共查询到20条相似文献,搜索用时 15 毫秒
1.
V. A. Vasin P. S. Petrov S. G. Kostryukov V. V. Razin 《Russian Journal of Organic Chemistry》2012,48(4):494-504
1-R-Tricyclo[4.1.0.02,7]heptanes (R = H, Me, Ph) take up methane- and halomethanesulfonyl thiocyanates XCH2SO2SCN (X = H, Cl, Br) at the central C1–C7 bond in benzene at 20°C with high anti-selectivity to give bicyclo[3.1.1]heptane derivatives with the 7-endo-oriented sulfonyl group and the thiocyanato group in the geminal position with respect to the R substituent. The syn-adducts lose HSCN molecule by the action of potassium tert-butoxide in THF at 0°C or on heating in boiling aqueous dioxane containing NaOH with formation of 1-(X-methylsulfonyl)tricyclo[4.1.0.02,7]heptanes. Under analogous conditions the anti-adducts (X = Me) are converted into 1,2-bis(7-syn-methylsulfonyl-6-endo-R-bicyclo[3.1.1]hept-6-exo-yl)disulfanes. The anti-adduct derived from unsubstituted tricyclo[4.1.0.02,7]heptane and MeSO2SCN reacted with methyllithium or phenylmagnesium bromide to produce 7-anti-methyl(phenyl)sulfanyl-6-endo-methylsulfonylbicyclo-[3.1.1]heptanes which were also obtained by photochemical addition of MeSO2SMe(or Ph) to tricyclo-[4.1.0.02,7]heptane. Geometric parameters of radical intermediates in the sulfonylation of 1-R-tricyclo-[4.1.0.02,7]heptanes were optimized ab initio using 6-31G basis set. 相似文献
2.
A. A. Kamyshova A. Z. Kreindlin P. V. Petrovskii A. S. Peregudov Yu. A. Borisov A. A. Koridze 《Russian Chemical Bulletin》2005,54(12):2805-2812
The reaction of [Cp*2RuBr]+Br− with bromine in CH2Cl2 (CD2Cl2) in an inert atmosphere at room temperature produces the complexes [Cp*Ru(Br)C5Me4CH2Br]+Br3
− (syn conformer), [Cp*Ru(Br)C5Me3(CH2Br)2]+ (syn and anti conformers), and [Ru(Br)(C5Me4CH2Br)2]+ (syn conformer). All complexes were characterized by 1H and 13C NMR spectroscopy; the former complex, by elemental analysis. These complexes were also prepared by the reaction of [Cp*RuC5Me4CH2]+BF4
− with bromine in CH2Cl2.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2712–2718, December, 2005. 相似文献
3.
Summary. The structure of 2-amino-4-aryl-1-arylideneaminoimidazoles in DMSO-d6 solution was investigated by means of NMR spectroscopic methods (1H, 13C, 15N). From these data the (E)-configuration at the excocyclic C=N bond and a strong preference for the conformer with the imidazole H-5 and the N=CH proton being spatially close (s-trans regarding the N–N bond) can be concluded. Reaction of the title compounds with acetic anhydride leads to mono and diacylation at the 2-amino group, whereas treatment with pivalic anhydride exclusively affords the corresponding monoacyl product. The mono- and diacylation products exhibit similar configurational and conformational properties as the parent compounds. 相似文献
4.
Danielle M. Chisholm J. Scott McIndoe Gabriella Bodizs Wee Han Ang Rosario Scopelliti Paul J. Dyson 《Journal of Cluster Science》2007,18(1):303-318
Reaction of [Ru6C(CO)16]2− with an excess of AgX (X = Cl, Br or I) affords heteronuclear clusters of formula [{Ru6C(CO)16Ag2X}2]2− in 80% yield, which for X = I and X = Br/Cl were crystallographically characterised. The formation of the cluster was followed
in solution using electrospray ionisation mass spectrometry (ESI-MS), which revealed the presence of a wide range of clusters
with the general formula [{Ru6C(CO)16}
x
Ag
y
X
z
](2x−y+z)− where x = 1 or 2, y = 1, 2, 3 or 4 and z = 0, 1 or 2. The high yield of the product despite the evident complicated solution speciation is attributed to selective
crystallisation of the observed compound driving the equilibrium toward this product. 相似文献
5.
