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Coordination compounds containing bis(2-pyridyl)ditellane as a precursor and transition metals are described. The cobalt-containing photocatalysts are active for H2 production.

Pyrimidine-2-thione (HSpym) reacts with lead(II) thiocyanate and lead(II) bromide in N,N-dimethylformamide (DMF) to form poly[(μ-isothiocyanato-κ2 N:S)(μ4-pyrimidine-2-thiolato-κ6 N 1,S:S:S:S,N 3)lead(II)], [Pb(C4H3N2S)(NCS)] n or [Pb(Spym)(NCS)] n , (I), and the polymeric one-dimensional (1D) compound catena-poly[[μ4-bromido-di-μ-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)] N,N-dimethylformamide monosolvate], {[Pb2Br3(C4H3N2S)(C4H4N2S)]·C3H7NO} n or {[Pb2Br3(Spym)(HSpym)]·DMF} n , (IIa), respectively. Poly[μ4-bromido-di-μ3-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)], [Pb2Br3(C4H3N2S)(C4H4N2S)] n or [Pb2Br3(Spym)(HSpym)] n , (IIb), could be obtained as a mixture with (IIa) when using a lesser amount of solvent. In the crystal structures of the pseudohalide/halide PbII stable compounds, coordination of anionic and neutral HSpym has been observed. Both Spym− (in the thiolate tautomeric form) and NCS− ligands were responsible for the two-dimensional (2D) arrangement in (I). The Br− ligands establish the 1D polymeric arrangement in (IIa). Eight-coordinated metal centres have been observed in both compounds, when considering the Pb...S and Pb...Br interactions. Both compounds were characterized by FT–IR and diffuse reflectance spectroscopies, as well as by powder X-ray diffraction. Compound (IIa) and its desolvated version (IIb) represent the first structurally characterized PbII compounds containing neutral HSpym and anionic Spym− ligands. After a prolonged time in solution, (IIa) is converted to another compound due to complete deprotonation of HSpym. The structural characterization of (I) and (II) suggests HSpym as a good candidate for the removal of PbII ions from solutions containing thiocyanate or bromide ions.

This study aimed to synthesize two novel Schiff-base ligands through the condensation between N-(2-aminoethyl)pyrazoles and 2-hydroxy-1-naphthaldehyde, which are: NaphPz ((E)-1-(((2-(1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol)) and NaphDPz ((E)-1-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol). These novel pyrazole-imines were synthesized, characterized and used as copper (II) ion complexing agents. Different synthetic routes have been adapted to obtain the [Cu(NaphPz)Cl], [Cu(NaphDPz)Cl] and [Cu(NaphPz)2] complexes in the solid state, the first two in the crystalline form and the latter as a powder. The minimum metal–ligand stoichiometry for the three complexes was defined by TGA–DSC thermoanalytical data and by single-crystal X-ray diffraction for the crystalline samples which belong to the P21/n space group. The products of the thermal decomposition of the material were also monitored by TGA–DSC/FT-IR in air and N2 atmospheres in order to suggest how thermal decomposition of the organic portion of the complex occurs. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations compared to experimental results (UV-Vis and FT-IR) show a high degree of correlation. From HOMO/LUMO orbitals, the main major charge distributions, responsible for the absorption bands of the complexes, were determined.

Reactions between 3-amine-2-((pyridin-2-ylmethyl)selanyl)pyridine (L) and MX2 (M = Co, Cu, Zn; X = Cl, Br) result in the formation of the metal(II) molecular complexes 1–5 with the general formula [MX2(L)]. The organic ligand is coordinated to the metal center through nitrogen atoms of the pyridine rings, without interaction with the selenium atom. The rhenium(V) complex [ReO(apySe)2]Cl (6) is formed in two different ways, using [ReOCl3(PPh3)2] as precursor. Firstly, the formation of 6 was observed in the mother liquor, through Csp3–Se bond cleavage of the ligand L and formation of new Re–Se bonds. Secondly, the direct reaction between bis(3-amino-2-pyridyl)diselane (apySe)2 and [ReOCl3(PPh3)2] gave complex 6 in higher yields. The coordination compounds were characterized by spectroscopic and crystallographic methods. Furthermore, the antibacterial activity of the complexes 1–5 was evaluated against Gram-positive bacteria, Staphylococcus aureus (ATCC® 25923), and Gram-negative bacteria, Escherichia coli (ATCC® 25922). The results suggest that the complexes [CoCl2(L)] (1), [CuCl2(L)] (3), [CuBr2(L)] (4) and, [ZnCl2(L)] (5) possess significant bactericidal activity when compared with those of the free ligand and metal salts used in the synthesis.

