Thione Groups Research Articles

A non-inhibitor flotation process for selective enrichment of chalcopyrite from molybdenite by using 5-methyl diethyl dithiocarbamate-1,3,4-oxadiazole-2-thione

During froth flotation, the separation of chalcopyrite from molybdenite is hindered by their similar surface properties. Therefore, it is imperative to develop an efficient selective collector with innovative minerophilic groups and reduce the use of inhibitors. In this study, 5-methyl diethyl dithiocarbamate-1,3,4-oxadiazole-2-thione (MDCODT) was first introduced as a collector in chalcopyrite flotation separation from molybdenite. Micro-flotation experiment results expressed that the selectively separation of chalcopyrite from molybdenite could be realized without the addition of inhibitor. Wettability tests, ζ-potential analyses and UV spectrum demonstrated that MDCODT specifically adsorbed on the surface of chalcopyrite rather than molybdenite. And the adsorption mechanism was future explored by AFM scan, electrochemical tests, FTIR spectrum, XPS spectrum and DFT calculation. The active centers of MDCODT are concentrated in dithiocarbamate and oxadiazole thione groups, and MDCODT-Cu(I) complexes can be covered on the chalcopyrite surface with formation of Cu-S and Cu-N bonds. The di-minerophilic group oxadiazole-thione collector, MDCODT, exhibits the advantages of cost-effectiveness and environmental friendliness, rendering it suitable for a wide range of industrial applications.

Rapid coating of polyamide, polyurea, and polythiourea on metal–organic framework surfaces

Well-defined metal–organic framework (MOF)@polymer core–shell composite particles with polyamide, polyurea, and polythiourea as the shell layer have been constructed for the first time using non-solvent-induced surface-aimed polymerization. This surface polymerization method utilizes non-solvent-induced phase separation to concentrate and direct monomers onto MOF particle surfaces, thus completing the coating process in less than 5 min. The generalizability of this method has been demonstrated with different MOFs. Coating MOF particles with any of the three polymers can effectively improve the stability of the MOF in harsh chemical environments. When used for heavy metal removal, polythiourea-coated composite particles (MOF@HDA-PDTC) exhibited a drastically improved Hg(II) removal rate and full utilization of the thione groups for Hg(II) binding compared to their neat polymer counterparts. This highlights the unique benefit of this core–shell architecture for the optimization of diffusion.

Experimental and computational studies of tautomerism pyridine carbonyl thiosemicarbazide derivatives

Tautomerism is one of the most important phenomena to consider when designing biologically active molecules. In this work, we use NMR spectroscopy, IR, and X-ray analysis as well as quantum-chemical calculations in the gas phase and in a solvent to study tautomerism of 1- (2-, 3- and 4-pyridinecarbonyl)-4-substituted thiosemicarbazide derivatives. The tautomer containing both carbonyl and thione groups turned out to be the most stable. The results of the calculations are consistent with the experimental data obtained from NMR and IR spectroscopy and with the crystalline forms from the X-ray studies. The obtained results broaden the knowledge in the field of structural studies of the thiosemicarbazide scaffold, which will translate into an understanding of the interactions of compounds with a potential molecular target.

New Hg(II) coordination polymers based on a thioimidazole ligand with good performance to detoxify Hg(II) and reversibly capture iodine.

In the current paper, we have successfully synthesized three new mercury coordination polymers with fascinating structures and properties via a flexible sulfur donor ligand, namely, {[Hg(μ2-Cl)(μ2-Ls)]}n[BF4]n(1), {[Hg(μ2-Cl)(μ2-Ls)]}n[ClO4]n(2), and [Hg(SCN)2(μ2-Ls)]n(3) [Ls = 1,1-bis(3-methyl-4-imidazoline-2-thione)methane]. These complexes have been characterized by means of different techniques such as single crystal X-ray crystallography, FT-IR, elemental analysis (CHNS), UV-Vis, PXRD, BET, and TGA. Suitable single crystals of all complexes were obtained using the branch tube method with a very high yield and good stability due to the high affinity of mercury to bind to the thione groups. The cationic moieties of polymers 1 and 2 were isostructural, with a HgCl2S2 coordination core structure. The voids of the quasi-hexagonal packing of the columnar chains were occupied by unbonded tetrahedral BF4- ions in 1 and perchlorate anions in polymer 2. Polymer 3 has a less distorted tetrahedral geometry than 1 and 2, with a HgS4 core structure. By considering the thiophilicity of mercury, a thioamide-based Ls ligand was used to detoxify Hg(II) into insoluble polymers 1-3. The results of an MTT assay for (HepG2) liver cells confirmed the excellent cytoprotective effect of this ligand against mercury. Based on IC50 calculations, their toxicity was in order of polymer 1 > polymer 2 > polymer 3. These polymers were also considered as adsorbents for the reversible removal of iodine from solution and the kinetics of the process has been studied in detail. Interestingly, all of them showed an excellent stability and high capacity, in order of 763.53 mg g-1, 877.10 mg g-1, and 905.31 mg g-1 for polymers 1-3, respectively.

