Complexes moléculaires d'hétérocycles soufrés et oxygénés. Étude spectrophotométrique de bandes de transfert de charge multiples

1982 ◽  
Vol 60 (7) ◽  
pp. 862-871 ◽  
Author(s):  
Jean-Paul Canselier ◽  
Serge Domenech ◽  
Štefan Stankovsky ◽  
Sabine Gautier
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Molecular Complexes ◽  
The Other ◽  
Ionization Potentials ◽  
Nonpolar Solvents ◽  
Other Hand ◽  
The One

As with benzenoid donors, the electronic absorption spectra of the molecular complexes of simple or condensed sulfur or oxygen-containing five-membered heterocycles with TCNE (or DDQ) often show two charge-transfer bands. In many cases, the knowledge of the actual frequencies requires a technique of resolution. The results so obtained are correlated with the ionization potentials of donors on the one hand, and the refractivity of nonpolar solvents on the other hand.

scholarly journals Electronic Absorption Spectra of Some Triazolopyrimidine Derivatives

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hussein Moustafa ◽  
M. F. Shibl ◽  
Rifaat Hilal ◽  
Laila I. Ali ◽  
Sheimaa Abdel Halim
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Dipole Moments ◽  
Molecular Orbital Calculations ◽  
Transition Energies ◽  
Density Distributions ◽  
Nonpolar Solvents ◽  
Experimental Transition

The electronic absorption spectra of triazolo pyrimidine and some of its derivatives were measured in polar as well as nonpolar solvents. Assignment of the observed transitions is facilitated via molecular orbital calculations. Charge density distributions, dipole moments, and the extent of delocalization of the MOS were used to interpret the observed solvent effects. The observed transitions are assigned as charge transfer (CT), localized, and delocalized according to the contribution of the various configurations in the CI-states. The correspondence between the calculated and experimental transition energies is satisfactory.

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.

Spectra of the 1:1 and 3:1 solid complexes of coronene-TCNQ

1977 ◽  
Vol 55 (21) ◽  
pp. 3712-3716 ◽  
Author(s):  
Kim Doan Truong ◽  
André D. Bandrauk
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Absorption Spectra ◽  
Charge Transfer Band ◽  
Out Of Plane ◽  
The Individual ◽  
A Charge ◽  
Solid Complexes

Two new solid TCNQ complexes have been isolated, coronene–TCNQ 1:1 and 3:1. The infrared and electronic absorption spectra are presented for the two different stoichiometries. From these spectra we infer that the complexes are covalent in the ground state with a charge transfer band appearing at 730 nm. The out of plane vibrations of the individual molecules are noticeably perturbed upon complexation.

Spectroelectrochemical Study of some μ3-Oxo-μ-acetato Trinuclear Rhodium(III) and Iridium(III) Complexes

1995 ◽  
Vol 50 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Kenta Takahashi ◽  
Keisuke Umakoshi ◽  
Akihiro Kikuchi ◽  
Yoichi Sasaki ◽  
Masato Tominaga ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Absorption Bands ◽  
Visible Absorption ◽  
The One ◽  
Species Being

New trinuclear rhodium(III) complexes, [Rh3(μ3-O)(μ-CH3COO)6(L)3]+ (L = imidazole (Him), 1-methylimidazole (Meim), and 4-methylpyridine (Mepy)) have been prepared. The Him, Meim, and Mepy complexes show reversible one-electron oxidation waves at E1/2 = +1.12, +1.12, and +1.28 V vs Ag/AgCl, respectively, in acetonitrile. Electronic absorption spectra of the one electron oxidized species of these complexes and [Rh3(μ3-O)(μ-CH3COO)6(py)3]+ (py = pyridine) (E1/2 = +1.32 V ) were obtained by spectroelectrochemical techniques. While the Rh3(III,III,III) states show no strong visible absorption, the Rh3(III,III,IV ) species give a band at ca. 700 nm (ε = 3390-5540 mol dm-3 cm-1). [Ir3(μ3-O)(μ-CH3COO)6(py)3]+ with no strong absorption in the visible region, shows two reversible one-electron oxidation waves at +0.68 and +1.86 V in acetonitrile. The electronic absorption spectrum of the one-electron oxidized species (Ir3(III,III,IV )) also shows some absorption bands (688 nm (ε, 5119), 1093 (2325) and 1400 (ca. 1800)). It is suggested that the oxidation removes an electron from the fully occupied anti-bonding orbital based on metal-dπ-μ3-O-pπ interactions, the absorption bands of the (III,III,IV ) species being assigned to transitions to the anti-bonding orbital.

Polarized electronic absorption spectra of crystalline charge transfer autocomplexes

1979 ◽  
Vol 35 (11) ◽  
pp. 1229-1234
Author(s):  
A.J. Mālmanis ◽  
Ya.A. Eiduss ◽  
J.F. Freimanis ◽  
J.J. Drēǧeris
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra

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.

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