Anomalous intensities and vibrational structure in the absorption spectra of benzene and benzene-d6

1992 ◽  
Vol 168 (2-3) ◽  
pp. 211-223 ◽  
Author(s):  
Gad Fischer ◽  
Alan E.W. Knight
Keyword(s):  
Absorption Spectra ◽  
Vibrational Structure

PYRIDINE N-OXIDE COMPLEXES OF ZIRCONYL, THORIUM, AND URANYL PERCHLORATES

1964 ◽  
Vol 42 (4) ◽  
pp. 856-860 ◽  
Author(s):  
P. Rama Murthy ◽  
C. C. Patel
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Lone Pair ◽  
Vibrational Structure ◽  
Uranyl Complexes ◽  
Bond Character

Pyridine N-oxide complexes having the composition ZrO(Py•O)6(ClO4)2, Th(Py•O)8(ClO4)4, and UO2(Py•O)5(ClO4)2 have been prepared. The infrared and electronic absorption spectra show that the bonding between the metal and pyridine N-oxide in the complexes has occurred by donation of the lone pair of p-electrons on oxygen to the metal, and that the π-bond character of NO group increases in the complexes as uranyl < thorium < zirconyl. The decrease in the vibrational structure of the UO22+ spectrum in the visible region indicates strong coordination of pyridine N-oxide to the uranyl group. The decomposition temperatures of zirconyl, thorium, and uranyl complexes are 307, 350, and 319 °C respectively.

Phenyl Substitution Effects on Triplet–Triplet Absorption Spectra: I. Study of 1,3,6,8-Tetraphenylpyrene

1975 ◽  
Vol 53 (21) ◽  
pp. 3269-3275 ◽  
Author(s):  
C. Rullière ◽  
E. C. Colson ◽  
P. C. Roberge
Keyword(s):  
Absorption Spectrum ◽  
Triplet State ◽  
Absorption Spectra ◽  
Rate Constant ◽  
Theoretical Calculations ◽  
Vibrational Structure ◽  
Substitution Effects ◽  
Quenching Rate ◽  
Diffusion Controlled ◽  
Quenching Rate Constant

The triplet–triplet (T–T) absorption spectrum of 1,3,6,8-tetraphenylpyrene (TPP) was measured from 400 to 620 nm. The data obtained are compared with theoretical calculations using the Ruedenberg–Scherr FEMO model. A planar triplet state is evidenced by fine vibrational structure. The T–T quenching rate constant measured (1.3 ± 0.1 × 109 M−1 s−1) is 20% of the expected diffusion-controlled value.

Interpretation of the vibrational structure of the emission and absorption spectra of C60

1992 ◽  
Vol 97 (9) ◽  
pp. 6496-6503 ◽  
Author(s):  
Fabrizia Negri ◽  
Giorgio Orlandi ◽  
Francesco Zerbetto
Keyword(s):  
Absorption Spectra ◽  
Vibrational Structure ◽  
Emission And Absorption Spectra

Polarized absorption spectra of radical ions of some azanaphthalenes and biphenyls in stretched polymer films

1987 ◽  
Vol 65 (6) ◽  
pp. 1185-1189 ◽  
Author(s):  
Hiroshi Hiratsuka ◽  
Ken'ichi Sekiguchi ◽  
Yoshihiko Hatano ◽  
Yoshie Tanizaki ◽  
Yuji Mori
Keyword(s):  
Absorption Spectra ◽  
Radical Cations ◽  
Linear Dichroism ◽  
Vibrational Structure ◽  
Radical Anions ◽  
Short Axis ◽  
Radical Ions ◽  
Γ Irradiation ◽  
Molecular Plane ◽  
Vibrational Bands

The stretched polymer film technique combined with -γ-irradiation has been employed to measure the polarized absorption (linear dichroism) spectra of radical anions of quinoline, isoquinoline, quinoxaline, phthalazine, phenylpyridine, 4,4′-bipyridyl, and 2,2′-bipyridyl. Profiles of polarized absorption spectra of all the radical anions are similar to those of the parent naphthalene or biphenyl radical anions. Those of radical cations of isoquinoline and 2,2′-bipyridyl are also similar to those of radical cations of their parent molecules. Quinoxaline radical cations, however, show quite a different spectrum from that of naphthalene radical cations; a long vibrational structure with ca. 550 cm−1 intervals was observed and peaks of these vibrational bands were polarized parallel to the molecular short-axis or normal to the molecular plane.

Comparative Interpretation of Absorption Spectra of Technetium (IV) and Rhenium (IV) Hexahalides

1965 ◽  
Vol 20 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Chr. Klixbüll Jørgensen ◽  
Klaus Schwochau
Keyword(s):  
Electron Transfer ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Vibrational Structure ◽  
Octahedral Symmetry ◽  
Absorption Bands ◽  
Nephelauxetic Effect

Absorption spectra of aqueous solutions of TcX6- and ReX6- (X = F, Cl, Br, I) are measured between 8 000 and ∼ 50 000 cm-1 and theoretically discussed. The electron transfer spectra indicate the optical electronegativity xopt= 2.25 for Tc (IV) and 2.05 for the less oxidizing Re (IV). The spectrochemical parameter Δ is determined to 28 400 cm-1 in TcF6 and 32 800 cm-1 in ReF6-. The nephelauxetic effect is evaluated from the spin-forbidden intra-sub-shell transitions in all eight species, and from the two spin-allowed bands of TcF6- The vibrational structure of the narrow absorption bands and the possible weak distortion from octahedral symmetry of Tc (IV) hexahalides are discussed.

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