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Abstract  

Transition metal dithiocarbamate complexes, [M(S2CN(C2H5)(CH2CH2OH)] (M=Co, Ni, Cu, Zn and Cd) have been prepared and characterized by elemental analysis and infrared spectra. Thermal decomposition of all the complexes occurs in two or three stages. The first stage in all the complexes is always fast with 65-70% mass loss. In all cases the end product is metal oxide except in the case of cobalt complex which gives Co metal as an end product. During decomposition of copper complex, first CuS is formed at ~300C which is converted into CuSO4 and finally CuO is formed. However, decomposition in helium atmosphere yields CuS. SEM studies of transition metal dithiocarbamates reveal needle shape crystalline phase at room temperature and formation of metal sulphide/oxide at higher temperatures. The activation energy varies in a large range of 33.8-188.3 kJ mol-1, being minimum for the Cu complex and maximum for the Zn complex possibly due to d 10 configuration. In the case of Ni, Zn and Cd complexes the order of reaction is two suggesting bimolecular process involving intermolecular rearrangement. However, in other cases it is a unimolecular process. Large negative values of ΔS # for all the complexes suggest that the decomposition process involves rearrangement.

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A chromatographic method for the determination of metal dithiocarbamates: antimonic(III) dipentyldithiocarbamate (Sb-5-DTC), zinc dipentyldithiocarbamate (Zn-5-DTC), zinc dibutyldithiocarbamate (Zn-4-DTC), ferric(III) dipentyldithiocarbamate (Fe-5-DTC), and lead(II) dipentyldithiocarbamate (Pb-5-DTC) was developed. Separations were performed on thin-layer chromatography (TLC) RP-18 silica gel with a propan-2-ol and water mixture (10:1, v/v) as the mobile phase. The chromatographed compounds were detected using the iodine-azide detection procedure. Plates were sprayed with a mixture of sodium azide (2%), potassium iodide (0.01 mol L−1), and starch solution (1%) adjusted to pH 6.0 and exposed to iodine vapor for 15 s. The compounds were visible as white spots against a violet background which were converted into chromatograms using TLSee software. The linear functions of concentration for Sb-5-DTC, Zn-5-DTC, Zn-4-DTC, Fe-5-DTC, and Pb-5-DTC were in the ranges of 100–2000, 50–1000, 50–1000, 50–1000, and 100–3000 pmol per spot, respectively. The limits of detection and quantification were at a level of tens of pmol per spot.

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Abstract  

At pH 2, Au, Pd, Pt, U and W form stable pyrrolidine-carbodithioate (PCDT) complexes which can be quantitatively retained by C18-bonded silica gel. Simultaneous determination of the adsorbed metal complexes can be achieved by instrumental neutron activation analysis (INAA). This method allows the determination of Au, Pd, U, and W in natural waters at ng/l levels. For Pt and W, the adsopriton method has an advantage over the solvent extraction technique which generally results in a partial recovery of the PCDT complexes.

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Abstract  

The research in thermal analysis and calorimetry, conducted by the author over the period 1964 to 1993, is summarised and concisely reviewed. The major investigations have focussed on thermal analysis studies of coordination compounds, particularly the metal dithiocarbamate complexes. A significant solution calorimetric study of some metal dithiocarbamate complexes has also been undertaken. DSC has been applied to determine the sublimation enthalpies of many metal dithiocarbamate and metal pentane-2,4-dionate complexes and solution calorimetry has been applied to study the thermochemistry of the latter group of complexes. Thermal analysis investigations of several inorganic molten salt systems have been initiated. Thermometric titrimetry has been applied to study metal-macrocyclic ligand systems in aqueous media and particularly those systems of environmental significance. Temperature calibration standards for TMA have been proposed and TMA has been applied to study the mechanical properties of several common inorganic compounds. DTA has been applied to study a wide variety of phenols and has subsequently been applied as an analytical technique to determine the components of solid state phenol mixtures. Thermometric titrimetry has been applied to determine the phenolic content of wines. A comprehensive thermal analysis study of Australian brown coal has been undertaken, involving the DSC determination of coal specific energy, a TG/DTA study of the coal pyrolysis and combustion processes and a TG/DTA and EGA study of the cation catalytic effect on the coal pyrolysis process. Thermal analysis and calorimetric techniques have been extensively publicised and promoted by the publication of specialist reviews, the presentation of symposia review papers and the oral presentation of short courses, particularly in the SE Asian region. This review essentially reveals the diversity of possible application of thermal analysis and calorimetric techniques and the primary significance of thermodynamic data in the fundamental rationalisation of chemical phenomena.

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Journal of Thermal Analysis and Calorimetry
Authors: A. V. Markin, V. A. Ruchenin, N. N. Smirnova, G. V. Markin, S. Yu. Ketkov, V. A. Kuropatov, V. K. Cherkasov, G. A. Abakumov and G. A. Domrachev

approach to the synthesis of [60]Fullerene-Metal dithiocarbamate complexes, (MII(R2dtc)2)x L C60 (M = Zn, Cd, Hg, Fe, and Mn; x = 1 and 2). The study of magnetic properties and photoconductivity . Cryst Growth Des 8 : 1161 – 1172 10.1021/cg0702481

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Introduction Number of studies as well as reports on antifungal [ 1 , 2 ], antibacterial [ 3 – 7 ], anti-alkylation [ 8 , 9 ], anticancer and apoptosis inducing activities [ 10 ] of the mixed-ligand metal dithiocarbamates

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