首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
It is shown that arylthiohydrazides of carboxylic acids undergo cyclization to give both bis (1-methyl-2-indolyl) disulfides and salts of the corresponding 1-methyl-2-aminoindole under the influence of phosphorus halides (POCl3 or PCl3).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 344–347, March, 1979.  相似文献   

2.
A Sr ion transport study across D2EHPA-TBP kerosene oil based liquid membranes supported on microporous polypropylene film has been performed. The parameters studied were the effect of di(2-ethylhexyl)phosphoric acid (D2EHPA) and TBP concentration variation in the membrane liquid, HNO3 concentration variation in the stripping phase and citric acid concentration variation in the feed solution. The optimum conditions of transport are 0.3 mol/dm3 D2EHPA, 0.1 mol/dm3 TBP, 0.01 mol/dm3 citric acid in feed and 2 mol/dm3 HNO3 in the stripping phase. The mechanism of transport observed is counter-ion coupled transport. The coupling ions are protons. The maximum flux for Sr ion transport observed is 5.33·10–5 mol·m–2·s–1 and maximum permeability under optimum conditions observed is 8.08·10–11 m–2·s–1.  相似文献   

3.
The reaction of 4-(3-indolyl)pyrimidine methiodide with alkali gives a stable anhydro base, which reacts under mild conditions with methyl iodide to give 1-methyl-4-(1-methyl-3-indolyl)pyrimidinium iodide. On the basis of the calculated molecular diagrams of both compounds it was concluded that they have high reactivities. The reaction of the anhydro base with an aqueous methanol solution of KOH, concentrated NH4OH, hydrazine hydrate, and a mixture of malonic acid dinitrile with triethylamine leads to 3-acetylindole, 4-(3-indolyl)pyrimidine, 3(5)-(3-indolyl)pyrazole, and 2-amino-3-cyano-6-(3-indolyl)pyridine, respectively. 1-Methyl-4-(1-methyl-3-indolyl)pyrimidinium iodide under the same conditions gives similar compounds that contain a methyl group attached to the indole nitrogen atom. The structures of the synthesized compounds were confirmed by their IR, UV, PMR, and mass spectra.See [1] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 212–218, February, 1982.  相似文献   

4.
Secondary phosphine selenides, R2P(Se)H (R = PhCH2CH2, PhCH(Me)CH2, 4-t-BuC6H4CH2CH2, NaphthylCH2CH2, Ph), react with the system Se/MOH (M = Li, Na, K, Rb, Cs) in the system THF/EtOH at ambient temperature unusually fast (20–30 s) to give cleanly and almost quantitatively (in 94–100% yield) earlier unknown diorganodiselenophosphinates of alkali metals.  相似文献   

5.
The electronic spectra of (3-indolyl)-, (1-methyl-3-indolyl)-, and (6-nitro-3-indolyl)-substituted ,-unsaturated ketones were measured and interpreted. 3-Indolyl and N-methyl-3-indolyl substituents have a considerable bathochromic effect as compared with the phenyl group in the investigated systems as a consequence of the electron-donor effect, which surpasses that for 4-anisyl, 2,4-dimethoxyphenyl, 2-furyl, 2-thienyl, and 2-selenienyl and differs only slightly from 2-pyrrolyl. The introduction of electron-donor substituents into the p position of the benzene ring of 1-(3-indolyl)-3-phenyl-1-propenone causes a red shift of the long-wave absorption band, the difference in frequencies of which correlates with the Hammett substituent constants. Except for compounds containing a nitro group,1-(3-indolyl)-3-aryl-3-propenones and their N-methyl derivatives fluoresce well in alcohol with max >475 nm.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–953, July, 1972.  相似文献   

6.
Conclusions A series of 5-substituted 2-phenylindoles has been synthesized; the13C chemical shifts have been measured for these compounds in acetone, and these data have been used to determine the I and R O constants of the 5-substituted 2-indolyl groups. Relationships have been found for the estimation of the constants of any 5-substituted 2-indolyl group.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 312–315, February, 1985.  相似文献   

