共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Kuzmanović V. Bojović J. Savović A. Antić-Jovanović 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(9):1515-1519
Relative intensities of eight vibronic bands, belonging to the Δυ = −2 sequence of the B
2Σ+ −X
2Σ+ electronic transition of four GaO isotopomers have been measured and interpreted in terms of possible isotope effects on
the parameters governing the band intensity. Obtained results showed very small isotope effect on the Franck-Condon factors
and r-centroids and revealed that the observed intensity ratios of the corresponding isotope bands are controlled mainly by the
isotope abundance of 69Ga and 71Ga in natural gallium.
The article is published in the original. 相似文献
2.
N. A. Ivanova A. G. Mustafin F. G. Usmanova S. P. Ivanov M. S. Miftakhov 《Russian Journal of Organic Chemistry》2009,45(2):256-258
By reaction of 2,3-dichloro-, 2,3,5-trichloro-, 2,5-dichloro-3-phenylsulfonyl-, 2-chloro-3-phenylsulfonyl-4,4-ethylenedioxycyclopent-2-en-1-ones with uracyl 3- and 2-uracyl derivatives were obtained of the corresponding chlorocyclopentenone. 相似文献
3.
O. A. Luk’yanov G. A. Smirnov P. B. Gordeev 《Russian Journal of Organic Chemistry》2007,43(8):1228-1231
A preparation method was developed for previously unknown tetrazole derivatives containing in the 1, 2, and/or 5 positions of the tetrazole ring N-methyldiazene-N-oxide-N′-oxymethyl groups. 相似文献
4.
O. I. Kolodyazhnyi E. V. Grishkun A. O. Kolodyazhnaya O. O. Kolodyazhna S. Yu. Sheiko 《Russian Journal of General Chemistry》2018,88(5):919-924
Flash vacuum thermolysis of trimethylsilyl tert-butylphosphonohalidates involved elimination of halo(trimethyl)silane with the formation of tert-butyl-λ5-phosphanedione whose structure was confirmed by chemical reactions. tert-Butyl-λ5-phosphanedione readily undergoes trimerization, reacts with 2-phenyloxirane to give cycloaddition product, and takes up alcohols. 相似文献
5.
I. N. Polyakova V. S. Sergienko E. E. Martsinko I. I. Seifullina E. A. Chebanenko 《Russian Journal of Coordination Chemistry》2018,44(2):155-161
The synthesis, IR spectroscopic study, and X-ray diffraction analysis (CIF file CCDC no. 1574078) are carried out for 1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (I). The structural units of a crystal of compound I are (H4.5HPdta)0.5– anions, (H5.5HPdta)0.5+ cations, and molecules of water of crystallization joined by a branched network of hydrogen bonds: strong intermolecular O–H…O and intramolecular N–H…O bonds. 相似文献
6.
V.?R.?Akhmetova E.?M.?Bikbulatova N.?S.?Akhmadiev V.?M.?Yanybin T.?F.?Boiko R.?V.?Kunakova A.?G.?Ibragimov
Catalytic aminomethylation of pyrrole and indole with N,N,N′,N′-tetramethylmethanediamine in the presence of 5 mol % of ZrOCl2·8H2O proceeds selectively at the positions 2, 5 of pyrrole and 1, 3 of indole. Carbazole under the same conditions affords 3-formyl-9-aminomethyl derivative. The reaction in the presence of 5 mol % of K2CO3 occurs as monoaminomethylation: for pyrrole at the position 2, for indole at the position 3, and for carbazole at the nitrogen atom of the substrate. Water-soluble 1,1′-(1H-pyrrole-2,5-diyl)bis(N,N-dimethylmethanamine) exhibits a fungistatic activity with respect to phytopathogenic fungi Rhizoctonia solani. 相似文献
7.
N. Begović Z. Marković S. Anić 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(13):2283-2287
The kinetics of gas reaction \(HOCl\underset{{k_r }}{\overset{{k_f }}{\longleftrightarrow}}H(^2 S) + OCl(X^2 \Pi _i )\) was analyzed by the MP4 method. In the temperature range of 100–373 K the rate constants k f and k r and equilibrium constant K were changed from 1.10 × 10?220 to 1.17 × 10?52 s?1, from 2.89 × 10?16 to 1.68 × 10?5s?1 and from 3.80 × 10?205 to 6.96 × 10?48 respectively. In the above temperature range, the activation energy of the forward reaction (E f) is 105.05 kcal/mol. In the same temperature interval there are two kinetic domains for the reverse reaction with activation energies (E r1 = 5.53 kcal/mol when T is 100–273 K and E r2 = 14.50 kcal/mol when T is 273–373 K, respectively. 相似文献
8.
