Xanthate Complexes Research Articles

SYNTHESIS, CHARACTERIZATION, DFT, AND BIOLOGICAL ASSAY OF NEW XANTHATE COMPLEXES WITH NITROGEN BASES

This study introduces a new series of complexes and adducts, denoted by [M(2-PhOEtXant)2.nL], where M represents Mn(II), Fe(II), Co(II), or Ni(II), and the ligand (2-PhOEtXant) is 2-Phenoxyethylxanthate. Varying ligands, including pyridine, piperidine, quinoline, ethylenediamine, and (1,10)-phenanthroline, are explored based on the value of n. Comprehensive characterization, encompassing techniques like 1H-NMR, 13C-NMR, FTIR, AA, CHN analysis, UV-visible spectroscopy, and magnetic property measurements, is employed. Results indicate an octahedral geometry for these complexes, as revealed by effective magnetic moment measurements and electronic spectra analysis. The compounds exhibit noteworthy antioxidant properties, demonstrated through the DPPH radical scavenging method, highlighting their potential as effective antioxidants. Moreover, the complexes display enhanced antibacterial activity against microbial strains compared to free ligands. This research not only delves into the coordination chemistry of these complexes but also underscores their diverse applications. Combining experimental methods with computational insights using Density Functional Theory (DFT) enhances the understanding of dithiolate transition metal complexes. The alignment of computational and experimental outcomes strengthens the reliability of the findings, laying a robust foundation for interdisciplinary exploration. The identified potential applications in optoelectronics, along with the notable antioxidant and antibacterial activities, position these complexes as promising contenders for advanced technologies and scientific applications.

Electronic analysis of n-propyl xanthate complexes with group 12 metals: a theoretical-experimental study.

Xanthates are organic compounds of great interest in coordination chemistry due to their different basic sites, which allow them to form complexes with different coordination modes and geometries. These compounds are relevant in the environment and act as heavy metal collectors in aqueous environments. In this theoretical-experimental work, electronic spectroscopy studies of n-propyl xanthate complexes with group 12 metals were performed. This study verified structural differences in these systems, depending on the environment in which they are inserted. In addition, structural differences were observed when the solid was changed to an n-hexane solution. Thus, it was observed that the complexes assume a mononuclear structure in solution, while they present a polymeric form in the solid phase. The electronic spectra obtained through TD-DFT calculations were compared to those of the previously synthesized complexes. In the final theoretical analysis, the main orbitals involved in these transitions were assigned using population analysis calculations. The synthesis of the complexes was confirmed through infrared (MID and FAR), UV‒Vis, Raman, and NMR-1H spectroscopic analyses. The structures of the mononuclear and polymeric complexes were optimized in vacuum and n-hexane. Under vacuum, DFT levels M06L/6-311 + + G** + LANL2TZ and M06L/def2-TZVP were used for the mononuclear complexes, and M06L/LANL2DZ + LANL2 were used for the polymer complexes. For the calculations of the mononuclear complexes in n-hexane, the same level of theory was used for the solid state. TD-DFT calculations for 300 excited states were performed with the same levels of theory and used the optimized structures of the complexes. Furthermore, population analysis was carried out on all the systems studied. Gaussian 09 software was used for the structure optimization, TD-DFT, and population analysis calculations. GaussSum software was used to evaluate the molecular orbitals and electronic spectra.

Semiconductor Deposition via Laser Printing of a Bespoke Toner Containing Metal Xanthate Complexes.

A methodology to use laser printing, a form of electrophotography, to print metal chalcogenide complexes on paper, is described. After fusing the toner to paper, a heating step is used to cause the printed metal xanthate complexes to thermolyze within the toner and form three target metal chalcogenides: CuS, SnS, and ZnS. To achieve this, we synthesize a poly(styrene-co-n-butyl acrylate) thermopolymer that emulates the thermal properties of a commercial toner and is also solution processable with the metal xanthate complexes used: [Zn(S2COEt)2], [Cu(S2COEt)·(PPh3)2], and [Sn(S2COEt)2]. We demonstrate through energy dispersive X-ray mapping that the toner is deposited following printing and that thermolysis of the metal xanthate complexes occurs in the fused toner, demonstrating the first example of laser printing of inorganic complexes and, in turn, semiconductors.

