scholarly journals Effect of Pressure on Iodine Complexes. II. Absorption Spectra of the Charge Transfer Bands with Diethyl Ether, Diethyl Sulfide, and Diethyl Selenide in Heptane

1979 ◽  
Vol 52 (2) ◽  
pp. 284-286 ◽  
Author(s):  
Seiji Sawamura ◽  
Yoshihiro Taniguchi ◽  
Keizo Suzuki
1976 ◽  
Vol 30 (2) ◽  
pp. 200-204 ◽  
Author(s):  
F. M. Abdel Kerim ◽  
F. Abou El Fotouh

The ir absorption spectra of some pyridine derivatives-iodine complexes were measured in the region 400 to 1400 cm−1 and the results are discussed. The effect of complex formation on the intensities of some of the bands was investigated. The thermodynamic constants of these complexes were calculated. It was found that the stability of the complex depends to a large extent on the electronegativity as well as the position of the substituent on the pyridine nucleus. The structures of formed complexes are discussed.


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.


Molekul ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 191
Author(s):  
Venty Suryanti ◽  
Fajar Rakhman Wibowo ◽  
Ahmad Marzuki ◽  
Meiyanti Ratna Kumala Sari

The cationic chemosensor based on organic compound bearing an aminophenol moiety as a receptor for metal analyte and a cinnamaldehyde moiety as chromophoric fragment has been developed. In this work, we report the colorimetric sensing of nitrophenyl cinnamaldehyde derivative, namely methyl-3-(2-hidroxy-5-nitrophenyl amino)-3-phenylpropanoate, towards a variety of metal cations, such as Cu2+, Fe3+, Ni2+ and Zn2+. The cation sensing abilities of the sensor were observed for Cu2+and Fe3+ with a color change from colorless to pink and faint yellow, respectively, The characteristic UV-Vis spectra changes were observed upon addition of Cu2+and Fe3+ cations. The hypsochromic absorption spectra shifts were obtained, indicating the cations and sensor complexations had formed. A metal-to-ligand-charge-transfer (MLCT) had occurred and the charge density of the sensor changed resulting in appearance of new absorption peaks in the UV-Vis spectra and color changes of the sensor solution upon addition of the Cu2+and Fe3+.  


2019 ◽  
Vol 61 (5) ◽  
pp. 817
Author(s):  
В.И. Соколов ◽  
Н.Б. Груздев ◽  
В.А. Важенин ◽  
А.В. Фокин ◽  
А.В. Дружинин

AbstractThe results of the study of optical absorption and EPR signals of single crystals of zinc oxide doped with manganese are presented. A broad impurity absorption band with the threshold energy about 2.1 eV, which was treated as a result of charge transfer transitions, has been observed for a long time in ZnO : Mn absorption spectra. In absorption spectra of a polarized light at 4.2 and 77.3 K, we first detected several lines of different intensity in a 1.877–1.936 eV range of energies of the light quanta. The observed lines are attributed to a donor exciton [( d ^5 + h ) e ] that emerges as a result of the Coulomb binding a free s electron and a hole, which is localized on p – d hybridized states. The EPR spectra of Mn^2+ ion signals, when corresponding to the impurity absorption band exposed to light, are found to be not photosensitive. The obtained results indicate that the ZnO : Mn impurity absorption is due to transitions from antibonding p – d hybridized DBH states to the conduction band.


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