Dithiocarbamate Complexes Research Articles

OLYMERIC NANOFORMULATION OF A NON-SYSTEMIC DITHIOCARBAMATE PESTICIDE: PREPARATION, CHARACTERIZATION, AND BIOASSAY

The current agricultural practice is to develop novel Nano agrochemicals in the form of Nano pesticides. Many researchers in the world have foretold an upheaval in present agricultural practice. This paper aims at the application of nanotechnology for plant protection in the form of Nano pesticides. Our study endowed with a novel polymeric Nano formulation of a dithiocarbamate nonsystemic agricultural fungicide called Mannose (MCB) by using polycaprolactone as a capping agent. The encapsulated dithiocarbamate complex was characterized by using analytical techniques like UV-Visible spectroscopy, Dynamic light scattering, Scanning electron microscope, and Transmission electron microscope. The particle size distribution emerged at 17-44nm. The bioassay was conducted against Aspergillus flavus, Aspergillus niger, Sclerotium rolfsii, and Rhizoctonia solani. The bioassay illustrated better results as compared to the commercial pesticide.

Synthesis, Spectroscopic, DFT, HOMO-LUMO, MEP, Mulliken Analysis and Antimicrobial Properties of Novel Arsenic(III) Dithiocarbamate Complex

The novel arsenic dithiocarbamate complex was synthesized and characterized by elemental analysis, NMR and FTIR. Density functional theory (DFT) was used to calculate quantum mechanical computations of a tris(N,N-difurfuryldithiocarbamato)arsenic(III) molecule employing the standard B3LYP basis set with the GAUSSIAN 09 program. The molecular structure was confirmed using geometrical parameters, vibrational analysis (FT-IR), 13C NMR and 1H NMR (GIAO technique). The HOMO-LUMO energy gap, Mulliken population analysis, contour map and molecular electrostatic potential (MEP) surfaces have all been determined using molecular orbital calculations. The minimal HOMO-LUMO energy values shows that charge transfer is possible within the molecule. Gram-positive and Gram-negative bacteria, as well as fungal species, were used to investigate the compound antimicrobial susceptibility. The results demonstrated that even at high concentrations, the complex was effective against the microorganisms.

A double co-sensitization strategy using heteroleptic transition metal ferrocenyl dithiocarbamate phenanthrolene-dione for enhancing the performance of N719-based DSSCs.

Three new heteroleptic dithiocarbamate complexes with formula [M(Phen-dione)(Fcdtc)]PF6 (where M = Ni(ii) Ni-Fc, Cu(ii) Cu-Fc) and [Co(Phen-dione)(Fcdtc)2]PF6 (Co-Fc) (Fcdtc = N-ethanol-N-methylferrocene dithiocarbamate and Phen-dione = 1,10-phenanthroline-5,6-dione; PF6 - = hexafluorophosphate) were synthesized and characterized using microanalysis, FTIR, electronic absorption spectroscopy and mass spectrometry. The solution state electronic absorption spectroscopy for all three complexes displayed a band at ∼430 nm corresponding to the ferrocene unit and another low-intensity band in the visible region arising because of the d-d transitions. These newly synthesized complexes were used as co-sensitizers for the state-of-the-art di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(ii) (N719) dye in dye-sensitized solar cells (DSSCs). Among the three co-sensitizers/co-adsorbent-based DSSC set-ups, the assembly fabricated using Co-Fc/N719 displayed good photovoltaic performance with 5.31% efficiency (η) while a new triple component strategy inculcating N719, Co-Fc and Cu-Fc dyes offered the best photovoltaic performance with 6.05% efficiency (η) with incident photon to current conversion efficiency (IPCE) of 63%. This indicated an upliftment of the DSSC performance by ∼38% in comparison to the set-up constructed by employing only N719 dye (η = 4.39%) under similar experimental conditions.