Five new PdII complexes are reported and have been obtained by the reaction of monomeric [Pd(bipy)(py)2]2+, which serves as a builing block, and substituted (ArSe)2 or Pd(SeAr)2. Complexes [Pd2(μ-SeAr)2(bipy)2](PF6)2, Ar = Ph (1), p-ClC6H4 (2), p-FC6H4 (3), [Pd3(μ3-Se)2(bipy)3](PF6)2·5THF (4) and [Pd3(μ-SeMes)4(bipy)2](PF6)2·2MeCN (5) showed that the nuclearity of these structures is affected by electron donating groups (EDGs) and electron withdrawing groups (EWGs) from the selenium-containing ligands, where changing the stoichiometry ratio of the reactants does not affect the number of palladium centers. The distinct behaviors of 1–5 in the solid state, solution phase and gas phase were investigated by single-crystal XRD, NMR and ESI-TOF-MS. In solution, the dinuclear 1–3 structures exist in equilibrium with trinuclear species. In the gas phase, trinuclear and tetranuclear aggregates of 1–3 are detected, as well as dinuclear and tetranuclear aggregates for 5, while compound 4 maintains the same nuclearity. The solid-state electrochemical behavior was studied, and all complexes were electrochemically active, exhibiting irreversible electrochemical processes, where selenium is indicated to be the active species which oxidizes under such conditions. The complexes are potential candidates to act as semiconductor sensitizers for photocatalytic hydrogen evolution, as they absorb in the visible region with optical band gap energies in the range of 2.6 eV.

A racemic mixture of (R)- and (S)-camphor thio­semicarbazone, which crystallizes in the centrosymmetric space group C2/c, is reported., The equimolar reaction between a racemic mixture of (R)- and (S)-camphorquinone with thio­semicarbazide yielded the title compound, C11H17N3OS [common name: (R)- and (S)-camphor thio­semicarbazone], which maintains the chirality of the methyl­ated chiral carbon atoms and crystallizes in the centrosymmetric space group C2/c. There are two mol­ecules in general positions in the asymmetric unit, one of them being the (1R)-camphor thio­semicarbazone isomer and the second the (1S)- isomer. In the crystal, the mol­ecular units are linked by C—H⋯S, N—H⋯O and N—H⋯S inter­actions, building a tape-like structure parallel to the (01) plane, generating R 2 1(7) and R 2 2(8) graph-set motifs for the H⋯S inter­actions. The Hirshfeld surface analysis indicates that the major contributions for crystal cohesion are from H⋯H (55.00%), H⋯S (22.00%), H⋯N (8.90%) and H⋯O (8.40%) inter­actions.

Novel tetranuclear zinc compounds, [Zn4(μ-SeO3)2(μ4-SeO3)2(bipy)4]·11H2O (1) and [Zn4(μ-SeO3)2(μ4-SeO3)2(phen)4]·9H2O (2), which are the first examples of organically templated zinc selenite compounds containing closed-frameworks, have been synthesized via solvothermal processes. The compounds were characterized by spectroscopy, crystallographic methods and DFT calculations.

