Thermochemistry on coordination behavior of samaric chloride hydrate with diethylammonium diethyldithiocarbamate

The complex of samaric chloride lower hydrate with diethylammoniumdiethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N_2atmosphere. The title complex was identified as Et_2NH_2[Sm(S_2CNEt_2)_4] by chemical and elementalanalyses, the bonding characteristics of which was characterized by IR. The enthalpies of solutionof samaric chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change ofliquid-phase reaction of formation for Et_2NH_2[Sm(S_2CNEt_2)_4] at different temperatures weredetermined by mi-crocalorimetry. On the basis of experimental and calculated results, threethermodynamic parameters (the activation enthalpy, the activation entropy, and the activation freeenergy), the rate constant, and three kinetic parameters (the apparent activation energy, thepre-exponential constant, and the reaction order) of liquid phase reaction of formation wereobtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by athermochemical cycle.

Heterotetranuclear Cu_2~IPd_2~Ⅱ Complex with Bis(diphenylphosphino)methane and Diethyldithiocarbamate

Self-assembly between the building blocks of Pd(Et2dtc)2 (Et2dtc = diethyldithio- carbamate) and [Cu2(m-dppm)2(MeCN)2]2+ (dppm = bis(diphenylphosphino)methane) gave a new heterotetranuclear complex [Cu2Pd2(m-dppm)2(m-Et2dtc)2(m3-Et2dtc)2](ClO4)2H2O (C70H86Cl2Cu2- N4O9P4Pd2S8, Mr = 1932.56), and its crystal structure has been determined by X-ray crystallo- graphy. It crystallizes in triclinic, space group P with a = 11.9834(6), b = 12.5624(6), c = 14.5603(8) ? a = 101.393 (1), b = 103.300 (1), g = 96.310(1), V = 2063.2(2) 3, Z = 1, Dc = 1.544 g/cm3, m(MoKa) = 1336 cm-1 and F(000) = 978. The total and unique reflections are 8710 and 5400, respectively. The structure was refined to R = 0.0860 and wR = 0.1996 for 3914 observed reflections with I > 2s(I). The title complex consists of the cation [Cu2Pd2(m-dppm)2(m-Et2dtc)2(m3- Et2dtc)2]2+, anion ClO4- and solvate H2O. The Pd(Ⅱ) atoms are located at the approximately square-planar environments with PS3 donors and the Cu(I) atoms display distorted tetrahedral geometries.

Thermochemical Study of Coordination of Holmium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

The complex of holmium chloride hydrate with diethylammonium diethyldithiocarbamate(D-DDC) was synthesized via mixing their solutions in absolute alcohol under a dry N 2 atmosphere. The elemental and chemical analyses show that the complex has the general formula Et 2NH 2[Ho(S 2CNEt 2) 4]. It was also characterized by IR spectroscopy. The enthalpies of the dissolution of holmium chloride hydrate and D-DDC in absolute alcohol at 298.15 K, and the enthalpy changes of liquid-phase reactions of the formation of Et 2NH 2[Ho(S 2CNEt 2) 4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters(the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters(the apparent activation energy, the pre-exponential constant and the reaction order) of the liquid-phase reaction of the complex formation were obtained. The enthalpy change of the solid-phase complex formation reaction at 298.15 K was calculated by means of a thermochemical cycle.

Electrode process of diethyldithiocarbamate on surface of pyrrhotite

The electrode process of diethyldithiocarbamate on the surface of pyrrhotite was studied using systematic electrochemical analysis, including cyclic voltammetry, chronopotentiometry and galvanostatic. Experimental results show that tetraethylthioram disulphide（TETD） is electrodeposited on pyrrhotite electrode surface in the presence of 1.0×10^-4 mol/L diethyldithiocarbamate when the electrode potential is higher than 0.25 V. The electrochemical kinetics parameters of the electrode process of diethyldithiocarbamate on surface of pyrrhotite are calculated as follows： the exchange current density is 2.48μA/cm^2 , and the transmission coefficient is 0.46. The electrodeposition includes two steps electrochemical reaction. The first reaction is electrochemical adsorption of diethyldithiocarbamatc ion, then the adsorbed ion associates with a diethyldithiocarbamate ion from the solution and forms tetraethylthioram disulphide on the surface of pyrrhotite.

