Synthesis, crystal structure and thermal properties of bis(1,3-dicyclohexylthiourea-κS)bis(isothiocyanato-κN)cobalt(II)

Crystals of the title compound, [Co(NCS)2(C13H24N2S)2], were obtained by the reaction of Co(NCS)2 with 1,3-dicyclohexylthiourea in ethanol. Its crystal structure consists of discrete complexes that are located on twofold rotation axes, in which the CoII cations are tetrahedrally coordinated by two terminal N-bonded thiocyanate anions and two 1,3-dicyclohexylthiourea ligands. These complexes are linked via intermolecular N—H...S and C—H...S hydrogen bonding into chains, which elongate in the b-axis direction. These chains are closely packed in a pseudo-hexagonal manner. The CN stretching vibration of the thiocyanate anions located at 2038 cm−1 is in agreement with only terminal bonded anionic ligands linked to metal cations in a tetrahedral coordination. TG–DTA measurements prove the decomposition of the compound at about 227°C. DSC measurements reveal a small endothermic signal before decomposition at about 174°C, which might correspond to melting.

Magnetic, structural and Mössbauer study of soils from an ancient mining area in Huancavelica-Peru

We present the magnetic, structural and 57Fe Mossbauer characterization of soils collected from an ancient mercury contaminated city named Huancavelica in Peru. The characterization results indicate that silicates and carbonates are the main mineralogical constituents in the samples. In addition, 57Fe Mössbauer spectra at room temperature reveal, the presence of two components: a magnetic component related to magnetic Fe-oxides (magnetite, hematite, goethite) and a high non-magnetic component related to Fe+3 in high spin configuration and tetrahedral coordination in silicates. The magnetization measurements present screening of paramagnetic, ferromagnetic and antiferromagnetic signals, typical from soils containing different silicates and iron minerals. Remarkably the Verwey and Morin transitions corresponding to magnetite and hematite, respectively, are screened by the paramagnetic signal corresponding to the major silicate components in the samples. Overall, the soils are mainly composed of crystalline and amorphous silicates, calcites and iron bearing which are typical from Andean soils.

Zinc Complexes Derived from 5-Bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenol: Microwave-Assisted Synthesis, Characterization, Crystal Structures and Antibacterial Activities

Three new zinc complexes [Zn3L2(μ2-η1:η1-CH3COO)2(μ2-η2:η0-CH3COO)2] (1), [ZnCl2(HL)] (2) and [ZnBr2(HL)] (3), where L = 5-bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenolate, HL = 5-bromo-2-(((2-isopropylammonio) ethyl)imino)methyl)phenolate, have been synthesized under microwave irradiation. The complexes were characterized by elemental analyses, IR, UV-Vis spectra, molar conductivity, and single crystal X-ray diffraction. X-ray analysis revealed that the Zn atoms in complex 1 are in square pyramidal and octahedral coordination, and those in complexes 2 and 3 are in tetrahedral coordination. The molecules of the complexes are linked through hydrogen bonds and π···π interactions. In order to evaluate the biological activity of the complexes, in vitro antibacterial against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa was assayed.

Structural and Chemical Properties of Geopolymer Gels Incorporated with Neodymium and Samarium

The present work was focused on doping of 1% and 5% both of Nd2O3 and Sm2O3 in geopolymer gels. One of the main goals was to determine the influence of the behavior of Nd and Sm as dopants and structural nanoparticles changes of the final geopolymer formed. It is shown that the disorder formed by alkali activation of metakaolin can accommodate the rare earth cations Nd3+ and Sm3+ into their aluminosilicate framework structure. The main geopolymerization product identified in gels is Al-rich (Na)-AS-H gel comprising Al and Si in tetrahedral coordination. Na+ ions were balancing the negative charge resulting from Al3+ in tetrahedral coordination. The changes in the structures of the final product (geopolymer/Nd2O3; Sm2O3), has been characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analysis with energy dispersive spectrometry (EDS). Nucleation at the seed surfaces leads to the formation of phase-separated gels from rare earth phase early in the reaction process. It is confirmed that Nd and Sm have been shown to form unstable hydroxides Nd(OH)3 and Sm(OH)3 that are in equilibrium with the corresponding oxides.

Anion Induced Synthesis, Structural Characterization and Antibacterial Activity of Zinc(II) Complexes Derived from 5-Bromo-2-((2-(diethylamino)ethylimino)methyl) phenol

By changing the anions of zinc salts, three different zinc(II) complexes, [Zn2(HL)2(NCS)4]·2CH3OH (1), [Zn2L(μ2-η1:η1-CH3COO)2(NCS)] (2) and [Zn(HL)I2]·CH3OH (3), where L = 5-bromo-2-((2-(diethylamino)ethylimino)methyl)phenolate, HL = 5-bromo-2-((2-(diethylammonio)ethylimino)methyl)phenolate, have been synthesized and characterized by IR and UV-Vis spectroscopy, as well as single-crystal X-ray diffraction. X-ray analysis indicates that the Zn atoms in the complexes are in trigonal bipyramidal, square pyramidal and tetrahedral coordination. The anions of the zinc salts lead to the formation of different structures of the complexes. Antibacterial activity of the complexes against Staphylococcus aureus, Escherichia coli, Klebsielle pneumoniae and Candida albicans strains was studied.