7.
Summary A differential pulse polarographic method has been applied to the determination of trace concentrations of TeO 4 2– , TeO 3 2– , AsO 2 and VO 3 . The dependence of the differential pulse peak on various parameters was studied and optimum conditions for the analytical determination of these oxyanions were found. Limits of detection and quantitation have been calculated for the differential pulse polarographic determination of the investigated oxyanions. The selectivity of this technique for the determination of binary (TeO 4 2– -TeO 3 2– , TeO 4 2– -AsO 2 and TeO 4 2– -VO 3 ) mixtures and a ternary (TeO 4 2– -TeO 3 2– -AsO 2 ) mixture has also been reported.
Spurenbestimmung von TeO 4 2– , TeO 3 2– , AsO 2 und VO 3 durch Differential-Puls-Polarographie und Trennung binÄrer sowie ternÄrer Gemische von ausgewÄhlten Oxyanionen
  相似文献   

8.
The oxidation of PdII by Fe(CN) 6 3– has been studied in 55% MeCO2H–H2O containing 4.0 mol dm–3 HCl, the oxidation being made possible by altering redox potentials. The active species of PdII and Fe(CN) 6 3– are PdCl 3 and H2Fe(CN) 6 , respectively. A possible mechanism is proposed and verified, and the reaction constants involved have been evaluated.  相似文献   

9.
Radiochemical and spectrophotometric studies on the solvent extraction of tetrachloronitridotechnetate(VI) ion with tetraphenylarsonium chloride into chloroform have been reported. Analysis of the dependence of the distribution ratio for technetium species on the concentration of hydrogen ion (0.1–1.0M) revealed that an equilibrium between tetrachloronitridotechnetate(VI) ion and [(H2OCl3NTc–O–TcNCl3(H2O)]2– is established in the aqueous phase. However, formation of di(-O) dimer was suggested, when the concentration of hydrochloric acid is less than 0.2M. The extraction constant for technetium and formation constant for -oxo technetium nitrido complex were evaluated.  相似文献   

10.
U3S5 has been prepared by chemical transport reaction and investigated using X-ray powder diffraction, FTIR spectroscopy, electrical resistivity measurements, and X-ray photoelectron spectroscopy. U3S5 is a semiconductor with a thermal band gap Eg=78.1(4) meV (298 K<T<50 K), which closes gradually to 3.4(4) meV for T<25 K. Photoelectron spectroscopy on single crystals of U3S5 and β-US2 suggest a mixed valency of uranium in U3S5. Physical and structural data are consistent with a mixed-valent model (U3+)2U4+ (S2−)5. A brief survey of literature data on crystal structure and physical properties of uranium sulfides and selenides is given.  相似文献   

11.
Single crystal structure determinations prove the two pyridine substituents in di(2-pyridyl)ketone (H4C4NC)2C=O to be twisted out of the carbonyl skeleton plane by torsion angles (OCCN) of 41° and –163°, in contrast to their planar arrangement in azo-di(2-pyridine) H4C4NC)-N=N-(CNC4H4). In order to rationalize the surprising difference between the two isoelectronic molecules, approximate PM3 enthalpy of formation hypersurfaces have been calculated for each of the two ring torsions, which are assumed to be the dominant ones among the 3N – 6 = 60 degrees of freedom. For both the ketone and the azo derivative, global minima are calculated, the torsion angles of which deviate from the crystal structure results, and, therefore, support the assumption that both the experimentally determined twisting of di(2-pyridyl)ketone as well as the flattening of azo-di(2-pyridine) might be affected by the crystal packing.  相似文献   

12.
A quantitative study of zinc(II) and copper(II) complex formation with orotic acid has been performed under physiological conditions (37°C; 0.15 mol-dm–3 NaCl) using the glass electrode potentiometric technique. Several species have been identified within the pH range 2–10 for the metal-to-ligand concentration ratios investigated. Three mononuclear complexes, ML, ML2, and ML2H–1, have been characterized with both metals. In addition, the polynuclear species M3L2H–2 has been found with copper(II). Formation constants for all these species have been calculated with the help of the SUPERQUAD computer program. UV absorption and IR spectroscopic measurements combined with speciation calculations have been used to confirm corresponding structures.  相似文献   

