Solvothermal synthesis of discrete cages and extended networks comprising {Cr(iii)₃O(O₂CR)₃(oxime)₃}²⁻ (R = H, CH₃, C(CH₃)₃, C₁₄H₉) building blocks

The synthesis, structural and magnetic characterisation of a family of related Cr(iii) cages are reported. Each member comprises {Cr(iii)₃O(O₂CR₁)₃(R₂-sao)₃}²⁻ (R₁ = H, CH₃, C(CH₃)₃, C₁₄H₉; R₂ = Me, Ph, ᵗBu, C₁₀H₈) triangles linked by Na⁺ cations, resulting in either the discrete complexes [H₃O][NEt₄]₂[NaCr(iii)₆O₂(O₂C-C₁₄H₉)₆(Naphth-sao)₆] (1) and [Na₄Cr(iii)₆O₂(O₂CC(CH₃)₃)₆(3,5-di-ᵗBu-sao)₆(MeCN)₆] (3); or the extended networks [H₃O]₂[Na₂Cr(iii)₆O₂(O₂CH)₆(Ph-sao)₆(MeCN)₂(H₂O)₂]ₙ·4MeCN (2); [H₃O][Na₃Cr(iii)₆O₂(O₂CCH₃)₆(Me-sao)₆(MeCN)]ₙ (4) and [Na₂Cr(iii)₃O(O₂CCH₃)₃(Me-sao)₃(H₂O)₆]ₙ·3MeCN (5). Magnetic susceptibility data obtained for 2 and 4 reveal weak antiferromagnetic exchange between the Cr(iii) ions in the triangles.