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31.
Yuehui Yang Bencheng Zuo Jingyin Li Guore Chen 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》1996,52(14):1915-1919
This paper systematically studies the structure and the internal mechanism of the stability of sulphur-coordinated four-membered rings in chelates of dialkyl dithiocarbamate. It was found that the conjugated π electron structure of the free ligand is Π46, while in the metal chelate it is Π44. The stable chelates have strong σ- and π-coordinated bonds. The actual strain of the sulphur-coordinated four-membered ring in chelates is not as strong as assumed. It mainly depends on the atomic radius of the metal. The stronger the electronegativity of the metal, the stronger the π-coordinated bond. The stabler the four-membered ring, the weaker the intensity of the C-S vibrational band. 相似文献
32.
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34.
Fartisincha P. Andrew 《Journal of Coordination Chemistry》2019,72(5-7):1171-1186
Cobalt(II) complexes of N-methyl phenyl, 1-phenylpiperazyl, and morpholinyl dithiocarbamates have been synthesized and characterized by UV–Visible, FTIR, 1H-, 13C-NMR, and mass spectrometry. The spectroscopic data indicated that two ligands coordinated in bidentate chelating to the metal ion to form four-coordinate cobalt(II) complexes (1–3), which was confirmed by mass analysis (TOF MS ES+) of the complexes with m/z [M]+ = 450.98, 382.94, and 382.94 for 1, 2, and 3, respectively. Single crystal analysis of 2A and 3A show centrosymmetric mononuclear cobalt(III) bonded to three dithiocarbamate ligands forming a distorted octahedral geometry, indicating the cobalt(II) undergoes aerial oxidation to cobalt(III) during recrystallization. In addition, 2A crystallized with one solvated molecule of toluene. The redox behaviors of the complexes were studied by cyclic and square wave voltammetry in dichloromethane; the result revealed a metal centered redox process consisting of a one-electron quasi-reversible process assigned to Co(III)/Co(IV) oxidation and a corresponding Co(IV)/Co(III) reduction. Randles–Sevcik plots (anodic peak current versus the square root of the scan rate (Ip,a versus ν1/2)) for the redox couples revealed diffusion-controlled behavior. 相似文献
35.
Bis(N‐(pyrrol‐2‐ylmethyl)‐N‐butyldithiocarbamato‐S,S′)copper(II) ( 1 ), bis(N‐(pyrrol‐2‐ylmethyl)‐N‐(2‐phenylethyl)dithiocarbamato‐S,S′)copper(II) ( 2 ), bis(N‐methylferrocenyl‐N‐(2‐phenylethyl)dithiocarbamato‐S,S′)copper(II) ( 3 ) and bis(N‐furfuryl‐N‐methylferrocenyldithiocarbamato‐S,S′)copper(II) ( 4 ) were prepared and characterized using elemental analysis and infrared and UV–visible spectroscopies. X‐ray diffraction (XRD) studies on 3 show that each copper centre adopts the square planar geometry by the coordination of four sulfur atoms of the metalloligand N‐methylferrocenyl‐N‐(2‐phenylethyl)dithiocarbamate. The Cu? S distances are symmetrical and are in the range 2.293–2.305 Å. The supramolecular architecture in complex 3 is sustained in the solid state by C? H???π, C? H???S, Fe???Fe and H???H interactions. Density functional theory calculations were carried out for 3 . Anion (F?, Cl?, Br? and I?) binding studies with complex 1 were performed using cyclic voltammetry. Copper sulfide, copper–iron sulfide‐ 1 and copper–iron sulfide‐ 2 nanoparticles were prepared from complexes 2 , 3 and 4 , respectively, and they were characterized using powder XRD, transmission electron microscopy (TEM) and energy‐dispersive X‐ray, UV–visible, photoluminescence and infrared spectroscopies. TEM images of copper–iron sulfide‐ 1 and copper–iron sulfide‐ 2 reveal that the particles are spherical and oval shaped, respectively. Photocatalytic activities of as‐prepared nanoparticles were studied by decolourization of methylene blue and rhodamine‐B under UV light. It was found that copper–iron sulfide degrades methylene blue and rhodamine‐B much better than does copper sulfide. 相似文献
36.