Made available in DSpace on 2021-06-25T10:48:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This work deals with two new molecule-based materials, namely NiII-complexes of general formulae [Ni(L1)2] (Ni1) and [Ni(L2)2] (Ni2), where L1 = trans-cinnamaldehyde-N(4)-methyl thiosemicarbazone and L2 = trans-cinnamaldehyde-N(4)-ethyl thiosemicarbazone, as potential antitumor agents. Both compounds were characterized by elemental analysis, molar conductivity and spectroscopic techniques (FTIR and NMR). Their molecular structures were obtained by single-crystal X-ray diffraction analysis. Each one crystallizes in a monoclinic space group P 21/c, also the asymmetric unit comprises of one NiII ion located on an inversion centre and one anionic ligand, which acts as a κ2N,S-donor affording a five-membered metallaring. The compounds were screened against two selected tumour cell lines (MCF-7 and A549) and non-tumour fibroblasts cell line (MRC-5) via MTT assays. In both tumour cells, all compounds exhibited higher cytotoxicity than the control drug (cisplatin). The IC50 values ranges of 3.70 – 41.37 μM and 1.06 – 14.91 μM were found for MCF-7 and A549, respectively. Importantly, all of them were less toxicity than cisplatin in MRC-5 with SI values ranged at 11.80 – 86.60. The red blood cell (RBC) assay revealed Ni2 as non-toxic due to its reduced haemolytic effect (0‐–9% at 1‐–10 μM). The DNA binding was investigated through a combination of spectrophotometric absorption and emission titrations, electrophoresis, and circular dichroism experiments. As a result, these metal complexes were not able to strongly binding to DNA (Kb values ~104 mol L‐−1) but suggesting groove-binding interactions. The scavenging ability of them towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical was also evaluated in this work, but no important antioxidant behaviour was detected. Further, the interaction of Ni1 and Ni2 to human serum albumin (HSA) was explored by quenching of tryptophan emission, warfarin competitive assay, and molecular docking protocols. The HSA binding analyses indicated good affinity of both complexes to Sudlow site I (Kb values ⁓103 mol L−1). Univ. Estadual Paulista (Unesp) Instituto de Química Departamento de Química Analítica Físico-Química e Inorgânica Univ. Estadual de Londrina (UEL) Departamento de Química Univ. Estadual Paulista (Unesp) Instituto de Química Laboratório de Química Medicinal Síntese Orgânica e Modelagem Molecular (LaQMedSOMM) Technische Universität Dresden (TUD) Department of Chemistry and Food Chemistry Univ. Federal de São Carlos (UFSCar) Departamento de Química Univ. Federal de Sergipe (UFS) Departamento de Química Univ. de São Paulo (USP) Instituto de Física de São Carlos Univ. Estadual Paulista (Unesp) Faculdade de Ciências Farmacêuticas Univ. Estadual Paulista (Unesp) Instituto de Química Departamento de Bioquímica e Química Orgânica Univ. Federal do Rio Grande (FURG) Escola de Química e Alimentos Univ. Federal de Santa Maria (UFSM) Departamento de Química Univ. Estadual Paulista (Unesp) Instituto de Química Departamento de Química Analítica Físico-Química e Inorgânica Univ. Estadual Paulista (Unesp) Instituto de Química Laboratório de Química Medicinal Síntese Orgânica e Modelagem Molecular (LaQMedSOMM) Univ. Estadual Paulista (Unesp) Faculdade de Ciências Farmacêuticas Univ. Estadual Paulista (Unesp) Instituto de Química Departamento de Bioquímica e Química Orgânica CAPES: 001 FAPESP: 15/12098-0 FAPESP: 2016/17711-5 CNPq: 305190/2017-2 CNPq: 422105/2016-3

The synthesis and characterisation of [Cu4In(PPh3)3SePh(μ-SePh)3(μ3-SePh)3] (1) is described together with its use as a precursor of CuInSe2. Compound 1 is a kind of single source precursor that has increased thermodynamic stability relative to many other organometallic compounds, and it can be used to generate the CuInSe2 sensitizer. The CuInSe2 generated from 1 was immobilized in TiO2 to give the composite CuInSe2/TiO2 (1a), which behaves as an active and robust photocatalyst for water splitting.

Vermicomposting is a biological process for efficient cattle manure treatment, but the vermicomposting time determines the quality of the vermicompost. The objective of this study was to evaluate the effect of cattle manure vermicomposting time on earthworm biomass and the changes in physical, chemical, and biological in properties of the vermicompost. The cattle manure was inoculated with Eisenia andrei earthworms and conducted vermicomposting for 0, 15, 30, 45, 60, and 120 days. The analysis of 44 chemical, physical, and biological properties allowed the vermicomposting process to be divided into initial (45 days) and final (45-120 days) phases. The initial phase was characterized by high microbial activity and the final by high physical-chemical transformation of the vermicompost and an increase in earthworm density. The organic matter aromaticity increased until the 45th day, subsequently decreasing. Although 30 d of vermicompost are sufficient to obtain a high-quality organic fertilizer, 120 d are necessary for producing matrices.

