Novel Cr(III), Ni(II), and Zn(II) complexes of thiocarbamide derivative: Synthesis,investigation, theoretical,catalytic, potentiometric,molecular docking and biological studies

Throughout this research, the thiocarbamide derivative (H₂L), and its Cr(III), Ni(II) and Zn(II) complexes have been reported. The thiocarbamide moiety was established with a reaction of benzoyl isothiocyanate and 1H-1,2,4-triazol-3-amine. Structural elucidation of such compounds was achieved using elementary examination, spectral and magnetic experiments. The octahedral construction of the Cr(III) complex, the tetrahedral geometry of the Zn(III) complex and the mixed geometry (tetrahedral and square planar) of the Ni(II) complex have been verified by the optimization of structure using DFT. The action of Zn²⁺ complex in the oxidative degradation of an organic azo-dye was investigated, and it showed promising results. The thermal degradation behavior of thiocarbamide metal complexes were studied as well as the calculation of the kinetic data for title compounds (E_a, A, ΔH*, ΔS* and ΔG*) of thermal degradation steps has been tested utilizing two different techniques. Liver carcinoma (HePG2) and breast carcinoma (MCF-7) cytotoxicity as well as ABTS-antioxidant activities demonstrated the effective inhibitory of the Ni(II)-complex relative to other tested compounds. The antimicrobial activity of the compounds suggests that Cr(III) has the highest activity. Furthermore, the Molecular Operating Environment (MOE) program was used to calculate the binding affinity between the EGFR protein and the compounds under investigation.     

NS and NSO-Donor ligands and their metal complexes. Synthesis and characterisation of a new low-spin iron(III) complex with 1,2-di(o-aminophenylthio)ethane and iron(III), cobalt(III) and manganese(III) complexes of 1,2-di(o-salicylaldiminophenylthio)ethane

Summary Iron(III) complexes of a quadridentate N₂S₂ donor ligand, 1,2-di(o-aminophenylthio)ethane (DAPTE) and its Schiff Base with salicylaldehyde, a hexadentate N₂S₂O₂ donor ligand,viz. 1,2-di(o-salicylaldiminophenylthio)ethane (H₂DSALPTE) have been synthesised and characterised.The Schiff base ligand (1 mol) gave a dark green tri-iron(III) [Fe₃(DSALPTE)(HDSALPTE)Cl₃]Cl₂ complex when reacted with anhydrous iron(III) chloride (1 mol). The Mössbauer data of this complex suggest the presence of three iron sites, one of which is octahedral and the other two tetrahedral. On the other hand, Fe(ClO₄)₃ reacted smoothly with H₂DSALPTE in ethanol to give a mononuclear pseudo-octahedral complex in which the ligand functions in a dibasic hexadentate fashion. Mössbauer data suggest the presence of a low-spin-high-spin equilibrium in the solid state. The manganese(III) and cobalt(III) complexes of the Schiff base, H₂DSALPTE, are also studied for the sake of comparison with the corresponding iron(III) complex. The N₂S₂ ligand, however, formed a low-spin pseudo-octahedral iron(III) complex. The complexes have been characterised by elemental analysis, molar conductance values, cryomagnetic data and i.r., electronic and Mössbauer spectral data.     

Synthesis and characterization of rhodium(III), iridium(III), ruthenium(III) and osmium(III) complexes containing sterically hindered heterocyclic ligands

Summary Some thiazolidine-2-thione and thiomorpholin-3-one complexes of rhodium(lll), iridium(III), ruthenium(III) and osmium(III) have been prepared and characterized by chemical analysis, conductivity measurements, room temperature magnetic moment studies, electronic, i.r. and far i.r. spectra and n.m.r. measurements. From the magnetic properties it was concluded that the above ligands form low-spin complexes with all the metal ions. The position and multiplicity of the metal-halogen stretching modes in the far-i.r. region have been extensively investigated and discussed; the results are particularly useful in distinguishing between themer- andfac-isomers in the octahedral compounds of the ML₃ X₃ type. The wavelengths of the principal electronic absorption peaks have been accounted for quantitatively in terms of the crystal field theory and the various parameters have been calculated. On the basis of the electronic spectra a trigonal bipyramidal geometry,D _3h, has been established for the Ru(tm)₂Cl₃ complex; the Ir(rm)₂Cl₃ · H₂O complex has also been prepared. It is penta-coordinated and a trigonal bipyramidal environment is suggested for the iridium(III) ion.     

