Ammonium Dithiocarbamate Research Articles

A Simple Approach for Fe Determination in Beer by using Dispersive Liquid-Liquid Microextraction and Flame Atomic Absorption Spectrometry

In this work, a new method for Fe extraction and preconcentration from beer by using dispersive liquid-liquid microextraction (DLLME) and determination by flame atomic absorption spectrometry (F AAS) was developed. Although in DLLME the use of an extraction solvent is mandatory (at least in theory), which is combined with a disperser solvent, in this work only the extraction solvent was used. For Fe extraction by DLLME, the type and volume of extraction solvent, sample volume, type of complexing agent, sample pH, salting out effect, and the number of washing cycles after extraction were evaluated. Thus, after optimization, 10 mL of beer, 75 µL of 1,2-dichlorobenzene of extraction solvent, 500 µL of 0.5% (w/v) pyrrolidine ammonium dithiocarbamate (APDC) as complexing agent were used. It is important to mention that pH adjustment, salt addition or washing cycles were no required. For Fe determination after DLLME, an external calibration curve was performed (R2 > 0.99) by direct extracts (reference solutions through DLLME) introduction in the conventional nebulization system of F AAS instrument. The accuracy evaluation was performed by results comparison with those obtained after microwave-assisted digestion (MAD) and Fe determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The Fe concentration in the studied samples ranged from 59.7 to 68.2 µg L-1 and the limit of quantification for DLLME/F AAS method was 9.0 µg L-1. Finally, the proposed method DLLME/F AAS was applied for Fe determination in several beer samples showing simplicity, low operational costs, suitable accuracy (104 to 119%) and precision (better than 13%), opening the possibility for its use in routine analysis for Fe determination in beer.

Flocculation activity and evaluation of chitosan-based flocculant CMCTS-g-P(AM-CA) for heavy metal removal

In order to effectively remove the dissolved heavy metals and the heavy metals on the colloidal particles during the flocculation process, a novel dual-functional chitosan flocculant CMCTS-g-P(AM-CA) is prepared by ultraviolet light-initiated graft polymerization using CMCTS, AM, and ammonium dithiocarbamate. The main influencing factors of monomer concentration, monomer ratio, pH value, photoinitiator concentration, and illumination time are investigated on the basis of intrinsic viscosity, grafting rate, and grafting efficiency of CMCTS-g-P(AM-CA). Characterization results provided empirical evidence for existence of chelating groups. In addition, CMCTS-g-P(AM-CA) was applied to treat the simulated heavy metals and electroplating wastewater. The effect of CMCTS-g-P(AM-CA) dosage, pH value, and reaction G value on flocculation efficiency was also explored. After the two-stage flocculation, the residual concentration of Ni(II), COD, and turbidity of actual electroplating wastewater decreased to 0.96 mg/L, 93.00 mg/L, and 1.71 NTU after flocculation tests at optimal condition, respectively. Finally, the “3E” triangular evaluation model is established and applied to evaluate the flocculation performance of CMCTS-g-P(AM-CA) on the actual heavy metal wastewater further, thereby proving its excellent chelation flocculation performance.

Cooperative adsorption of carbon disulfide in diamine-appended metal\u2013organic frameworks

Over one million tons of CS2 are produced annually, and emissions of this volatile and toxic liquid, known to generate acid rain, remain poorly controlled. As such, materials capable of reversibly capturing this commodity chemical in an energy-efficient manner are of interest. Recently, we detailed diamine-appended metal–organic frameworks capable of selectively capturing CO2 through a cooperative insertion mechanism that promotes efficient adsorption–desorption cycling. We therefore sought to explore the ability of these materials to capture CS2 through a similar mechanism. Employing crystallography, spectroscopy, and gas adsorption analysis, we demonstrate that CS2 is indeed cooperatively adsorbed in N,N-dimethylethylenediamine-appended M2(dobpdc) (M = Mg, Mn, Zn; dobpdc4- = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate), via the formation of electrostatically paired ammonium dithiocarbamate chains. In the weakly thiophilic Mg congener, chemisorption is cleanly reversible with mild thermal input. This work demonstrates that the cooperative insertion mechanism can be generalized to other high-impact target molecules.

