Electronic-Transitions in the Near-Ultraviolet Spectra of Uracil, Thymine, Uridylyl(3'-5')uridine and Thymidylyl(3'-5')thymidine

1988 ◽  
Vol 41 (10) ◽  
pp. 1509 ◽  
Author(s):  
KE Connell ◽  
T Kurucsev ◽  
B Norden
Keyword(s):  
Energy Transfer ◽  
Absorption Spectra ◽  
Energy Transition ◽  
Electronic Transitions ◽  
Ultraviolet Region ◽  
Transfer Rates ◽  
Exciton Coupling ◽  
Low Intensity ◽  
Near Ultraviolet ◽  
Exciton Interactions

The absorption spectra in the near-ultraviolet region of uracil and thymine, and of their derivatives may be deconvoluted into two vibronic progressions; the higher-energy progression has a relatively low intensity. The corresponding component spectra coincide with the two separate transitions manifested in the circular dichroism of the relevant nucleoside derivatives. A series of apparent contradictions may be resolved by the assumption that the higher-energy transition in absorption is a vibronically allowed (π*,n) transition. This interpretation is further supported by an analysis of the spectra of uridylyl (3′-5′) uridine and thimidylyl (3′-5′) thymidine in terms of exciton interactions. The magnitude of exciton coupling in the dinucleoside phosphates is found to be small but significant in terms of energy transfer rates.

Polarized Crystal Absorption Spectra of Pd(II) and Pt(II) Tetrahalo and Tetrathiocyanato Complexes

1979 ◽  
Vol 34 (2) ◽  
pp. 211-219
Author(s):  
W. Tuszynski ◽  
G. Gliemann
Keyword(s):  
Single Crystal ◽  
Absorption Spectra ◽  
Theoretical Calculations ◽  
Electron Interaction ◽  
Ultraviolet Region ◽  
Ligand Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Near Ultraviolet ◽  
Spectral Assignment

Abstract Single crystal absorption spectra of tetrachloro, tetrabromo, and tetrathiocyanato complexes of Pd(II) and Pt(II) have been measured in the visible and near-ultraviolet region at temperatures between 10 K and 295 K. A spectral assignment of the observed d-d transitions based on ligand field theoretical calculations including electron-electron interaction and spin-orbit coupling is proposed which is consistent for all the systems investigated

Electronic absorption spectra and π-electron structure of 2-propenylidene-1,2-dihydropyridine and its derivatives

1979 ◽  
Vol 44 (3) ◽  
pp. 884-894 ◽  
Author(s):  
Josef Kuthan ◽  
Dušan Ilavský ◽  
Jiří Krechl
Keyword(s):  
Absorption Spectra ◽  
Satisfactory Agreement ◽  
Electronic Absorption ◽  
Heterocyclic System ◽  
Electronic Absorption Spectra ◽  
Electron Structure ◽  
Ultraviolet Region ◽  
Near Ultraviolet ◽  
Experimental Absorption

The results of the PPP calculations of the singlet-singlet transitions of 1-methyl-3'-cyano-3'-alkoxycarbonyl-2-propenylidene-1,2-dihydropyridines II and 1-methyl-4-amino-3,3'-dicyano-3',5-di(methoxycarbonyl)-2-propenylidene-1,2-dihydropyridine (III) are in a satisfactory agreement with the experimental absorption curves in the visible and near ultraviolet region. Based on this finding, the absorption of the parent heterocyclic system of 2-propenylidene-1,2-dihydropyridine (I) is predicted. Some aspects of the π-electron structure of the substances I-III in the S0, S1 S2 and states are discussed.