H. López-González M. Jiménez-Reyes M. Solache-Ríos A. Rojas-Hernández 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(1):103-108
Solubility product (Lu(OH)3(s)⇆Lu3++3OH−) and first hydrolysis (Lu3++H2O⇆Lu(OH)2++H+) constants were determined for an initial lutetium concentration range from 3.72·10−5 mol·dm−3 to 2.09·10−3 mol·dm−3. Measurements were made in 2 mol·dm−3 NaClO4 ionic strength, under CO2-free conditions and temperature was controlled at 303 K. Solubility diagrams (pLuaq vs. pC
H) were determined by means of a radiochemical method using 177Lu. The pC
H for the beginning of precipitation and solubility product constant were determined from these diagrams and both the first
hydrolysis and solubility product constants were calculated by fitting the diagrams to the solubility equation. The pC
H values of precipitation increases inversely to [Lu3+]initial and the values for the first hydrolysis and solubility product constants were log10
β*
Lu,H
= −7.92±0.07 and log10
K*sp,Lu(OH)3 = −23.37±0.14. Individual solubility values for pC
H range between the beginning of precipitation and 8.5 were S
Lu3+ = 3.5·10−7 mol·dm−3, S
Lu(OH)2+ = 6.2·10−7 mol·dm−3, and then total solubility was 9.7·10−7 mol·dm−3. 相似文献
6.
A. G. Nozad S. Meftah M. H. Ghasemi M. Aghazadeh 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(13):2270-2277
DFT calculations of electric field gradient (EFG) tensors at the sites of 14N, 17O, and 2H nuclei are carried out to characterize the hydrogen bond (HB) interactions in the sulfapyridine crystal structure. One-molecule
(monomer) and hydrogen-bonded hexameric cluster models of sulfapyridine are constructed according to available X-ray coordinates
where the proton positions are optimized. Then, EFG tensors are calculated for both monomer and target molecule in the hexameric
cluster of sulfapyridine to show the effect of HB interactions on the tensors. The calculated EFG tensors are converted to
the experimentally measurable nuclear quadrupole resonance (NQR) parameters: quadrupole coupling constant (C
Q
) and asymmetry parameter (η
Q
). The results reveal different contribution of various nuclei to N-H⋯N and N-H⋯O HB interactions in the cluster where the
N2 and O1 have major contributions. The computations are performed with B3LYP and B3PW91 functionals DFT method and 6-311+G*
and 6-311++G** standard basis sets using the Gaussian 98 package. 相似文献
7.
K. P. Butin A. A. Moiseeva E. K. Beloglazkina Yu. B. Chudinov A. A. Chizhevskii A. V. Mironov B. N. Tarasevich A. V. Lalov N. V. Zyk 《Russian Chemical Bulletin》2005,54(1):173-188
N,N’-Polymethylenebis(thiosalicylidene)iminate and macrocyclic dithiadiazadibenzocycloalkadiene complexes of nickel(II) were synthesized and their electrochemical and spectroscopic properties were studied. Dithiadiazadibenzocycloalkadiene complexes containing two DMSO molecules coordinated to Ni2+ and two outer-sphere ClO4
− anions were synthesized by the reaction of the corresponding macrocyclic ligands with Ni(ClO4)2·6H2O. The structure of 3,6-dithia-10,14-diazadibenzo[a,g]cyclopentadeca-9,14-dienylnickel(II)[bis(dimethyl sulfoxide) bis-perchlorate] was established by X-ray diffraction. The UV-Vis spectroscopic data are consistent with octahedral structures of diiminobis(sulfide) complexes, a square-planar structure of the thiosalen complex, and distorted tetrahedral structures of other diiminodithiolate complexes. The reaction of S-tert-butylthiosalicylaldehyde with hydrazine hydrate afforded di(ortho-tert-butylthiobenzal)azine. The reaction of the latter with anhydrous NiCl2 produced a colored complex with the simplest molecular formula Ni(C16H12N2S2) in 15% yield. Semiempirical PM3(tm) calculations and the results of UV-Vis, ESR, and 1H NMR spectroscopy demonstrate that this complex has most probably a dimeric structure, in which two Ni centers adopt a nearly square-planar configuration. The complexes are clearly divided into two types according to their electrochemical behavior in DMF solutions. The type 1 is characterized by reversibility of the first reduction steps. The type 2 is characterized by irreversible two-electron reduction as the first step accompanied by deposition of Ni metal on the electrode surface. Rapid electrochemically initiated alkylation occurs in the presence of various alkylating agents (BunI, BunBr, (DmgH)2CoCH3) in a solution of complex 1 in DMF.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 169–183, January, 2005. 相似文献
8.