Thermal behaviour of the homopolynuclear glyoxylate complex combinations with Cu(II) and Cr(III)

Homopolynuclear complexes of Cu(II) respectively Cr(III) with the glyoxylate dianion, C₂H₂O₄ ^2-, have been studied in non-isothermal regime in air and nitrogen. The results of the non-isothermal analysis performed for the synthesised complexes, Cu(C₂H₂O₄)·0.5H₂O, respectively [Cr₂(OH)₂(C₂H₂O₄)₂(OH₂)₄]·2H₂O, correlated with the results of the IR and TG analysis of the compounds obtained by thermal treatment from the initial complexes and the results of the GLC and XR analysis have led to the establishment of the thermal decomposition mechanisms for the two studied complexes. The decomposition mechanisms confirm the stoichiometric and structural formulae proposed for the two synthesised homopolynuclear complexes. This revised version was published online in July 2006 with corrections to the Cover Date.     

Lanthanum(III) and praseodymium(III) complexes of acetylferrocenyl mercaptotriazoles

Schiff base complexes derived from 3-substituted phenyl-4-amino-thiolato-1,2,4-triazoles and acetylferrocene (LH), with lanthanum(III) and praseodymium(III) of the type [M(L)₃] have been prepared and characterised by elemental analysis, electrical conductance, magnetic moments and spectral (electronic, i.r., ¹H-n.m.r. and ¹³C-n.m.r.) data. The thermal behaviour of selected complexes was investigated by t.g. and d.t.g. techniques.     

Stability and thermodynamics of La(III)-, Pr(III)-, Nd(III)-, Gd(III)- and Eu(III)-p-nitrobenzaldehyde thiosemicarbazone systems

Three complexes containing bidentate N-2,3-dimethylphenylglycine, (2,3-HDPG), N-2,4-dimethylphenylglycine, (2,4-HDPG) and N-2-ethylphenylglycine, (2-HEPG) acids have been prepared and characterized. These compounds have the general formula Zn(2,3-DPG)₂·2 H₂O, Zn(2,4-DPG)₂ and Zn(2-EPG)₂·2 H₂O, respectively. The structure of the complexes as inferred from their chemistries have been found to be compatible with the infrared spectral data. The thermal behaviour of these complexes has been studied from their TG, DTG and DSC diagrams obtained in a dynamic atmosphere of pure air. Heats of dehydration have been calculated from DSC curves.     

Thermal and spectroscopic studies of terbium(III) and dysprosium(III) complexes with piperidin-4-ones

Terbium(III) and dysprosium(III) nitrate complexes with variously substituted 2,6-diphenylpiperidin-4-ones (L¹)-(L¹⁰) of general formula [Ln(L)(NO₃)₂(H₂O)₂]NO₃ have been synthesized. These complexes have been characterized by analytical, spectral and thermal studies. Molar conductance data show that these complexes are 1:1 electrolytes. The presence of two coordinated water molecules is confirmed by thermal and infrared spectral studies. IR spectral data indicate that piperidin-4-ones, in spite of having two coordinating sites, are monodentate, coordinating only through ring nitrogen. The IR and conductance data reveal the presence of two bidentate and one ionic nitrate groups. The nephelauxetic ratio (β), covalency factor (b^1/2) and Sinha’s parameter (δ) evaluated from electronic spectral data of dysprosium(III) complexes indicate a little covalency in metal-ligand bonding.     

Thermal Decomposition of Thallium(I) Bis-oxalatodiaquaindate(III) Monohydrate

Thallium(I) bis-oxalatodiaquaindate(III) monohydrate was obtained by precipitation of indium(III) withoxalic acid from slightly acidic solution in the presence of thallium(I). The complex was subjected to chemical analysis. The thermal decomposition behavior of the complex was studied using TG, DTA and DTG techniques. The solid complex salt and the intermediate product of its thermal decomposition were characterized using IR absorption and X-ray diffraction spectra. Based on data from these physicochemical investigations the structural formula of the complex was proposed as Tl[In (C₂O₄)₂ (H₂O)₂]⋅H₂O. This revised version was published online in August 2006 with corrections to the Cover Date.     

