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 0 毫秒
1.
Reactions of N-arylsulfonyl(acyl)arenesulfenamide sodium salts with phenyl isothiocyanate afforded N-arylsulfanyl-N-arylsulfonyl(acyl)-N-phenylthioura sodium salts which were found to increase thermal stability of finely dispersed poly(vinyl chloride).Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1532–1535.Original Russian Text Copyright © 2004 by Koval, Oleinik.  相似文献   

2.
The CoLX2 complexes were obtained by the reaction of N,N-dimethyl-N′,N′-dimethylthio-carbamoylsulfenamide (L) with CoX2 (X = Cl, Br, I, NCS). The complexes were investigated by elemental and X-ray analysis, IR, 1H NMR, and electron spectroscopy, conductometry, magnetochemistry, thermogravimetry. It is found that these compounds are high-spin complexes of pseudotetraedral structure with bidentate coordination of L through the thione sulfur atom and sulfenamide nitrogen atom.  相似文献   

3.
A new complex, bis(triethylene glycol-O,O′,O′’,O?)manganese(II) dibromide [Mn(TEG)2]2+·2Br?, was prepared. Its structure was studied by single crystal X-ray diffraction. The complex cation [Mn(TEG)2]2+ is of the host-guest type with two TEG ligands (podands) as hosts. Both TEG ligands are disordered and tetradentate, with all the four oxygen atoms of each ligand participating in the coordination. The Mn2+ cation has coordination number 8, and its coordination polyhedron is a distorted bisdisphenoid (trigonal dodecahedron). The geometric parameters (bond lengths, bond and torsion angles) of the complex were determined relatively accurately. In the crystal structure, the ions form infinite thick layers by interionic hydrogen bonds O-H···Br?.  相似文献   

4.
A system aluminum (and titanium) tert-butoxide—tert-butyl hydroperoxide (1 : 2) under mild conditions (20 °C, 1 h) oxidizes aliphatic and alkylaromatic sulfides and diphenyl sulfide to the corresponding sulfones in yields close to 100%. The oxidation is induced by electron-excited dioxygen formed upon thermal decomposition of intermediate metal-containing peroxy trioxides (ozonides). The latter are formed as a result of the reversible reaction of aluminum or titanium tert-butoxides with tert-butyl hydroperoxide followed by the interaction of di-tert-butoxy-tert-butylperoxyaluminum and tri-tert-butoxy-tert-butylperoxytitanium that formed with another ButOOH molecule. Aluminum-containing peroxide (ButO)2AlOOBut oxidizes sulfides to sulfoxides.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1663–1668, August, 2004.  相似文献   

5.
Oxidative dehydrogenation of pyrocatechol and 1,4-benzoquinone with 3,3′,5,5′-tetra-tert-butyl-trans-stilbenequinone as oxidant afforded oligomeric polyhydroquinones and polyquinones. Appropriate reaction conditions have been found, and the resulting oligomers have been characterized by IR and MALDI TOF mass spectra and elemental analyses.  相似文献   

6.
Two tetranuclear copper(II) complexes bridged by asymmetrical N,N′-bis(substituted)oxamides have been synthesized and characterized as [Cu4(dmapob)2(Me2bpy)2](pic)2·6H2O (1) and [Cu4(oxbe)2(dabt)2](pic)2 (2), where H3dmapob and H3oxbe denote N-benzoato-N′-[3-(dimethylamino)propyl]oxamido and N-benzoato-N′-(2-aminoethyl)oxamide, respectively; and Me2bpy, dabt, and pic represent 4,4′-dimethyl-2,2′-bipyridine 2,2′-diamino-4,4′-bithiazole, and 2,4,6-trinitrophenol, respectively. Complex 1 was characterized by elemental analyses, IR and electronic spectra, and single-crystal X-ray diffraction. Its structure consists of two asymmetrical binuclear copper(II) units linked by carboxyl bridges into a circular tetranuclear copper(II) complex with an embedded center of inversion. The copper(II) centers are in square-planar and distorted square-pyramidal environments. Hydrogen bonds and aromatic stacking interactions link the tetranuclear copper(II) fragments into a 3D supramolecular structure. The interactions of complexes 1 and 2 with herring sperm DNA (HS-DNA) were investigated by electronic and fluorescence spectra and viscosity measurements. Both complexes bind to HS-DNA via the intercalative mode, and complex 2 displays a significant binding propensity to HS-DNA.  相似文献   