V. M. Novotortsev S. F. Marenkin I. V. Fedorchenko A. V. Kochura 《Russian Journal of Inorganic Chemistry》2010,55(11):1762-1773
The results of studying phase equilibria of ternary AIIBIVCV systems have been reported. Physicochemical foundations have been developed for the synthesis of new ferromagnets with Curie
temperatures above room temperature structurally compatible with basic semiconducting materials. Methods of synthesis and
physicochemical properties of manganese-doped AIIBIVC2V ferromagnets have been described. The results of theoretical simulation of magnetic properties have been considered and basic
approaches to the explanation of the emergence of ferromagnetism in AIIBIVC2V doped with 3d metals have been surveyed. The most promising ways to produce and study dilute magnetic semiconductors as spintronics materials
have been presented. 相似文献
9.
I. I. Dovhyi D. A. Kremenchutskii V. Yu. Proskurnin O. N. Kozlovskaya 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(3):1643-1648
90Y was separated from 90Sr using an extraction chromatographic resin consisting of 4, 4′(5′)-bis-t-butylcyclohexano-18-crown-6 (DtBuCH18C6), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) amide (C2mimNTf2), and a polymer (Amberlite XAD-7). Ionic liquid was introduced into the column to improve the separation efficiency. The column showed an excellent performance for the separation of Y from Sr. After the separation, the ratio of 90Sr/90Y was <2.0 × 10?5; the column was recycled for >18 times. This study provides preliminary results on columns to produce 90Y with a high purity in radiopharmaceuticals. 相似文献
10.
Hideaki Ishida Makoto Handa Takahisa Ikeue Jun Taguchi Masahiro Mikuriya 《Chemical Papers》2010,64(6):767-775
Deuterated dinuclear ruthenium(II,III) 3,4,5-tri(ethoxy-d
5)benzoate, [Ru2{3,4,5-(C2D5O)3C6H2-COO}4Cl]
n
, was synthesized by a reaction of [Ru2(C2H5COO)4Cl]
n
and 3,4,5-tri(ethoxy-d
5)benzoic acid and characterized by single-crystal X-ray analysis as well as IR, UV-VIS, and 1H NMR spectra, and compared with those of the undeuterated complex [Ru2{3,4,5-(C2H5O)3C6H2COO}4Cl]
n
. Single-crystal X-ray analysis showed that chloride ligands bridge the dinuclear ruthenium(II,III) units at the axial positions
to form a zigzag chain molecule with the Ru1-Cl-Ru2 angle of 123.82(4)°. 1H NMR spectra in CD2Cl2 displayed a broad signal attributable to o-H atoms on the phenyl rings of the benzoate ligands from approximately δ = 23 to δ = 32 at 25°C and several signals from approximately δ = −50 to δ = 50 at −80°C. These spectra show the preservation of the polymeric or oligomeric chain structure in dichloromethane, which
is supported by the solution behavior confirmed by the UV-VIS spectra and electronic conductance. 相似文献
11.
