Russian Journal of General Chemistry - A novel and efficient method for the synthesis of biologically active organic di-, tri- and tetrasulfides has been proposed. Different methods of redox... 相似文献
The antiradical activity of the functionalized triphenylantimony(V) catecholates Ph3Sb[4-O(CH2CH2)2N-3,6-DBCat] (I), Ph3Sb[4,5-Piperaz-3,6-DBCat] (II), and Ph3Sb[4-PhN(CH2CH2)2N-3,6-DBCat] (III) (where [4-O(CH2CH2)2N-3,6-DBCat]2?, [4,5-Piperaz-3,6-DBCat]2?, and [4-PhN(CH2CH2)2N-3,6-DBCat]2? are the dianionic ligands 3,6-di-tert-butyl-4-(morpholin-1-yl)-, 3,6-di-tert-butyl-4,5-(piperazine-1,4-diyl)-, and 3,6-di-tert-butyl-4-(4-phenylpiperazin-1-yl)catecholates, respectively) was studied in reactions with the diphenylpicrylhydrazyl radical during autooxidation of unsaturated fatty (oleic and linoleic) acids with lipid peroxidation of Russian sturgeon (Acipenser gueldenstaedti B.) sperm and human blood erythrocytes in vitro as examples. The EC50 and nDPPH values obtained indicate the high antiradical activity of complexes II and III in the reactions with the stable radical. On the whole, complexes I–III inhibit the lipid peroxidation in both model (oxidation of unsaturated fatty acids) and in vitro experiments. The inhibiting effects of the complexes are comparable with and even, in some cases, higher than those of the known antioxidant ionol. 相似文献
The broadband enhancement of single‑photon emission from nitrogen‐vacancy centers in nanodiamonds coupled to a planar multilayer metamaterial with hyperbolic dispersion is studied experimentally. The metamaterial is fabricated as an epitaxial metal/dielectric superlattice consisting of CMOS‐compatible ceramics: titanium nitride (TiN) and aluminum scandium nitride (AlxSc1‐xN). It is demonstrated that employing the metamaterial results in significant enhancement of collected single‑photon emission and reduction of the excited‐state lifetime. Our results could have an impact on future CMOS‐compatible integrated quantum sources.
A new series of triphenylantimony(V) 3-alkylthio/arylthio-substituted 4,6-di-tert-butylcatecholates of the type (3-RS-4,6-DBCat)SbPh3, where R = n-butyl (1), n-hexyl (2), n-octyl (3), cyclopentyl (4), cyclohexyl (5), benzyl (6), phenyl (7), and naphthyl-2 (8), were synthesized from the corresponding catechol thioethers and Ph3SbBr2 in the presence of a base. The crystal structures of 1, 2, 3, and 5 were determined by single-crystal X-ray analysis. The coordination polyhedron of 1–3 is better described as a tetragonal pyramid with a different degree of distortion, while that for 5- was a distorted trigonal bipyramid (τ = 0.014, 0.177, 0.26, 0.56, respectively). Complexes demonstrated different crystal packing of molecules. The electrochemical oxidation of the complexes involved the catecholate group as well as the thioether linker. The introduction of a thioether fragment into the aromatic ring of catechol ligand led to a shift in the potential of the “catechol/o-semiquinone” redox transition to the anodic region, which indicated the electron-withdrawing nature of the RS group. The radical scavenging activity of the complexes was determined in the reaction with DPPH radical. 相似文献
A series of new tin(IV) complexes based on 2-hydroxy-3,6-di-tert-butyl-para-benzoquinone (LH) of the general formula L2SnR2 (R = Me (I), Et (II), Bun (III), Ph (IV)) and LSnMe3 (V) were synthesized. The obtained compounds were characterized by IR and 1H, 13C and 119Sn NMR spectroscopy and elemental analysis. The X-ray diffraction analysis was carried out for complexes L2Sn(Bun)2 (III) and LSnMe3 (V). The low-frequency region of the IR spectra, which has not earlier been studied in detail, was interpreted for compounds I–V and previously described complex LSnPh3 (VI). The electrochemical properties of LH and related tin complexes I–VI were studied. The nature of the hydrocarbon groups at the metal atom affects the stability of the intermediates formed in the electrochemical reactions. 相似文献
The electrochemical transformations and antiradical activity of trialkylantimony(V) o-amidophenolate derivatives, (AP)SbR3 (AP = 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-amidophenolate); R = CH3 (I), C2H5 (II), and C6H11 (III), are studied. The electrochemical oxidation of compounds I–III proceeds successively to form mono- and dicationic forms of the complexes. The presence of the donor hydrocarbon groups at the antimony(V) atom shifts the oxidation potentials to the cathodic range and decreases the stability of the monocationic complexes formed in electrochemical oxidation. The second anodic process is irreversible and accompanied by o-iminoquinone decoordination. The antiradical activity of compounds I–III is studied in the reaction with the diphenylpicrylhydrazyl radical and oleic acid autooxidation. The values obtained for indices EC50 and IC50 indicate the antiradical activity of the studied compounds. Complexes I–III were found to be the efficient inhibitors of oleic acid oxidation and act as efficient destructors of hydroperoxides. 相似文献
The electrochemical transformations and antiradical activity of penta- and hexacoordinate antimony(V) complexes I–V containing the tridentate O,N,O-donor ligand, N,N-bis(di-3,5-tert-butyl-2-hydroxyphenyl)amine, are studied. The oxidation of hexacoordinate triarylantimony(V) compounds R3Sb(Cat-NH-Cat) (I–III) leads to the formation of neutral paramagnetic intermediates Ia–IIIa. Two anodic reversible one-electron stages are observed for pentacoordinate complexes R′2Sb(Cat-N-Cat) (IV, V). The possibility of the formation of stable paramagnetic species in electrochemical oxidation is a reason for the antiradical activity of the complexes. The study of the reactions of compounds I–V with the electrogenerated superoxide radical anion, diphenylpicrylhydrazyl radical, peroxy radicals, and hydroperoxides formed by the autooxidation of unsaturated fatty acids (oleic, linoleic) shows that all complexes exhibit a pronounced antiradical activity. The highest effect is observed for compounds I, IV, and V characterized by the prolonged action. 相似文献
The spectral dependences of polarized optical transmission of a metal film with a periodic array of elliptical nanoholes have been studied. Such nanostructured metal films exhibit enhanced broadband optical transmission that one can control by selecting the polarization of incident and (or) transmitted light. 相似文献
A new design for a single-photon tunneling device based on tunneling of light through a gap in a photonic crystal linear waveguide containing a deep defect state is suggested. Unlike recently observed single-photon tunneling through nanometer scale nonlinear pinholes in a thick gold film, in the device described here the photon current should be strictly conserved. By appropriate design of the barrier width, defect level position in the bandgap, and defect spatial position in the barrier, a desired photon tunneling rate can readily be engineered. 相似文献