13.
29Si NMR peaks due to species with the double four-membered ring siloxane backbone composed of both Si(O)4/2 and CH3Si(O)3/2 units, (CH3) n Si8O 20 – n /(8 – n) – (n=1–3), formed by co-hydrolysis of tetraethoxysilane and methyltriethoxysilane in the presence of tetramethylammonium ions in methanol have been assigned. It has been found that 29Si NMR peaks due to Si(OSi)3(O) units shift to lower frequencies by replacement of the adjacent Si(O)4/2 units by CH3Si(O)3/2 units, in other words, with increasing m value in Si[OSi(O)3]3 – m [OSi(CH3) (O)2] m (O) (m=0–2). Peaks from CH3 Si(OSi)3 units in the species have also appeared as separated due to the kind of neighbor structural units. On the basis of the assignments, positions of CH3Si(O)3/2 units in the cubic octameric siloxane framework of (CH3) n Si8O 20 – n /(8 – n) – (n=2, 3), for both of which three isomers are present, have been estimated.  相似文献   

14.
    
The isomerization of 5-vinyl-2-norbornene (1) has been studied in the presence of Co (R1-COCHCOR2)x–Et6–yAl2Cly (x=2, 3; y=2–4) catalytic systems. Co(acac)2–AlEt3 and Co(acac)3–AlEt3 systems isomerize1 to 5-ethylidene-2-norbornene (2), whereas the Co(PhCOCHCOPh)2–AlEt3 system selectively forms 3-vinylnortricyclene (3).2 is always accompanied by formation of ethylidene norbornane (4). A possible mechanism for formation of products is proposed.  相似文献   

15.
Summary The kinetics and mechanism of the reaction between [Fe2L(OH)2]2– and cyanide ion (L = TTHA, triethylenetetraaminehexaacetate) have been studied spectrophotometrically atpH=11.0±0.1,I=0.1 M(NaClO4) and T = 25±0.1 °C. The overall reaction consists of three distinct, observable stages. The first stage involves the dissociation of the binuclear complex into a mononuclear complex [FeL(OH)]4– which then reacts with cyanide to form [Fe(CN)5OH]3–. The species [Fe(CN)5OH]3– reacts further with an excess of cyanide and forms [Fe(CN)6]3– in the second stage of reaction. The last stage involves the reduction of [Fe(CN)6]3– formed in the second stage by the TTHA6– released in the first stage of reaction. The formation of [Fe(CN)5OH]3– in the first stage is firstorder in [Fe2L(OH)2]2– and third-order in cyanide over a large range of cyanide concentrations but becomes zero-order in cyanide at [CN] < 4×10–2M.These observations enable us to suggest the presence of a slow step in which [Fe2L(OH)2]2– dissociates into [FeL(OH)]4– and [FeOH]2+ at low cyanide concentrations and a cyanide assisted rapid dissociation of [Fe2L(OH)2]2– to [FeL(OH)(CN)]5– at higher cyanide concentrations. The species [FeL(OH)(CN)]5– reacts further with an excess of cyanide to produce [Fe(CN)5OH]3– finally.The reverse reaction between [Fe(CN)5OH]3– and TTHA6– follows first-order dependence in each of [Fe(CN)5OH]3– and TTHA6– and inverse first-order dependence on cyanide concentration. A six-step mechanism has been proposed for the first stage of reaction in which the fifth has been identified as the rate-determining step.  相似文献   