Preparation and Characterization of Some Complexes of Nickel(II), Copper (II), and Zinc (II) With Decylxanthate and their Adducts with Nitrogen Base Ligands, and their Biological Activity

This research includes the synthesis and characterization of twelve new complexes of mono nuclear xanthate for a number of transition metal ions Ni(II), Cu(II), and Zn(II) and through the interaction with ligand (potassium decyl xanthate) and complexes of formula [M(DEXANT)2] were prepared: M= Ni(II), Cu(II), and Zn(II), and then the interaction of these complexes with Lewis bidentate bases, to give complexes with the formula [M(DEXANT)2.L], where L= 1,10-phenanthroline, 8-hydroxyquinoline, and 2,2-bipyridine. The prepared complexes were characterized by melting point, atomic absorption spectrometry, micro elemental analysis, infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, molar electrical conductivity, electronic absorption spectra, and magnetic susceptibility measurements. Magnetic moment and electronic spectra indicated that the complexes of type [M(DEXANT)2] had a tetrahedral geometry, while complexes of type [M(DEXANT)2.L] had an octahedral geometry. The conductivity measurements proved the non-electrolytic behavior of all compounds. The biological evaluation against bacterial species indicated that the xanthate complexes were effective against all bacterial types.

Establishment of a Hydrometallurgical Scheme for the Recovery of Copper, Nickel, and Cobalt from Smelter Slag and Its Economic Evaluation

In pursuit of carbon neutrality, the demand for metals that are necessary for the development of clean energy technologies is rapidly increasing. Metallurgical waste, such as slag, presents a promising secondary source of these key metals. This research aims to develop an eco-friendly hydrometallurgical process to recover Cu, Ni, and Co from discarded copper/nickel slag. High-pressure acid leaching (HPAL) was used to selectively leach Ni, Cu, and Co from the fayalite slag, yielding high leaching efficiencies of 99.9%, 89.4%, and 99.9%, respectively, with low Fe and Si tenors to the pregnant leach solution (PLS). The solvent extraction (SX) technique utilizing LIX 984N was used to selectively extract and enrich copper from the dilute PLS to about 23 g/L Cu with a very low Fe concentration of 0.05 g/L. Potassium amyl xanthate (PAX) solution was used to form Ni and Co xanthate complexes from the raffinate solution. Nickel was selectively recovered using ammonia solution, while the cobalt xanthate complex was thermally decomposed and recovered as cobalt oxide solids of about 25 wt.% Co. A comprehensive process flowsheet is presented. Furthermore, to realize the real application of the developed slag cleaning process, a preliminary economic evaluation was performed.

Synthesis of new dithiocarbamate and xanthate complexes and their application in enrichment processes

Ore flotation is the main and defining technological process in ore benefication and non-ferrous metals production. The flotation process requires the use of a variety of chemical reagents, including collectors, frothers, surface modifiers, and pH regulators. The development and selection of suitable reagents for the processed material play a vital role in efficient flotation. The flotation activity of collectors depends fundamentally on the composition and structure of the hydrophobic and hydrophilic fragments forming the flotation agent molecule, as well as on the nature of the ore that undergoes flotation processing. In this regard, the identification and study of the “substance structure–flotation activity” relation, as well as the search for new effective flotation reagents gain importance within applied organic and organoelement chemistry and related branches of science and technology. In this article, we review syntheses of effective collector reagents, namely xanthates and dithiocarbamates, based on the literature data for the past five years. Where necessary, earlier sources are provided. The reaction conditions and yields of the target compounds are presented using schemes. In addition, we present the results of flotation tests on the surfaces of various ores and the data on the mechanism of concentrate extraction. According to the reviewed publications, the fixation of collector reagents on the surface of minerals can be regarded as a complexation process of the collector functional groups and metal ions located on the surface of the mineral.

