Ion-Ion Pairs in the Superionic Conductors

1990 ◽  
Vol 210 ◽  
Author(s):  
Sergei E. Sigaryov

AbstractOn the base of numerous experimental data and theoretical approaches it is shown that ion-ion pairs with the intrapair distance about a sum of the corresponding ionic radii is the feature of charge transfer in the superionic conductors.

Polyhedron ◽  
2016 ◽  
Vol 119 ◽  
pp. 1-6 ◽  
Author(s):  
Beata Nowicka ◽  
Wojciech Nitek ◽  
Piotr Pietrzyk ◽  
Barbara Sieklucka
Keyword(s):  

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.


1975 ◽  
Vol 6 (23) ◽  
pp. no-no
Author(s):  
MASAHIRO IRIE ◽  
SETSUKO IRIE ◽  
YUKIO YAMAMOTO ◽  
KOICHIRO HAYASHI
Keyword(s):  

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1641
Author(s):  
Irina B. Fedotova ◽  
Natalia M. Surina ◽  
Georgy M. Nikolaev ◽  
Alexandre V. Revishchin ◽  
Inga I. Poletaeva

The review presents data which provides evidence for the internal relationship between the stages of rodent audiogenic seizures and post-ictal catalepsy with the general pattern of animal reaction to the dangerous stimuli and/or situation. The wild run stage of audiogenic seizure fit could be regarded as an intense panic reaction, and this view found support in numerous experimental data. The phenomenon of audiogenic epilepsy probably attracted the attention of physiologists as rodents are extremely sensitive to dangerous sound stimuli. The seizure proneness in this group shares common physiological characteristics and depends on animal genotype. This concept could be the new platform for the study of epileptogenesis mechanisms.


2021 ◽  
Vol 129 (9) ◽  
pp. 1111
Author(s):  
А.И. Мурзашев ◽  
А.П. Жуманазаров ◽  
М.Ю. Кокурин

The article simulates the optical absorption spectra (OAS) of endohedral complexes Er2C2 @ C90 based on isomers No. 44 (C2) No. 21 (C1) of fullerene C90. For this purpose, the energy spectra of the indicated isomers have been calculated. The calculation was carried out within the framework of two models. Within the framework of the first model, which is traditional, only hops of π-electrons from site to site were taken into account (the integral of hopping to the nearest sites B ~ -2.6 eV). Within the framework of the second model, developed in a series of our works [1-5], in addition to hopping from site to site (the integral of hopping to the nearest sites B ~ -1.0 eV), the intrasite Coulomb interaction (ICCI) of π-electrons was also taken into account (the integral of the Coulomb interaction U ~ 7.0 eV). Comparison of the OSS curves obtained by us with the experimental data [5] convincingly indicates that the second model adequately describes the OSS of the endohedral Er2C2 @ C90 complexes based on the investigated isomers. The magnitude of charge transfer from the Er2C2 system to the fullerene shell turned out to be -4e.


2001 ◽  
Vol 57 (2) ◽  
pp. 163-177 ◽  
Author(s):  
V. Milman ◽  
E. V. Akhmatskaya ◽  
R. H. Nobes ◽  
B. Winkler ◽  
C. J. Pickard ◽  
...  

The structural properties of the silicate garnets andradite, Ca3Fe2Si3O12, uvarovite, Ca3Cr2Si3O12, knorringite, Mg3Cr2Si3O12, goldmanite, Ca3V2Si3O12, blythite, Mn^{2+}_3Mn^{3+}_2Si3O12, skiagite, Fe^{2+}_3Fe^{3+}_2Si3O12, calderite, Mn^{2+}_3Fe^{3+}_2Si3O12, and khoharite, Mg3Fe^{3+}_2Si3O12, have been investigated with a quantum-mechanical model as a function of applied pressure. The study has been performed with the density functional theory code CASTEP, which uses pseudopotentials and a plane-wave basis set. All structural parameters have been optimized. The calculated static geometries (cell parameters, internal coordinates of atoms and bond lengths), bulk moduli and their pressure derivatives are in good agreement with the experimental data available. Predictions are made for those cases where no experimental data have been reported. The data clearly indicate that the elastic properties of all silicate garnets are dominated by the compressibility of the dodecahedral site. The compression mechanism is found to be based on a bending of the angle between the centers of the SiO4 tetrahedra and the adjacent octahedra, as in the aluminosilicate garnets. An analysis of the relationship between ionic radii of the cations and the compressibility of silicate garnets is presented.


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