Zinc(II) Complexes Derived from Schiff Bases: Syntheses, Structures, and Biological Activity

Three new zinc(II) complexes, [Zn2I2(L1)2] (1), [Zn(HL2)2(NCS)2] (2), and [ZnIL3] (3), where L1 is the anionic form of 2-[(6-methylpyridin-2-ylimino)methyl]phenol (HL1), HL2 is the zwitterionic form of 2-(cyclopropyliminomethyl)-5-fluorophenol (HL2), and L3 is the anionic form of 5-bromo-2-[(3-morpholin-4-ylpropylimino)methyl] phenol (HL3), have been prepared and characterized by elemental analyses, IR, UV and NMR spectra, and single crystal X-ray crystallographic determination. Complex 1 is a dinuclear zinc complex, and complexes 2 and 3 are mononuclear zinc complexes. The Zn atoms in the complexes are in tetrahedral coordination. The effect of the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were evaluated.

Reactions of Pentaphenylantimony and Penta-Para-Tolylanimony with Calixarene [4-t-BuC6H2OH(S-2)]4

Pentaphenylantimony and penta-para-tolylantimony react with calixarene [4-t-BuC6H2OH(S-2)]4 (СArH) by way of arene elimination and formation of the [Ph4Sb]+[СAr]- × TolH (1), [p-Tol4Sb]+[CAr]- × H2O (2) ionic products with a yield up to 96%. The compound has been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction data, compounds 1 and 2 are ionic complexes with solvate molecules of toluene (1) and water (2). The cation has a tetrahedral coordination of the antimony atom with aryl ligands at the polyhedron vertices; the anion is represented by the deprotonated form of p-tert-butylthiacalix[4]arene. The three tert-butyl groups, the phenyl ring and solvated toluene in the structure of compound 1, and two tert-butyl fragments in the structure of compound 2 are disordered over two positions. The tetrahedral coordination of antimony atoms in the cations of compounds 1 and 2 is slightly distorted. The CSbC angles deviate from the theoretical value and vary within 106.0(4)−117.7(4)° (1), 105.75(15)−112.84(15)° (2). The average Sb–C bond lengths are 2.101(3) and 2.106(4) Å in structures 1 and 2, respectively. The [СAr]- anion is in the cone conformation, the upper rim of which is represented by the tert-butyl groups in the para-position, while the lower one is represented by hydroxy groups, one of which is deprotonated. The СAr–O– bond length (1.318(4) (1) and 1.326(4) (2) Å) is less than the average value of the СAr–OH bond lengths (1.338(4) (1) and 1.343(4) (2) Å), which indicates increasing multiplicity of the bond and localization of a negative charge on the oxygen atom. Intramolecular hydrogen bonds with the neiboring O atom are observed. The H∙∙∙O distances are 2.16, 1.69, 1.77 Å in 1 and 1.92, 1.79, 1.76 Å in 2. Dihedral angles between opposite phenoxide rings are 60.64° and 87.07° (1) and 83.85° and 80.42° (2), which indicates somewhat less symmetric anion in structure 1 than in structure 2. The formation of the crystal spatial structure is due to the formation of hydrogen bonds between ions with participation of oxygen and sulfur atoms, as well as СН∙∙∙π–interactions, while the ions form chains in the crystal of compound 1, and layers in the crystal of compound 2. Complete tables of atom coordinates, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Center (No. 1850118 (1); No. 2013220 (2); [email protected] or http://www.ccdc.cam.ac.uk/data_request/cif).

Structure and Synthesis of Dihalogenodicyanoaurate Complexes [Ph3PR][Au(CN)2Hal2], Hal = Cl, R = Me, СH2Ph; Hal = Br, R = cyclo-C6H11; Hal = I, R = Ph

Interaction of organyltriphenylphosphonium halides with potassium dihalogenodicyanoaurates in water followed by recrystallization of reaction products from acetonitrile or DMSO has been used to synthesize gold(III) ionic complexes [Ph3PMe][Au(CN)2Cl2] (1), [Ph3PCH2Ph][Au(CN)2Cl2] (2), [Ph3PC6H11-cyclo][Au(CN)2Br2] (3), and [Ph4P][Au(CN)2I2] (4), which have been structurally characterized by the X-ray analysis method (CIF files CCDC No. 1901681 (1), 1912903 (2), 1912919 (3), 2048146 (4)). According to the X-ray data crystals 1–4 consist of centrosymmetric square-planar [Au(CN)2Hal2]– anions (the Au–Hal average bond lengths are 2.417(3) Å (1), 2.280(2) Å (2), 2.4203(13) Å (3), and 2.6035(10) Å (4); the Au–C average bond lengths are 2.06(2) Å (1), 2.010(7) Å (2), 2.009(7) Å (3,) and 1.998(6) Å (4)); the phosphorus atoms in organyltriphenylphosphonium cations have a slightly distorted tetrahedral coordination (the P–C bond lengths are 1.782(9)-1.806(8) Å (1), 1.788(4)-1.813(5) Å (2), 1.790(5)-1.813(5) Å (3) and 1.793(6)-1.799(5) Å (4)). The structural organization in crystals 2–4 is caused by the interionic С–H∙∙∙N≡C hydrogen bonds (C–HPh∙∙∙N≡C 2.56 Å (2); C–HPh∙∙∙N≡C 2.43–2.59 Å, C–Hcyclohexyl∙∙∙N≡C 2.47 Å (3), C–HPh∙∙∙N≡C 2.63 Å (4)), while in crystals 1 no significant interionic contacts are observed.