Organotin(IV) complexes derived from N-ethyl-N-phenyldithiocarbamate: Synthesis, characterization and thermal studies

Organotin(IV) dithiocarbamate complexes, RSnClL2 and R2SnL2 (R=Me, Bu, Ph, and L=N-ethyl-N-phenyldithiocarbamate), have been synthesized by the reaction of mono- and disubstituted organotin(IV) with ammonium dithiocarbamate. The complexes were characterized by elemental analyses, and spectroscopic techniques (1H, 13C NMR and FTIR). The structures of Me2SnL2 and Bu2SnL2 were further established by single crystal X-ray diffraction technique. The crystal structure analysis showed that both complexes (Me2SnL2 and Bu2SnL2) exist as monomers. One of the dithiocarbamate ligands formed a chelate, while the other dithiocarbamate bonded to the central tin atom through one of the sulfur atoms and the second sulfur atom existed as a pendant to form distorted trigonal bipyramidal geometry. The thermal stability of all the complexes was studied using simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC). The TG-DSC results showed that Me2SnL2, BuSnClL2, Bu2SnL2, and PhSnClL2 displayed similar decomposition pathway via isothiocyanate intermediate, while MeSnClL2 and Ph2SnL2 showed decomposition pathways different from the rest of the complexes. All the complexes resulted in SnS as the final product of the thermal decomposition process.

Novel self-condensation of ammonium dithiocarbamates leading to symmetrical substituted thioureas

GRAPHICAL ABSTRACT

Thio residue from thermal processing of cometary ices containing carbon disulfide and ammonia

We have carried out experimental investigation on binary ice mixture containing carbon disulfide (CS2) and ammonia (NH3) ices formed at 10K. Icy films were formed in various combinations to investigate the reactivity of CS2 and NH3 molecules on cometary nucleus. In the case of NH3 ices, deposition carried out at 10K was found to contain NH3 homo-dimers that was found to reorient upon annealing to 40K. Phase transition was found to take place as the 10K ice was warmed to higher temperatures and the phase transition temperature was found to be 5K higher for the mixed ice in comparison to the layered deposits. Thermal processing of the mixed deposition of CS2NH3 ice was found to leave thio residue, which could be ammonium dithiocarbamate that was even found to be present at 340K.

암모니움 디티오카바메이트계 이온성 액체의 합성 및 내마모성능 (I)

The friction-reducing properties of lubricants containing ionic liquids based on ammonium dithiocarbamate are studied. The ionic liquids are produced through the following two steps: the synthesis of sodium alkyl dithiocarbamates via the substitution reaction of dialkylamine and carbon disulfide and their subsequent conversion into ammonium dithiocarbamate-based ionic liquids through an ion-exchange reaction with a quaternary alkyl ammonium halide salt. The structures of the ionic liquids are characterized by NMR spectroscopy and Fourier transform infrared spectroscopy. The isolated yields of the ionic liquids, which are viscous and pale yellow, are approximately 92%. The Brookfield viscosities and pour points of the ionic liquids are determined. Further, their wear resistances are measured through the four-ball wear test and the Schwingung Reibung Ver-schleiss (oscillation, friction, wear) test. The wear scar diameter of the lubricants containing 1 wt of the quaternary alkyl ammonium dithiocarbamate-based ionic liquids (0.475-0.631 mm) is significantly lower than that of the base oil (0.825 mm), proving that the ammonium dithiocarbamate-based ionic liquids have good friction-reducing characteristics. However, these friction-reducing characteristics fade significantly after long-term storage, owing to the degradation of the ionic liquids.

Modified carbon sorbents for recovering platinum(IV)

Sibunite, a carbon sorbent, has been modified with organosilicon monomers containing aminoguanidine, thiocarbamide, malonodiamide, and ammonium dithiocarbamate moieties. The high adsorption activity of the synthesized materials in hydrochloric acid solutions with respect to platinum(IV) ions results from the formation of ion-coordinated platinum(IV) complexes with the chemically active moieties of modifying compounds.

Synthesis and characterization of dithiocarbamate chitosan derivatives with enhanced antifungal activity

In this study, ammonium dithiocarbamate chitosan (ADTCCS) and triethylene diamine dithiocarbamate chitosan (TEDADTCCS) derivatives were obtained respectively by mixing chitosan with carbon disulfide and ammonia (triethylenediamine). Their structures were confirmed by FT-IR, 1H NMR, XRD, DSC, SEM, and elemental analysis. Antifungal properties of them against the plant pathogenic fungi Fusarium oxysporum and Alternaria porri were investigated at concentrations ranged from 31.25 to 500mg/L. The dithiocarbamate chitosan derivatives had enhanced antifungal activity compared with chitosan. Particularly, they showed obvious inhibitory effect on Fusarium oxysporum. At 500mg/L, TEDADTCCS inhibited growth of F. oxysporum at 60.4%, stronger than polyoxin and triadimefon whose antifungal indexes were found to be 25.3% and 37.7%. The chitosan derivatives described here deserve further study for use in crop protection.