Allyl complexes of dicyclopentadienyl-niobium(III) and -tantalum(III)

The synthesis and the properties of the complexes Cp₂TaCl₂, Cp₂M(allyl), Cp₂M(1-methylallyl) and Cp₂M(2-methylallyl) with M  Nb, Ta are described. The complex Cp₂TaCl₂ has one unpaired electron per tantalum atom, while the allyl complexes are diamagnetic. The IR and PMR spectra indicate that the allyl group is π-bonded to the metal. The mass spectra of the complexes are discussed; the thermal stability of the Cp₂Nb- and Cp₂Ta-(allyl) complexes was investigated by differential thermal analysis. The properties of the niobium and tantalum complexes are compared with those of the corresponding titanium complexes.     

Synthesis,structural characterization and biological studies of neodymium(III) and samarium(III) complexes with mercaptotriazole Schiff bases

A series of neodymium(III) and samarium(III) complexes of type [Ln(L)Cl(H₂O)₃] have been synthesized with Schiff bases (LH₂) derived from 3‐(phenyl/substituted phenyl)‐4‐amino‐5‐mercapto‐1,2,4‐triazoles and isatin. The structures of the complexes were established using elemental analysis, molar conductivities, magnetic moments, infrared, NMR (¹H, ¹³C) and UV–visible spectra, X‐ray diffraction and mass spectrometry. The thermal behaviour of these compounds under non‐isothermal conditions was investigated using thermogravimetry and differential thermogravimetry. The intermediates obtained at the end of various thermal decomposition steps were identified from elemental analysis and infrared spectral studies. All the ligands and their complexes were also screened for their antibacterial activity against Staphylococcus aureus and Bacillus subtilis and antifungal activity against Aspergillus niger, Aspergillus flavus and Colletotrichum capsici. The screening results were correlated with the structural features of the compounds. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and characterization of Ru(III), Rh(III), Pt(IV) and Ir(III) thiosemicarbazone complexes

Ru(III), Rh(III), Pt(IV) and Ir(III) complexes of 2-furfural thiosemicarbazone as ligand have been synthesised. These complexes have the composition [M(ligand)₂X₂]X (M = Ru(III) Rh(III) and Ir(III) X = Cl and Br) and [Pt(ligand)₂ X₂] X₂ (X = Cl, Br and 1/2SO₄). The deprotonated ligand forms the complexes of the formulae M(ligand-H)₃ and Pt(ligand-H)₃Cl. All these complexes have been characterized by elemental analysis, magnetic measurements, electronic and infrared spectral studies. All the complexes are six-coordinate octahedral.     

N/P-ethoxyphenyl/dithiocarbamato complexes of Au(III), As(III), Fe(III), Co(III) and Mo(V)

The complexes of Au(III), As(III), Fe(III), Co (III) and Mo(V) with N(p-ethoxyphenyl)-dithiocarbamate have been synthesized and characterized on the basis of elemental analyses, conductance measurements, infrared and electronic spectra, molecular weight determinations and magnetic moment data. The thermal behaviours of these complexes have been studied with the aid of TG and DTA techniques.     

Chloromethylthio-Substituted Chromium(III), Cobalt(III), and Aluminum(III) Acetylacetonates

SCl-Substituted chromium(III), cobalt(III), and aluminum(III) acetylacetonates react with carbenes similarly to organylsulfenyl chlorides, with insertion of the carbenes into the S-Cl bond. Reaction with diazomethane gave chloromethylthio-substituted complexes whose structure was proved by IR, ¹H NMR, and mass spectroscopy. The thermal oxidative degradation of the complexes was studied. Chlorination of SCH₃-substituted acetylacetonates does not yield such complexes.     

Recent Advances in Organic Reactions Catalyzed by Lanthanide（Ⅲ） Complexes

Lanthanide compounds have been attracting much attention in organic synthesis.Chiral Ln-substituted BINOL have been widely studied in several asymmetric organic reactions.LnCl3 and Ln(OTf)3 have been expected to serve as Lewis acide and have been applied to many important synthetic reactions in a one-pot manner,Ln(O-i-Pr)3 exhibits some basic characters,which also can be utilized in some special organic transformation.This article deals with some lanthanides(Ⅲ）complexes promoted organic reactios,which we have recently developed.     