Structure and Bonding of 1,2,4-Triazole Thiones Derived from Nitron

The molecular structures of two 1,2,4-triazole thiones derived from Nitron, namely Nitron(S) and Nitron(S)Me, have been determined by single crystal X-ray diffraction. Comparison with the structure of Nitron indicates that the formation of the thiones is accompanied by a shortening of the C–N bond within the 5-membered ring that is opposite to the thione group, and a lengthening of the exocyclic C–N bond. Analysis of the structures of Nitron, Nitron(S) and Nitron(S)Me, together with hypothetical versions in which the phenyl substituents are replaced by hydrogen, indicates that these changes are in accord with bond order differences predicted by natural bond orbital methods. A similar evaluation of the thione groups of Nitron(S) and Nitron(S)Me indicates that the C–S bonds are composed of both covalent and ionic components and are best described by a combination of resonance structures that feature CS double and C–S single bonds.

Investigating the selectivity of a xanthate derivative for the flotation separation of chalcopyrite from pyrite

Separating chalcopyrite, an important copper-containing ore, from pyrite is an important mineral-processing objective. Herein, we report the synthesis of S-hydroxyethyl-O-isobutyl xanthate (HEIBX), a novel surfactant bearing both hydroxyl and thione groups, through the attachment of a hydroxyethyl group to sodium isobutyl xanthate (SIBX), and its first application as a flotation collector for the selective flotation-separation of chalcopyrite from pyrite. The flotation mechanism involving HEIBX and chalcopyrite or pyrite was investigated by DFT calculations, UV–vis spectroscopy, contact-angle and surface-tension measurements, flotation and zeta-potential experiments, as well as FTIR spectroscopy and XPS. Incorporation of the hydroxyethyl group was observed to increase the molecular properties of SIBX by increasing the number of active sites, arrangement density, selectivity and hydrophobicity, thereby improving its flotation performance. Chalcopyrite was separated from pyrite using 4 × 10−5 mol·L−1 HEIBX at pH ∼8.0. Furthermore, we found that the hydroxyl and thione functional groups adsorb onto the chalcopyrite surface though the formation of COCu and CSCu bonds.

Synthesis, crystal structure, computational analysis and biological properties of 1-(4-chlorobenzoyl)-3-[2-(2-{2-[3-(4-chlorobenzoyl)-thioureido]-ethoxy}ethoxy)ethyl]-thiourea and its Ni(II) and Cu(II) complexes

A new dianionic ligand, 1-(4-chlorobenzoyl)-3-[2-(2-{2-[3-(4-chlorobenzoyl)-thioureido]-ethoxy}ethoxy)ethyl]-thiourea(CBEDEA), and its Ni(II) and Cu(II) complexes have been synthesized. X-ray single crystal analysis of CBEDEA shows that the molecule crystallized in the triclinic crystal system, space group P-1, with two molecules per unit cell. The studied compounds were further characterized by FT-IR, UV-VIS,1H NMR and mass spectroscopy. The metal complexes were isolated as four coordinated ML(M: Ni(II), Cu(II), L:CBEDEA) molecules. Computational studies on CBEDEA gave electrostatic potential energy isovalues which showed that there is a higher probability of metal coordination around the carbonyl and thione groups. Results of non-covalent interaction studies revealed the presence of significant amount of hydrogen bonding and other weak non-covalent interactions in the molecule. Docking calculations on CBEDEA and its Ni(II) and Cu(II) metal complexes revealed that they have affinity for beta-lactamase, a protein implicated in antibiotic drug-resistant mechanism. Complexation with the metal ion shrank the size of the molecule and enabled the metal complexes to fit more appropriately within the binding groove of the protein resulting in the improved affinity over CBEDEA ligand. Target-ligand binding interactions resulted from hydrophobicity and possibility of hydrogen bonding of the molecules. In vitro screening of the compounds against 17 bacteria and 4 yeasts confirmed their antimicrobial potency against more susceptible Gram-positive bacteria. Results of this study suggest that the metal complexes could be developed into novel antimicrobial compounds.

ChemInform Abstract: Heterocycles from the Reaction of Thione Groups with Acetylenic Bonds

AbstractReview: 179 refs.

Crystal structure of di-chlorido-bis-(1,3-diisopropyl-4,5-dimethyl-2H-imidazole-2-thione-κS)zinc(II).