Four new macrocyclic dinuclear dibutyltin(IV) dithiocarbamate complexes of the type [Bu2Sn(dtc)]2, where dtc = hexane‐1,6‐diylbis(4‐fluorobenzyldithiocarbamate) anion ( 1 ), hexane‐1,6‐diylbis(4‐chlorobenzyldithiocarbamate) anion ( 2 ), hexane‐1,6‐diylbis(furfuryldithiocarbamate) anion ( 3 ) and hexane‐1,6‐diylbis(pyrrole‐2‐ylmethyldithiocarbamate) anion ( 4 ), have been prepared. The dithiocarbamate ligands efficiently self‐assemble with Bu2Sn(IV) to form bimetallic 26‐membered macrocycles. All the complexes have been characterized using elemental analysis, infrared and NMR (1H and 13C) spectroscopies and X‐ray crystallography. Single‐crystal X‐ray diffraction analysis of all the complexes confirms the formation of the dinuclear metallomacrocycles in which dithiocarbamate ligands are asymmetrically bound to the tin atoms. The coordination sphere around the tin atom in 1 – 4 can be described as a skew trapezoidal bipyramid. The dimensions of the cavity of the macrocycles of 1 – 4 are ca 8.0 × 9.0 Å2. Complexes 1 – 4 were evaluated for their in vitro anticancer activity against MCF‐7 and HL‐60 cells. Complexes 1 and 2 are more active against MCF‐7 and HL‐60. Thermal decomposition of 1 and 4 yielded tin sulfides. They were characterized using powder X‐ray diffraction (PXRD), high‐resolution transmission electron microscopy and UV diffuse reflectance and energy‐dispersive X‐ray spectroscopies. PXRD studies reveal that the as‐prepared tin sulfides are composed of orthorhombic phase of SnS. 相似文献
37.
《Analytical letters》2012,45(5):327-334
Abstract The quantitative determination of N,N-dialkyl dithiocarbamates tetramethylthiuram disulfide and tetramethyl-thiuram monosulfide in industrial wastewater was studied by thin-layer densitometry of their copper complexes. It has been demonstrated that a densitometer provides a simple and rapid means to quantitate these compounds. N,N-dialkyl dithiocarbamates have been analyzed in microgram quantities using this method. Coefficients of variation of 2–6 per cent were obtained. 相似文献
38.
Abstract A gas chromatographic method for the determination of N,N-dialkyl dithiocarbamates in industrial wastewater at the nanogram level is described. The sample is freeze-dried, extracted with ethanol and then esterified with 1-iodopropane. The method is sensitive, specific, and free from interference of metals. The sensitivity of the method is in the order of 1 ng (injected). 相似文献
39.
Compounds 1-7 form a novel group of dithiocarbamates, first synthesized from the reaction of a series of primary amines with carbon disulfide and 3-bromo ethyl pyruvate in the presence of anhydrous potassium phosphate. Structure elucidation of this group of compounds was accomplished using extensive 1D and 2D NMR spectroscopic studies, including (1)H, (13)C, COSY, NOESY, HSQC, and gHMBC experiments. The distinction between the linear structures I, II and the cyclic structure III was made mainly on the basis of the analysis of the cross peak between H-2 and H-4a in the COSY spectra, in combination with the long-range correlation between H-2 and C-4, 6 in the gHMBC spectra. 相似文献
40.
M. C. D Silva M. M. Concei??o M. F. S. Trindade A. G. Souza C. D. Pinheiro J. C. Machado P. F. A. Filho 《Journal of Thermal Analysis and Calorimetry》2004,75(2):583-590
The thermodynamic and kinetic parameters of the thermal decomposition of Zn(S2CNR2)2 complexes (R=CH3, C2H5 and n-C3H7) were determined with the dynamic thermogravimetric method. Superimposed TG/DTG/DSC curves show that thermal decomposition
reactions for chelates with R=C2H5 and n-C3H7 occur in the liquid phase, at temperatures far away from their melting points, whereas for the complex with R=CH3 the thermal decomposition begins at a temperature closer to its melting point, suggesting a rather complex decomposition
mechanism.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献