Facile synthesis of PbS, Bi2S3 and Bi-doped PbS nanoparticles from metal piperidine dithiocarbamates complexes

Single source precursors are advantageous starting materials to the syntheses of nanomaterials. In this study, lead and bismuth piperidine dithiocarbamate complexes have been synthesized and used as efficient precursors for synthesizing PbS and Bi2S3 nanoparticles using hot injection techniques. The bismuth piperidine dithiocarbamate complex was then used as a dopant to form Bi-doped PbS nanoparticles. Alloys are functional materials for present day applications. In the energy sector, they allow for band gap engineering and size dependent quantum confinement effects. The p-XRD pattern of the PbS was indexed to a cubic rocksalt structure, whereas the Bi2S3 was indexed to an orthorhombic structure. The morphological studies using the TEM revealed the formation of cubes and rods for the PbS and Bi2S3, respectively. An interplay of these structures was observed for the alloy depending on the mole fraction of Bi doping in the injected precursor solution. The optical band gaps were blue-shifted to 0.72 and 1.94 eV for PbS and Bi2S3, respectively. The Bi-doped PbS nanoparticles displayed optical band gaps in between the binary materials.

Antimony(III) Dithiocarbamates: Synthesis, Spectral, Theoretical and Biological Activities

Antimony(III) dithiocarbamate complexes tris(N,N-difurfuryldithiocarbamato-S,S′)antimony(III) (1) and tris(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S′)antimony(III) (2) have been synthesized and characterized by CHN analysis, FT-IR, 1H NMR, 13C NMR spectra and antimicrobial studies. The characteristic thioureide ν(C-N) bands occur at 1459 and 1469 cm-1 for complexes 1 and 2, respectively. 1H NMR and 13C NMR chemical shifts have been calculated using GIAO approach and the calculated chemical shifts shows good agreement with experiential shifts. The computational calculations of the antimony(III) complexes have been carried out by DFT/B3LYP using LANL2DZ basis set. The FMOs, MEP, Mulliken charge distribution and chemical activity parameters were calculated at the same level of theory. The antimicrobial activities of the antimony(III) complexes were assayed at the concentrations 400 and 800 μg/mL against four bacterial (Vibrio cholera, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli) and two fungal species (Candida albicans and Aspergillus niger) by Agar-well disc diffusion method.

Selective syntheses of kuramite (Cu2SnS3) and petrukite (Cu3SnS4) phases of copper tin sulphide, and their electrochemical and photocatalytic properties

Semiconductor materials of the type Cu–Sn–S (CTS) have recently been the focus of intense research due to their unique optical and thermoelectric properties. Their properties are also tunable by varying reaction parameters such as precursor concentration, solvent chemistry and reaction temperature. In this study, two phases of CTS: Cu2SnS3 and Cu3SnS4, were synthesized by the co-thermolysis of two dithiocarbamate complexes through the tuning of reaction temperature and solvent type. Cu2SnS3 nanoparticles with average crystalline size of 13.1 nm and band gap energy of 1.16 eV were synthesized in oleylamine at 220 ̊C, while Cu3SnS4 nanoparticles with average size of 12.3 nm and band gap energy of 1.57 eV was obtained in a mixture of oleylamine and dodecanthiol at 180 ̊C. The electrochemical and photocatalytic properties of the two CTS phases were further studied, with the Cu2SnS3 phase showing better properties compared to the Cu3SnS4 phase. The ability to achieve phase selectivity in synthesizing CTS with different crystal structures and band gap energies in a facile solvothermal process could be valuable in developing semiconductor materials with unique properties.

Evaluation of the photocatalytic and persulfate activation properties of GO-CuSbS2 composite

The photocatalytic and persulfate activities of graphene oxide composited with copper antimony sulfide (CuSbS2) nanoparticles have been explored in this study. Pure phase CuSbS2 obtained by the co-thermolysis of metal dithiocarbamate complexes was composited with graphene oxide (GO) and explored as catalysts in a photocatalytic and persulfate activation processes. The charge carrier separation efficiency study, used in screening the different ratio of CuSbS2-GO composite, showed the optimum level of CuSbS2 in the composite to be at 10 wt.% of the catalyst. The photocatalytic and persulfate activation activities of the composites for tetracycline degradation reached 94% and 74% efficiency respectively after 60 min, confirming the potential of the catalyst for both processes. The reaction rate constant for the photocatalytic process was 5.0 0 × 10−2 min−1, while the persulfate activation process recorded a rate constant of 1.6 × 10−2min−1. Compositing of CuSbS2 with GO resulted in enhancement of the photocatalytic activity by 59 and 23 times compared to CuSbS2 and GO alone. Confirming a high synergistic effect between the materials. The radical scavenging experiment showed that photogenerated holes (h+) were the most significant radical species in the photocatalytic process, while in the persulfate activation process, electron transfer between GO-CAS(10%) and PS was the most significant process in the degradation process. Thus, in this study, the enhancement of the catalytic activity of CuSbS2 through its incorporation within the matrices of graphene oxide has been established.