20S-Protopanaxadiol (3β,12β,20S-trihydroxydammar-24-ene) 3-, 12-, and 20-O-β-D-galactopyranosides were synthesized for the first time. Condensation of 12β-acetoxy-3β,20S-dihydroxydammar-24-ene (1) and 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosylbromide (α-acetobromogalactose) (2) under Koenigs–Knorr conditions with subsequent removal of the protecting groups resulted in regio- and stereoselective formation
of 20S-protopanaxadiol 3-O-β-D-galactopyranoside, an analog of the natural ginsenoside Rh2. Glycosylation of 12β,20S-dihydroxydammar-24-en-3-one (5) by 2 with subsequent treatment of the reaction products with NaBH4 in isopropanol and deacetylation with NaOMe gave 20S-protopanaxadiol 12- and 20-O-β-Dgalactopyranosides. 相似文献
9.
The Diels–Alder reactions of three β-chloro-α,β-unsaturated carbonyl compounds 1–3 with different dienes were carried out to afford highly functionalized cyclohexenes 4–9, bearing quaternary centers, in good yields. These cycloadducts (CAs) undergo dehydrochlorination with subsequent aromatization in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene DBU to produce new substituted benzenes 11–14. Compound 10 is the product of lactonization and removal of an HCl molecule from compound 7. All products were characterized by NMR, IR, elementary analysis and some of them by MS. Structure assignments of isomers were carried out on the basis of NMR chemical shifts and coupling constants using 1D, 2D and heteronOe NMR techniques. 相似文献
10.
11.
Using the eutectic-type T–x–y diagram as an example, it can be represented the analysis of its geometrical construction dependence on the temperature of
a component two polymorphous modifications which participate in mono- and invariant metatectic and invariant eutectic (eutectoid)
transformations above or below (and within) binary eutectics temperature intervals and below a ternary eutectic temperature.
Computer models for considered phase diagrams have been designed. Such models help to solve applied tasks like visualization,
isopleths and isothermal sections decoding, mass balances calculation and evaluation of phase and conglomerate concentration
in microstructure. 相似文献
12.
Aruna P. Maharolkar A. G. Murugkar P. W. Khirade S. C. Mehrotra 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(9):1710-1716
The refraction, dielectric, viscosity, density, data of the binary mixtures of N,N-dimethylacetamide (DMA) with n-butanol at 308.15 and 313.15 K. The measured parameters used to obtain derived properties like Bruggeman factor, molar refraction and excess static dielectric constant, excess inverse relaxation time, excess molar volume and excess viscosity, excess molar refraction. The variation in magnitude with composition and temperature of these quantities has been used to discuss the type, strength and nature of binary interactions. Results confirm that there are strong hydrogen-bond interactions between unlike molecules of DMA+ n-butanol mixtures and that 1: 1 complexes are formed and strength of intermolecular interaction increases with temperature. 相似文献
13.
β-Methoxycarbonyl-γ-butyrolactones bearing a γ-aromatic substituent were prepared via copper-catalyzed reductive aldol addition/lactonization domino reactions of ketones with α,β-unsaturated dicarboxylate esters and a silane under ambient temperature. The reaction has advantage of using readily available reagents, mild conditions and high efficiency. 相似文献
14.
Bohumil Proksa Richard Hercek Tibor Liptaj Nada Prónayová 《Monatshefte für Chemie / Chemical Monthly》2009,140(5):485-487
Abstract A new compound was isolated from the reaction mixture after O-demethylation of 6-O-acetyl-10α-acetoxycodeine with boron tribromide. The structure of this compound, 10α-hydroxy-β-isomorphine, was elucidated by spectral data, and its spatial arrangement was deduced from an NOE experiment. Capillary zone
electrophoresis was used for separation of morphine and its 10-hydroxy analogues.
Graphical abstract
相似文献
15.