Synthesis of Both Ionic Species of Ammonium Dithiocarbamate Derived Cholic Acid Moieties

The reaction of 3-aminopropylamide of cholic acid with CS2 produced a bile acid derivative of dithiocarbamic acid which further formed an ammonium salt with another molecule of 3-aminopropylamide of cholic acid. The cationic 3-ammonium propylamide of cholic acid did not react further with CS2 and the formed salt was stable in the reaction mixture, even when excess CS2 was used. When the reaction was carried out in the presence of aqueous sodium hydroxide, only the bile acid derivative of sodium dithiocarbamate was formed. The dithiocarbamate derivatives were characterized by 1H- and 13C-NMR spectroscopy and ESI-TOF mass spectrometry.

BIS-ISOTHIOCYANATES IN HETEROCYCLIC SYNTHESIS: SYNTHESIS OF BIS 4-THIAZOLIDINONES, BIS THIAZOLES, AND BIS 4-AMINO-THIAZOLE DERIVATIVES

Bis 2-thioxo-4-thiazolidinones (5a,b) were achieved by cyclocondensation of bis-isothiocyanates (3a,b) with sulfanylacetic acid at reflux temperature. Compounds (5a-c) were exploited to synthesize the versatile hitherto unknown bis(2-thioxo-4-thiazolidinone) deriva-tives (8, 9, 11, 12 & 16) via its reaction with some electrophiles. Reaction of bis ammonium dithiocarbamate derivatives [2b, (2a,c)] with chloroacetone, 4-nitrophenacyl bromide and 3-(2-bromoacetyl)-2H-chromene-2-one gave the corresponding bis thiazoles [18, (23a,b), 24], respectively, whereas, reaction of 2a,b with chloroacetonitrile gives bis (4-aminothiazoles) 21a,b. The synthesized compounds were characterized by IR, 1HNMR and mass spectral studies.

In situ Formation of Thermally Stable, Room-Temperature Ionic Liquids from CS2 and Amidine/Amine Mixtures.

Amidinium dithiocarbamates salts with diverse structures are prepared in situ by adding one equivalent of CS2 to an equimolar mixture of two nonionic molecules, an amidine and an amine. Many of the salts made in this way are room temperature ionic liquids (RTILs) and the others (ILs) melt well below the decomposition temperature of the salts, ca. 80 °C. Unlike the analogous amidinium carbamate RTILs, which are made by adding CO2 to amidine/amine mixtures and decompose near 50 °C, the amidinium dithiocarbamates do not revert to their amidine/amine mixtures when they are heated. The thermal, rheological, conductance, and spectroscopic properties of representative examples from a total of 50 of these ILs and RTILs are reported, comparisons between them and their nonionic phases (as well as with their amidinium carbamates analogues) are made, and the thermolysis pathways of the ammonium dithiocarbamates are investigated.

Reversibly Cross-Linking Amino-Polysiloxanes by Simple Triatomic Molecules. Facile Methods for Tuning Thermal, Rheological, and Adhesive Properties

The physical properties of five siloxane polymers with different types and frequencies of amino functional groups along the polymer side chains have been manipulated from flowing liquids to gels and to rubber-like materials by the simple addition or subtraction of a neutral triatomic molecule, CO 2 or CS 2 , at room temperature. The chemical changes, formation of ammonium carbamates and ammonium dithiocarbamates, create materials whose properties are totally different from those of the parent polymers as a result of the introduction of ionic cross-links. These materials can be returned to their original forms by heating (in the case of the CO 2 adducts) or to their protonated original forms by treatment with an acid (in the case of the CO 2 and CS 2 adducts). Heating the ammonium dithiocarbamates leads to loss of H 2 S and permanent (covalent) thiourea cross-links between the polymer chains. The new materials adhere strongly to other surfaces and can be swelled to several times their original volumes by different liquids. The rheological, swelling, and physical properties of the new materials have been correlated with the structures of the original polymers to provide a comprehensive picture of how changes at the nanometric length scale are translated to macroscopic changes. At least for the polysiloxanes examined here, the properties of the adducts do not correlate with the molecular weights of the original polymers, but do with the frequency of amino groups. The results demonstrate a simple, new method to cross-link polysiloxanes (and, in principle, a wide range of other polymers), transforming them into materials with totally different and potentially commercially useful properties.

Online Flow Injection Preconcentration and Flame Atomic Absorption Spectrometric Determination of Palladium(II) Using Inorganic and Inorganic‐Organic Hybrid Materials–Packed Microcolumns

Various inorganic and inorganic‐organic hybrid materials–packed columns, including commercially available C18 bonded silica gel and alumina columns, were tested for the on‐line preconcentration of palladium(II) and subsequent determination by flame atomic absorption spectrometry (AAS). Several thioligands were investigated for complexing palladium(II) and subsequent sorption, elution, and determination by flame atomic absorption spectrometer. Among them, diethyl ammonium dithiocarbamate was found to give the highest enrichment factor for a given concentration of palladium(II) under optimized conditions. After testing the accuracy of the developed method by analyzing certified reference material (SARM 7), it was applied for the analysis of street and domestic fan blade dust samples.