7.
Nitration of N,N′-bis(trimethylsilyl)carbodiimide with N2O5 or (NO2)2SiF6 afforded N-nitro-N´-(trimethylsilyl)carbodiimide, the first representative of N-nitro carbodiimides. Its further nitration led to the release of CO2, which is presumably formed in the course of N,N´-dinitrocarbodiimide decomposition. The reactions of N-nitro-N´-(trimethylsilyl)carbodiimide with nucleophiles take place both at the tri methylsilyl group (for example, with NH3) to give nitrocyanamide salts and at the carbodiimide C atom (for example, with Et2NH) to give the corresponding nitroguan idines.  相似文献   

8.
The oxidation of 2,6-di-tert-butyl-4-methylphenol with hydrogen peroxide in the presence of potassium iodide gave 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone which catalyzed liquid-phase oxidation of sodium sulfide with oxygen more efficiently than did 3,3′,5,5′-tetra-tert-butyl-4,4′-diphenoquinone.  相似文献   

9.
Peroxydisulfate (PDS) oxidizes N,N′-ethylenebis(isonitrosoacetyleacetoneimine)copper(II) complex, CuIIL, to the corresponding copper(III) complex, [CuIIIL]+. The kinetic runs were performed in the presence of EDTA to scavenge any trace metal impurities. The kinetics of the reaction at constant pH, ionic strength, and temperature obeys the rate law d[CuIIIL]/dt = 2k 2[CuIIL][S2O8 2−] with k 2 having a value of (8.85 ± 0.32) × 10−2 M−1 s−1 at μ = 0.30 M and T = 25.0 °C. The rate constant k 2 is not affected by variation of pH over the range 3.60–5.20. The second order rate constant is also unaffected by changing ionic strength. The values of k obs were determined over the temperature 25.0–40.0 °C range. The enthalpy of activation, ∆H*, and entropy of activation, ∆S*, have been calculated as 34.9 ± 0.5 kJ mol−1 and −173.3 ± 11.4 J K−1 mol−1, respectively. The kinetics of this reaction, as far as we know, is the first evidence that copper(III) is the likely reactive species in copper catalyzed PDS oxidation reactions.  相似文献   

10.
2,2′-Diaryl-5,5,5′,5′-tetramethyl-3,3′-bi(pyrrol-3-ylidene)-4,4′(5H,5′H)-dione 1,1′-dioxides containing a carboxy, alkoxycarbonyl, or carbamoyl group in the para position of one or both benzene rings were synthesized. These compounds may be regarded as cyclic dinitrones with conjugated C=C bond. Mild aminolysis of carboxy groups in the title compounds may be used to introduce dinitrone fragments into oligonucleotide or polypeptide structures. Electrochemical reduction of the resulting amides involves reversible oneelectron transfer in the first step at a near-zero potential, which makes it possible to use the title compounds as electrochemically active labels in applied bioorganic electrochemistry.  相似文献   

11.
The synthesis and characterization of azo dyes containing o,o′-dihydroxy groups and their azo-metal(II) [Cu, Co, Ni, Zn] chelates by 1H N.M.R., IR, AAS, UV–VIS, magnetic susceptibility and thin-layer chromatography techniques are reported. The stochiometry of the azo-metal chelates was determined by the spectroscopic titration method to be 1:2 (ML2). The synthesized azo dyes and azo-metal chelate dyes were applied on wool fabric. Fastness to light and washing were measured.  相似文献   

12.
Summary. The reaction of 3-chloro-5,6-diphenylpyridazine-4-carbonitrile with potassium thiocyanate gave the corresponding isothiocyanate derivative. This was reacted with aromatic amines in ethanol to afford pyrimido[4,5-c]pyridazine derivatives. The reaction of the latter compounds with hydrazine hydrate led to the formation of 6-hydrazino derivatives. One hydrazino compound was reacted with a variety of reagents to produce other new pyrimidopyridazines as well as a number of s-triazolo derivatives.  相似文献   

13.
The thermal decomposition kinetics of sterically hindered salen type ligand (L) and its metal complexes [M=Co(II), Ni(II), Cu(II)] were investigated by thermogravimetric analysis. A direct insertion probe-mass spectrometer (DIP-MS) was used for the characterization of metal complexes of L and all fragmentations and stable ions were characterized. The thermogravimetry and differential thermogravimetry (TG-DTG) plots of salen type salicylaldimine ligand and complexes showed a single step. The kinetic analysis of thermogravimetric data was performed by using the invariant kinetic parameter method (IKP). The values of the invariant activation energy, E inv and the invariant pre-exponential factor, A inv, were calculated by using Coats-Redfern (CR) method. The thermal stabilities and activation energies of metal complexes of sterically hindered salen type ligand (L) were found as Co(II)>Cu(II)>Ni(II)>L and E Cu>E Ni>E Co>L. Also, the probabilities of decomposition functions were investigated. The diffusion functions (D n) are most probable for the thermal decomposition of all complexes.  相似文献   