Bis(4-methylpiperidine-1-carbodithioato)-lead(II) and Bis(4-benzylpiperidine-1-carbodithioato)-lead(II) as Precursors for Lead Sulphide Nano Photocatalysts for the Degradation of Rhodamine B.

Bis(4-methylpiperidine-1-carbodithioato)-lead(II) and bis(4-benzylpiperidine-1-carbodithioato)-lead(II) were prepared and their molecular structures elucidated using single crystal X-ray crystallography and spectroscopic techniques. The compounds were used as precursors for the preparation of lead sulphide nano photocatalysts for the degradation of rhodamine B. The single crystal structures of the lead(II) dithiocarbamate complexes show mononuclear lead(II) compounds in which each lead(II) ion coordinates two dithiocarbamato anions in a distorted tetrahedral geometry. The compounds were thermolyzed at 180 ℃ in hexadecylamine (HDA), octadecylamine (ODA), and trioctylphosphine oxide (TOPO) to prepare HDA, ODA, and TOPO capped lead sulphide (PbS) nanoparticles. Powder X-ray diffraction (pXRD) patterns of the lead sulphide nanoparticles were indexed to the rock cubic salt crystalline phase of lead sulphide. The lead sulphide nanoparticles were used as photocatalysts for the degradation of rhodamine B with ODA-PbS1 achieving photodegradation efficiency of 45.28% after 360 min. The photostability and reusability studies of the as-prepared PbS nanoparticles were studied in four consecutive cycles, showing that the percentage degradation efficiency decreased slightly by about 0.51–1.93%. The results show that the as-prepared PbS nanoparticles are relatively photostable with a slight loss of photodegradation activities as the reusability cycles progress.

Selective Anticancer and Antimicrobial Metallodrugs Based on Gold(III) Dithiocarbamate Complexes

New dithiocarbamate cycloaurated complexes have been synthesized and their physicochemical and in vitro antitumor properties have been evaluated. All the performed studies highlighted good transport through the blood and biodistribution, according to the balance between the properties of hydrophilicity/lipophilicity and the binding of moderate strength to the BSA protein. Furthermore, none of the complexes exhibited reduction or decomposition reactions, presenting excellent physiological stability. The in vitro cytotoxic effect was evaluated on human colon cancer cell line Caco-2/TC7, and the complexes showed great antiproliferative activity and excellent selectivity, as much less effect was detected on normal Caco-2/TC7 cells. Most of the complexes exhibit antiproliferative activity that was better than or similar to auranofin, and at least nine times better than that of cisplatin. Its action mechanism is still under discussion since no evidence of cell cycle arrest was found, but an antioxidant role was shown for some of the selective complexes. All complexes were also tested as antimicrobial drugs, exhibiting good activity towards S. aureus and E. coli. bacteria and C. albicans and C. neoformans fungi.

Molecular precursor route for the phase selective synthesis of α-MnS or metastable γ-MnS nanomaterials for magnetic studies and deposition of thin films by AACVD

Heterocyclic dithiocarbamate complex of manganese and the adducts of the complex with 1,10-phenanthroline and 2,2-bipyridyl respectively were synthesized and characterized. The complexes were used as single-source precursors for the preparation of MnS nanoparticles via thermolysis in oleylamine (OLA) and dodecanethiol (DT). The optimized reaction parameters have resulted in the formation of α-MnS and γ-MnS nanoparticles depending on the dispersion medium and the nature of the precursor. The same precursors were also used for the deposition of MnS thin films by the aerosol-assisted chemical vapour deposition (AACVD) method in varying solvents and temperatures. The morphology and phase of the synthesized nanoparticles were shown to be affected by the precursor type and the nature of the surfactants. TEM images show the formation of nanoparticles of various morphologies ranging from spherical monodispersed to large elongated pointed rods, depending on the precursor type. SEM images showed that the morphology of the deposited thin films is affected by precursor type and the deposition temperature. Worm-like to rod-like films were observed on TEM images at 350 °C, which changes to spherical or cubic films at 450 °C. Magnetic measurements at room temperature showed the α-MnS and γ-MnS nanoparticles in paramagnetic states due to Mn2+ moments. The susceptibility for the γ-phase is at least double that of the α-phase. Finite and small hysteretic effects in low fields are indicative of small ordered antiferromagnetic phases due to negative exchange interaction between Mn2+ ions.