Determination of xanthates as Cu(II) complexes by high-performance liquid chromatography - Inductively coupled plasma tandem mass spectrometry.

The present study provides a novel, selective analysis method for the determination of low xanthate concentrations. The rising concern over the environmental effects of xanthates demands the development of analysis methods which this study answers. Complex formation in aqueous solution between xanthates and an excess of Co(II), Ni(II), Pb(II), Cd(II), Cu(II), and Zn(II) ions was utilized to selectively determine xanthates by high-performance liquid chromatography-inductively coupled plasma tandem mass spectrometry for the first time. The complexes that were formed were extracted to ethyl acetate using liquid-liquid extraction and separated by high-performance liquid chromatography technique before the quantitative determination of metal ions and sulfur in the xanthate complexes. Good separation and high measurement sensitivity were achieved using Cu(II) as the complex metal ion. The analysis method was optimized for the determination of sodium isopropyl xanthate and sodium isobutyl xanthate with detection limits of 24.7 and 13.3μg/L, respectively. With a linear calibration range of 0.1-15mg/L and a total analysis time of 4-5min, the present method is a fast and sensitive option for selective xanthate determination.

Synthesis of Nickel Sulfide Thin Films and Nanocrystals from the Nickel Ethyl Xanthate Complex

Nickel sulfides have unique and diverse structural features, making them ideal for energy conversion and storage. This research focuses on the synthesis and characterization of nickel sulfide thin films and nanocrystals from nickel ethyl xanthate complex using spin-coating and solventless methods. The nickel ethyl xanthate complex (C6H10S4NiO2) was characterized using Fourier-transformed infrared (FT-IR), ultraviolet-visible (UV-Vis), and nuclear magnetic resonance (NMR) spectroscopies as well as thermogravimetric analysis (TGA). The NiS thin films and nanoparticles were analyzed with energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD). Nickel ethyl xanthate was synthesized in an 81.2% yield. The bandgaps of the nickel sulfide obtained from the spin-coating method ranged from 4.35–4.88 eV. For the solventless method, the bandgap of the nickel sulfide ranged from 3.93–3.96 eV. The crystal phase observed from the spin-coating and solventless methods was α-NiS (hexagonal). A direct correlation was observed between annealing temperature, bandgap, and particle size.

Synthesis, X-ray Structures, and spectroscopic characterization of cis and trans-bis(O-propyldithiocarbonato)bis(pyridine)nickel(II), cis and trans-[Ni(CH3CH2CH2OC(S)S)2(C5H5N)2

Single crystals of cis and trans-bis(O-propyldithiocarbonato)bis(pyridine)nickel(II), cis and trans-[Ni(CH3CH2CH2OC(S)S)2(C5H5N)2], have been prepared and studied using single crystal X-ray diffraction method and IR spectroscopy. The crystal structure of tetracoordinated Ni(II) xanthate complex, bis(O-propyldithiocarbonato)nickel(II), [Ni(CH3CH2CH2OC(S)S)2], was also determined and compared with the previously reported structure. The existence of a cis form for a hexacoordinated species of the [NiS4N2] type is infrequent for this family of complexes.

Synthesis, characterization, and analysis of intermolecular interactions of isostructural diorganotin compounds containing enantiomeric 1,1-dithioligands

The reaction of enantiomerically pure (+) and (−) menthol as well as (R)-(+)- and (S)-(−)N-benzyl-1-phenylethylamine with carbon disulfide in presence of potassium hydroxide yielded, respectively, chiral xanthate and dithiocarbamates as their potassium salts. These chiral 1,1-dithioligands were reacted with diphenyltin dihalides to produce four enantiomeric and isostructural pairs of diorganotin complexes of formula (+)-[SnPh2{xanMEN}Cl] (1), (−)-[SnPh2{xanMEN}Cl] (1m), (+)-[SnPh2{xanMEN}Br] (2), (−)-[SnPh2{xanMEN}Br] (2m), (+)-[SnPh2{dtcBPE}Cl] (3), (−)-[SnPh2{dtcBPE}Cl] (3m), (+)-[SnPh2{dtcBPE}Br] (4), and (−)-[SnPh2{dtcBPE}Br] (4m). The 119Sn{1H} NMR data and the X-ray single-crystal diffraction studies of the eight heteroleptic compounds confirmed the anisobidentate pattern of the {(RnECS2}− (E = O, n = 1; E = N, n = 2) monoanionic ligand. The presence of halides and sulfur atoms enhanced the formation of CH⋯X, S⋯H, S⋯S, and pi⋯H non-covalent interactions in the crystalline state. A Hirshfeld surface analysis was carried out to identify these significant intermolecular contacts in the complexes. The less hindered tin atom in the xanthate complexes displayed a CS⋯X–Sn interaction of attractive nature.

