Electronic absorption, fluorescence and polarisation spectra of α,β-diamino-9,10-anthraquinones and their interpretation by the method of configuration analysis

1982 ◽  
Vol 47 (10) ◽  
pp. 2604-2614 ◽  
Author(s):  
Miloš Nepraš ◽  
Miloš Titz ◽  
Jürgen Fabian ◽  
Bohuslav Gaš

On the basis of measurement of absorption frequency-dependent polarisation spectra of fluorescence (APF) and dichroism on oriented polyvinyl alcohol sheets, interpretation has been carried out of absorption spectra of α,β-diamino-9,10-anthraquinones in the wavelength range 250 to 600 nm. Character of the excited states has been investigated by the method of configuration analysis (PPP-CA).

1982 ◽  
Vol 47 (10) ◽  
pp. 2583-2593 ◽  
Author(s):  
Miloš Nepraš ◽  
Bohuslav Gaš ◽  
Jürgen Fabian ◽  
Miloš Titz

On the basis of measurement of absorption frequency-dependent polarisation spectra of fluorescence (APF) and dichroism on oriented polyvinyl alcohol sheets interpretation has been carried out of absorption spectra of α,α'-diamino-9,10-anthraquinones in the wavelength range 250 to 600 nm. Character of the excited states has been determined by the method of configuration analysis (PPP-CA).


1982 ◽  
Vol 47 (10) ◽  
pp. 2594-2603 ◽  
Author(s):  
Miloš Nepraš ◽  
Miloš Titz ◽  
Bohuslav Gaš ◽  
Jürgen Fabian

On the basis of measurement of absorption frequency-dependent polarisation spectra of fluorescence (APF) and dichroism on oriented polyvinyl alcohol sheets, interpretation has been carried out of electronic absorption spectra of β,β'-diamino-9,10-anthraquinones in the wavelength range 250 to 600 nm. Character of the excited ππ* states has been determined by the method of configuration analysis (PPP-CA).


1982 ◽  
Vol 47 (10) ◽  
pp. 2569-2582 ◽  
Author(s):  
Miloš Nepraš ◽  
Jürgen Fabian ◽  
Miloš Titz ◽  
Bohuslav Gaš

Absorption frequency-dependent polarisation spectra of fluorescence (APF) and dichroism on oriented polyvinyl alcohol sheets have been measured and used as a basis for interpretation of absorption spectra of 1- and 2-amino-9,10-anthraquinones in the region 250-600 nm. Character of the excited states was determined by the method of configuration analysis (PPP-CA).


2017 ◽  
Vol 68 (2) ◽  
pp. 307-310 ◽  
Author(s):  
Ana Maria Ciubara ◽  
Andreea Celia Benchea ◽  
Carmen Beatrice Zelinschi ◽  
Dana Ortansa Dorohoi

The electronic absorption spectra of five polycyclic polyenes were recorded in non-polar solvents in order to determine their polarizability in excited states from the strength of the dispersive interactions in their diluted solutions. The bathochromic shifts of p-p* vibronic bands prove the increase of the molecular polarizabilty in the photon absorption process. Some molecular parameters of the analyzed polyenes in their ground state were computed by using the programs from Spartan�14.


1968 ◽  
Vol 8 (2) ◽  
pp. 197-202 ◽  
Author(s):  
L. V. Smirnov ◽  
N. V. Platonova ◽  
N. P. Kulikova

1984 ◽  
Vol 49 (3) ◽  
pp. 680-683 ◽  
Author(s):  
Bohumil Hájek ◽  
Dagmar Sýkorová ◽  
Jiří Chyba

The λ-C1-cis(N), δ-C1-cis(N), λ-C2-cis(N) and δ-C2-cis(N) isomers of the complex K[Co((S)-Pro)2CO3] were chromatographically separated and characterized by their electronic absorption spectra and CD spectra.


1995 ◽  
Vol 60 (10) ◽  
pp. 1621-1633 ◽  
Author(s):  
Stanislav Böhm ◽  
Mojmír Adamec ◽  
Stanislav Nešpůrek ◽  
Josef Kuthan

Molecular geometries of 2,4,4,6-tetraphenyl-4H-pyran (Ia), 4,4-(biphenyl-2,2e-diyl)-2,6-diphenyl-4H-pyran (Ib) and their heterocyclic isomers II-V were optimized by the PM3 method and used for the calculation of electronic absorption spectra by the CNDO/S-CI procedure. Comparison of the theoretical data with experimental UV-VIS absorption spectra made possible to select hypervalent molecules IIIa, IIIb, IVa and IVb being responsible for the photocolouration of 4H-pyrans Ia, Ib, while compounds Va, Vb, VI and VII come into account as possible photodegradation products. The bleaching process of the UV illuminated compound Ia is analyzed in terms of dispersive first-order reaction kinetics.


1998 ◽  
Vol 63 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík

The effect of the halide ligand on the bonding of niobium in niobocene dichloride and niobocene diiodide was investigated. The electronic absorption spectra of the two compounds in the range of d-d transitions were resolved into four bands corresponding to transitions of the d1 electron between five frontier orbitals in a molecule of symmetry point group C2v. The energies of the frontier molecular orbitals were determined relatively to the energy of the orbitals in the spherically symmetric ligand field formed by the appropriate halide ligands. The effect of the halide ligands on the spin-orbital interaction of the HOMO orbital is discussed qualitatively on the basis the ESR spectra.


Sign in / Sign up

Export Citation Format

Share Document