DIETHYLDITHIOCARBAMATE MAY ENHANCE THE ANTITUMOR EFFECT OF ADRIAMYCIN NANOPARTICLE-LIPIODOL EMULSION

Objective: To studied the effect of Diethyldithiocarbamate (DDC) on the antitumor activity of adriamycin (ADM) nanoparticle-lipiodol emulsion. Methods: The SD rats bearing liver carcinoma were divided into six groups and treated by saline, adriamycin, adriamycin nanoparticle-lipiodol emulsion, adriamycin liposome-lipiodol emulsion, DDC plus adriamycin nanoparticle-lipiodol emulsion, DDC plus adriamycin liposome-lipiodol emulsion respectively. The volume of the tumors, tumor growth rate (G%) and life prolonging rate PL% in six groups were determined. Results: The values of the IC50 (μg/ml) of adriamycin were reduced from 18.40 to 0.74 for the resistant cells SGC7901/CVR, and from 4.00 to 0.32 for the sensitive cells SGC7901/WT by pretreating the tumor cells with DDC. The tumor growth rate (G%) and life prolonging rate PL% increased significantly (P<0.05) in the DDC pretreated groups than adriamycin nanoparticle-lipiodol or adriamycin liposome-lipiodol emulsion groups. Conclusion: The antitumor effect of adriamycin can be enhanced by inhibiting the superoxide dismutase (SOD) in tumor cells by DDC.

Effects of diethyldithiocarbamate on myelin basic protein expression in the rat lateral olfactory tract

BACKGROUND： Dithiocarbamates can cause demyelination of axons in the peripheral nervous system. Its derivate, diethyldithiocarbamate, is cytotoxic, and causes olfactory mucosal damage and atrophy of the olfactory bulb. However, it is still unclear whether the myelin sheath of the lateral olfactory tract is affected by diethyldithiocarbamate. OBJECTIVE： To investigate the effects of diethyldithiocarbamate on the myelin sheath of the rat lateral olfactory tract. This was done by examining changes in myelin basic protein expression after diethyldithiocarbamate treatment. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Laboratory of the Department of Human Anatomy and Neurobiology, Xiangya School of Medicine, Central South University, China from July to November 2007. MATERIALS： A total of 72 Sprague Dawley rats were randomly assigned into a diethyldithiocarbamate group （n = 32）, a solvent control group （n = 32）, and a blank control group （n = 8）. The diethyldithiocarbamate and solvent control groups were separately divided into 3-d, 7-d, 14-d and 28-d survival subgroups, with eight rats in each. Diethyldithiocarbamate （Sigma, USA） and goat anti-myelin basic protein polyclonal antibody （Santa Cruz, USA） were used in this study. METHODS： Rats in the diethyldithiocarbamate and solvent control groups were subcutaneously injected with diethyldithiocarbamate （600 mg/kg） and 0.01 mol/L phosphate buffered saline （600 mg/kg） at the posterior neck, respectively. Rats in the blank control group received no treatment. MAIN OUTCOME MEASURES： Immunohistochemical staining and Western blot assay were used to measure myelin basic protein expression in the rat lateral olfactory tract. RESULTS： Following immunohistochemical staining, myelin basic protein was uniformly distributed in the rat lateral olfactory tract in the blank control and solvent control groups. Western blot assay showed 21.5, 18, 17 and 14 ku positive bands. No significant difference was found in myelin basic protein distribution and blot pattern, in the rat lateral olfactory tract, in the diethyldithiocarbamate group, following immunohistochemical staining and Western blot assay. Myelin basic protein expression gradually decreased at day 3, reached the lowest level at day 7, and gradually increased again at days 14 and 28. CONCLUSION： Demyelination is induced by diethyldithiocarbamate in the rat lateral olfactory tract in an early stage, followed by remyelination at later stages.