Structural Investigations of α-MnS Nanocrystals and Thin Films Synthesized from Manganese(II) Xanthates by Hot Injection, Solvent-Less Thermolysis, and Doctor Blade Routes.

Manganese(II) xanthate complexes of the form [Mn(S2COR)2(TMEDA)], where TMEDA = tetramethylethylenediamine and R = methyl (1), ethyl (2), n-propyl (3), n-butyl (4), n-pentyl (5), n-hexyl (6), and n-octyl (7), have been synthesized and structures elucidated using single-crystal X-ray diffraction. Complexes 1–7 were used as molecular precursors to synthesize manganese sulfide (MnS). Olelyamine-capped nanocrystals have been produced via hot injection, while the doctor blading followed by thermolysis yielded thick films. Free-standing polycrystalline powders of MnS are produced by direct thermolysis of precursor powders. All thermolysis techniques produced cubic MnS, as confirmed by powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Raman spectroscopy. Magnetic measurements reveal that the α-MnS nanocrystals exhibit ferromagnetic behavior with a large coercive field strength (e.g., 0.723 kOe for 6.8 nm nanocrystals).

Chemical Vapour Deposition of CdS Thin Films at Low Temperatures from Cadmium Ethyl Xanthate

Thin films of nanometer sized cadmium sulfide were directly prepared by aerosol-assisted chemical vapor deposition (AA-CVD) method, cadmium ethyl xanthate complex was used as precursor material at 225 oC, 250 oC and 275 oC. The thermal decomposition of complex was characterized by thermal analysis, (thermogravimetric analysis (TGA) and a differential scanning calorimetry (DSC)). The prepared CdS thin films have been characterized by XRD and SEM- EDX analysis. TGA curves ensured that the rapid decomposition of [Cd(S2COEt)2] gives a CdS in single step between 150 oC and 200 oC. XRD patterns confirmed that the CdS particles crystalized as a hexagonal crystallographic phase at low temperatures. The grain size of particles increased with increasing the preparation temperatures from 225 oC to 275 oC,. The spherical CdS nanoparticals were observed in SEM analysis.

Comparative study on the effect of precursors on the morphology and electronic properties of CdS nanoparticles.

Cadmium dithiocarbamate and cadmium ethyl xanthate complexes were synthesized and characterized by microanalysis, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analyses. The complexes were employed as molecular precursors for the fabrication of CdS nanoparticles in hexadecylamine (HDA) and oleylamine (OLA) at a temperature of 250 °C. Spherical and oval shaped particles with sizes ranging from 9.93 ± 1.89 to 16.74 ± 2.78 nm were obtained in OLA while spherical, oval and rod shaped particles with sizes ranging from 9.40 ± 1.65 to 29.90 ± 5.32 nm were obtained in HDA. Optical properties of the nanoparticles showed blue shifts as compared to the bulk CdS, with the OLA capped nanoparticles slightly more blue shifted than the corresponding HDA capped nanoparticles. Results of crystallinity patterns revealed hexagonal phase of CdS.

