  
Long Wavelength ◽  
Amino Benzoic Acid

The electronic absorption spectra of some drugs derived from p-amino benzoic acid were studied. The effect of the substituent on the position of band maxima and intensity has been rationalized. Long wavelength energies have been found to agree well with calculated energies of the intramolecular charge transfer bands.

Spectroscopic Studies of Dimethylamino Derivatives of Fluorene

2000 ◽  
Vol 55 (11-12) ◽  
pp. 902-908 ◽  
Author(s):  
J. Heldt ◽  
J. R. Heldt ◽  
T. Redzimski ◽  
H. Diehl ◽  
P. Schultz
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Fluorescence Spectra ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Spectroscopic Studies ◽  
Polar Solvents ◽  
Derivatives Of ◽  
Transfer State

Abstract 2-dimethylamino-9-fluorenol and 2-dimethylamino-9(4'dimethylamino)phenyl-9-fiuorenol in polar solvents in the excited state undergo conformation changes in which two fluorescent isomers are created. The isomers (in the local excited (LE) and charge transfer (CT) configuration) possess separate fluorescence bands, one appearing from the S1 (LE) state and the second from the intramolecular charge transfer state S1 (CT) of the neutral, aromatic molecule. Both bands show a solvatochromic effect. Using the method of the solvent induced Stokes shift of the absorption and fluorescence spectra the permanent dipole moment of the excited state of fluorene and its two derivatives have been determined. The dipole moment of the ground state and the Onsager cavity radius of the studied molecules were calculated with the Auestion Model 1 (AM1) program.

Elektronenspektren der Fluoro-Chloro-Osmate(V), [OsFnCl6–n]–, n = 0 — 6

1986 ◽  
Vol 41 (10) ◽  
pp. 1222-1227 ◽  
Author(s):  
Th. Groth ◽  
W. Preetz
Keyword(s):  
Fine Structure ◽  
Charge Transfer ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Absorption Bands ◽  
Charge Transfer Transitions ◽  
Temperature Spectra ◽  
Tetraethylammonium Salts

The electronic absorption spectra of the solid tetraethylammonium salts of [OsFnCl6-n]- are measured at 10 K. The strong bands in the UV/YIS region are assigned to charge transfer transitions from π(t1 u, t2 u) and σ(t1 u ) Cl orbitals into the π(t2g3) Os(V) level. The weak intraconfigurational excitations within the t2g3 manifold of Os(V) are split by spin-orbit coupling and lowered symmetry into Kramers doublets, observed in the range 5500-18000 cm-1. The 0 - 0-transitions are deduced from vibrational fine structure; for the centrosymmetric complexes they are confirmed by hot bands recorded in the normal temperature spectra. There is a systematical shift of all absorption bands to higher energy with increasing number of F-ligands.

Spectroscopic Studies of Some Organic Azides

1971 ◽  
Vol 25 (1) ◽  
pp. 90-93 ◽  
Author(s):  
R. Abu-Eittah ◽  
A. El-Shahawy
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Intramolecular Charge Transfer ◽  
Spectroscopic Studies ◽  
Locally Excited ◽  
Organic Azides ◽  
Charge Transfer Transitions

The absorption spectra of some organic azides have been studied in the visible and uv region using different solvents. Interpretation of the obtained results is attempted. The different transitions obtained are assigned to either intramolecular charge–transfer transitions or to locally excited ones. The energies of the charge–transfer states are computed. No evidence was found for an n → π* transition.

Optical Spectroscopy of Mixed Metamagnetic FexCo1-xCl2 Crystals

1980 ◽  
Vol 35 (10) ◽  
pp. 1013-1019 ◽  
Author(s):  
Friedrich Seitz ◽  
Terence E. Wood ◽  
Peter Day
Keyword(s):  
Charge Transfer ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Absorption Spectra ◽  
Optical Spectroscopy ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Broad Band ◽  
Mixed Crystals ◽  
Magnetic Exchange

Abstract Electronic absorption spectra are reported for single crystals of composition FexCo1-xCl2 as a function of temperature from 300 K to 4 K. A broad band at 436 nm is assigned to Fe (II) → Co (II) charge transfer and the temperature dependence of its intensity is related to the magnetic exchange between the ions. The 2T1g(2H) excitation of Co (II) in the mixed crystals has an unusual temperature dependence which correlates with the Néel temperature.

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