Co-operative influence of co-crystallized solvent in sustaining supramolecular architectures of Zn(II)/Cd(II) homoleptic pyridyl functionalized dithiocarbamates complexes via non-covalent interactions

Homoleptic pyridyl-3(N) functionalized dithiocarbamate complexes namely, [Zn(L1)2]2 1 (L1 = (C5H4NCH2)2NCS2) and [Cd(L2)2] ∞ 2 (L2 = CH3C6H4CH2NCS2CH2C4H3O) have been synthesized and characterized by elemental analysis and different spectroscopic techniques. Single crystal structural studies reveal that compound 1 is binuclear while, 2 is polymeric structure. The presence of weak interactions between complexes and solvent molecules in the lattice results in one-dimensional and three-dimensional supramolecular structures of 1 and 2 respectively. In the case of complex 2, a rare and significant S···Cl chalcogen bonding interaction was found, which involve the solvent molecule in chain motifs. Complex 2 is a unique example of homoleptic metal dithiocarbamate complexes exhibiting such types of interactions. Complexes showed emission in the solid state. The TGA studies of complexes revealed that complex 1 would be a good precursor for the preparation of ZnS thin film via metal organic chemical vapor deposition (MOCVD).

Mn-Doped Quinary Ag-In-Ga-Zn-S Quantum Dots for Dual-Modal Imaging.

Doping of transition metals within a semiconductor quantum dot (QD) has a high impact on the optical and magnetic properties of the QD. In this study, we report the synthesis of Mn2+-doped Ag–In–Ga–Zn–S (Mn:AIGZS) QDs via thermolysis of a dithiocarbamate complex of Ag+, In3+, Ga3+, and Zn2+ and of Mn(stearate)2 in oleylamine. The influence of the Mn2+ loading on the photoluminescence (PL) and magnetic properties of the dots are investigated. Mn:AIGZS QDs exhibit a diameter of ca. 2 nm, a high PL quantum yield (up to 41.3% for a 2.5% doping in Mn2+), and robust photo- and colloidal stabilities. The optical properties of Mn:AIGZS QDs are preserved upon transfer into water using the glutathione tetramethylammonium ligand. At the same time, Mn:AIGZS QDs exhibit high relaxivity (r1 = 0.15 mM–1 s–1 and r2 = 0.57 mM–1 s–1 at 298 K and 2.34 T), which shows their potential applicability for bimodal PL/magnetic resonance imaging (MRI) probes.

Synthesis, optical and structural characterisation of ZnS nanoparticles derived from Zn(ii) dithiocarbamate complexes

Abstract Zinc sulphide nanoparticles represented as ZnS1, ZnS2 and ZnS3 have been prepared from Zn(ii) N-methyl-N-ethanoldithiocarbamate (1) complex and its 2,2′-bipyridine (2) and 1,10′-phenanthroline (3) adducts, respectively. Both the parent complex (1) and the adducts (2) and (3) were characterised by spectroscopic techniques and elemental analysis. In the solid state, the structures of complexes (1) and (2) were established using single-crystal X-ray analysis. Complex (1) possessed a distorted trigonal bipyramidal geometry about the zinc centre, whilst forming a dimer via bidentate bridging coordination between two opposite dithiocarbamate motifs. On the other hand, complex (2) formed a trigonal prismatic geometry about the Zn centre with a ZnS4N2 chromophore. The decomposition of the complexes in hexadecylamine afforded spherical-shaped ZnS nanoparticles of the cubic sphalerite crystal phase. The transmission electron microscopy (TEM) micrographs showed that the average particles size of ZnS1, ZnS2 and ZnS3 were 2.63, 5.27 and 6.52 nm, respectively. In the optical study, the estimated bandgap energies were found in the range between 4.34 and 4.08 eV, which indicated a blue shift when compared with the bandgap energy of bulk ZnS.