Nickel(II) complexes of m-ethylphenylxanthate with nitrogen donors and their biological screening

A series of five adducts of m-ethylphenylxanthate of nickel(II) [(m-C2H5C6H4OCS2)2Ni] with nitrogen donors have been synthesized in 1:2 molar ratio by the reaction of aqueous solution of NiCl2.6H2O with aqueous solution of sodium salt of m-ethylphenylxanthate. These metal complexes are reacted with nitrogen donors to give donor stabilized complex, [(m-C2H5C6H4OCS2)2(L)2Ni] where, L= 2-, 3-, 4-ethylpyridine and 2-, 3-chloropyridine. The adducts have been characterized by elemental analysis, molar conductance and magnetic susceptibility measurements, IR, electronic, mass spectral studies, thermogravimetric analysis, powder X-ray diffraction, biological studies. The spectral studies have revealed the octahedral coordination of ligands around Ni(II) metal ion. The adducts are found to be paramagnetic and non-ionic in nature. Mass studies show the monomeric nature of the adducts. The complexes have depicted potential antifungal activity against Bipolaris maydis and Rhizoctonia solani. Some of the synthesized Ni(II) xanthate complexes display in vitro cytotoxic efficacy against human cancer cell lines.

Synthesis of CdS and PbS nanoparticles by the thermal decomposition of ethyl xanthate complexes in castor oil using the heat-up technique

Castor oil contains a range of fatty acids of which a high proportion is ricinoleic acid. We report the syntheses of CdS and PbS nanoparticles by the thermal decomposition of ethyl xanthate complexes of cadmium and lead in castor oil using the heat-up synthesis technique. The castor-oil capped CdS nanoparticles showed cubic zinc blende and wurtzite crystal structures and displayed band gap range of 2.63–2.84 eV. The CdS formed near-spherical clusters of nanocrystals with average particle size of 6.78 (±1.89) nm. The castor-oil capped PbS nanoparticles showed a rocksalt crystal structure and displayed an average band gap of 0.85 eV. The PbS showed variety of morphologies of nanostructured particles ranging from rods to belts. The average width and length of the PbS nanobelts observed were 22.2 (±2.3) nm and 225.9 (±23.3) nm respectively.

The Alkali Metal Salts of Methyl Xanthic Acid

Methyl xanthates of the type M(SSC‐OMe) (M = Li–Cs) are readily formed when carbon disulfide is reacted with the corresponding alkali metal hydroxides in methanol exposed to air, or with the alkali metal methoxides in dry methanol or THF under exclusion of air. The reactions are easily monitored by 13C NMR spectroscopy. The Na, K, Rb, and Cs salt could be isolated in high yields, while the Li salt decomposed upon attempted isolation. All compounds are readily complexed by crown ethers and form isolable 1:1 adducts, including the elusive Li salt. All products were studied by NMR (1H, 13C, and alkali metal nuclei) and IR spectroscopy, and most of them where structurally characterized by single‐crystal X‐ray diffraction. Li(SSC‐OMe)(12c4) (12c4 = [12]crown‐4) and Cs(SSC‐OMe)(18c6) (18c6 = [18]crown‐6) represent the first structurally characterized lithium and caesium xanthate complexes, respectively.

Direct solvent free synthesis of bare \u03b1-NiS, \u03b2-NiS and \u03b1-\u03b2-NiS composite as excellent electrocatalysts: Effect of self-capping on supercapacitance and overall water splitting activity

Nickel sulfide is regarded as a material with tremendous potential for energy storage and conversion applications. However, it exists in a variety of stable compositions and obtaining a pure phase is a challenge. This study demonstrates a potentially scalable, solvent free and phase selective synthesis of uncapped α-NiS, β-NiS and α-β-NiS composites using nickel alkyl (ethyl, octyl) xanthate precursors. Phase transformation and morphology were observed by powder-X-ray diffraction (p-XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The comparative efficiency of the synthesized samples was investigated for energy storage and generation applications, in which superior performance was observed for the NiS synthesized from the short chain xanthate complex. A high specific capacitance of 1,940 F/g, 2,150 F/g and 2,250 F/g was observed at 2 mV/s for bare α-NiS, β-NiS and α-β-NiS composite respectively. At high current density of 1 A/g, α-NiS showed the highest capacitance of 1,287 F/g, with 100% of Coulombic efficiency and 79% of capacitance retention. In the case of the oxygen evolution reaction (OER), β-NiS showed an overpotential of 139 mV at a current density of 10 mA/cm2, with a Tafel slope of only 32 mV/dec, showing a fast and efficient process. It was observed that the increase in carbon chain of the synthesized self-capped nickel sulfide nanoparticles decreased the overall efficiency, both for energy storage and energy generation applications.