Hantzsch reaction of 3‐(2‐bromoacetyl)‐4‐hydroxy‐chromen‐2‐one. Synthesis of 3‐(thiazol‐4‐yl)‐4‐hydroxy coumarines

Abstract3‐Acetyl‐4‐hydroxy‐chromen‐2‐one (1) was brominated with phenyltrimethylammonium tribromide to afford 3‐(2‐bromoacetyl)‐4‐hydroxy‐chromen‐2‐one (2) whose reactions with thiourea, thioacetamide and ammonium dithiocarbamate gave respectively 3‐(2‐amino‐thiazol‐4‐yl)‐4‐hydroxy‐, 4‐hydroxy‐3‐(2‐phenyl‐thiazol‐4‐yl)‐ and 4‐hydroxy‐3‐(2‐mercapto‐thiazol‐4‐yl)chromen‐2‐one. In a similar manner, com pound 2 was treated with four 1‐substituted‐2‐thioureas and thiobenzamide to give the corresponding 4‐hydroxy‐3‐(thiazol‐4‐yl)‐chromen‐2‐one derivatives.

Synthesis and Evaluation of Some Substituted Mercaptothiazoles and Their Derivatives of Biological Interest.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of some 3-(thiazol- 4-yl)-4-hydroxy coumarines

In this work, an easy and efficient procedure for the synthesis of eight 3-(thiazol-4-yl)-4-hydroxychromen-2-one derivatives is presented. 3-Acetyl-4-hydroxychromen-2-one (1) was brominated with phenyltrimethylammonium tribromide to afford 3-(2-bromoacetyl)-4-hydroxychromen-2-one (2). Compound 2 reacts with thiourea, thioacetamide and ammonium dithiocarbamate to afford 3-(2-aminothiazol-4-yl)-4-hydroxychromen-2-one (3), 4-hydroxy-3-(2-methylthiazol-4-yl)chromen-2-one (4a) and -1-hydroxy-3-(2-mercaptothiazol-4-yl)chromen-2-one (5), respectively. In a similar manner, compound 2 was treated with four mono-N-substituted thioureas and thiobenzamide to give the corresponding 3-(thiazol-4-yl)-4-hydroxychromen-2-one derivatives.

ChemInform Abstract: Hypervalent Iodine in Synthesis. Part 60. A Novel Method for the Synthesis of 2‐Mercaptothiazoles by Cyclocondensation of Alkynyl(phenyl)iodonium Salts and Ammonium Dithiocarbamate.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Photochemical reactions of quaternary ammonium dithiocarbamates as photobase generators and their use in the photoinitiated thermal crosslinking of poly(glycidyl methacrylate)

AbstractThe photochemical behavior of quaternary ammonium salts (QA salts) with N,N‐dimethyldithiocarbamate as photobase generators and the photoinitiated thermal crosslinking of poly(glycidyl methacrylate) (PGMA) with the QA salts were investigated. The formation of basic compounds in the photolysis of 1‐phenacyl‐(1‐azonia‐4‐azabicyclo[2,2,2]octane) N,N‐dimethyldithiocarbamate was ascertained by the color change of phenol red as an acid–base indicator. 1H NMR spectra of photoproducts in CDCl3 under N2 showed that the photolysis of 1‐naphthoylmethyl‐(1‐azonia‐4‐azabicyclo[2,2,2]octane) N,N‐dimethyldithiocarbamate resulted in the quantitative formation of triethylenediamine and a dithiocarbamate derivative. The presence of oxygen in the photolysis decreased the photolysis rate. The amine was also detected in its photolysis in polystyrene films. The effects of ammonio groups and counteranions of QA salts on the photoinitiated thermal crosslinking of PGMA films were also investigated. Quaternary ammonium dithiocarbamates acted as excellent photobase generators and effective photoinitiated thermal crosslinkers for PGMA. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1329–1341, 2001

HYPERVALENT IODINE IN SYNTHESIS. 48. A ONE-POT CONVENIENT PROCEDURE FOR THE SYNTHESIS OF 2-MERCAPTOTHIAZOLES BY CYCLOCONDENSATION OF KETONES WITH [HYDROXY(TOSYLOXY)IODO]-BENZENE AND AMMONIUM DITHIOCARBAMATE

α-Tosyloxylation of ketones with [hydroxy(tosyloxy)iodo]-benzene (HTIB), followed by treatment with ammonium dithiocarbamate, provides a one-pot convenient procedure for the synthesis of 2-mercaptothiazoles with good yields.