SBR compounds including the N-isopropyl-N’-phenyl-p-phenylenediamine-modified clay(organoclay) were prepared.Effects of modified clay and antioxidant(IPPD) contents on mechanical and rheological properties of SBR composites were studied.FTIR results confirmed that the clay was chemically modified by IPPD and changed into an organoclay.X-ray diffraction(XRD) results confirmed the increase in interlayer distance of the clay due to the insertion of IPPD.Rheological and cure characteristics of SBR compounds were determined using RPA(Rubber Process Analyzer) and rheometer.Scorch time and cure time of SBR compounds decreased with introduction of the organoclay.Mechanical properties and heat aging resistance of the SBR composites were improved significantly by incorporation of the organoclay. 相似文献
16.
S. P. Panchenko A. C. Abel A. D. Averin O. A. Maloshitskaya E. N. Savelyev B. S. Orlinson I. A. Novakov I. P. Beletskaya 《Russian Chemical Bulletin》2016,65(6):1550-1555
A copper(I) complex-catalyzed N,N’-diarylation of diamines based on 1,3-disubstituted adamantane, using aryl iodides bearing electron-donating and electron-withdrawing substituents, was studied. In the case of 2,2’-(adamantane-1,3-diyl)ethanediamine, the optimal catalyst system is CuI—2-(isobutyryl)cyclohexanone—Cs2CO3—DMF. The highest yield of diarylation product was reached in the case of 4-methoxyiodobenzene (79%). In the case of more spatially hindered adamantane-1,3-diyldimethanamine, 1,1’-binaphthalene-2,2’-diol (BINOL) should be used, with the highest yield of the target product (84%) being reached in the reaction with iodobenzene. 相似文献
17.
S. N. Gridchin 《Russian Journal of General Chemistry》2016,86(5):1069-1072
Stability constants and heat effects of the formation reactions of magnesium and calcium trimethylenediaminetetraacetates at 298.15 K and ionic strength of 0.1, 0.5, and 1.0 (mol/L KNO3) have been determined by means of potentiometry and calorimetry. Standard thermodynamic parameters (log K0, ΔrG0, ΔrH0, and ΔrS0) of the studied equilibriums have been determined. 相似文献
18.
Yasunori Matsui Minoru Shigemori Toshiyuki Endo Takuya Ogaki Eisuke Ohta Kazuhiko Mizuno Hiroyoshi Naito Hiroshi Ikeda 《Research on Chemical Intermediates》2018,44(8):4765-4774
The semiconductor properties of the earliest known stable radical, α,γ-bisdiphenylene-β-phenylallyl radical (Koelsch radical, 1?) were assessed using spectroscopic and electrical techniques. This radical undergoes reversible redox processes, and it has low redox potentials. In addition, 1? possesses long wavelength absorption bands, owing to the existence of a singly-occupied molecular orbital whose energy level lies between those of the HOMO and LUMO. A spin-coated thin-film of 1? displays photocurrent and an electron mobility of 6.3 × 10?7 cm2 V?1 s?1 on a trially-fabricated organic field effect transistor. 相似文献
19.
The sodium salt of N-(6-chloronicotinoyl)-γ-aminobutyric acid, a structural analog of the known nootropic and vasidilating drug picamilon, was synthesized via Schotten–Baumann
acylation of γ-aminobutyric acid with 6-chloronicotinoyl chloride and subsequent neutralization of the N-(6-chloronicotinoyl)-γ-aminobutyric acid that was obtained in >60% yield. 相似文献
20.
Two-dimensional (2D) inhomogeneous electron assemblies are becoming increasingly important in Condensed Matter and associated
technologies. Here, therefore, we contribute to the Density Functional Theory of such 2D electronic systems by calculating,
analytically, (i) the idempotent Dirac density matrix γ(r, r′) generated by two closed shells for the bare Coulomb potential −Ze
2/r and (ii) the exchange energy density ex(r){\varepsilon_x({\bf r})} . Some progress is also possible concerning the exchange potential V
x
(r), one non-local approximation being the Slater potential 2ex(r)/n(r){2\varepsilon_x(r)/n(r)} , with n(r) the ground state electron density. However, to complete the theory of V
x
(r), the functional derivative of the single-particle kinetic energy per unit area δt(s)/δn(r) is still required. 相似文献