Monoselenoether ligand [PySeCH2Py] (L) reacts with CoCl2, CuCl2, CuI and Pd(OAc)2 resulting in the formation of molecular or polymeric complexes. The synthesis and structural elucidation of the complexes [CoCl2(L)] (1), [Cu2Cl4(L)2] (2a), [CuCl2(L)] (2b), [Cu2Cl2(PySe)2] (2c), [Cu(2-PyCOO)2] (2d), [Cu2I2(L)2] (3), [Cu2I2(L)]n (4) and [Pd2(CH3COO)2(PySeCHPy)2]·7H2O (5) demonstrate the versatility of this class of pyridylselenium ligands. For all compounds, the ligand offers N and/or Se atoms as donors and, in the case of 5, the ligand also builds C–Pd bonds to generate a cyclometallated palladium(II) complex.

The first total synthesis of melovinone, a nonrutaceous 3-methoxy-4-quinolone alkaloid isolated from Melochia tomentosa L., is reported. The target was acquired in a convergent fashion through the Suzuki?Miyaura cross-coupling reaction between an ortho-nitrobenzoic acid acetonyl ester derivative prepared from vanillin and potassium 5-phenyl-1-pentyltrifluoroborate, obtained from β-phenethyl bromide. The coupling was followed by a chemoselective reduction of the nitro group and a microwave-assisted and AcOH-promoted cyclization with rearrangement of the resulting acetonyl anthranilate. This afforded a pseudane intermediate, which was selectively methylated on the 3-OH. The synthetic pathway enabled to reach the objective in 11 steps and 18% overall yield. The 1H NMR spectra of the synthetic and natural product were in full agreement. Fil: Arroyo Aguilar, Abel Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Ledesma, Gabriela Nanci. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Tirloni, Bárbara. Universidade Federal de Santa Maria; Brasil Fil: Kaufman, Teodoro Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Larghi, Enrique Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina

This study investigated the synthesis and structural characterization of mercury(II) selenolate molecular clusters and mixed mercury(II) seleninate/selenolate polymeric clusters. The novel tetranuclear mercury(II) selenolate molecular clusters [Hg4Br4(SePh)4(phen)2] (1) and [Hg4I4(SePh)4(phen)2] (2) were prepared by reacting Hg(SePh)2 with mercury salts and 1,10-phenanthroline. The mixed mercury(II) seleninate/selenolate polymeric clusters [Hg2Br(O2SePh)(SePh)2]n (3) and [Hg2I(O2SePh)(SePh)2]n (4) were synthesized by reacting Hg(SePh)2 with 3-chloroperbenzoic acid and mercury salts. Compounds 3 and 4 represent new examples of extended one-dimensional chains of closed ME (M = mercury; E = Se) systems, which result from the partial oxidation of mercury phenylselenolate clusters. The compounds 1 − 4 have been characterized by spectroscopic and crystallographic methods. Optical band gap values for 1 − 4 were estimated by UV–vis spectroscopy in the solid state.

The hydrazone ligands 2-acetylpyridine benzoylhydrazone HL1 and 2,6-diacetylpyridinebis(benzoylhydrazone) H2L2 were reacted with Pb(SCN)2, affording [Pb(HL1)(µ-NCS)2] (1) and [Pb(H2L2)(SCN)2] (3), respectively. Recrystallization of 1 or 3 in DMF (or DMSO) produced [Pb(L1)(µ-SCN)] (2) and [Pb(HL2)(NCS)] (4), respectively. Compounds 1-4 were characterized by single crystal X-ray diffraction, Fourier transform infrared spectroscopy and elemental analysis. Compounds 1 and 3 were also characterized by thermogravimetry (with simultaneous differential scanning calorimetry), diffuse reflectance spectroscopy and powder X-ray diffraction. In the solid state, compounds 1, 3 and 4 have shown hydrogen bonds involving the amide hydrogen atoms. Both Pb···N(imine) tetrel bonds and π-stacking interactions were observed in 2 and 4. The thiocyanate/isothiocyanate ligands are responsible for the formation of chains due to Pb···S tetrel bonds in 1 and Pb···N, in 2.

