The chemistry of cobalt acetate. X. The preparations of the mixed ligand cobalt oligomers, [Co3O(C6H5N2O)3(CH3CO2)3][PF6].CH3CN (I), [Co4(μ2-OH)2(η1:η1:μ2-CH3COO)2(CH3CO2)2 (η1:η1:μ2-C11H8NO)2(η1:η1:η1:η1:μ2-C11H8N3O)2][PF6]2.CH3OH.3H2O (II) and [Co3O(CH3CO2)5(C7H6NO2)(py)3][PF6] (III) and the crystal structures of (I) and (II). Comparisons with homoleptic cobalt acetate dimers and trimers

Abstract

The preparations of the compounds, [Co3O(C6H5N2O)3(CH3COO)3][PF6].CH3CN (I), [Co4(μ2-OH)2(η1:η1:μ2-CH3COO)2(CH3COO)2 (η1:η1:μ2-C11H8NO)2(η1:η1:η1:η1:μ2-C11H8N3O)2][PF6]2.CH3OH.3H2O (II) and [Co3O(OAc)5(C7H6NO2)(py)3][PF6] (III) and the crystal structures of (I) and (II) are reported. The cation of (I) is an oxo-centred trimer, of a structural type similar to cobalt oxo trimers such as [Co3O(OAc)6(py)3]+, whilst the dication of (II) has a “metallo-crown” structure. Complex (III) is assigned an oxo-centred trimeric structure. The cations, [Co3O(OAc)6(py)3]+, [Co3O(OAc)5(OH)(py)3]+, and sym-[Co2(OH)2(OAc)3(py)4]+, as their PF6− salts, catalyse the oxidation of cyclohexane in the presence of N-hydroxyphthalimide (NHPI). However, the multinuclear species, (I), (II) and (III) do not catalyse cyclohexane oxidation in the presence or absence of NHPI.