Inhibition of nitrification in soil by metal diethyldithiocarbamates

Nitrification acts as a key process in determining fertilizer use efficiency by crops as well as nitrogen losses from soils. Metal dithiocarbamates in addition to their pesticidal properties can also inhibit biological oxidation of ammonium(nitrification) in soil. Metal [M=V(Ⅲ), Cr(Ⅲ), Mn(Ⅱ), Fe(Ⅲ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ) and Co(Ⅱ)] diethyldithiocarbamates (DEDTC) were synthesized by the reaction of sodium diethyldithiocarbamate with metal chloride in dichloromethane/water mixture. These metal diethyldithiocarbamates were screened for their ability to inhibit nitrification at different concentrations(10 μg/g soil, 50 μg/g soil and 100 μg/g soil). With increasing concentration of the complex, capacity to retard nitrification increased but the extent of increase varied for different metals. At 100 μg/g soil, different complexes showed nitrification inhibition from 22 36% to 46 45%. Among the diethyldithiocarbamates tested, Zn(DEDTC) 2 proved to be the most effective nitrification inhibitor at 100 μg/g soil. Manganese, iron and chromium diethyldithiocarbamates also proved to be effective nitrification inhibitors than the others at 100 μg/g soil. The order of percent nitrification inhibition in soil by metal diethyldithiocarbamates was: Zn(Ⅱ) > Mn(Ⅱ) > Fe(Ⅲ) > Cr(Ⅲ) >V(Ⅲ) > Co(Ⅱ) > Ni(Ⅱ) > Cu(Ⅱ).

Synthesis and Crystal Structure of a Dicopper(Ⅰ) Complex with Bis(diphenylphosphino)methane and Diethyldithiocarbamate

The title complex [Cu2(-dppm)2(-Et2dtc)](ClO4)EtOH0.25H2O (dppm = bis- (diphenylphosphino)methane, Et2dtc = diethyldithiocarbamate) has been synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal structure is of monoclinic, space group C2/c with a = 42.587(1), b = 14.1653(4), c = 20.5649(5) ? = 105.945(1)? V =11928.6 3, C57H60.5ClCu2NO5.25P4S2, Mr = 1194.09, Z = 8, Dc = 1.330 g/cm3, (MoK) = 0.98 mm-1 and F(000) = 4948. A total of 15243 reflections were collected, of which 7322 were unique. The structure was refined to R = 0.0739 and wR = 0.1846 for 5135 observed reflections with I > 2(I). The crystal structure consists of the complex cation [Cu2(-dppm)2(-Et2dtc)]+, anion ClO4- and solvate H2O and EtOH, where the dinuclear Cu(Ⅰ) atoms are bridged doubly by two dppm ligands and singly by Et2dtc to give three five-membered rings. The Cu(Ⅰ) atom is in an approxi- mately trigonal-planar environment with the P2S chromophore. The short Cu贩稢u separation (2.7111 ? suggests the presence of metal-metal contact.

Electrochemical flotation of diethyldithiocarbamate-pyrrhotite system

Using sodium diethyldithiocarbamate as a collector the flotation behavior of pyrrhotite was investigated. The relationship between potential and pH range for pyrrhotite flotation was established. The results show that the flotation of pyrrhotite is dependent on pulp potential at certain pH values. Pyrrhotite has good floatability from pH 2 to pH 12, and poor flotability at pH>12. Cyclic voltammetry and Fourier transform infrared spectrum analysis show that the major adsorption product of DDTC on pyrrhotite is tetraethylthiuram disulfide. The intensity of Fourier transform infrared signals of tetraethylthiuram disulfide adsorbed on pyrrhotite and the anode current of a pyrrhotite electrode and flotation response of pyrrhotite are correlated with pulp potentials.

Synthesis, Structure and Transesterification of the Derivatives of β-Alkoxycarbonylethyltin Trichlorides with Diethyldithiocarbamate

The derivatives of β-alkoxycarbonylethyltin trichlorides with diethyldithiocarbamate,ROCOCH2CH2Sn(S2CNEt2)Cl2, were synthesized and characterized by the means of elemental analysis, IR, 1H NMR and X-ray single crystal diffraction. The structural features of the compounds were described, and the possible mechanism of transesterification for compound 2a was suggested.