Photocatalytic Degradation of Tetracycline in Aqueous Solution Using Copper Sulfide Nanoparticles

In this paper, spherical-shaped pure phase djurleite (Cu31S16) and roxbyite (Cu7S4) nanoparticles were prepared by a solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol (DDT). The reaction temperature was used to control the phases of the samples, which were represented as Cu31S16 (120 °C), Cu31S16 (150 °C), Cu7S4 (220 °C), and Cu7S4 (250 °C) and were characterized by using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and absorption spectroscopy. The samples were used as photocatalysts for the degradation of tetracycline (TC) under visible light irradiation. The results of the study showed that Cu7S4 (250 °C) exhibited the best activity in the reaction system with the TC degradation rate of up to 99% within 120 min of light exposure, while the Cu31S16 (120 °C) system was only 46.5% at the same reaction condition. In general, roxbyite Cu7S4 (250 °C) could be considered as a potential catalyst for the degradation of TC in solution.

Synthesis and Characterization of Manganese Dithiocarbamate Complexes: New Evidence of Dioxygen Activation.

(1) Background: Metal dithiocarbamate compounds have long been the subject of research due to their ease of formation, excellent properties and potential applications. However, manganese complexes with dithiocarbamates, to our knowledge, have never been used for medical imaging applications. With the aim of developing a new class of mononuclear manganese(II)-based agents for molecular imaging applications, we performed a specific investigation into the synthesis of mononuclear bis-substituted Mn(II) complexes with dithiocarbamate ligands. (2) Methods: Synthesis in either open or inert atmosphere at different Mn(II) to diethyldithiocarbamate molar ratios were performed and the products characterized by IR, EA, ESI-MS and XRD analysis. (3) Results: We found that only under oxygen-free atmospheric conditions the Mn(II) complex MnL2, where L = diethyldithiocarbamate ligand, is obtained, which was further observed to react with dioxygen in the solid state to form the intermediate superoxo Mn(III) complex [MnL2(η2-O2)]. The existence of the superoxo complex was revealed by mass spectroscopy, and this species was interpreted as an intermediate step in the reaction that led the bis-substituted Mn(II) complex, MnL2, to transform into the tris-substituted Mn(III) complex, MnL3. A similar result was found with the ligand L’ (= bis(N-ethoxyethyl)dithiocarbamate). (4) Conclusions: We found that in open atmosphere and in aqueous solution, only manganese(III) diethyldithiocarbamate complexes can be prepared. We report here a new example of a small-molecule Mn(II) complex that efficiently activates dioxygen in the solid state through the formation of an intermediate superoxide adduct.

Copper Dithiocarbamates: Coordination Chemistry and Applications in Materials Science, Biosciences and Beyond

Copper dithiocarbamate complexes have been known for ca. 120 years and find relevance in biology and medicine, especially as anticancer agents and applications in materials science as a single-source precursor (SSPs) to nanoscale copper sulfides. Dithiocarbamates support Cu(I), Cu(II) and Cu(III) and show a rich and diverse coordination chemistry. Homoleptic [Cu(S2CNR2)2] are most common, being known for hundreds of substituents. All contain a Cu(II) centre, being either monomeric (distorted square planar) or dimeric (distorted trigonal bipyramidal) in the solid state, the latter being held together by intermolecular C···S interactions. Their d9 electronic configuration renders them paramagnetic and thus readily detected by electron paramagnetic resonance (EPR) spectroscopy. Reaction with a range of oxidants affords d8 Cu(III) complexes, [Cu(S2CNR2)2][X], in which copper remains in a square-planar geometry, but Cu–S bonds shorten by ca. 0.1 Å. These show a wide range of different structural motifs in the solid-state, varying with changes in anion and dithiocarbamate substituents. Cu(I) complexes, [Cu(S2CNR2)2]−, are (briefly) accessible in an electrochemical cell, and the only stable example is recently reported [Cu(S2CNH2)2][NH4]·H2O. Others readily lose a dithiocarbamate and the d10 centres can either be trapped with other coordinating ligands, especially phosphines, or form clusters with tetrahedral [Cu(μ3-S2CNR2)]4 being most common. Over the past decade, a wide range of Cu(I) dithiocarbamate clusters have been prepared and structurally characterised with nuclearities of 3–28, especially exciting being those with interstitial hydride and/or acetylide co-ligands. A range of mixed-valence Cu(I)–Cu(II) and Cu(II)–Cu(III) complexes are known, many of which show novel physical properties, and one Cu(I)–Cu(II)–Cu(III) species has been reported. Copper dithiocarbamates have been widely used as SSPs to nanoscale copper sulfides, allowing control over the phase, particle size and morphology of nanomaterials, and thus giving access to materials with tuneable physical properties. The identification of copper in a range of neurological diseases and the use of disulfiram as a drug for over 50 years makes understanding of the biological formation and action of [Cu(S2CNEt2)2] especially important. Furthermore, the finding that it and related Cu(II) dithiocarbamates are active anticancer agents has pushed them to the fore in studies of metal-based biomedicines.