16.
A new method for the synthesis of 1, 2-dithiolium hydrogen sulfates by the oxidation of 1, 2-dithiole-3-thiones with hydrogen peroxide in acetic acid has been developed. From 4-(p-tolyl) 1, 2-dithiolium hydrogen sulfate a series of salts containing anions of inorganic, heteroorganic, and organic acids (Cl, Br, I, ClO 4 , CNS, VO 3 , HMoOO 4 , S2O 3 2– , S2O 8 2– , Cr2O 7 2– , Fe(CN) 6 3– , Fe(CN) 6 4– , B(C6H5) 4 , F3CCOO, C6H2(NO2)3O) has been obtained. 4-(p-tolyl)-1, 2-dithiolium salts containing the anions NO 2 , NO 3 , ClO 3 , BrO 3 , SO 3 2– , SO 4 2– , S2O 5 2– and Cl3CCOO dissolve in water and do not precipitate in double decomposition reactions. The reactions of 4-(p-tolyl)-1, 2-dithiolium hydrogen sulfate with sodium sulfite, disulfide, and hydrogen sulfide lead to the formation of bis[4-(p-tolyl)-1, 2-dithiol-3-yl] sulfide and disulfide and the sodium salt of 4-(p-tolyl-1, 2-dithiole-3-thiol, respectively. The reaction of 4-(p-tolyl)-1, 2-dithiolium hydrogen sulfate with solutions of salts of the alkali metals containing the anions of weak acids F, CNO, HCO 3 , CO 3 2– , B4O 7 2– , HAsO 4 2– , PO 4 3– , CH3COO, ClCH2COO, etc.) forms bis[4-(p-tolyl)-1, 2-dithlol-3-yl] oxide. [8, Table 3].For part I, see [1].  相似文献   

17.
The novel zeolite CF-3, with a high ratio of SiO2/Al2O3 and a characteristic X-ray powder diffraction pattern, has been synthesized hydrothermally from a TMEDA-Na2O–SiO2–Al2O3–H2O system at 200°C. The molar composition of CF-3 is (0.4–0.6)Na2O·(1.5–6.3)TMEDA·Al2O3·(80–400)SiO2·(0–17)H2O·CF-3 is similar to ZSM-39 and melanophlogite, which have a clathrate-type structure.  相似文献   

18.
Indole and N-methylindole react with oxa stabilized carbocations generated in situ from orthoformates to yield tris(3-indolyl)methane. The unsymmetrical isomers, e.g. 2-(N-methyl-3-indolyl)di(N-methyl-3-indolyl)-methane ( 4 ), were not formed as established by an independent synthesis. N,N-Dimethylacetamide dimethyl-acetal reacted with 2-alkyl substituted indoles to produce 1,1-bis(3-indolyl)ethanes ( 3 ).  相似文献   

19.
A systematic investigation on glass formation in the ternary system InF3–BaF2–Sc(PO3)3n has been carried out. Scandium polyphosphate Sc(PO3)3n has been used as a third component in order to investigate the possibilities of obtaining new stable glasses. The above long-chain polyphosphate has been prepared using a specially elaborated cryo-technique, which allowed the preparation of high-purity product. Stable ternary compositions have been obtained within the compositions range (in mol%): 5–75 InF3, 0–80% BaF2, 0–50% Sc(PO3)3n. Glasses were characterized by Differential Scanning Calorimetry, vibrational spectroscopy (Raman) and 31P NMR. Structural features for the glass were put forward. Isolated P(O,F)4 groups or fluoroindated metaphosphate units could be identified depending on glass compositions.  相似文献   

20.
Synthesis of five binary complex salts with an [Ir(NH3)5Cl]2+ complex cation is described. The counterions are [ReCl6]2–, [IrCl6]2–, [ReBr6]2–, and Cl. A polycrystal X-ray diffraction study has been performed for [Ir(NH3)5Cl]2[ReCl6]Cl2, and its crystal structure has been determined. A series of Ir x Re1–x phases (0.5 x > 1) were obtained by reductive thermolysis. For the Ir-Re system, the history of the V/Z(x) dependence has been refined.Original Russian Text Copyright © 2004 by S. A. Gromilov, S. V. Korenev, I. V. Korolkov, K. V. Yusenko, and I. A. BaidinaTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 508–515, May–June 2004.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号