The mol­ecular structure of the title compound, [ZnCl2(C11H20N2S)2], shows tetra­hedral Zn coordination from two Cl ligands and two thione groups. The Zn—Cl bond lengths differ sligthly at 2.2310 (10) and 2.2396 (11) Å while the Zn—S bond lengths are equal at 2.3663 (9) and 2.3701 (10) Å. The Cl—Zn—Cl angle is 116.04 (4) and S—Zn—S is 101.98 (3)°. All other angles at the central Zn atom range from 108.108 (3) to 110.21 (4)°. The C—S—Zn angles are 100.75 (10) and 103.68 (11)°, the difference most probably resulting from packing effects, as both the C—S and both the S—Zn bonds are equal in each case. The two imidazole ring planes make a dihedral angle of 67.9 (1)°. The CH3 groups of one isopropyl moiety are disordered over two sets of sites with occupation factors of 0.567 (15) and 0.433 (15). It may be noteworthy that the isomolecular Cu complex shows a different crystal packing (group–subgroup relation) with the Cu atom lying on a twofold rotation axis. In the crystal, the shortest non-bonding contact is a C—H⋯Cl inter­action. This leads to the formation of centrosymmetric dimers that are stacked along the c-axis.

Octyl (2E)-2-[2-(diphenylphosphanyl)benzylidene]hydrazinecarbodithioate

The title compound, C28H33N2S2P, adopts the thione tautomeric form, as supported by the C—S distance [1.6744 (18) Å]. The Schiff base exhibits an E conformation about the C=N bond but a Z conformation about the C—N bond. The terminal chain is disordered over two sets of sites with an occupancy ratio of 0.732 (3):0.268 (3). In the crystal, pairs of N—N—H hydrogen bonds between the thione groups link neighbouring mol­ecules into centrosymmetric dimers.

Synthesis of Pyrrolidine-Fused 1,3-Dithiolane Oligomers by the Cycloaddition of Polycyclic Dithiolethiones to Maleimides and Evaluation as Mercury(II) Indicators

The scandium triflate-catalyzed cycloaddition reaction of polycyclic 1,2-dithiolethiones to maleimides is described. The reaction constitutes an easy approach to linear as well as branched oligomeric cis-fused dihydro[1,3]dithiolo[4,5-c]pyrrole-4,6-dione rings interconnected by 3,5-diylidenethiomorpholine-2,6-dithione or ylidene-6-thioxo[1,2]dithiolo[3,4-b][1,4]thiazin-3-one groups. The presence of highly colored, highly polarized push-pull α,β-unsaturated thione groups in their structures make these compounds sensitive to the presence of mercury(II) cation in organic or mixed organic/aqueous solvents.

Site selectivity in reactions of hydrazonoyl halides with heterocycles containing amino and thione groups leading to fused heterocycles of potential antimicrobial activity

Reaction of hydrazonoyl halides with 6-(benzylidenamino)-2-thioxo-2,3-dihydro-1H-pyrimidin-4-one and 2,3-diaminoquinazolin-4-one site-selectively afforded 3-substituted-7-(benzylidenamino)-1-phenyl-[1,2,4]triazolo[4,3-a]-pyrimidin-5(1H)-ones, [1,2,4,5]tetrazino[6,1-b]quinazolin-6(4H)-one, and 3-methyl-2-(4-substituted-phenylhydrazo)-[1,2,4]triazino[3,2-b]quinazolin-10-ones in good yields. The structures of the newly synthesized compounds were elucidated by chemical evidence and their IR, 1H, 13C NMR, and MS spectra. Furthermore, some of the products were screened against different strains of bacteria and fungi.

Site Selectivity in Reactions of Hydrazonoyl Halides with Heterocycles Containing Amino and Thione Groups Leading to Fused Heterocycles of Potential Antimicrobial Activity

Site Selectivity in Reactions of Hydrazonoyl Halides with Heterocycles Containing Amino and Thione Groups Leading to Fused Heterocycles of Potential Antimicrobial Activity

Bis{N-ethyl-2-[3-(hydroxyimino-κN)butan-2-ylidene]hydrazinecarbothioamide-κ2N2,S}nickel(II) dichloride

In the title complex, [Ni(C7H14N4OS)2]Cl2, the NiII ion is six-coordinated in a distorted octa­hedral geometry by four N atoms from the two imine and two oxime groups, and two S atoms from the thione groups. Two chloride ions complete the asymmetric unit. In the crystal, mol­ecules are linked through N—H⋯Cl and O—H⋯Cl hydrogen bonds into an infinite chain propagating along [101].