[PdI(TePy-2)(I2TePy-2)2] is obtained via a rare oxidation reaction of palladium powder by the in situ generated diiodine adduct of bis-2-pyridylditelluride at room temperature. An X-ray diffraction study reveals the molecular structure of [PdI(TePy-2)(I2TePy-2)2], where the palladium atom is surrounded by an iodide and three tellurium atoms (two [I2TePy-2] and one [TePy-2] groups). The oxidation states for the tellurium atoms were analysed using calculated atomic charges and electron localization function (ELF). The optical bang gap for [PdI(TePy-2)(I2TePy-2)2] was determined through theoretical (DFT) and experimental (diffuse reflectance UV–Visible) studies and the electrochemical behavior for the compound was examined by cyclic voltammetry.

The isophthaloylbis(N,N-diphenylthiourea) molecule (H2L ligand) reacts with CuI, CuII, MnIII, FeII, FeIII and CoII ions to form binuclear complexes with formula [M2(L-O,S)2] (M = CuII (1), NiII (2)) or [M2(L-O,S)3] (M = FeIII (4), CoIII (5)). In presence of dimethyl sulfoxide, [Mn2(L-O,S)2(dmso)2] (3) was successfully obtained and represents the first manganese complex with any thiourea derivative ligand. The ligand and the complexes were characterized by spectroscopic techniques and elemental analysis. Complexes 1, 3, 4 and 5 were structurally analyzed by single crystal X-ray diffraction data, confirming the O,S chelating coordination mode. The stoichiometries were confirmed by thermal analysis with formation of the corresponding metal oxides. The set of the performed analysis corroborated that some metal ions undergo oxidation or reduction to form stable 2:2 or 2:3 metal to ligand stoichiometric complexes with H2L.

Semicarbazones can exist in two tautomeric forms. In the solid state, they are found in the keto form. This work presents the synthesis, structures and spectroscopic characterization (IR and NMR spectroscopy) of four such compounds, namely the neutral molecule 4-phenyl-1-[phenyl(pyridin-2-yl)methylidene]semicarbazide, C19H16N4O, (I), abbreviated as HBzPyS, and three different hydrated salts, namely the chloride dihydrate, C19H17N4O+·Cl−·2H2O, (II), the nitrate dihydrate, C19H17N4O+·NO3 −·2H2O, (III), and the thiocyanate 2.5-hydrate, C19H17N4O+·SCN−·2.5H2O, (IV), of 2-[phenyl({[(phenylcarbamoyl)amino]imino})methyl]pyridinium, abbreviated as [H2BzPyS]+·X −·nH2O, with X = Cl− and n = 2 for (II), X = NO3 − and n = 2 for (III), and X = SCN− and n = 2.5 for (IV), showing the influence of the anionic form in the intermolecular interactions. Water molecules and counter-ions (chloride or nitrate) are involved in the formation of a two-dimensional arrangement by the establishment of hydrogen bonds with the N—H groups of the cation, stabilizing the E isomers in the solid state. The neutral HBzPyS molecule crystallized as the E isomer due to the existence of weak π–π interactions between pairs of molecules. The calculated IR spectrum of the hydrated [H2BzPyS]+ cation is in good agreement with the experimental results.

The focus of this study was to explore reactions of (RTe)2 with palladium(II) salts. These reactions led to Te–Te bond cleavage and the formation of three tellurolate-bridged dinuclear complexes and a mononuclear telluro-ether palladium(II) complex. The methodologies used yielded single source precursors for interesting materials. UV/vis spectroscopy results supported the measured optical bandgap for the complexes in the solid state. A study on the structure of all complexes in the solid state was carried out using single-crystal X-ray diffraction. Other analytical methodologies, such as elemental analysis and infrared spectroscopy, were also used for the characterization of the complexes.