Some Studies in Inorganic Complexes. XIV. Reactions of 2-Methyl-6-aminopyridine and 2-Thioamidopyridine with Some Transition Metal Ions

1963 ◽  
Vol 16 (3) ◽  
pp. 371 ◽  
Author(s):  
GJ Sutton
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Absorption Spectra ◽  
Copper Complexes ◽  
Transition Metal Ions ◽  
The Other ◽  
Ultraviolet Region ◽  
Chelating Ligands ◽  
Near Ultraviolet ◽  
Inorganic Complexes

The following complexes of the chelating ligands 2-methyl-6-aminomethylpyridine (6-methyl-2-picolylamine or mepic) and 2-thioamidopyridine (thiopic) have been prepared and studied: [Cu mepic2X]X, where X = Cl, Br, I, NO3, ClO4, [Cu mepic2C2O4], [Ni mepic3][ClO4]2, [M(II) thiopic3][ClO4]2, [M(III) thiopic3][ClO4]3, (M(II) = Co, Ni; M(III) = CO, Fe), and [Co thiopic3]Cl2. Conductance measurements in ethanol, nitromethane, and nitrobenzene indicate that the [Cu mepic2X]X complexes are 5-covalent whilst the other complexes studied are 6-covalent. All the complexes are "spin free" excepting those of Co(III). Absorption spectra of the copper complexes in the near ultraviolet region were also made.

Electronic Absorption Spectra of Benzylchloride Vapor

1969 ◽  
Vol 23 (6) ◽  
pp. 616-617 ◽  
Author(s):  
R. Ammini Amma ◽  
K. P. R. Nair ◽  
D. K. Rai
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Ultraviolet Absorption ◽  
The Other ◽  
Electronic Transitions ◽  
Near Ultraviolet ◽  
Two Systems ◽  
Quartz Spectrograph

The near-ultraviolet absorption spectra of benzylchloride vapor have been photographed on a medium quartz spectrograph. Two systems of bands have been observed, one at 37 115 cm−1 and the other at 41 748 cm−1, which correspond to B2 ↓ A1 and A1 ↓ A1 electronic transitions. The observed spectra have been analysed in terms of fundamentals and overtones.

Some Studies in Inorganic Complexes. VI. Nickel(II) with 2-Picolylamine

1960 ◽  
Vol 13 (1) ◽  
pp. 74 ◽  
Author(s):  
GJ Sutton
Keyword(s):  
Solid State ◽  
Absorption Spectra ◽  
Magnetic Measurements ◽  
Visible Spectrum ◽  
Ultraviolet Region ◽  
Near Ultraviolet ◽  
Chelating Ligand ◽  
Inorganic Complexes ◽  
Solvent Molecules

Complexes of the type Nipic2X2, Nipic3X2.nH2O, and Nipic3(ClO4)2.H2O have been prepared and studied, where X is Cl, Br, or I and pic is the chelating ligand 2-picolylamine. Conductance measurements in nitrobenzene, nitromethane, methanol, and water show that the blue compounds Nipic2X2, whilst being hexacovalent complexes in the solid state, are progressively ionized in the respective solvents as halogen is replaced by solvent molecules. Conductance measurements also verified a hexacovalent structure for the Ni pic32+ ion complex whose salts are bi-univalent electrolytes. Magnetic measurements show that a11 the complexes are paramagnetic with a mean moment of 3.0 B.M. Their absorption spectra in the near ultraviolet region are characteristic of that of the ligand. A study in the visible spectrum was also made.

Origin of the Red Sites and Energy Transfer Rates in Single MEH-PPV Chains at Low Temperature

ChemPhysChem ◽  
2011 ◽  
Vol 12 (8) ◽  
pp. 1499-1508 ◽  
Author(s):  
Florian A. Feist ◽  
Martin F. Zickler ◽  
Thomas Basché
Keyword(s):  
Energy Transfer ◽  
Low Temperature ◽  
Transfer Rates

Achieving 17.38% efficiency of ternary organic solar cells enabled by a large-bandgap donor with noncovalent conformational lock

2021 ◽  
Author(s):  
Linyong Xu ◽  
Wuxi Tao ◽  
Heng Liu ◽  
Junhua Ning ◽  
Meihua Huang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Ultraviolet Region ◽  
Near Ultraviolet

A large-bandgap donor BTBR-2F based on noncovalent conformational lock has been designed and synthesized to achieve more complementary absorption with the PM6: Y6 blend in the near-ultraviolet region. The ternary...

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