Efficient dual catalytic enantioselective diethylzinc addition to the exocyclic C [dbnd]N double bond of some 1,2,4- N-triazinylarylimines using polymer-supported chiral β-amino alcohols derived from norephedrine

Chiral N, N-dialkylnorephedrines and their corresponding copolymers were evaluated as chiral ligands for the enantioselective diethylzinc addition to the exocyclic C N double bond of some 4-arylideneamino-3-mercapto-6-methyl-4 H-1,2,4-triazin-5-ones 2a– f. The use of a dual catalytic system (amino alcohol/halosilane) in the titled asymmetric reaction was examined. The enantioselective ethylation reaction has been successfully carried out in the heterogeneous system even at low temperature. The corresponding 4-(1-arylpropyl)amino-3-mercapto-6-methyl-4 H-1,2,4-triazin-5-ones 4a– f were obtained in high yields with high enantioselectivities using chiral polymers (up to 91% ee), which are almost the same as those obtained from homogeneous analogues (up to 92% ee). The diethylzinc reagent neither opened the 1,2,4-triazinyl heterocyclic ring nor attacked the carbonyl or the thione groups of the 1,2,4-triazinyl heterocyclic ring and the addition reaction took place exclusively at the exocyclic electrophilic carbon atom yielding the C-ethylated products 4a– f. Reductive cleavage of the 1,2,4-triazinyl heterocyclic ring led smoothly to the corresponding primary aromatic amines 11a– f without significant loss of enantiomeric purity. A suggestion about the possible transition state for the addition reaction is also presented.

5-[(1H-1,2,4-Triazol-1-yl)methyl]-1,3,4-thiadiazole-2(3H)-thione

In the title mol­ecule, C5H5N5S2, the dihedral angle between the mean planes of the triazole and 1,3,4-thia­diazole-2(3H)-thione groups is 74.21 (3)°. In the crystal structure, inter­molecular N—H⋯N hydrogen bonds link the mol­ecules into zigzag linear chains extended along the b axis.

Bis(3-methyl-2-thioxo-2,3-dihydro-1H-imidazolyl)borato-κ2 S,S′]dibromoindium(III)

The structure of the title compound, [InBr2(C8H12N4BS2)], the first bis(mercaptoimidazolyl)borate (BmMe) complex of indium to be structurally characterized, has been determined by single-crystal X-ray diffraction. The four-coordinate In atom displays a distorted tetrahedral geometry in the solid state and is surrounded by the two thione groups of a BmMe ligand and two bromides, with an average In—Br bond distance of 2.494 Å. The presence of a crystallographically imposed mirror plane results in the observation of a unique In—S bond length of 2.4407 (11) Å.

Cis-Dichlorotetrakis(2-mercapto-1-tert-butylimidazole)lead(II)

The crystal and molecular structure of the title compound, [PbCl2(C7H12N2S)4], the first mononuclear lead complex containing a 2-mercapto-1-alkyl­imidazole ligand to be structurally characterized, has been determined by single-crystal X-ray diffraction. The six-coordinate Pb atom displays a distorted octahedral geometry and is surrounded by four thione groups and two cis chloro ligands, with average Pb—S and Pb—Cl bond distances of 2.946 (3) and 3.058 (2) A, respectively.

“Scission–template–transportation” route to controllably synthesize CdIn2S4 nanorods

By using a novel method denoted the “Scission–template–transportation” route, CdIn2S4 nanorods with stoichiometric composition and high quality can be prepared in an ethylenediamine–ethanol mixed solvent at a relatively low temperature. Transmission electron microscopy images showed that the product from the 1∶1 mixed solvent was rod-like with an average size of 25 × 700 nm. Ethylenediamine serves as the nucleophile for the formation of the inorganic [Cd2S2] core by scission of the thione groups of cadmium bis(diethyldithiocarbanate) [Cd(DDTC)2]2 while ethanol acts as the transportation reagent for InCl3 in the process. These factors are both conducive to the growth of CdIn2S4 nanorods. The reaction proceeds through one-dimensional [CdS]n clusters, which act as intermediate templates for the subsequent growth of CdIn2S4 nanorods. Through adjusting the ethylenediamine∶ethanol ratio, the size of the CdIn2S4 nanorods can be easily controlled. The products were also investigated by X-ray powder diffraction, X-ray photoelectron spectroscopy and ICP elemental analysis.

A Simple Route to Synthesize MInS2 (M = Cu, Ag) Nanorods from Single-Molecule Precursors

Abstract CuInS2 and AgInS2 semiconductor nanorods are prepared readily from a stoichiometric mixture of In(S2CNEt2)3 and Cu(S2CNEt2)2 or Ag(S2CNEt2), by remove of the thione groups with ethylenediamine at 195 °C in a solvothermal process.