A Family of Cagelike Mn-Silsesquioxane/Bathophenanthroline Complexes: Synthesis, Structure, and Catalytic and Antifungal Activity

This study reports a novel family of cage manganesesilsesquioxanes prepared via complexation with bathophenanthroline (4,7-diphenyl-1,10-phenanthroline). The resulting Mn4-, Mn6Li2-, and Mn4Na-compounds exhibit several unprecedented cage metallasilsesquioxane structural features, including intriguing self-assembly of silsesquioxane ligands. Complexes were tested in vitro for fungicidal activity against seven classes of phytopathogenic fungi. The representative Mn4Na-complex acts as a catalyst in the cycloaddition of CO2 to epoxides under solvent-free conditions to form cyclic carbonates in good yields.

Carboxylic acid-tuned nickel(ii) clusters: syntheses, structures, solution behaviours and magnetic properties

Three novel cicada-like nickel(ii) clusters, formulated as [Ni₆(bdped)₂(mba)₆(Hdmpz)₂(NO₃)₂(H₂O)₂]·4MeCN (SD/Ni6b), [Ni₅(bdped)₂(tca)₆(Hdmpz)(MeOH)₂(H₂O)]·MeOH (SD/Ni5a) and [Ni₄(Hbdped)₂(ba)₄(Hdmpz)₂]·2NO₃·2MeCN (SD/Ni4a), were obtained by tuning the auxiliary carboxylic acids, where H₂bdped = 1,2-bis-(3,5-dimethylpyrazol-1-yl)-ethane-1,2-diol; Hmba = 2-methylbenzoic acid; Hdmpz = 3,5-dimethyl-1H-pyrazole; Htca = 3-thiophenecarboxylic acid; and Hba = benzoic acid. The structures of SD/Ni6b, SD/Ni5a and SD/Ni4a are built from a central Ni₄O₄ opened cube, appending two to zero NiNO₅ octahedra. The solution behaviours of SD/Ni6b, SD/Ni5a and SD/Ni4a were studied in detail via an ESI-MS technique and their solution stabilities were confirmed. Magnetic analysis indicated the presence of Ising-type anisotropy: D = -13, -10, and -11 cm^-1 for SD/Ni6b, SD/Ni5a, and SD/Ni4a, respectively; moreover, dominantly ferromagnetic interactions were found between magnetic centers: J₁ = 6.5 cm^-1, J₂ = -0.44 cm^-1 and J₁ = 5.9 cm^-1, J₂ = 2.6 cm^-1 for SD/Ni5a and SD/Ni4a, respectively. Besides, the photocurrent signals were observed and they reached the maximum very quickly for these three nickel(ii) clusters and then their current intensities remained almost constant, which provide a possibility to be used for light-harvesting and photo-related catalysis.

Space Craft-like Octanuclear Co(II)-Silsesquioxane Nanocages: Synthesis, Structure, Magnetic Properties, Solution Behavior, and Catalytic Activity for Hydroboration of Ketones

Two novel space craft-like octanuclear Co(II)-silsesquioxane nanocages, {Co₈[(MeSiO₂)₄]₂(dmpz)₈} (SD/Co8a) and {Co₈[(PhSiO₂)₄]₂(dmpz)₈} (SD/Co8b) (SD = SunDi; Hdmpz = 3,5-dimethylpyrazole), have been constructed from two similar multidentate silsesquioxane ligands assisted with a pyrazole ligand. The Co₈ skeleton consists of eight tetrahedral Co(II) ions arranged in a ring and is further capped by two (MeSiO₂)₄ ligands up and down. The auxiliary dmpz^- ligands seal the ring finally. Electrospray ionization mass spectrometry revealed SD/Co8a and SD/Co8b are highly stable in CH₂Cl₂. Magnetic analysis implies that SD/Co8a announces antiferromagnetic interactions between Co(II) ions. Moreover, both of them display good homogeneous catalytic activity for hydroboration of ketones in the presence of pinacolborane under mild conditions.

Copper(ii) complexes with 2,2′:6′,2′′-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine substituted with quinolines. Synthesis, structure, antiproliferative activity, and catalytic activity in the oxidation of alkanes and alcohols with peroxides

The toxicity of six new Cu(ii) complexes was evaluated in cancer derived cell lines. A model of competitive interaction of hydroxyl radicals with CH₃CN and RH in the catalyst cavity has been proposed.

Cu42Ge24Na4—A Giant Trimetallic Sesquioxane Cage: Synthesis, Structure, and Catalytic Activity

Unprecedented germanium-based sesquioxane exhibits an extremely high nuclearity (Cu42Ge24Na4) and unusual encapsulation features. The compound demonstrated a high catalytic activity in the oxidative amidation of alcohols, with cost-effective catalyst loading down to 400 ppm of copper, and in the oxidation of cyclohexane and other alkanes with H2O2 in acetonitrile in the presence of nitric acid. Selectivity parameters and the mode of dependence of initial cyclohexane oxidation rate on initial concentration of the hydrocarbon indicate that the reaction occurs with the participation of hydroxyl radicals and alkyl hydroperoxides are formed as the main primary product. Alcohols have been transformed into the corresponding ketones by the catalytic oxidation with tert-butyl hydroperoxide.