Chlorine Solutions in Molten Alkali Chlorides

2007 ◽  
Vol 62 (3-4) ◽  
pp. 205-212 ◽  
Author(s):  
Artem Kolobov ◽  
Vladimir Khokhlov ◽  
Alexei Potapov ◽  
Victor Kochedykov

Electronic absorption spectra of gaseous chlorine and their saturated solutions in molten alkali chlorides were studied in wide ranges of temperature and wavelength. It was found that gaseous chlorine has a wide absorption band between 20 000 and 43 500 cm−1. There is a tendency to both widening of the band and shifting of the absorption maximum to the short-waves region with rising temperature.The absorption bands of saturated solutions of chlorine in all molten alkali chlorides show a maximum in the neighborhood of 30 000 cm−1. A good correlation was found between the optical density of molten salt-Cl2 systems and the solubility of chlorine.

2018 ◽  
pp. 57-62
Author(s):  
V. M. Odyntsova

The development of pharmaceutical chemistry confronts molecular spectroscopy the problem of calculating the electronic states, assumptions and explanations of the various properties of complex organic compounds. In recent years, following the basic optical characteristics of the electronic absorption spectra: the wave number of maximum absorption – νmax (in cm-1), the half-width of the absorption bands of – ∆ν1/2 (cm-1), the integral intensity of the absorption band (in l/mol·cm2), the oscillator strength of the electronic transition – f, the matrix element of the transition of electrons – Mik. began widely used. These constants allow you to determine the chromophores in the investigated substances, to establish the probability and the resolution of the electrons’ transition. Our goal was the calculation and study of the basic optical characteristics of the electronic absorption spectra of 5-(adamantane-1-yl)-4R-1,2,4-triazole-3-thione, namely 5-(adamantane-1-yl)-4-methyl-1,2,4-triazole-3-thione and 5-(adamantane-1-yl)-4-phenyl-1,2,4-triazole-3-thione derivatives. When deciding about the purity of the compounds we used melting point, thin layer chromatography and the results of elemental analysis. UV spectra of the investigated compounds was measured with a spectrophotometer Specord 200-222U214 (Germany). Elemental analyzer GmbH (Germany) was used for carrying out the elemental analysis. It is determined that the values of the half-width Δν½ and integrated intensity of the absorption bands (A), the oscillator strength (f) and matrix element of the transition (Mik) can be used as an important constants of 5-(adamantane-1-yl)-4R-1,2,4-triazole-3-thione derivatives for their identification and establishing a deep connection between spectra and structure of the molecule. For the studied compounds is the most characteristic absorption band in the medium wave spectrum with high values of A and f, which indicate about the permitted and probable transitions of electrons which give rise to the observed maxima. Based on the study of the basic optical characteristics of the electronic absorption spectra of 5-(adamantane-1-yl)-4R-1,2,4-triazole-3-thione derivatives is found that chromatofor in the studied molecules is the structure of 1,2,4-triazole and substituents (adamantane, methyl and phenyl radicals). A distinctive feature, namely 5-(adamantane-1-yl)-4-phenyl-1,2,4-triazole-3-thione 5-(adamantane-1-yl)-4-methyl-1,2,4-triazole-3-tion are the values A, f, Mik, which can be used to identify the investigated compounds.


1995 ◽  
Vol 50 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Kenta Takahashi ◽  
Keisuke Umakoshi ◽  
Akihiro Kikuchi ◽  
Yoichi Sasaki ◽  
Masato Tominaga ◽  
...  

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.


2020 ◽  
Vol 787 (12) ◽  
pp. 16-20
Author(s):  
D.I. Shchikaltsova ◽  
◽  
Yu.T. Platov ◽  
V.A. Rassulov ◽  
R.A. Platova ◽  
...  

Diffuse reflection UV-VIS-NIR spectroscopy was used to study changes in the color of facing bricks from the content of the additive of manganese tetraoxide (Mn3O4) into the ceramic mass. This investigation was shown that with an increase of the additive content, both the intensity of the absorption bands of colored bricks corresponding to hematite decreases, and the absorption intensity increases with a shift in the maximum of the wide absorption band from the visible to the near-infrared range of the spectrum. By changing the values of the color coordinates in the CIE L*a*b* and Mansell systems: lightness and color, and the values of the indicator-relative color ability, it is fixed that the color of a brick depends on the ratio of two pigments: yellowish-red of hematite and black, probably jacobsite in its composition.


2018 ◽  
Vol 86 (14) ◽  
pp. 367-376
Author(s):  
Vladimir A. Volkovich ◽  
Yaroslav A. Shatkovskyi ◽  
Denis E. Aleksandrov ◽  
Dmitry S. Maltsev

1997 ◽  
Vol 178 ◽  
pp. 287-294
Author(s):  
John P. Maier

The electronic absorption spectra of a variety of carbon chains have been identified in the laboratory. The measurements were carried out in 5 K neon matrices on mass-selected species. On the basis of the trends evident in the homologous series, it can be predicted in which region absorption bands of the carbon chains are to be expected for the not yet measured longer and isoelectronic species. The spectroscopic characteristics, photostability and structural considerations point out which and what size carbon chains could be the diffuse interstellar bands absorbers.


