Morpholine Dithiocarbamate Research Articles

Highly selective flotation separation of chalcopyrite and pyrite by a novel dithiocarbamate collector with morpholine group

Efficient and selective flotation separation of chalcopyrite and pyrite in copper-sulfur ores remains a challenging issue in mineral processing. In the present work, a newly-synthesized organic compound morpholine dithiocarbamate propylene ester (MDPE) was first developed as a flotation collector in the chalcopyrite-pyrite system. Microflotation results indicated that MDPE exhibited surpassing flotation selectivity for chalcopyrite against pyrite at low alkalinity (pH = 8.5) compared with traditional sodium isobutyl xanthate (SIBX) or sodium diethyldithiocarbamate (DTC). UV–vis spectra showed that MDPE was preferable to interact with Cu+ or Cu2+ rather than with Fe2+ or Fe3+. The results of zeta potential and FTIR spectra proved that MDPE had a stronger adsorption affinity towards chalcopyrite rather than pyrite. FTIR and XPS results confirmed that MDPE might chemically absorb on chalcopyrite surfaces by the formation of Cu-MDPE complexes with C-S-Cu structure.

Synthesis of a novel dithiocarbamate collector and its selective adsorption mechanism in galena flotation

The high consumption of depressants in the flotation separation of sulfide lead-zinc ores would cause serious environmental problems, and conventional dithiocarbamate collectors suffered from the drawbacks of low flotation activity and poor selectivity. Hence, it’s urgent to develop efficient collectors for the separation of galena and sphalerite. In this study, a novel morpholine dithiocarbamate propylene ester (MDPE) was designed and synthesized by the introduction of morpholine structure containing the C-O-C group, aiming to improve the surface activity and selectivity of the molecule. Surface tension tests indicated that MDPE exhibited a higher surface activity and stronger hydrophobicity than conventional collector N,N-diethyl dithiocarbamate propiononitrile ester (Ester-105) due to the introduction of morpholine structure. Microflotation experiments revealed that compared with Ester-105, higher flotation recovery of galena (90.75%) with significantly improved flotation selectivity against sphalerite by using MDPE of 2 × 10−4 mol/L at low alkalinity (pH=8.5) was obtained. Surface wettability measurements displayed that MDPE enhanced the hydrophobicity of galena surfaces more obviously than sphalerite. UV–vis spectra showed that MDPE preferred to interact with Pb2+ rather than with Zn2+. Adsorption experiments elucidated that the adsorption capacity of MDPE for galena was stronger than that for sphalerite. FTIR spectra and XPS proved that MDPE might chemically adsorb on the surface of galena through the formation of C-S-Pb structure. DFT calculations were conducted to demonstrate that the introduction of morpholine structure improved the chemical activity of the molecule.

Mechanism of Interaction between Morpholine Dithiocarbamate and Cyanoethyl Diethyldithiocarbamate Reagents and Low-Dimensional Gold on the Surface of Sulfide Minerals in Flotation of Difficult Gold-Bearing Ore

Mechanism of Interaction between Morpholine Dithiocarbamate and Cyanoethyl Diethyldithiocarbamate Reagents and Low-Dimensional Gold on the Surface of Sulfide Minerals in Flotation of Difficult Gold-Bearing Ore

Mechanism of Interaction between Morpholine Dithiocarbamate and Cyanoethyl Diethyldithiocarbamate Reagents and Low-Dimensional Gold on the Surface of Sulfide Minerals in Flotation of Difficult Gold-Bearing Ore

Mechanism of Interaction between Morpholine Dithiocarbamate and Cyanoethyl Diethyldithiocarbamate Reagents and Low-Dimensional Gold on the Surface of Sulfide Minerals in Flotation of Difficult Gold-Bearing Ore

Lead Sulphide Nanoparticles as Photocatalyst for the Degradation of Methylene Blue: Effects of pH, Time, Adsorption Kinetics and Recyclability Studies