14.
The interaction of 5,5′-dibromophenyl-17-crown-5 with triisopropylphosphite (NiBr2 catalysis) was employed to prepare 5,5′-bis(di-iso-propoxyphosphoryl)biphenyl-17-crown-5, its molecular structure (X-ray crystallography) being compared with the data for the unsubstituted biphenyl-17-crown-5 and an acyclic analog 2,2′-dimethoxy-5,5′-bis(di-iso-propoxyphosphoryl)biphenyl. For both crown-ethers the macrocycle shape in the crystal state is defined by mutual rotation of the benzene rings, whilst bulky isopropoxyphosphoryl groups in the 5(5′) positions gave little influence on the dihedral angle made by the aromatic cycles. The P=O bonds of these groups are pointing into opposite directions and are virtually parallel to the benzene ring planes. The 2,2′-oxygen atoms of the biphenyl fragment have the gauche orientation in all compounds studied.  相似文献   

15.
(4E)-6,6′,7,7′-tetrahydro-5H,5′H-4,4′-bis-1-benzothiophene and (4Z)-6,6′,7,7′-tetrahydro-5H,5′H-4,4′-bis-1-benzothiophene are studied by means of X-ray diffraction. The intermolecular interaction energy is calculated and the structural subclass of each compound is derived. These compounds have been found to have similar full crystal energies and packing efficiencies. The observed pseudosymmetry effects are described.  相似文献   

16.
The crystal and molecular structure of (4′R,5′R,22R)-22-hydroxy-22-(3′, 4′-dimethylisoxazolin-5′-yl)-6β-methoxy-3α,5-cyclo-23,24-dinorcholane was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group C2; a 19.649(7), b 7.680(2), c 17.254(6) Å; β 101.05(3)°. The only diastereomer formed by the 1,3-dipolar cycloaddition of acetonitriole oxide has the 4′R,5′R stereochemistry of the arising chiral centers. The conformation of the side chain of the molecule is additionally stabilized by an intramolecular hydrogen bond.  相似文献   

17.
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   

18.
Nine new μ-oxamido-bridged copper(II)-lanthanide(III)-copper(II) heterotrinuclear complexes described by the overall formula Cu2(dmoxae)2Ln(NO3)3 {Ln = Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er; dmoxae = N,N′-bis[2-(dimethylamino)ethyl]oxamido dianions} have been synthesized by the strategy of ‘complex as ligand’, and characterized by elemental analyses, molar conductivity measurements, i.r. and electronic spectral studies. The variable-temperature susceptibility (2–300 K), e.s.r. measurements, and studies of the Cu2(dmoxae)2Gd(NO3)3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J(Cu-Gd) = +2.1 cm−1, while an antiferromagnetic coupling is detected between the terminal copper(II) ions with J(Cu-Cu)=−0.36 cm−1, on the basis of the spin Hamiltonian operator . A plausible mechanism for the ferromagnetic coupling between copper(II) and gadolinium(III) is discussed in terms of spin polarization.  相似文献   

19.
Copper(II) complexing with N′,N′-diethylbenzohydrazide (DEBH) in aqueous isopropanol was studied. The formation of cationic complexes with the ratio [Cu2+]: [DEBH] = 1: 1 and 1: 2 in week acid solution and an uncharged complex with the ratio [Cu2+]: [DEBH] = 1: 2 in neutral and alkaline solutions was established. Their stability constants K st were determined. The complexes were isolated in a solid state and characterized by IR spectroscopy and elemental analysis for copper.  相似文献   

20.
Treatment of N,N′-methylenedipyridinium dichloride [C5H5N-CH2-NC5H5]Cl2 with MCl2 (M = Zn or Cd) in aqueous solution gives the organic-inorganic hybrid ionic compounds [C5H5N-CH2-NC5H5] · [MCl4]. Both complex salts were fully characterised by multinuclear NMR spectroscopy, elemental analysis, and their molecular structures confirmed by powder X-ray diffraction studies. The most striking feature in both solid state structures was the presence of the C…Cl-M short contacts between the organic [C5H5N-CH2-NC5H5] dication and inorganic [MCl4] anion, which led to different crystal packing. For [C5H5N-CH2-NC5H5]·[ZnCl4], the C…Cl-Zn interactions led to the alternating arrangement of [C5H5N-CH2-NC5H5]2+[ZnCl4]2− to form 1-D chains in the direction [010], and each individual chain had a two-fold rotational axis along the b axis, while for [C5H5N-CH2-NC5H5] · [CdCl4] the C…Cl-Cd associations gave 2-D network. In both solid state structures, the presence of Cl-ring centroid distances gave a strong indication of some form of Cl-π interactions.  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