Hypersensitivity in the 4f–4f absorption spectra of tris (acetylacetonato) neodymium(III) complexes with imidazole and pyrazole in non-aqueous solutions. Effect of environment on hypersensitive transitions

2012 ◽  
Vol 132 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Anees A. Ansari ◽  
Rashid Ilmi ◽  
K. Iftikhar
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Hypersensitive Transitions

scholarly journals Spectral Probe for Electron Transfer and Addition Reactions of Azide Radicals with Substituted Quinoxalin-2-Ones in Aqueous Solutions

2021 ◽  
Vol 22 (2) ◽  
pp. 633
Author(s):  
Konrad Skotnicki ◽  
Slawomir Ostrowski ◽  
Jan Cz. Dobrowolski ◽  
Julio R. De la Fuente ◽  
Alvaro Cañete ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Density Functional ◽  
Reduction Potential ◽  
Biological Significance ◽  
Radical Cations ◽  
Basis Sets ◽  
Double Bonds ◽  
Reduction Potentials

The azide radical (N3●) is one of the most important one-electron oxidants used extensively in radiation chemistry studies involving molecules of biological significance. Generally, it was assumed that N3● reacts in aqueous solutions only by electron transfer. However, there were several reports indicating the possibility of N3● addition in aqueous solutions to organic compounds containing double bonds. The main purpose of this study was to find an experimental approach that allows a clear assignment of the nature of obtained products either to its one-electron oxidation or its addition products. Radiolysis of water provides a convenient source of one-electron oxidizing radicals characterized by a very broad range of reduction potentials. Two inorganic radicals (SO4●−, CO3●−) and Tl2+ ions with the reduction potentials higher, and one radical (SCN)2●− with the reduction potential slightly lower than the reduction potential of N3● were selected as dominant electron-acceptors. Transient absorption spectra formed in their reactions with a series of quinoxalin-2-one derivatives were confronted with absorption spectra formed from reactions of N3● with the same series of compounds. Cases, in which the absorption spectra formed in reactions involving N3● differ from the absorption spectra formed in the reactions involving other one-electron oxidants, strongly indicate that N3● is involved in the other reaction channel such as addition to double bonds. Moreover, it was shown that high-rate constants of reactions of N3● with quinoxalin-2-ones do not ultimately prove that they are electron transfer reactions. The optimized structures of the radical cations (7-R-3-MeQ)●+, radicals (7-R-3-MeQ)● and N3● adducts at the C2 carbon atom in pyrazine moiety and their absorption spectra are reasonably well reproduced by density functional theory quantum mechanics calculations employing the ωB97XD functional combined with the Dunning’s aug-cc-pVTZ correlation-consistent polarized basis sets augmented with diffuse functions.

scholarly journals Electronic Absorption Spectra of Aqueous Solutions and Adsorbed Layers of 1-Methyl-4-(4-diethylaminophenylazo)pyridinium iodide.

1991 ◽  
pp. 1582-1587 ◽  
Author(s):  
Michio KOBAYASHI ◽  
Yoshio MAEDA ◽  
Hitoshi TOKUNAGA ◽  
Norio TAKAHASHI ◽  
Toshihiko HOSHI ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Adsorbed Layers

Absorption spectra of the OH and O- radicals in aqueous solutions

1993 ◽  
Vol 41 (3) ◽  
pp. 503-505 ◽  
Author(s):  
Gidon Czapski ◽  
Benon H.J. Bielski
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra

Complexation studies of 3-substituted β-diketones with selected d- and f-metal ions

2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Grzegorz Pawlicki ◽  
Bartosz Staniszewski ◽  
Katarzyna Witt ◽  
Włodzimierz Urbaniak ◽  
Stefan Lis
Keyword(s):  
Metal Ions ◽  
Absorption Spectra ◽  
Lanthanide Ions ◽  
Computer Assisted ◽  
Hypersensitive Transition ◽  
Complexation Studies ◽  
Target Factor Analysis ◽  
Derivatives Of ◽  
Hypersensitive Transitions

AbstractResults of spectroscopic investigations related to complex compositions of 3-substituted derivatives of pentane-2,4-dione (β-diketonate) complexes with chosen d- and f-metal ions are presented. Ligands 3-allylacetylacetone (3all-acac) and 3-benzylacetylacetone (3ben-acac) were prepared and used for the complexation study with Cu(II), Co(II), Nd(III), and Ho(III) metal ions. Based on the absorption spectra of lanthanide ions in their hypersensitive transitions, with the use of computer assisted target factor analysis (CAT) and absorption spectra of the ligands with Cu(II) and Co(II), the verification of complex compositions and the determination of their stability constants were achieved. In case of Nd(III) and Ho(III) complexes with β-diketone ligands, absorption of their maxima were studied in the range of hypersensitive transitions 4 I 9/2 → 4 F 7/2 + 4 S 3/2 (λ max ∼ 734 nm and 748 nm) for Nd(III) and in the range of 435–465 nm, corresponding to the hypersensitive transition 5 G 6 → 5 I 8 (λ max ∼ 450 nm), for Ho(III).

Absorption spectra of aqueous solutions of europium dichloride

1966 ◽  
Vol 5 (6) ◽  
pp. 575-576 ◽  
Author(s):  
V. I. Ganopol'skii ◽  
V. F. Barkovskii ◽  
N. P. Ipatova
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra
Sign in / Sign up

Export Citation Format

Share Document