We report the synthesis and morphological studies of lead sulphide nanoparticles prepared from lead(II) complexes of morpholine dithiocarbamate (PbS1), thiomorpholine dithiocarbamate (PbS2), and N-(2-hydroxyethyl)phenyl dithiocarbamate (PbS3). Powder X-ray diffraction patterns (p-XRD) of the PbS nanoparticles are indexed to face-centered cubic phase of PbS. High-resolution transmission electron microscopy (HRTEM) micrograph revealed quasi-spherical PbS nanoparticles with particle size in the range 13.86–36.06 nm while scanning electron microscopy (SEM) revealed flaky/spherical/rough surface morphology. Photocatalytic degradation of methylene blue dye by the PbS nanoparticles showed degradation efficiency of 72.6 % for PbS1, 75.9 % for PbS2, and 47.4 % for PbS3. The photodegradation efficiency shows a correlation between efficiency and morphological properties. Total organic content removal by PbS2 is 69.5 % while that of PbS1 is 64.2 % and PbS3 is 40.1 %. The as-prepared PbS nanoparticles exhibited remarkable photostability in the recyclability studies.

Analysis of Complexing and Adsorption Properties of Dithiocarbamates Based on Cyclic and Aliphatic Amines for Gold Ore Flotation

The authors find that morpholine dithiocarbamate (MDTC) and S-cyanoethyl N, N-diethyl dithiocarbamate (CEDETC) are capable to form stable compounds with gold in the solution and to form an adsorption layer on the surface of gold-bearing sulphides, which points at them as new selective collectors for gold recovery from rebellious ore. The coating area of MDTC on the surface of chalcopyrite, arsenopyrite and pyrite, with new discrete growths is quantitatively assessed. CEDETC improves floatability of chalcopyrite by 1.5–2.0 times as against butyl xanthate at low consumption of reagents, while difference in floatability of chalcopyrite and arsenopyrite considerably grows, which is indicative of a beneficial effect on production of Au-Cu concentrates with lower As content by flotation.

Synthesis and crystal structure of bis(morpholino dithiocarbamato) Cd(II) complex and its use as precursor for CdS quantum dots using different capping agents

ABSTRACTCadmium(II) morpholine dithiocarbamate complex [Cd(morphdtc)2] was synthesized and characterized by single crystal X-ray crystallography. The molecular structure of the complex showed Cd(II) ion in a distorted 4 + 2 octahedral geometry, in which the two morpholine dithiocarbamates act as bidentate chelating and the central Cd ion bond the sulfur atoms of adjacent morpholine acting as bridging ligands to form centrosymmetric five coordinate dimeric molecules. The Cd(II) complex was thermolysed at 180°C to prepare CdS nanoparticles using three different capping agents. The pXRD patterns revealed a mixture of hexagonal and cubic crystalline phases of CdS nanocrystals. TEM images revealed semi-spherical and spherical nanoparticles, with the size range of 4.50–5.70 nm for OLM-CdS, 3.33–5.96 nm for HDA-CdS, and 3.00–5.83 nm for ODA-CdS. The particle size distribution of the CdS nanocrystallite is within the range 1.06 nm (SD ± 0.73) for OLM-CdS, 0.68 nm, (SD ±0.73) for HDA-CdS and 1.18 nm, (SD ± 0.60) for ODA-CdS. The lattice fringes showed that the particles are almost in the same environment with the interplanar of 0.32 nm for OLM-CdS, 0.34 nm for HDA-CdS, and 0.32 nm ODA-CdS. The band gaps energy were confirmed to be 1.59 eV for OLM-CdS, 1.65 eV for HDA-CdS, and 1.62 eV for ODA-CdS nanoparticles, respectively.