Syntheses, Structures and Antitumor Activities of Tri(o-bromobenzyl)tin Diethyldithiocarbamate and Tri(m-fluorobenzyl)tin Pyrrolidine Dithiocarbamate

Tri(o-bromobenzyl)tin diethyldithiocarbamate(1) and tri(m-fluorobenzyl)tin pyrrolidine dithiocarbamate(2) have been synthesized and characterized by elemental analysis, IR spectroscopy, NMR(~1 H, ^(13)C and ^(119)Sn), thermogravimetric analysis and single-crystal X-ray diffraction. The two complexes crystallize in the triclinic system space group P1. For complex 1, a = 0.9770(1), b = 1.1011(1), c = 1.4583(1) nm, α = 78.431(1)°, β = 86.307(1)°, γ = 69.712(1)°, V = 1.4417(2) nm^3, Z = 2, Dc = 1.790 g/cm^3, m(Mo Kα) = 52.04 cm–1, F(000) = 756, R = 0.0434 and wR = 0.0593. For complex 2, a = 0.7055(1), b = 1.3349(3), c = 1.3782(3) nm, α = 89.216(2)°, β = 82.044(2)°, γ = 84.637(2)°, V = 1.2799(5) nm^3, Z = 2, Dc = 1.537 g/cm^3, m(Mo Kα) = 11.98 cm^(–1), F(000) = 596, R = 0.0313 and wR = 0.0333. The two complexes represent mononuclear structures with five-coordinated [SnC3S2] cores forming a distorted trigonal bipyramid. The quantum chemical calculations of 1 and 2 have been investigated. The antitumor activity shows that 1 and 2 have higher activities than cisplatinum against Colo205, HepG2, MCF-7, Hela and H460 cell line in vitro.

Thermochemistry on Coordination Behavior of Praseodymium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

The complex of praseodymium chloride lower hydrate with diethylammonium diethyldithiocarbamate (D-DDC) has been synthesized conveniently in absolute alcohol and dry N_2 atmosphere. The title complex was identified as Et_2NH_2[Pr- (S_2CNEt_2)_4] by chemical and elemental analyses, the bonding characteristics of which were characterized by IR spectrum. The enthalpy of solution for praseodymium chloride hydrate and D-DDC in absolute alcohol at 298.15 K, and the enthalpy changes of liquid-phase reaction of formation for Et_2NH_2[Pr-(S_2CNEt_2)_4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of liquid phase reaction of formation were obtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle.

Determination of Trace Non Rare Earth Elements in High Purity Rare Earth Oxides by ICP－AES with Microcolumn Preconcentration in a Flow Injection System

A new method for the determination of trace non-rare earth elements in high purity rare earth oxides by ICP-AES with preconcentration on an active carbon-silica gel microcolumn in a flow injection system is described in this paper. Experimental parameters such as pH, flow rate,reagent concentration,length of reaction coil,eluent acidity,etc. were optimized. In the buffer solution of NH3. H2O/NH4Cl at pH 4. 6,Al,Cr,Cu,Fe, Pb, V and Zn can be preconcentrated and then eluted with 4. 5 mol/L nitric acid utilizing stop-flow technique. The enrichment factors were in range of 8. 1￣12. 6 with detection limits of μg/m level ,and the RSD with metals at μg/g level were 2. 3￣5. 0% (n= 7). The method proposed can reduce the matrix interference effectively , and has been applied to the determination of non-rare earth metals atμg/g level in high purity Eu2O3 with satisfactory results.