Preparation and evaluation of [<Superscript>201</Superscript>Tl](III)-DTPA complex for cell labeling
A. R. Jalilian Y. Yari-Kamrani M. Kamali-Dehghan S. Rajabifar 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(1):109-114
Due to interesting physical properties and wide availability of 201Tl as a SPECT radionuclide, the incorporation of this nuclide into DTPA for cell labeling was targeted. Thallium-201 (T
1/2 = 3.04 d) in Tl+ form was converted to Tl3+ cation in the presence of O3/6M HCl and di-isopropyl ether, controlled by RTLC/gel electrophoresis methods. The final evaporated activity reacted with
cDTPA in normal saline to yield [201Tl](III)DTPA at room temperature after 0.5 hour, followed by solid phase extraction purification using C18 Sep-Pak column (radiochemical yield >95%). Radiochemical purity of more than 99% was obtained using RTLC with specific activity
of about 260 GBq/mmol. The stability of the tracer was checked in the final product in the presence of human serum at 37 °C
up to 3 days. The partition coefficient was also measured. The labeled compound was used in red blood cell (RBC) labeling.
The cell uptake ratio was determined at 4, 25 and 37 °C up to 3 hours. 相似文献
12.
13C 2D-PASS spectra of two new cis-dioxo catecholatomolybdenum complexes (NH2CH2NH2CHCH2)2(H+)3[MovO
2(C6H4O2)2] and (NH2CH2CH2CH2NH2)2(H+)3[Mo(v)O2 (C2H2O2)2] have been obtained by solid-state nuclear magnetic resonance (NMR), in which the spinning sidebands were well-separated.
The principal components of the 13C shielding tensors were extracted by theoretically fitting the intensities of 13C spinning sidebands. The effects of counter cations on 13C chemical shift isotropy and shielding tensor of cis-dioxo catecholatomolybdenum complex anion [Mo (v)O2(C6H4O2)2]3− were studied, comparing the 13C CSA of those carbon sites in complex anions with that of the counter cations. Based on the known structure of the molybdenum
complex crystal, theoretical values of 13C shielding tensors were calculated by the ainitio GIAO method, in comparison with the experimental results. 相似文献
13.
Ranjini Raghunandan Fabio J. Mazzotti John P. Maier 《Journal of the American Society for Mass Spectrometry》2010,21(5):694-697
Measurement of the 3Π-3Π transition of C6H+ in the gas phase near 19486 cm−1 is reported. The experiment was carried out with a supersonic slit-jet expansion discharge using cavity ringdown absorption
spectroscopy. Partly resolved P lines and observation of band heads permitted a rotational contour fit. Spectroscopic constants
in the ground and excited-state were determined. The density of ions being sampled is merely 2×108 cm−3. Broadening of the spectral lines indicates the excited-state lifetime to be ≈100 ps. The electronic transition of HC6H2+ at 26402 cm−1 assumed to be 1A1-X1A1 in C2v symmetry could not be rotationally resolved. 相似文献
14.
A. V. Il’yasov N. K. Gaisin B. I. Buzykin R. B. Zaripov 《Russian Chemical Bulletin》2010,59(8):1506-1511
The 1H spin-lattice relaxation times of the proton-bearing groups and the 31P spin-lattice relaxation times in C-phosphorylated oximes R1C(=NOH)P(=O)R2R3 (R1 = Ph, R2 = R3 = OMe; R1 = Ph, R2 = OMe, R3 = OCH2CH2Br; R1 = PhCH2, R2 = R3 = OCHMe2) and dioxime R2P(=O)C(=NOH)(CH2)4C(=NOH)P(=O)R2 (R = OMe) in DMSO-d6 were measured. The characteristic reorientation times of the whole molecules were estimated using the measured values of
the 1H relaxation times and the results of semiempirical PM3 quantum chemical calculations of the molecular geometries. The reorientation
times were used to identify the contributions of different relaxation mechanisms to the rate of 31P spin-lattice relaxation. The anisotropy of the chemical shielding of 31P nuclei was evaluated from the difference between the 31P relaxation rates measured at 101.27 and 161.92 MHz. 相似文献
15.
Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Michel Delamar Florence Babonneau Jacques Livage 《Journal of Sol-Gel Science and Technology》2007,41(1):3-10
A new insoluble solid functionalized ligand system bearing chelating ligand group of the general formula P-(CH2)3-N[CH2CONH(C6H4)NH2]2, where P represents [Si–O]
n
polysiloxane network, was prepared by the reaction of the immobilized diethyliminodiacetate polysiloxane ligand system, P-(CH2)3N(CH2CO2Et)2 with 1,2-diaminobenzene in toluene. 13C CP-MAS NMR, XPS and FTIR results showed that most ethylacetate groups (–COOEt) were converted into the amide groups (–N–C=O).
The new functionalized ligand system exhibits high capacity for extraction and removal of the metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+) with efficiency of 95–97% after recovery from its primary metal complexes. This functionalized ligand system formed 1:1
metal to ligand complexes. 相似文献
16.
V. A. Vasin P. S. Petrov V. A. Kalyazin V. V. Razin 《Russian Journal of Organic Chemistry》2010,46(6):812-819
Hydromethoxylation of tricyclo[4.1.0.02,7]hept-1-yl and 7-methyltricyclo[4.1.0.02,7]hept-1-yl phenyl sulfones with methanol at 20°C in the presence of a catalytic amount of perchloric acid is initiated by
the endo attack of proton at the C1 atom, and the subsequent cleavage of the side C1–C2 bond leads to formation of mixtures of diastereoisomeric exo-7-phenylsulfonyl-2-methoxybicyclo[4.1.0]heptanes, the endo-2 isomer prevailing. Probable factors responsible for the observed chemo-, regio-, and stereoselectivity of the addition
are discussed. 相似文献
17.
S. Anilkumar A. K. Deepa K. Narayani A. K. Rekha P. V. Achuthan G. Krishnamachari D. N. Sharma 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(1):161-166
The migration of 237Np in an undisturbed Chinese loess column was investigated by direct γ-ray method. The column was taken from a field test site and installed in a laboratory simulation hall. Radionuclide 237Np in the form of neptunium nitrate, mixed with quartz, was introduced into the column and covered with loess. Artificial
rainfall was applied to the column for about 3 years and, the counting rates of 237Np in the column from 56 to 616 days at different vertical positions were detected with a γ-ray detection system. Based on the counting rates of 237Np in the simulation column at different vertical positions and the distance from the source layer, the relationship of the
mass center of 237Np in the column at different experimental periods to the experimental time was established, C
m = 0.36 log(t)-2.75. Here C
m is the mass center of 237Np in the column, cm, and t is the experimental time in days. Based on this relationship, the mass center of 237Np for the 1,073-day experiment was predicted and compared to that obtained with the final destructive method. The good agreement
between the prediction and the experimental values indicates that the direct γ-ray method could be used to predict the migration of strongly adsorbed radionuclides such as 237Np in environmental media with the help of laboratory simulation columns. 相似文献
18.
V. A. Vasin P. S. Petrov V. A. Kalyazin V. V. Razin 《Russian Journal of Organic Chemistry》2012,48(3):358-367
Reactions of 1-methylsulfonyl- and 1-phenylsulfonyltricyclo[4.1.0.02,7]heptanes with iodine, dioxane dibromide, and dichloro-λ3-iodanylbenzene (under irradiation) gave products of stereoselective syn addition of halogen at the C1–C7 central bicyclobutane bond. 7-Methyl-1-phenylsulfonyltricyclo[4.1.0.02,7]-heptane reacted with dioxane dibromide in carbon tetrachloride to produce a mixture of 2-bromo- and 2,3-dibromo-1-methyl-exo-7-phenylsulfonylnorcaranes at a ratio of 1: 4 as a result of cleavage of the C1–C2 bicyclobutane bond. 7-Bromo- and 7-methoxycarbonyl-1-phenylsulfonyltricyclo[4.1.0.02,7]heptanes take up bromine exclusively at the C1–C7 central bond with strict syn stereoselectively. The regio- and stereoselectivity of the addition and their relations with the halogen nature were interpreted
with account taken of structural specificities of intermediate 6-sulfonyl-substituted 6-norpinanyl radicals determined by
ab initio quantumchemical calculations using 6-31G basis set. 相似文献
19.