Syntheses, physicochemical characterization, antibacterial studies on potassium morpholine dithiocarbamate nickel (II), copper (II) metal complexes and their ligands

Organic molecule dithiocarbamate transition metal complexes are novel and very attractive pharmaceutical targets for the management and control of antibiotic resistant bacteria. The direct reaction has synthesized new transition metal nickel (II), copper (II) complexes of potassium morpholine dithiocarbamate (K+C5H8NOS2−) ligands and characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), as well as NMR physicochemical techniques. Antibacterial bioefficacy of the ligand and its metal complexes has been investigated in vitro on the growth of Gram-positive (Staphylococcus aureus MTCC 737, Bacillus cereus MTCC 1272) and the Gram-negative (Listeria monocytogenes MTCC 657, Shigella flexeneri MTCC 1457) bacteria. The obtained electronic spectral bands are characteristic and consistent with the proposed composition of the ligand as well as its metal complexes. It also provides a further example of the bidentate coordination of dithiocarbamate ligands. Absorption peak values of FTIR are characteristic of the ligand as well as dithiocarbamate group molecules and exhibit their metal coordination. NMR 1H signal variations also correlate with the coordination mediated chemical shifts. Both the metal complexes showed significant antibacterial activity. However, enhanced antimicrobial activity of the ligands than metal complexes against Gram positive and Gram negative bacteria were observed. Thus, further study on this approach could pave a way for the development of dithiocarbamate-metal complex based antibacterial agent.

Syntheses, characterization, powder X‐ray diffraction analysis and antibacterial and antioxidant activities of triphenylantimony(V) heteroleptic derivatives containing substituted oximes and morpholine dithiocarbamate

Triphenylantimony(V) heteroleptic derivatives containing substituted oximes and morpholine dithiocarbamate of the type Ph3Sb[R(R′)C:NO]2[S2CN(CH2CH2)2O] (where R = ─C6H5, R′ = ─CH3 (I); R = ─C6H4CH3, R′ = ─CH3 (II); R = ─C6H4Cl, R′ = ─CH3 (III); R = ─C6H4Br, R′ = ─CH3 (IV); R = ─C6H4OH, R′ = ─H (V); R(R′)C = CCH2(CH2)3CH2 (VI)) were synthesized by successive substitution reactions of triphenylantimony(V) dibromide with the sodium salt of substituted oximes and morpholine dithiocarbamate in unimolar ratio. All these newly synthesized derivatives were characterized using physicochemical and elemental analyses and tentative structures have been proposed on the basis of infrared, (1H, 13C) NMR and liquid chromatography–mass spectra. Spectral data revealed that the oxime behaves in a monodentate manner whereas morpholine dithiocarbamate behaves in an anisobidentate manner and thus distorted octahedral geometry has been proposed for these derivatives. Nanometric particle size (ca 25 nm) and monoclinic crystal system have been determined using power X‐ray diffraction data of two representative derivatives. Furthermore, these newly synthesized derivatives were screened against two bacteria, Bacillus subtilis (Gram‐positive) and Escherichia coli (Gram‐negative), to evaluate their antibacterial potential. Derivative VI exhibited maximum zone of inhibition (30 mm) against E. coli. Additionally two derivatives (I and II) were tested for their antioxidant potential, with derivative II exhibiting higher antioxidant potential (233 μM g−1). Structure–activity relationships were also investigated.

Biological effect and molecular docking of anticancer palladium and platinum complexes with morpholine dithiocarbamate on human serum albumin as a blood carrier protein.

