Group 12 dithiocarbamate complexes: Synthesis, characterization, and X-ray crystal structures of Zn(II) and Hg(II) complexes and their use as precursors for metal sulfide nanoparticles

Antiproliferative activity of Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of dithiocarbamate: synthesis, structural characterization, and thermal studies

Five new metal complexes of Fe(II) (1), Co(II) (2), Ni(II) (3), Cu(II) (4), and Zn(II) (5), derived from an N-cyclohexyl N-(3,4-dimethoxybenzyl) dithiocarbamate ligand, have been successfully synthesized and fully characterized by different analytical techniques i.e. elemental analyses, FT-IR, UV-Vis, 1H & 13C NMR, and HRMS. Furthermore, complexes 4 and 5 have been characterized by the SC-XRD technique. Complex 4 adopts a distorted square planar geometry around the Cu(II) center while complex 5 adopts a distorted tetrahedral geometry around the Zn(II) center. In addition, an eight-membered symmetric chair-like metallacycle ring containing two Zn(II) centers has also been found in complex 5. XRD data also show that complexes 4 and 5 are stabilized by various weak intermolecular hydrogen bonding interactions. The course of the thermal degradation of metal complexes 1-5 has been examined by TG-DTA data which revealed that metal sulphide formed as the final residue. Complexes 1-5 demonstrated concentration-dependent cytotoxicity and growth inhibition of DL tumor cells. Among the compounds, complexes 1, 4, and 5 showed significant cytotoxicity and induced a loss in the viability of DL cells. Therapy with complexes 1, 4, and 5 protects DL tumor-bearing animals from exacerbation of the disease, increases lifespan, and significantly improves the histopathological parameters of the vascularized organ, including preventing metastasis. Overall cytotoxicity assay results indicate that all complexes have remarkable cytotoxic potential in comparison with the free ligand.

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.

The structural chemistry of zinc(ii) and nickel(ii) dithiocarbamate complexes

Dithiocarbamate complexes are of immense interest due to their diverse structural properties and extensive application in various areas. They possess two sulfur atoms that often act as the binding sites for metal coordination in a monodentate, bidentate, or anisodentate fashion. These different coordination modes enhance the possibility for complex formation and make them useful in different areas especially in biomedical fields. A synergy exists in the metal ions and dithiocarbamate moieties, which tends to exert better properties than the respective individual components of the complex. These improved properties have also been attributed to the presence of the C–S bonds. Zinc and nickel ions have been majorly found to bind to the dithiocarbamate in bidentate modes, and consequently different geometries have resulted from this interaction. The aim of this review is to present some studies on the synthesis, structural chemistry, and the relevance of zinc and nickel dithiocarbamates complexes especially in biological systems.

Role of non-covalent interactions in the supramolecular architectures of mercury(ii) diphenyldithiophosphates: An experimental and theoretical investigation

The H-bond, spodium bond and CH⋯π interactions playing an important role in the supramolecular organization of two mercury(ii) diphenyldithiophosphate complexes have been discussed.

Dithiocarbamates: Challenges, Control, and Approaches to Excellent Yield, Characterization, and Their Biological Applications

Progresses made in previous researches on syntheses of dithiocarbamates led to increase in further researches. This paper reviews concisely the challenges experienced during the synthesis of dithiocarbamate and mechanisms to overcome them in order to obtain accurate results. Aspects of its precursor's uses to synthesize adducts, nanoparticles, and nanocomposites are reported. Some common characterization techniques used for the synthesized products were assessed. Biological applications are also reported.

Exploring the Topological Landscape Exhibited by Binary Zinc-triad 1,1-dithiolates

The crystal chemistry of the zinc-triad binary 1,1-dithiolates, that is, compounds of xanthate [−S2COR], dithiophosphate [−S2P(OR)2], and dithiocarbamate [−S2CNR2] ligands, is reviewed. Owing to a wide range of coordination modes that can be adopted by 1,1-dithiolate anions, such as monodentate, chelating, μ2-bridging, μ3-bridging, etc., there exists a rich diversity in supramolecular assemblies for these compounds, including examples of zero-, one-, and two-dimensional architectures. While there are similarities in structural motifs across the series of 1,1-dithiolate ligands, specific architectures are sometimes found, depending on the metal centre and/or on the 1,1-dithiolate ligand. Further, an influence of steric bulk upon supramolecular aggregation is apparent. Thus, bulky R groups generally preclude the close approach of molecules in order to reduce steric hindrance and therefore, lead to lower dimensional aggregation patterns. The ligating ability of the 1,1-dithiolate ligands also proves crucial in determining the extent of supramolecular aggregation, in particular for dithiocarbamate species where the relatively greater chelating ability of this ligand reduces the Lewis acidity of the zinc-triad element, which thereby reduces its ability to significantly expand its coordination number. Often, the functionalisation of the organic substituents in the 1,1-dithiolate ligands, for example, by incorporating pyridyl groups, can lead to different supramolecular association patterns. Herein, the diverse assemblies of supramolecular architectures are classified and compared. In all, 27 structurally distinct motifs have been identified.

Synthesis, Optical, and Structural Studies of Iron Sulphide Nanoparticles and Iron Sulphide Hydroxyethyl Cellulose Nanocomposites from Bis-(Dithiocarbamato)Iron(II) Single-Source Precursors

In this study, Fe(II) complexes of phenyldithiocarbamate, dimethyldithiocarbamate and imidazolyldithiocarbamate were used as single-source precursors to prepare iron sulphide nanoparticles by thermolysis in oleic acid/octadecylamine (ODA) at 180 °C. The nanoparticles were dispersed into hydroxyethyl cellulose (HEC) to prepare iron sulphide/HEC nanocomposites. Ultraviolet-Visible (UV-Vis), Photoluminescence (PL), Fourier Transform Infrared (FTIR), powder X-ray diffraction (pXRD), high-resolution transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS) were used to characterize the iron sulphide nanoparticles and corresponding HEC nanocomposites. The absorption spectra studies revealed that the nanoparticles were blue shifted due to quantum confinement and the optical band gaps of the nanoparticles are 4.85 eV for FeS1, 4.36 eV for FeS2, and 4.77 eV for FeS3. The emission maxima are red-shifted and broader for the nanoparticles prepared from phenyldithiocarbamate. Rod-like and spherically shaped iron sulphide particles were observed from the HRTEM images. The crystallite sizes from the HRTEM images are 23.90-38.89 nm for FeS1, 4.50-10.50 nm for FeS2, and 6.05-6.19 nm for FeS3 iron sulphide nanoparticles, respectively. pXRD diffraction patterns confirmed that FeS1 is in the pyrrhotite-4M crystalline phase, FeS2 is in the pyrrhotite phase, and FeS3 is in the troilite phase of iron sulphide. The phases of the iron sulphide nanoparticles indicate that the nature of the precursor complex affects the obtained crystalline phase. FTIR spectra studies confirmed the incorporation of the nanoparticles in the HEC matrix by the slight shift of the O-H and C-O bonds and the intense peaks on the nanoparticles. FESEM images of the iron sulphide nanoparticles showed flake-like or leaf-like morphologies with some hollow spheres. The EDS confirmed the formation of iron sulphide nanoparticles by showing the peaks of Fe and S.