R. Srikanth P. Nagi Reddy K. Bhanuprakash R. Srinivas Xiaohong Chen Frantisek Tureček 《Journal of the American Society for Mass Spectrometry》2005,16(8):1353-1366
Dissociative electron ionization of diethyl dithiophosphate (I) and O,O′-diethyl methylphosphonothioate (II) generates moderately abundant m/z 81 ions of composition [P, O, S, H2]+. From tandem mass spectrometry experiments and theoretical calculations at the B3LYP/6-31G(d,p), G2, and G2 (MP2) levels
it is concluded that the majority of the ions have the structure of HS-P-OH+ (1a
+) and it is separated by high-energy barriers from its isomers P(= S)OH2+ (1b
+), P(= O)SH2+ (1c
+), HP(= S)OH+ (1d
+), and HP(= O)SH+ (1e
+). Low-energy (metastable) ions 1a
+ dissociate via losses of H2O and H2S to yield m/z 63 (PS+) and m/z 47 (PO+) product ions, respectively. These reactions involve isomerization of 1a
+ into the stable isomers 1b
+ and 1c
+. Neutralization-reionization experiments confirm the theoretical prediction that radical 1a
· is a stable species in the gas-phase. Variable-time NR experiments indicated that only a small fraction of metastable 1a
· radicals dissociate in the 0.4–4.6 μs time window, while most dissociations occurred on a shorter time scale. RRKM calculations were performed to investigate
unimolecular dissociation kinetics of 1a
· which were found to be in agreement with the fragmentation observed in the NR spectrum. The 70-eV electron ionization of
(I) and diethyl chlorothiophosphate (III) yields m/z 97 ions, predominantly of the structure S = P(OH)2+ (2a
+). This conclusion follows from tandem mass spectrometry experiments and theoretical calculations. The calculations predict
that (2a
+) is separated by high-energy barriers from its isomers O = P(SH)OH+ (2b
+), S = P(= O)OH2+ (2c
+), and O = P(= O)SH2+ (2d
+). Neutralization-reionization experiments confirmed that 2a
· radical is a kinetically stable species on the time scale of up to 5 μs, which is in agreement with ab initio calculations. However, owing to a mismatch of Franck-Condon factors a large fraction
of 2a
· dissociates by loss of SH· yielding O=P-OH. 相似文献
20.
E. E. Faingol’d I. V. Zharkov N. M. Bravaya A. V. Chernyak 《Russian Chemical Bulletin》2016,65(8):1958-1965
The results of 1H NMR and quantum chemical studies of hydrolysis of isobutylaluminum aryloxides are presented. According to the data of 1H NMR spectroscopy, the hydrolysis of monomeric diisobutylaluminum aryloxides (2,6-Bu2 t—C6H3O)AlBu2 i and (2,6-Bu2 t,4-Me—C6H2O)AlBu2 i occurs selectively at the Al—OAr bond to form the corresponding sterically bulky phenol and polyisobutylaluminoxane. At the molar ratios Al: H2O = 2, the formed sterically bulky phenol reacts slowly with diisobutylaluminum monoaryloxide to form isobutylaluminum diaryloxide. Dimeric aryloxide [(2-But—C6H4O)AlBu2 i]2 is not hydrolyzed under similar conditions. The quantum chemical calculations confirmed the experimental results: the hydrolysis at the Al—OAr bond has a lower energy barrier than that at the Al—C bond because of the formation of \({H_{{H_2}O}} \ldots {O_{O - Ar}}\) hydrogen bonds. 相似文献