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•New 8-oxadiazole spiropyrans undergo positive photochromism.•8-oxadiazole spiropyrans form complexes with transition metal ions.•Complexes of merocyanines with Zn2+, Cd2+ possess ...negative photochromism.•Cation induced isomerization into merocyanine complexe can be controlled by light.•Photochromic transformations can be driven by transition metal ions.
New 8-(5-(p-tolyl)-1,3,4-oxadiazol-2-yl) substituted spirobenzopyrans appear as polychromogenic molecular system demonstrating both positive photochromism and ionochromic properties. Introduction of electron withdrawing formyl group into 6-position of the pyran part leads to increasing of spiropyran photocoloration reaction efficiency but decreases thermodynamical stability of merocyanine form complexes. Upon irradiation with visible light colored solutions of complexes with Zn2+, Cd2+ ions exhibiting negative photochromism, undergo reversible discoloration as a result of photodissociation characterized by the quantum yields reaching 46%. On one side this allows realizing controlled by light irradiation cation induced isomerizations into complexes of the merocyanine form. On the other hand, a system, in which direction of photochromic transformations can be driven by transition metal ions, can be designed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The review presents information on the role of hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) (HBV) X gene and the protein it encodes (X protein) in the pathogenesis of ...viral hepatitis B. The evolution of HBV from primordial to the modern version of hepadnaviruses (Hepadnaviridae), is outlined as a process that began about 407 million years ago and continues to the present. The results of scientific works of foreign researchers on the variety of the influence of X protein on the infectious process and its role in the mechanisms of carcinogenesis are summarized. The differences in the effect of the X protein on the course of the disease in patients of different ethnic groups with regard to HBV genotypes are described. The significance of determining the genetic variability of X gene as a fundamental characteristic of the virus that has significance for the assessment of risks of hepatocellular carcinoma (HCC) spread among the population of the Russian Federation is discussed.
The product of 3-formyl-2-quinolone condensation with trimethylammonium chloride acethydrazide, (H
2
L
+
)Сl
–
hydrazone, was synthesized. Complexes of Zn(II) and Cu(II), M(HL)OCH
3
ClO
4
, with a ...distorted square-planar strucrure of coordination sites and asymmetric chelate сomplexes of Mn(II), Ni(II), and Co(II), M(HL)(H
2
L)·(ClO
4
)
3
, of pseudo-octahedral structure were obtained on its basis. The protistocidal, antibacterial, and fungistatic activities of the synthesized compounds were studied.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We present the earliest astronomical observation of a high-energy neutrino error box of which the variability was discovered after high-energy-neutrino detection. The one robotic telescope of the ...MASTER global international networks automatically imaged the error box of the very high-energy-neutrino event IceCube-170922A. Observations were carried out in minutes after the IceCube-170922A neutrino event was detected by the IceCube observatory at the South Pole. MASTER found the blazar TXS 0506+056 to be in the off-state after one minute and then switched to the on-state no later than two hours after the event. The effect is observed at a 50 significance level. We also present own a unique 16 yr light curve of blazar TXS 0506+056 (518 data set).
A number of chlorine-substituted azomethines of 2-hydroxybenzaldehydes and their zinc(II) complexes were synthesized. Structure of azomethines and zinc complexes was established by elemental ...analysis, IR,
1
H NMR, and X-ray spectroscopy data. Complexes ZnL
2
have a tetrahedral structure. The complexes exhibit weak photoluminescent properties in methylene chloride, whereas the photoluminescence quantum yields of the solid complexes are 100 times higher. Biological activity of the azomethines and zinc complexes was studied.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Isonicotinic acid
N
′-(10-oxo-10
H
-phenanthren-9-ylidene)hydrazide (HL) and its complexes ML
2
and MHLCl
2
М = Cu(II), Ni(II), Co(II), Fe(II), and Zn(II) were synthesized. The structure and ...properties of the obtained compounds were studied by
1
H NMR, IR, and X-ray absorption spectroscopy. The hydrazide structure was determined by X-ray diffraction. Quantum-chemical calculations of its tautomeric forms and electronic absorption spectra were carried out. In ML
2
chelate complexes, the ligand is coordinated to metal atoms in the enol form, whereas in MHLCl
2
complexes it is coordinated in the keto form.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Atomic and electronic structures of cyclic organosilicon compound 9,9,10,10-tetraethynyl-9,10-dihydrodisilaanthracene are studied by the density functional theory. The calculated structural ...parameters of this molecule are compared with the respective crystallographic values for a series of dihydrosilanthrene derivatives. Based on the calculations, the electronic structure of the studied compound is analyzed and the results are in good agreement with the X-ray emission spectroscopy data.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Azomethines were synthesized from 2,4,6-trimethylaniline, salicylaldehyde, and its 3(5)-halogen derivatives, as well as their complexes with zinc(II) (ZnL
2
). The structure and composition of the ...compounds were determined by elemental analysis, IR,
1
H NMR, and X-ray spectroscopy. The ZnL
2
complexes have a tetrahedral structure. The photoluminescent properties of azomethines and their zinc complexes in methylene chloride solutions and in solid state have been studied. The photoluminescence quantum yields of azomethines lie in the range 4.66–12.16%; for zinc complexes they decrease to 0.45–2.02%. The average photoluminescence lifetimes for azomethines and their complexes range from 2.00 to 2.87 ns. Azomethine, obtained from 2,4,6-trimethylaniline and dichlorosalicylic aldehyde, and its complex with zinc have significant protistocidal activity.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Light-emitting diodes are budget-friendly solid-state light sources that find use in the very diverse areas: from lighting to data display devices. The history of the discovery of the ...electroluminescence phenomenon and development of the technology of inorganic (LED) and organic light-emitting diodes (OLED) is presented. Today, there has been a widespread transition to light-emitting diode sources based on inorganic semiconductors, ensuring significant energy savings. However, OLED technologies continue to undergo intensive development. Advantages of OLED over other light sources and areas of their practical use are considered. We discussed the fundamental principles of manufacturing organic light sources with a white emission spectrum, based on low-molecular-weight and polymeric compounds, and considered various approaches for developing polymeric materials with a white emission spectrum. Prospects of the development of the market of OLED light sources are evaluated.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A new anionic Co(III) complex with 2-((E)-(2-(ethylamino)-5-nitrophenylimino)methyl)-4-(phenyl diazenyl)-phenol is prepared and characterized by
1
H NMR, IR spectroscopy, and elemental analysis. The ...crystal structure of the complex is studied by single crystal X-ray diffraction (XRD). From the single crystal XRD data it is found that in the complex, two structurally non-equivalent molecules of the doubly deprotonated ligand are tridentate-chelated by the central Co atom. The cobalt(III) ion is in a slightly distorted octahedral environment of four N and two O atoms.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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