Synthesis, X-ray crystal structures and anticancer studies of four Pd(II) dithiocarbamate complexes

Bis(piperidinyldithiocarbamato)palladium(II) ([Pd(Pipdtc) 2 ]), bis(1-phenylpiperazinyldithiocarbamato)palladium(II) [Pd(1-PhPzdtc) 2 ], bis(phenyldithiocarbamato)palladium(II) ([Pd(Phdtc) 2 ]) and bis(4-benzylpiperidinyl)palladium(II) ([Pd(4-BenzPipdtc) 2 ]) were prepared and characterized by elemental analysis, spectroscopic techniques and single crystal X-ray crystallography. Molecular structures of the Pd(II) complexes revealed square planar PdS 4 geometry in which each Pd(II) is coordinated to two chelating dithiocarbamato anions. [Pd(Pipdtc) 2 ] and [Pd(1-PhPzdtc) 2 ] crystallized in monoclinic P2 1/c space group while [Pd(Phdtc) 2 ] and [Pd(4-BenzPipdtc) 2 ] crystallized in triclinic P-1 space group. Cytotoxic studies of the dithiocarbamate ligands and corresponding Pd(II) dithiocarbamate complexes were tested against three human cell lines: Cervical cancer, breast adenocarcinoma, and epithelial colorectal adenocarcinoma at four different concentrations. All the compounds displayed high to moderate potency against the cell lines. [Pd(Pipdtc) 2 ] and [Pd(Phdtc) 2 ] are very potent against the three cell lines and are more active than the corresponding dithiocarbamate ligands whereas the anticancer potency of 1-PhPzdtc-Na and 4-BenzPipdtc-Na are generally higher than the corresponding Pd(II) complexes.

Synthesis, crystal structures, biological and thermal decomposition evaluation of homo and heteroleptic Zn(Ⅱ) dithiocarbamate complexes and use of Zn(Ⅱ) dithiocarbamate to prepare zinc sulfide nanoparticles

New functionalized homoleptic and heteroleptic zinc(II) and cadmium(II) dithiocarbamate complexes of formulae [Zn(cpebdtc)2] (1), [Zn(cpebdtc)2(py)] (2), [Cd(cpebdtc)2] (3), [Cd(cpebdtc)2(2,2ʹ-bipy)] (4) (where, cpebdtc = N-cyclopropyl-N-2-ethoxybenzyldithiocarbamate; py = pyridine and 2,2ʹ-bipy = 2,2ʹ-bipyridine) were synthesized and then characterized by CHNS analysis, IR, UV–Vis., 1H and 13C NMR spectroscopy. The molecular structures confirmed by X-ray crystallography revealed that complexes 1 and 2 adopt distorted tetrahedral and pentagonal geometry with ZnS4 and ZnS4N chromospheres respectively. Supramolecular networks are being sustained by CH…π and CC intermolecular interactions. Anti-leishmanial activity evaluation revealed the promising anti‑promastigote activity of complexes 1 and 2 with IC50 values 4.6 ± 0.41 and 3.37 ± 0.28 μg mL−1 respectively. The DNA binding study confirmed that complexes 1 and 2 bind effectively with Ct-DNA through groove binding/electrostatic interaction as suggested by hyperchromism and it was further validated by molecular docking. All the complexes showed potential antioxidant activity. TG analyses showed one step for 1, 3 and two step decomposition for 2, 4 complexes with the formation of binary ZnS (1, 2) and CdS (3, 4) materials. Complex 1 was utilized as a single source precursor to prepare ZnS nanoparticles. Single phase (rhombohedral) of ZnS nanomaterial was confirmed by X-ray diffraction analysis. TEM micrograph revealed spherical shape of ZnS nanoparticles with dimensions in the nanoscale (50–80 nm).