In this article we present the results of a study on the synthesis of In–E–MI ternary clusters (E = S, Se; MI = Cu, Ag) and an evaluation of the optical band gap energy. Characterization of three new compounds is reported: [Cu2In(PPh3)2SPh(μ-SPh)4] (1), [Cu2In(PPh3)2SePh(μ-SePh)4] (2) and [Ag2In(PPh3)2SPh(μ-SPh)4] (3). We discuss the hard-soft migratory tendency of the chalcogenolate ligands between the metal centers involved. In addition, the experimental conditions applied to obtain the desired products in a pure crystalline form are described. These methodologies provide good yields in a short period of time and single source precursors for interesting materials can be obtained.

Aminoguanidine and its derivatives have shown antiglycation activity and are effective antioxidants. Complexes with ligands derived from aminoguanidine are relevant to both medicinal and bioinorganic chemistry. In this article, we describe the synthesis and characterization of a new mononuclear complex of copper(II) with a chelating ligand derived from aminoguanidine. Single crystals of the resulting complex were obtained by recrystallization from isopropanol. The molecular structure of the complex was obtained by X-ray diffraction which shows a distorted square pyramidal geometry, where copper(II) is coordinated to four nitrogen atoms (base of the pyramid) and to one chlorine atom (pyramid peak). The spectroscopic behavior (FT-IR and UV–vis) of both the complex and the ligand were examined.

The compounds [Pd2I2{Te((2,6-OCH3)2C6H3)}2(PCy3)2] (1), [Pd2I2{Te((2,6-OCH3)2C6H3)}2(PR2R')2]∙2CH3CN (2), [Pd2{Te((2,6-OCH3)2C6H3)}2(phen)2][Hg2Br6(phen)2] (3), [Pd2Cl2(TePh2)2(TePh)2] ∙ DMF (4), [Pd2(SePh)2(2,2′-bipy)2][HgBr4]∙2DMF (5), [Pd2(SePh)2-(phen)2][HgI4]∙5DMF (6), [Pd2{Te((2,6-OCH3)2C6H3)}2(phen)2][Hg2I6]-[Hg((2,6-OCH3)2C6H3)2] (7) containing [Pd2(µ-ER)2] core (E = Se, Te; R = aryl) were synthesized and characterized by IR spectroscopy, elemental analysis and X-ray crystallography. Intermolecular metallophilic interactions were evaluated through crystallographic studies combined with Density Functional Theory calculations. The structural stability of 4–7 were investigated taking in account the interactions E⋯E, Pd⋯Pd and Pd⋯Hg between [Pd2(µ-ER)2] cores.

A synthetic route to obtain [p-H2NC6H4Se]2 (1) in good yield was developed, and the crystal structure of the product was characterized for the first time. The synthesis and structure of the mercury(II) derivative [Hg(SeC6H4NH2)2] (2) was also investigated and is reported herein. The versatile coordination chemistry of [Hg(SeC6H4NH2)2] with halides of the same metal and PCy3 allows the synthesis of [Hg(X)(SeC6H4NH2)(PCy3)] (X = Cl, Br, I) (3–5). The products 1, 3–5 were isolated in crystalline form and characterized by X-ray structure analysis.

Thiocarbamoylbenzimidophenylselenide and -telluride have been prepared from N-[N′,N′-methylphenylamino(thiocarbonyl)]benzimidoyl chloride and the in situ-prepared phenylselenolate or -tellurolate, and their structures have been determined by X-ray diffraction. The air-stable compounds react with metal ions such as HgCl2, PdCl2 or Pd(acetate)2 under cleavage of their C N or C–Se/Te bonds. The decomposition fragments react with the transition metal ions under formation of stable products such as [HgCl(SePh)]∞, (3-methylphenylamino-5-phenyl-1,2,4-dithiazolium)2[HgCl4], [Pd(MePhbtu)2] (HMePhbtu = N-methyl-N-phenyl-N′-benzoylthiourea) or [Pd(MePhtu)4]Cl2 (MePhtu = N-methyl-N-phenylthiourea). The products have been isolated in crystalline form and characterized spectroscopically and by X-ray structure analysis.