EFFECT OF SUPEROXIDE DISMUTASE AND DIETHYLDITHICARBAMATE ON THE INDUCTION OF SQUAMOUS CELL CARCINOMA OF LUNG WITHMETHYLCHOLANTHREN IN RATS

The 3rd Hospital of Wuchang District ,Wuhan 432600)The squamous cell carcinoma of lung was induced with methylcholanthrene (MCA) in iodized oil in wistar rts- During the development of the cancer, the animals were given superoxide dismutase (SOD) or its inhibitor diethyldio-carhamate (DDC). In DDC group, 3 out of 50 rats developed cancer and 4 developed atypical hyperplasia of hronchial epithelium within 35 to 40 days.In SOD group, no cancer developed in all of the 52 rats.and only one had atypical hyperplasia in the lungs. Only one of 42 control rats had cancer and 2 rats had atypical hyperplasia of bronchial epithelium . The difference in cancer frequency between groups DDC and SOD was significant (P<0.05). The results suggest that there is a synergism between DDC and MCA in the induction of lung cancer, while SOD can inhibit MCA-induced lung cancer development. The mechanism of the effect of SOD and DDC was discussed.

Copper and Mercury in Food, Biological and Pharmaceutical Samples: Spectrophotometric Estimation as Cu(DDTC)₂

An alternative spectrophotometric method was optimized and validated for the estimation of mercury using diethyldithiocarbamate (DDTC), a common reagent, widely used for the preconcentration and isolation of metal ions in complex matrices followed by their estimation by varied techniques. Diethyldithiocarbamate forms yellow Cu(DDTC)2 with copper and white Hg(DDTC)2 with mercury (having d10 system) which are extracted in CCl4. The UV-visible spectrum of Cu(DDTC)2 is very stable at pH 5.0 and has a maximum absorption (λmax) at 435 nm. Hg(DDTC)2 is more stable than Cu(DDTC)2. Estimation of mercury is based on a quantitative displacement of Cu(II) of Cu(DDTC)2 with the addition of mercury followed by the measurement of reduced absorbance. Primarily, method was optimized and validated for the estimation of copper. Therefore, simultaneous determination of Cu(II) and Hg(II) in mixture is proposed fractionating the extract. The molar specific coefficient (ε) for the mercury was 1.4 × 104 mol﹣1·L·cm﹣1 and for copper was 3.16 × 105 mol﹣1·L·cm﹣1 at 435 nm. The detection limits of Cu2+ and Hg2+ were 0.023 μg·mL﹣1 and 0.029 μg·mL﹣1, respectively. The calibration curve shows good linearity of 0.02 - 12.0 and 0.02 - 15.0 μg·mL﹣1 for the Cu2+ and Hg2+ determination, respectively. Proposed technique was applied to food, biological and pharmaceutical samples for the determination of Cu(II) and Hg(II).

Preconcentration and Determination of Chromium Species Using Octadecyl Silica Membrane Disks and Flame Atomic Absorption Spectrometry

A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate complexes at different pH in the presence of Mn（Ⅱ） as an enhancement agent of chromium signals followed by elution with organic eluents and determination by atomic flame absorption spectrometry. The maximum capacity of the employed disks was found to be （396±3） pg and （376±2） pg for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The detection limit of the proposed method is 49 and 43 ng·L^-1 for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The proposed method was successfully applied for determination of chromium species Cr（Ⅲ） and Cr（Ⅵ） in different water samples.

A nanosystem of copper(II)-disulfiram for cancer treatment with high efficacy and few side effects

Developing chemotherapy drugs with high efficacy and few side effects has been a bottleneck problem that requires an efficient solution.The active cancer treatment ingredient disulfiram(DSF),inspired by the copper(II)diethyldithiocarbamate complex(CuET),can be used in a one-pot synthesis method to construct a CuET delivery nanosystem(CuET-ZIFCu@HA).Due to the high biocompatibility,targeting of CD44 overexpressed cancer cells,and acid response of zeolitic imidazolate framework(ZIF)materials of hyaluronic acid(HA),we realized that CuET-ZIFCu@HA could become an effective and highly selective cancer treatment.Both in vivo and in vitro experiments have demonstrated that CuET-ZIFCu@HA has robust anti-tumor properties without evident side effects.This research provided a promising strategy for DSF nanosystems that involves simple preparation and high efficacy,both of which are key to reusing DSF in cancer treatment.