Synthesis and evaluation of new mixed “2 + 1” Re, 99mTc and 186Re tricarbonyl dithiocarbamate complexes with different monodentate ligands

A series of “2 + 1” mixed ligand tricarbonyl complexes of the general formula fac-[Re/99mTc/186Re(CO)3(DDTC)(L)] containing diethyldithiocarbamate (DDTC) as a monoanionic bidentate ligand and a series of monodentate ligands L was synthesized, characterized and evaluated. The impact of ligand L on the radiochemical yield (RCY) and biodistribution of the final compounds was also investigated. DDTC and the appropriate L ligand [cyclohexyl isocyanide (cisc), tert-butyl isocyanide (tbi), triphenylphosphine (PPh3), methyldiphenylphosphine (PPh2Me), triphenylarsine (AsPh3), imidazole (im), and 4-aminopyridine (4AP)] readily reacted in equimolar amounts with the [Et4N]2[Re(CO)3Br3] precursor to afford fac-[Re(CO)3(DDTC)(cisc)], Re1, fac-[Re(CO)3(DDTC)(tbi)], Re2, fac-[Re(CO)3(DDTC)(PPh3)], Re3, fac-[Re(CO)3(DDTC)(PPh2Me)], Re4, fac-[Re(CO)3(DDTC)(AsPh3)], Re5, fac-[Re(CO)3(DDTC)(im)], Re6 and fac-[Re(CO)3(DDTC)(4AP)], Re7, complexes in high yields (>80%). All Re complexes were fully characterized by IR, NMR, and in addition Re4, Re5, and Re7 with X-ray crystallography. Analogous reactions as performed with Re were subsequently explored on the 99mTc and 186Re-tracer levels using the corresponding fac-[99mTc/186Re(CO)3(H2O)3]+ precursor. Complexes 99mTc1 – 99mTc5, 186Re1 and 186Re3 were obtained in high radiochemical yield (>91%), while the complexes 99mTc6, 99mTc7 and 186Re7 formed with radiochemical yields of 55%, 28%, and 75%, respectively. The 99mTc and 186Re-complexes were characterized by comparative HPLC analysis using the analogous Re complexes. During histidine and cysteine challenge experiments at 37 °C through 6 h, complexes 99mTc1 – 99mTc5 remained > 92% stable, while complexes 99mTc6 and 99mTc7 remained only 8% stable through 3 h. Similar studies for 186Re-complexes showed that 186Re1 and 186Re3 remained > 95% stable for up to 48 h, while 186Re7 had decreased to 7% after 3 h. LogD7.4 data of 99mTc1 – 99mTc5, 186Re1, and 186Re3 complexes, which ranged from 2.59 to 3.39, suggested high lipophilicity. Biodistribution studies in healthy Swiss albino mice showed hepatobiliary excretion for 99mTc1, 99mTc2, and 99mTc4, fast blood clearance for 99mTc4, while high liver uptake and retention for 99mTc3 and 99mTc5 were measured. Moreover, 99mTc2 showed high accumulation in the lungs with sustained retention (52.80% ID/g at 4 h p.i.) and significant brain uptake at 2 min p.i. (1.89% ID/g). The study showed the great influence of monodentate ligand in the synthesis and biodistribution of the mixed ligand complexes.

Molecular Precursor Route to Bournonite (CuPbSbS3) Thin Films and Powders.

Quaternary metal chalcogenides have attracted attention as candidates for absorber materials for inexpensive and sustainable solar energy generation. One of these materials, bournonite (orthorhombic CuPbSbS3), has attracted much interest of late for its properties commensurate with photovoltaic energy conversion. This paper outlines the synthesis of bournonite for the first time by a discrete molecular precursor strategy. The metal dithiocarbamate complexes bis(diethyldithiocarbamato)copper (II) (Cu(S2CNEt2)2, (1)), bis(diethyldithiocarbamato)lead (II) (Pb(S2CNEt2)2, (2)), and bis(diethyldithiocarbamato)antimony (III) (Sb(S2CNEt2)3, (3)) were prepared, characterized, and employed as molecular precursors for the synthesis of bournonite powders and the thin film by solvent-less pyrolysis and spray-coat-pyrolysis techniques, respectively. The polycrystalline powders and thin films were characterized by powder X-ray diffraction (p-XRD), which could be indexed to orthorhombic CuPbSbS3. The morphology of the powder at the microscale was studied using scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDX) was used to elucidate an approximately 1:1:1:3 Cu/Pb/Sb/S elemental ratio. An optical band gap energy of 1.55 eV was estimated from a Tauc plot, which is close to the theoretical value of 1.41 eV.