Hg(SePh)2 reacts respectively with the chemical mixtures HgI2/2,2′-bipyridine, HgI2/1,10-phenantroline, HgI2/triphenylphosphine and HgBr2/ 2,2′-bipyridine to give the cluster compounds [Hg4I4(SePh)4(2,2-bipy)2]·2dmf (Ph = phenyl; dmf = dimethylformamide) (1), [Hg4I2(SePh)6(phen)2] (2), [Hg8I2Se(SePh)12(dmf)2] (3) and [Hg8Br5Se(SePh)9(2,2-bipy)2] (4). The 8-membered ring 1 alternates mercury and selenium atoms. Cluster 2 presents similar structure, but contains six [Se–Ph]− units and only two iodine ions. The bulky nanoclusters 3 and 4 differ mainly with respect to the existence of terminal and bridging bromide ions in 4. With basis on the Kubelka–Munk function the optical band gap of the title compounds could be determined by measuring their UV–Vis diffuse reflectance spectra.

Hg(TePh) 2 reacts with P(Cy) 3 {P(Cy) 3 = tricyclohexylphosphine} under Ar atmosphere and ultrasonic bath to give the dinuclear cluster [Hg 2 (μ-PhTe) 2 (PhTe) 2 (PCy 3 ) 2 ] ( 1 ). Earlier attempts had not success because of the low solubility of Hg(PhTe) 2 and the use of inadequate phosphines. TGA and IR data confirm the formation of 1 and the optical band gap of the compound could be estimated by means of UV–vis diffuse reflectance spectra.

The versatile coordination chemistry of the Bis(phenylselenolate) (Hg(SePh)2) with Hg(SCN)2 salt allows the synthesis of a cluster and a 2D coordination polymer. The reaction at low temperature in dimethylformamide (dmf) affords single crystals containing neutral clusters with the formula [Hg8S(SCN)2(SePh)12(dmf)2] (1). Then, the 2D coordination polymer [Hg(SCN)(SePh)] (2) is obtained in comparable yielding. The use of bis(2-pyridylthio)methane as secondary ligand significantly improves the synthesis of 2, since it is synthesized at room temperature, in a short time and in a good yield. The effects of the weak interactions in the crystal packing were also analyzed.

Three new cluster compounds were synthesized from Hg(EPh)2 (E = Se, Te; Ph = phenyl) in organic solvents. Two of these compounds, [Hg2Cl2(SePh)2(PCy3)2], (1), and [Hg2Br2(SePh)2(PCy3)2], (2), were prepared by reaction of Hg(SePh)2, HgX2 (X = Cl, Br) and tricyclohexylphosphine, PCy3, in dimethylformamide. The reaction of Hg(TePh)2 with HgBr2 in tetrahydrofuran using triphenylphosphine or 2,2’-bipyridine as co-ligands gave the polymeric cluster [{Hg5Br3(TePh)7}n] (3), whose dissolution in dimethylsulfoxide yielded the cluster [Hg3Br3(TePh)3]·2dmso. The influence of different ligands, coordinating solvents and reaction stoichiometries on the formation of the title compounds is also discussed. All complexes were characterized by elemental analysis, thermogravimetric analysis and single crystal X-ray diffractometry. Três novos compostos foram preparados a partir de Hg(EPh)2 (E = Se, Te; Ph = fenila) em solventes orgânicos. Dois destes compostos são clusters moleculares, [Hg2Cl2(SePh)2(PCy3)2], (1), e [Hg2Br2(SePh)2(PCy3)2], (2), obtidos pela reação de Hg(SePh)2 com HgX2 (X = Cl, Br) e tricicloexilfosfina, PCy3, em dimetilformamida. A reação de Hg(TePh)2 e HgBr2 em tetrahidrofurano usando trifenilfosfina ou 2,2’-bipiridina como co-ligantes produz o cluster polimérico [{Hg5Br3(TePh)7}n], (3), cuja dissolução em dimetilsulfóxido leva à formação do cluster [Hg3Br3(TePh)3]·2dmso. Neste trabalho avalia-se a influência de diferentes ligantes, solventes coordenantes e estequiometrias de reações na formação dos produtos. Todos os compostos foram caracterizados por análise elementar, análise termogravimétrica e tiveram suas estruturas cristalinas determinadas por difratometria de raios X em monocristais.

