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Reactions between CuCl2and the functionalized scorpionate 2,2,2-tris(1-pyrazolyl)ethanol HOCH2C(pz)31(pz = pyrazolyl) or 2,2,2-tris(1-pyrazolyl)ethyl methanesulfonate CH3SO2OCH2C(pz)32yield the corresponding water soluble CuIIcomplexes [CuCl2{HOCH2C(pz)3}] 3or [CuCl2{CH3SO2OCH2C(pz)3}]24. In 3the scorpionate ligand shows the typical N,N,N-coordination mode, whereas in the dinuclear complex 4it binds the metal as a bidentate species. Compounds 1-4have been characterized by IR, far-IR, elemental analysis and (for 2-4) single crystal X-ray diffraction. The new scorpionate complexes 3and 4are shown to act as catalyst precursors for the peroxidative oxidation of cyclohexane to cyclohexanol (main product) and cyclohexanone, under mild conditions (at room temperature and using an aqueous solution of H2O2) reaching TON values up to 186 in NCMe/H2O. Their hydrosolubility allows them to operate also in pure aqueous media (without any organic solvent, although less effectively), a rare feature of significance towards a green alkane oxidation process. [ABSTRACT FROM AUTHOR]

The study of chelating ligands is undoubtedly one of the most significant fields of research in chemistry. The present work is directed to the synthesis of new functionalized derivatives of tripodal C-scorpionate compounds. Tris-2,2,2-(1-pyrazolyl)ethanol, HOCH2C(pz)3 (1), one of the most important derivatives of hydrotris(pyrazolyl)methane, was used as a building block for the synthesis of new functionalized C-scorpionates, aiming to expand the scope of this unexplored class of compounds. The first dendritic C-scorpionate was successfully prepared and used in the important industrial catalytic reactions, Sonogashira and Heck C-C cross-couplings. [ABSTRACT FROM AUTHOR]

The reaction between copper(II) chloride dihydrate and excess tris(1-pyrazolyl)methane results in the formation of the title complex, [Cu(C10H10N6)2]Cl2·2CH3OH. The centrosymmetric complex cation is mononuclear with octahedral coordination for Cu and two tridentate ligands. Two short and one long Cu—N distances [2.002 (3), 2.011 (2) and 2.413 (2) Å] are found, as expected for Jahn–Teller distortion. [ABSTRACT FROM AUTHOR]

[CoCl(μ-Cl)(Hpz(Ph))3]2 (1) and [CoCl2(Hpz(Ph))4] (2) were obtained by reaction of CoCl2 with HC(pz(Ph))3 and Hpz(Ph), respectively (Hpz(Ph)=3-phenylpyrazole). The compounds were isolated as air-stable solids and fully characterized by IR and far-IR spectroscopy, MS(ESI+/-), elemental analysis, cyclic voltammetry (CV), controlled potential electrolysis, and single-crystal X-ray diffraction. Electrochemical studies showed that 1 and 2 undergo single-electron irreversible Co(II)→Co(III) oxidations and Co(II)→Co(I) reductions at potentials measured by CV, which also allowed, in the case of dinuclear complex 1, the detection of electronic communication between the Co centers through the chloride bridging ligands. The electrochemical behavior of models of 1 and 2 were also investigated by density functional theory (DFT) methods, which indicated that the vertical oxidation of 1 and 2 (that before structural relaxation) affects mostly the chloride and pyrazolyl ligands, whereas adiabatic oxidation (that after the geometry relaxation) and reduction are mostly metal centered. Compounds 1 and 2 and, for comparative purposes, other related scorpionate and pyrazole cobalt complexes, exhibit catalytic activity for the peroxidative oxidation of cyclohexane to cyclohexanol and cyclohexanone under mild conditions (room temperature, aqueous H2O2). In situ X-ray absorption spectroscopy studies indicated that the species derived from complexes 1 and 2 during the oxidation of cyclohexane (i.e., Ox-1 and Ox-2, respectively) are analogous and contain a Co(III) site. Complex 2 showed low in vitro cytotoxicity toward the HCT116 colorectal carcinoma and MCF7 breast adenocarcinoma cell lines., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: The discovery of cisplatin's antitumor activity led to a great interest in the potential application of coordination compounds as chemotherapeutic agents. It is essential to identify new compounds that selectively inhibit tumor proliferation, evading secondary effects and resistance associated with chemotherapeutics., Methods: The in vitro antiproliferative potential of an organotin(IV) compound was evaluated using colorectal and hepatocellular carcinoma, mammary gland adenocarcinoma cell lines, and human fibroblasts. Tumor cell death was evaluated by fluorescence microscopy and flow cytometry for the Sn(IV) compound and also for a Co(II) compound bearing 1,10-phenanthroline-5,6-dione as ligand. Comparative proteomic analysis for both compounds was assessed in the colorectal cancer cell line., Results: The Sn(IV) compound presented a high cytotoxic effect in colorectal and hepatocellular carcinoma cell lines (IC50 of 0.238 ± 0.011 μM, 0.199 ± 0.003 μM, respectively), and a lower cytotoxicity in human fibroblasts. Both compounds induced cell apoptosis and promoted the overexpression of oxidative stress-related enzyme superoxide dismutase [Cu-Zn] (SODC). The Co(II) compound induced a decreased expression of anti-apoptotic proteins (translationally-controlled tumor protein and endoplasmin), and the Sn(IV) compound decreased expression of proteins involved in microtubule stabilization, TCTP, and cofilin-1., Conclusions: Our data reveals a high in vitro antiproliferative potential against cancer cell lines and a moderate selectivity promoted by the Sn(IV) compound. Proteomic analysis of Sn(IV) and Co(II) compounds in the colorectal cancer cell line allowed an insight to their mechanisms of action, particularly by affecting the expression of proteins typically deregulated in cancer, and also suggesting a promising therapeutic potential for both compounds.