The species [Cu8(dmpz)8(OH)8] (2) (Hdmpz = 3,5-dimethylpyrazole) has been obtained by reacting [Cu(dmpz)]n (1) with O2 at atmospheric pressure and room temperature in wet solvents. Crystal data for [Cu8(dmpz)8(OH)8].2C6H5NO2 (22-degrees-C): a = 10.229 (3) angstrom, b = 27.217 (2) angstrom, c = 14.532 (1) angstrom, beta = 98.51 (1)-degrees with Z = 2 in the space group P2(1)/m. [Cu8(dmpz)8(OH)8] consists of a discrete octameric molecule with a cyclic planar system of copper(II) atoms, bridged by OH and dmpz ligands, forming a molecule of toroidal shape; in the crystal, its cavity (viable diameter of ca. 6 angstrom) contains crystallographically disordered, possibly water, molecules; in addition, fully orderd clathrated nitrobenzene molecules have been found between the octameric units. Complex 2 is catalytically active in the oxidation reactions of organic substrates such as triphenylphosphine, aromatic primary amines, dibenzylamine, and carbon monoxide, triphenylphosphine oxide, azobenzenes, N-benzylidenebenzylamine and carbon dioxide being respectively formed. Its reaction with PPh3 under an inert atmosphere gave 4 mol of O=PPh3 per mole of 2, suggesting that 2 gives rise, in solution, to tautomeric species of the general formula [Cu8(dmpz)8(O)x(OH)8-2x(H2O)x] (x = 1-4), which might behave as the active species. Complex 2 allowed also the stoichiometric oxidation of cyclohexyl isocyanide into the corresponding isocyanate in the absence or in the presence of O2. The reaction of 2 with primary alcohols R'OH(R' = Me, Et, Pr(n), allyl) affords the octaalkoxo derivatives [Cu8(dmpz)8(OR')8] (3) whose formulation is suggested on the basis of analytical and spectroscopic data, as well as on chemical properties.
Ardizzoia, G., Angaroni, M., Lamonica, G., Cariati, F., Cenini, S., Moret, M., et al. (1991). REACTION OF DIOXYGEN WITH [CU(DMPZ)]N (HDMPZ = 3,5-DIMETHYLPYRAZOLE) - CRYSTAL-STRUCTURE, REACTIVITY, AND CATALYTIC PROPERTIES OF [CU8(DMPZ)8(OH)8]. INORGANIC CHEMISTRY, 30(23), 4347-4353 [10.1021/ic00023a012].
REACTION OF DIOXYGEN WITH [CU(DMPZ)]N (HDMPZ = 3,5-DIMETHYLPYRAZOLE) - CRYSTAL-STRUCTURE, REACTIVITY, AND CATALYTIC PROPERTIES OF [CU8(DMPZ)8(OH)8]
MORET, MASSIMO;
1991
Abstract
The species [Cu8(dmpz)8(OH)8] (2) (Hdmpz = 3,5-dimethylpyrazole) has been obtained by reacting [Cu(dmpz)]n (1) with O2 at atmospheric pressure and room temperature in wet solvents. Crystal data for [Cu8(dmpz)8(OH)8].2C6H5NO2 (22-degrees-C): a = 10.229 (3) angstrom, b = 27.217 (2) angstrom, c = 14.532 (1) angstrom, beta = 98.51 (1)-degrees with Z = 2 in the space group P2(1)/m. [Cu8(dmpz)8(OH)8] consists of a discrete octameric molecule with a cyclic planar system of copper(II) atoms, bridged by OH and dmpz ligands, forming a molecule of toroidal shape; in the crystal, its cavity (viable diameter of ca. 6 angstrom) contains crystallographically disordered, possibly water, molecules; in addition, fully orderd clathrated nitrobenzene molecules have been found between the octameric units. Complex 2 is catalytically active in the oxidation reactions of organic substrates such as triphenylphosphine, aromatic primary amines, dibenzylamine, and carbon monoxide, triphenylphosphine oxide, azobenzenes, N-benzylidenebenzylamine and carbon dioxide being respectively formed. Its reaction with PPh3 under an inert atmosphere gave 4 mol of O=PPh3 per mole of 2, suggesting that 2 gives rise, in solution, to tautomeric species of the general formula [Cu8(dmpz)8(O)x(OH)8-2x(H2O)x] (x = 1-4), which might behave as the active species. Complex 2 allowed also the stoichiometric oxidation of cyclohexyl isocyanide into the corresponding isocyanate in the absence or in the presence of O2. The reaction of 2 with primary alcohols R'OH(R' = Me, Et, Pr(n), allyl) affords the octaalkoxo derivatives [Cu8(dmpz)8(OR')8] (3) whose formulation is suggested on the basis of analytical and spectroscopic data, as well as on chemical properties.
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