The aim of this study was to examine the interaction of [Pd(2,2'-bipyridine) (morpholinedithiocarbamate)]NO3 and [Pt (2,2'-bipyridine)(morpholinedithiocarbamate)]NO3 with human serum albumin under physiological conditions by using fluorescence, absorption, and circular dichroism spectroscopic techniques. Spectroscopic analysis of the emission quenching at different temperatures demonstrated that the quenching mechanism was static quenching. From the circular dichroism results, thermal stability study, it was found that the interaction of the complexes with human serum albumin caused a conformational change of the protein reversibly. These 2 anticancer Pd and Pt complexes were activated against chronic myelogenous leukemia cell line K562, so that 50% cytotoxic concentration values of 16 and 26 μM for Pd and Pt complexes, respectively, were observed, which were much lower than that of cisplatin (154 μM). Biological activities of both Pd and Pt complexes were also assayed against selective microorganisms by the disc diffusion method. These results showed that the Pd(II) complex is antifungal agent but Pt(II) complex has antibacterial activity. Also, the interaction of both metal derivative complexes was studied by molecular docking. Complementary molecular docking results may be useful to determine the binding mechanism of human serum albumin in pharmaceutical and biophysical studies providing new insight in the novel pharmacology.

Styrenation of air blown linseed oil via RAFT–mediated miniemulsion polymerization

Abstract In this study styrenated oil products were prepared under miniemulsion conditions by reversible addition-fragmentation chain transfer polymerization (RAFT) technique using phenacyl morpholine dithiocarbamate (PMDC) as a RAFT agent. First, hydroperoxide groups were formed on the oil structure by air-blowing process. Then the prepared miniemulsion of air blown linseed oil (ABLO)-styrene mixture was subjected to styrenation in the presence of the RAFT agent. Miniemulsion was prepared by means of ultrasonication by using cetyl trimethyl ammonium bromide (CTAB) and hexadecane (HD) as surfactant and co-surfactant, respectively. The best miniemulsion conditions were determined by a new strategy based on the determination of the conditions ensuring not to change of droplet/particle size throughout the polymerization. In this way, the conditions for the elimination of monomer diffusion between droplets were established. The styrenated oil product obtained under optimum conditions was characterized by FT-IR, 1 H NMR and GPC measurements. In order to understand the effect of miniemulsion conditions on molecular weight and polydispersity index (PDI), styrenated oil samples were also prepared in solvent (dioxane) medium. Tests for film properties of product prepared by RAFT in miniemulsion medium were applied according to related standards. The styrenated oil obtained in this study exhibited molecular weight distribution values lower than styrenated oil products obtained by the classical RAFT polymerization in solvent medium. The film properties showed that these styrenated oil samples could be used as an oil based binder.

Dithiocarbamates as Selective Ligands for Polarographic Study of Manganese(II) at DME

Two new ligands, ammonium 2,6-dimethyl morpholine dithiocarbamate (ADMM- DTC) and ammonium 3-methyl piperdine dithiocarbamate (AMP-DTC) were synthesized in the laboratory. The method was based on chelation of manganese(II) with ADMM-DTC/AMP-DTC in the presence of NH4OH at pH 6.2 and 6.8 to produce catalytic hydrogen currents at -0.72 V and -0.62 V vs. SCE respectively and prior detected by D.C poarography. Optimized polarographic conditions were established by studying effect of pH, supporting electrolyte (NH4Cl), ligand and metal ion concentrations and effect of adverse ions on peak height to improve the sensitivity, selectivity and detection limits of the present method. This technique is successfully applied for the analysis of manganese(II) in different matrices with recoveries ranging from 97 - 99% and the results obtained were comparable with the differential pulse polarography (DPP).

Beta-casein and its complexes with chitosan as nanovehicles for delivery of a platinum anticancer drug