2019 ◽  
Vol 60 (11) ◽  
pp. 106-113
Author(s):  
Anh Thi Ngoc Vu ◽  
◽  
Mikhail A. Ryabov ◽  
Olga V. Kovalchukova ◽  
Dmitry S. Gusarov ◽  
...  

In this paper, using the method DFT/B3LYP of quantum chemical modeling, the stability of tautomeric, conformer, and anionic forms of 2-(2-(2-hydroxy-5-sulfamoylphenyl)hydrazone-3-oxo-N-phenylbutanamide (H2L) was studied and the geometric, electronic structure and bond lengths of molecules in various tautomeric forms were determined. It was shown that the stability of tautomeric molecules H2L as anionic forms was determined by the number of existing intermolecular hydrogen bonds (closing six-membered and five-membered cycles). The most stable tautomeric and conformal forms of an organic molecule and its dianion are proposed. The interatomic distances, angles, charges on atoms, IR and electronic absorption spectra of tautomeric forms of the molecule and dianion (H2L and L2-) were calculated. In this work, we studied the electronic absorption spectra in an aqueous-alcoholic solution and found that in an alkaline medium the molecule transforms into the ionic form with a bathochromic shift of 47 nm, corresponding to the results of the shift of the long-wavelength band electronic absorption spectra upon transition from the hydrazotautomer (form a) to the dianion form (form b’’) at 92 nm obtained by TD-DFT. The calculated results for the distance and angles between atoms are in good agreement with the experimental data of the molecule by X-ray diffraction analysis. It was shown that the IR spectrum of the stable form appears two absorption bands in the region of 1690 and 1655 cm–1, which are attributed to stretching vibrations of carbonyl groups (C=O), bound by a strong intramolecular hydrogen bond and the presence of the NH-hydrazone fragment of the 1H NMR spectrum confirmed the most stable for a neutral molecule is the hydrazone form.


1986 ◽  
Vol 41 (10) ◽  
pp. 1222-1227 ◽  
Author(s):  
Th. Groth ◽  
W. Preetz

The electronic absorption spectra of the solid tetraethylammonium salts of [OsFnCl6-n]- are measured at 10 K. The strong bands in the UV/YIS region are assigned to charge transfer transitions from π(t1 u, t2 u) and σ(t1 u ) Cl orbitals into the π(t2g3) Os(V) level. The weak intraconfigurational excitations within the t2g3 manifold of Os(V) are split by spin-orbit coupling and lowered symmetry into Kramers doublets, observed in the range 5500-18000 cm-1. The 0 - 0-transitions are deduced from vibrational fine structure; for the centrosymmetric complexes they are confirmed by hot bands recorded in the normal temperature spectra. There is a systematical shift of all absorption bands to higher energy with increasing number of F-ligands.


1997 ◽  
Vol 75 (4) ◽  
pp. 365-376 ◽  
Author(s):  
Valery F. Traven ◽  
Larisa I. Vorobjeva ◽  
Tatjana A. Chibisova ◽  
Edward Andrew Carberry ◽  
Noelle Jean Beyer

Electronic absorption spectra of 18 hydroxycoumarin derivatives and their ionized forms have been studied. Close agreement between experimental and the PPP CI calculated electron absorption band energies has been found in most cases. Strong polarization of the carbonyl function of the pyrone ring in the 7-hydroxycoumarin derivatives, H-bonding between the hydroxyl group and neighboring substituent in the ortho-substituted hydroxycoumarins, as well as their tautomeric transformations, have been suggested in the discussion of the electronic absorption spectra of the hydroxycoumarin derivatives. In accord also with calculational results, ionization of the hydroxyl function leads to a bathochromic shift of the longest-wavelength absorption bands in the spectra of 7-hydroxycoumarin derivatives. The ionization has no effect on the electronic absorption of the 4-hydroxycoumarin derivatives. Relative stabilities of the tautomeric forms of hydroxycoumarin derivatives and their ionized forms have also been compared by MNDO calculations. Keywords: hydroxycoumarins, intramolecular H-bonding, ionization, electronic absorption spectra, keto–enol tautomerism.


2003 ◽  
Vol 07 (08) ◽  
pp. 551-557 ◽  
Author(s):  
Hiroshi Ogata ◽  
Ryuji Higashi ◽  
Nagao Kobayashi

The electronic absorption spectra of several phthalocyanines substituted at the so-called α-, β- and α and β-positions of the macrocycle have been recorded in solution and as films (α = 1,4,8,11,15,18,22, and 25 positions or 1,8 (or 11),15 (or 18), and 22 (or 25) positions, and β = 2,3,9,10,16,17,23, and 24 positions or 2,9 (or 10),16 (or 17), and 23 (or 24) positions). Phthalocyanines substituted with bulky groups at the α-positions prevent cofacial aggregation so that their Q-absorption band remains at a similar wavelength both in solution and films, although the film spectra are generally broader. Phthalocyanines substituted at the β-positions are apt to aggregate cofacially in polar solvents but in films they may show broad Q-bands which spread out to both shorter and longer wavelengths of the solution Q-band, depending on the bulkiness of the substituents. The film spectra of hexadeca-substituted phthalocyanines exhibit Q-bands at a similar wavelength as in solution, with insignificant broadening of the Q-band on film formation. However, the Soret bands for most of the substituted phthalocyanines are shifted and broadened to longer wavelength in the films.


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