Cobalt sulfide nanoparticles: Synthesis, water splitting and supercapacitance studies

Different alkyl xanthate complexes of cobalt (alkyl = Ethyl, Hexyl, Octyl) were synthesized and used for the synthesis of nanoparticles by a solvent-less route. The p-XRD of the nanoparticles showed the formation of the CoS phase only from all precursors. The effect of size and surface capping on energy generation and energy storage applications was investigated. The electrocatalytic performance of the synthesized samples for hydrogen (HER) and oxygen evolution reaction (OER), indicates that CoS synthesized from the octyl xanthate complex (CoS-Oct) showed higher electrocatalytic performance. A lower over potential of 325 mV and 200 mV was observed for CoS-Oct, at a current density of 10 mA/cm2, for OER and HER, respectively. The charge storage performance was also investigated, where an inverse trend was observed i.e. the highest specific capacitance (1500 F/g, at scan rate 2 mV/s) was observed for the CoS sample synthesized from ethyl xanthate (CoS-ET). Similarly, the discharge time for CoS-ET was longer as compared to the other samples, suggesting better performance for the charge storage applications. The use of cobalt xanthate complexes for the preparation of CoS by melt method, and the effect of self-capped and uncapped surface of CoS on supercapacitance and OER/HER performance, has never been investigated before.

Synthesis and characterization of zinc di(O-2,2-dimethylpentan-3-yl dithiocarbonates) bearing pyridine or tetramethylethylenediamine coligands and investigation of their thermal conversion mechanisms towards nanocrystalline zinc sulfide.

Metal xanthates are versatile single source precursors for the preparation of various metal sulfides. In this study, we present the synthesis of the two novel zinc xanthate complexes bis(O-2,2-dimethylpentan-3-yl-dithiocarbonato)(N,N,N',N'-tetramethylethylenediamine)zinc(ii) and bis(O-2,2-dimethylpentan-3-yl-dithiocarbonato)(pyridine)zinc(ii). A thorough investigation of these compounds revealed distinct differences in their structural and thermal properties. While in the complex containing the chelating tetramethylethylenediamine, the xanthate groups coordinate in a monodentate way, they are bidentally coordinated to the zinc atom in the pyridine containing complex. Both compounds show a two-step thermal decomposition with an onset temperature of 151 °C and 156 °C for the tetramethylethylenediamine and pyridine containing complex, respectively. Moreover, different mechanisms are revealed for the two phases of the decomposition based on high resolution mass spectrometry investigations. By the thermal conversion process nanocrystalline zinc sulfide is produced and the coligand significantly influences its primary crystallite size, which is 4.4 nm using the tetramethylethylenediamine and 11.4 nm using the pyridine containing complex for samples prepared at a temperature of 400 °C.

Crystal structure and Hirshfeld surface analysis of a zinc xanthate complex containing the 2,2'-bi-pyridine ligand.

In the title compound, (2,2'-bi-pyridine-κ2 N,N')bis-(2-meth-oxy-ethyl xanthato-κS)zinc(II), [Zn(C4H7O2S2)2(C10H8N2)], the ZnII ion is coordinated to two N atoms of the 2,2'-bi-pyridine ligand and two S atoms from two 2-meth-oxy-ethyl xanthate ligands. The ZnII ion lies on a crystallographic twofold rotation axis and has distorted tetra-hedral coordination geometry. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming supramolecular chains propagating along the a-axis direction. Weak intra-molecular C-H⋯S hydrogen bonds are also observed. The inter-molecular contacts in the crystal were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are H⋯H (36.3%), followed by S⋯H/H⋯S (24.7%), C⋯H/H⋯C (15.1%), O⋯H/H⋯O (14.4%), N⋯H/H⋯N (4.1%) and C⋯C (2.9%).