The clinical application of platinum-based anticancer drugs is greatly limited by severe toxicity. Drug-delivery systems are much sought after to improve the efficacy and applicability of these drugs. Here, we describe a new drug-delivery system comprising a novel platinum complex (bipyridine morpholine dithiocarbamate Pt(II) nitrate) within nanoparticles composed of β-casein (β-CN) and chitosan (CS). The influence of pH on the formation of a colloidally-stable nanocarrier system composed of Pt complex-loaded β-CN and chitosan nanoparticles was investigated using UV–vis spectrometry, dynamic light scattering (DLS) and scanning electron microscopy (SEM). The particles of Pt complex-loaded beta-casein–chitosan formed were stable and soluble in the pH range 5.7–6.2. Hence, the optimal pH for complex formation is between the pI of casein (5.3) and the pKa of chitosan (6.5). DLS data showed that, at both pH values of 5.7 and 6.2, the particles formed had sizes between 200 and 300nm. However, the optimum pH for particle formation was pH 5.7. At this pH, the zeta-potential values of nanoparticles were positive and the particles were stable. SEM analysis confirmed the formation of nanoparticles with good colloidal stability and an average particle size of 200nm. The cytotoxicity of both free and encapsulated Pt complex was evaluated on colorectal carcinoma HCT116 cells. The results obtained indicated that both the cytotoxicity and cellular uptake of platinum were enhanced by its entrapment in β-CN–CS nanovehicles. These findings suggest that this novel drug-delivery system enables drugs to be thermodynamically stable in aqueous solutions and is potentially useful for targeted oral-delivery applications.

Multivariate optimization of differential pulse polarographic–catalytic hydrogen wave technique for the determination of nickel(II) in real samples

Multivariate optimized experimental conditions were established for the determination of nickel(II) in 92 grape samples after complexation with ammonium piperidine dithiocarbamate (APDC) and ammonium morpholine dithiocarbamate (AMDC). Differential pulse polarographic (DPP) studies of the wave characteristics indicated that it is of the catalytic hydrogen wave (CHW) type sensitive to pH, concentration and scan rates. A single, sharp peak obtained at −1.22V allowed for the trace determination of nickel(II) in the range of 3.2×10−6 to 1.17×10−3M with a linear calibration and a detection limit of 1.8×10−6 and 2.7×10−6M for APDC and AMDC respectively. Mechanistic aspects between APDC/AMDC and nickel(II) were confirmed with cyclic voltammetry and supported by theoretical calculations. The DFT calculations of piperidine adduct reveal a smaller HOMO–LUMO energy gap than morpholine adduct, suggesting that piperidine adduct has a greater tendency to act as an electron donor.

The crystal structure of [Cu(S2CNC4H8O)2]: An interesting structural motif constructed by intermolecular S⋯S and C–H⋯Cu interactions

The crystal structure of the morpholine–dithiocarbamate complex [Cu(S2CNC4H8O)2] has been carried out and reveals an aggregation pattern in which molecular sub-units are linked by C–H⋯Cu and S⋯S interactions. The isomorphous piperidine–dithiocarbamate complexes [M(S2CNC5H10)2] (M=Cu, Ni) also show this structural motif suggesting that it may be common in square-planar bis(dithiocarbamate) complexes with six-membered backbones.

Dithiocarbamates Strongly Inhibit Carbonic Anhydrases and Show Antiglaucoma Action in Vivo

A series of dithiocarbamates were prepared by reaction of primary/secondary amines with carbon disulfide in the presence of bases. These compounds were tested for the inhibition of four human (h) isoforms of the zinc enzyme carbonic anhydrase, CA (EC 4.2.1.1), hCA I, II, IX, and XII, involved in pathologies such as glaucoma (CA II and XII) or cancer (CA IX). Several low nanomolar inhibitors targeting these CAs were detected. The X-ray crystal structure of the hCA II adduct with morpholine dithiocarbamate evidenced the inhibition mechanism of these compounds, which coordinate to the metal ion through a sulfur atom from the dithiocarbamate zinc-binding function. Some dithiocarbamates showed an effective intraocular pressure lowering activity in an animal model of glucoma.