Properties and X-ray structural study of volatile dimethylgold(III) β-iminoketonates

Three complexes of dimethylgold(III) of a general formula of (CH₃)₂Au(R¹-CNH-CH-CO-R²) involving β-imino-derivatives of acetylacetone (k-acac), trifluoroacetylacetone (k-tfa), and pivaloyltrifluoroacetone (k-pta) are studied for the first time with single crystal X-ray diffraction. Synthesis and properties of these compounds are presented along with thermal properties determined by the DTA technique. The structures of the compounds in question are based on monomeric complexes. Gold atoms have a slightly distorted square-planar coordination involving oxygen and nitrogen atoms of the β-iminoketonate ligand and two methyl groups. Geometrical characteristics of the coordination cores are the following: bond lengths of Au-C_Me fall within 2.008–2.050 Å; average Au-O and Au-N distances are 2.094 Å and 2.068 Å respectively. In the structure of (CH₃)₂Au(k-acac) gold complexes are joined by hydrogen bonds to give infinite chains with the shortest Au...Au separation of 5.396 Å. In the crystals of the fluorinated compounds coplanar molecules make infinite stacks. The shortest intra-stack Au...Au separation of 3.416 Å is observed for the complex of (CH₃)₂Au(k-pta) that possesses the largest thermal stability among the investigated compounds.     

Synthesis,characterization and thermal behaviour of solid-state compounds of europium(III) and gadolinium(III) 3-methoxybenzoate

Solid-state Ln–C₈H₇O₃ compounds, where Ln stands for Eu(III) and Gd(III) and C₈H₇O₃ is 3-methoxybenzoate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy, elemental analysis and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, thermal stability and decomposition of the isolated compounds.     

Synthesis and infrared studies of Methylgallium(III) and Gallium(III) Complexes with Tridentate Ligands

Several new 1:1 complexes, neutral or anionic, formed by Methylgallium(III) and Gallium(III) with tridentate ligands (H₂L; ONO and SNO donor atoms), as well as a glycylglycine derivative, have been synthesized, and characterized in the solid state by infrared spectroscopy. Data have been interpreted in terms of trigonal bipyramidal type configurations of the environment of the metal centre, in the complex anions [Cl₂GaL]^? as well as in compounds CH₃GaL and ClGaL: in the latter two, dimerization would occur through bridging, three-coordinating oxygen atoms.     

Synthesis,structure, and optical properties of lanthanum(III), cerium(III), praseodymium(III), and nickel(II) heterometallic complexes with glycine

New cluster complexes of lanthanides(III) and nickel(II) [Ln{Ni(Gly)₂}₆]³⁺[Ln(NO₃)₆]^3– have been synthesized, where Ln = La (I), Ce (II), and Pr (III); and Gly is glycinate. The structures of compounds I–III are determined by X-ray diffraction. The icosahedral cavity in the complex cation, where the lanthanide ion resides, has a fixed size independent of the nature of the central Ln(III) ion. In the complex anion, on the contrary, the Ln–O distances naturally decrease from La(III) to Pr(III). The optical properties of cationanion complexes I–III are studied. Based on the assignment in the electronic absorption spectra of the complexes, it is shown that the absorption bands are caused by d–d electronic transitions.     

Iron(III) Schiff base complexes with asymmetric tetradentate ligands: synthesis,spectroscopy, and antimicrobial properties

The synthesis and characterization is reported of four iron(III) complexes of general formula [Fe(pythsalX)(H₂O)₂]Cl₂, derived from the NSNO-donor tetradentate Schiff base ligands pythsalHX ([5-X-N-(2-pyridylethylsulfanylethyl)salicylideneimine] (X = OMe, N₂Ph, I, NO₂). The complexes were characterized by physico-chemical and spectroscopic methods. The thermal stabilities of both the free Schiff bases and their complexes were studied by differential scanning calorimetry and thermogravimetric analyses. The spectroscopic data suggest that the Schiff base ligands coordinate through deprotonated phenolic oxygen, imine, and pyridine-type nitrogens and the thioether sulfur atoms to give an octahedral geometry around the iron(III) atom in all these complexes. The free Schiff bases and their complexes have been screened for antimicrobial activities and the results show that the free Schiff bases are more potent antibacterials than the complexes.     

Thermochemistry of some complexes of chromium(III) with imidazoles

The thermal decomposition in air of several complexes of chromium(III) with imidazole,N-methylimidazole and 2-methylimidazole has been studied with the aid of differential thermal analysis (DTA), thermogravimetry (TG) and derivative thermogravimetry (DTG) in the temperature range 25–600°C. Although the final process of the decomposition gives Cr₂O₃, there are interesting differences in the complete process of decomposition. The reasons for these differences appear to be related to the trans-effect and to the presence in the imidazole complexes of hydrogen bonds. Enthalpies of the several decomposition reactions have been determined by differential thermal analysis.