(PhSe)2Hg reacts in DMF with HgX2 (X = Cl, Br) in the presence of bis(pyrimidin-2-thio)methane/triphenylphosphine/4,4′-bipyridine, to give the polymeric cages [Hg5Cl3(PhSe)7] n (1), [Hg7Cl3(PhSe)11] n (2) and [Hg7Br3(PhSe)11] n (3). In compound 1 the polymeric chains along the a axis are linked through H···Cl interactions in the c axis, assembling a two-dimensional lattice in the ac plane. The analogue compounds 2 and 3 attain bulky single clusters with the general formula Hg14X6(SePh)22 (X = Cl, Br), accomplished by the symmetrical combination of two asymmetric units [Hg7X3(PhSe)11]. While the polymerization of the single units of 2 along the c axis occurs through 4 selenium atoms, the polymerization of 3 arises through 6 bonds involving Hg and Se atoms. Although 2 and 3 seem to be resultant from the random assembly of asymmetrical rings, both cluster compounds present symmetry centers.

(PhTe)2Hg reacts with HgCl2 and triphenylphosphine to give the clusters [(PhTe)6(Ph3P)2Hg5Cl4] · 2THF (1) and [(PhTe)8Hg6Py2Cl4] · Py (Py = pyridine) (2). In 1 each tellurium atom connects two Hg atoms, with Hg–Te distances around 2.75 A. Phosphorus atoms of the triphenylphosphine groups complete the tetrahedral coordination of the Hg1 atoms. The second set of Hg atoms (Hg2) is also coordinated to chlorine atoms. The three-dimensional assembling of 1 encloses circular channels with medium diameter of 12.5 A. The cluster 2 results from substitution of the oxidized triphenylphosphine ligands of 1 by one molecule of Hg(PhTe)2 in the course of the synthetic procedures. The alternated Te–Hg bonds of 2 close a 12-membered ring with two inverted 4-membered rings in the middle. Thermogravimetrical evaluations and Raman scattering lines of 1 and 2 are also discussed.

A three-step one-pot synthetic procedure to synthesize the neutral tellurium(IV) coordination compounds PhTeX3L (X = Br, I and L = ethylenethiourea) has been developed and is described in this article. Oxidative halogenation of PhTeTePh in methanol generates the tellurium(II) derivative, PhTeX, which is subsequently complexed with ethylenethiourea, and, finally, further oxidative addition of additional halogen affords the corresponding tellurium(IV) compound PhTeX3L in good yields. The final product was obtained by the slow evaporation of the reaction mixture as black crystals. The X-ray structural analyses of the compounds show Te···X and X···X secondary interactions in the solid state and suggest a weak dependence of the formation of supramolecular assemblies on the nature of the halogen bonded to the tellurium atom.

N-[N′,N′-Methylphenylamino(thiocarbonyl)]benzimidoyl chloride (1) reacts with in situ-prepared arylselenolates or aryltellurolates under formation of the first representatives of the corresponding iminoselenides or -tellurides. The products are air-stable solids, which have been studied spectroscopically and by single-crystal X-ray diffraction.

Two synthetic routes to prepare [Hg3(O2SePh)(SePh)5]n and its structural characterization are presented in this paper. This compound results either from the partial oxidation of mercury phenylselenolate clusters or from a mixture of its components with defined stoichiometry. This compound was observed in almost all of our reactions as a by-product, during the development of the synthesis of new mercury selenolate clusters. It was now characterized by single-crystal X-ray diffractometry, elemental analysis, and infrared spectroscopy.

(MesTe) 2 reacts with HgBr 2 to give [(HgBr 2 TeMes 2 ) 2 HgBr 2 ], a polymeric one-dimensional assembly of (μ-Br)Hg and alternating mercury···η 6 -π-aryl interactions. This polymeric structure is based on [{HgBr 2 (TeMes 2 )} 2 HgBr 2 ] centrosymmetric units with three mercury atoms having two different coordination geometries. The central Hg II ion is coordinated to four bromine atoms in the same plane and to two mesityl groups from TeMes 2 via η 6 –π-aryl interactions. Each TeMes 2 is bonded to one of the surrounding Hg II ions through the tellurium atom. The central Hg II ion is located in a crystallographic centre of inversion and sandwiched by its coordinating mesityl groups. The [{HgBr 2 (TeMes 2 )} 2 HgBr 2 ] units are linked by weak Hg···Br interactions in chains running along the c- axis.