Lanthanum dithiocarbamates as potential extreme pressure lubrication additives

The extreme pressure lubrication (EPL) properties of bipyridyl adducts of different lanthanum dithiocarbamates of the type LaL3·bipy (where LH = dimethyl dithiocarbamate (Me2DTCH), piperidine dithiocarbamate (PipDTCH), morpholine dithiocarbamate (MorphDTCH), and diphenyl dithiocarbamate (Ph2DTCH); bipy = 2,2′-bipyridyl) have been evaluated with a four-ball lubricant tester using steel balls of 12.7-mm diameter and molybdenum disulfide as a reference additive. Various tribological parameters, viz. mean wear scar diameter, friction coefficient, mean specific pressure, initial seizure load, 2.5-s seizure delay load, weld load, flash temperature parameter, mean Hertz load, pressure wear index, etc., have been determined. The surface topography of wear scar has been studied by atomic force microscopy and scanning electron microscopy. Energy-dispersive X-ray analysis has been performed to give the composition of the wear scar surface. Experimental results indicate that admixtures containing bipyridyl adducts of lanthanum dithiocarbamates in paraffin oil exhibit better EPL properties than paraffin oil alone or with a reference additive (MoS2). In view of very high efficiency, the synthesized compounds can be recommended for their application as EPL additives.

Styrenated sunflower oil polymers from raft process for coating application

AbstractOil‐based macroinitiator (MI) obtained from sunflower oil was styrenated using reversible addition–fragmentation chain transfer polymerization (RAFT) in the presence of phenacyl morpholine dithiocarbamate (PMDC) as chain transfer agent. The solvent effect and effect of the molar ratio of the transfer agent, PMDC, on polydispersity and molecular weight of the polymers were investigated. The obtained results showed that, 1,4‐dioxane is a better solvent and 1/4 molar ratio of [MI]/[PMDC] provides relatively low polydispersities. No homopolystyrene was detected under these conditions, indicating the efficiency of PMDC in the chain transfer process. Livingness of the polymerization process was confirmed by chain extension with styrene using the preformed polymer as macrotransfer agent. The film properties of styrenated oil samples were determined according to the related standards. To improve film properties, the polymer obtained by RAFT technique was modified by reaction with MI. The resulting material gave transparent films with good film properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis and Conducting Properties of a New Mixed-valence Cu(I)–Cu(II) 1-D Coordination Polymer Bridged by Morpholine Dithiocarbamate

Abstract A novel mixed-valence Cu(I)–Cu(II) coordination polymer with an infinite one-dimensional (1-D) structure, [CuI4CuIII4(Mor-dtc)2(CH3CN)2]n (Mor-dtc−: morpholine dithiocarbamate), was prepared and structurally characterized by X-ray diffraction. This complex consists of a mononuclear copper(II) unit of [CuII(Mor-dtc)2] and a tetranuclear Cu(I) unit of [Cu4I4(CH3CN)2]. It also shows semiconductive behaviors with a relatively small activation energy, which was revealed by impedance analysis.

The determination of cobalt(II) at DME using catalytic hydrogen current technique in various water samples, agricultural materials and pharmaceuticals

Two novel and facile ligands ammonium piperidine dithiocarbamate (Amm Pip-DTC) and ammonium morpholine dithiocarbamate (Amm Mor-DTC) were synthesized for the development of rapid and cost effective catalytic hydrogen current technique to analyze cobalt(II) in the presence of NH(4)Cl-NH(4)OH at pH 7.8 and 8.4 with Amm Pip-DTC and Amm Mor-DTC. These ligands produce catalytic hydrogen currents with Co(II) at peak potentials -1.24 V and -1.44 V vs. SCE respectively. Quantitative experimental conditions are developed by studying effect of pH, supporting electrolyte (NH(4)Cl), ligand and metal ion concentrations and effect of adverse ions on peak height to improve the sensitivity, selectivity and detection limits of the catalytic hydrogen current technique and compared it in terms of Student's t test and variance ratio f test with differential pulse polarographic (DPP) method. The developed technique was applied for the analysis of cobalt(II) in various water samples, agricultural materials and pharmaceuticals and the results obtained are in good agreement with the DPP data.