Structure and magnetic properties of [Cr(en)2(ox)][Cr(en)(ox)2]·2H2O,Δ-[Cr(en)3]Δ-[Cr(ox)3] and Δ-[Co(en)3]Δ-[Cr(ox)3]

Interactions between metal ion complexes in the compounds Δ-[Cr(en)3]Δ-[Cr(ox)3] and Δ-[Co(en)3]Δ-[Cr(ox)3] have been investigated by X-ray crystallography and magnetic susceptibility measurements. Crystals of both compounds are hexagonal and are isostructural with the known Δ-[Co(en)3]Δ-[Rh(ox)3] [Inorg. Chem. 30 (1991) 4954] with chains of alternating anions and cations parallel to the crystallographic c-axis. The susceptibility behavior suggests that magnetic interactions are stronger in Δ-[Cr(en)3]Δ-[Cr(ox)3] where both anion and cation are paramagnetic than in Δ-[Co(en)3]Δ-[Cr(ox)3] where only the anion is paramagnetic. Single crystal studies with the former compound reveal that magnetic interactions along the c-axis chains, where the Cr–Cr distances are shortest, are weaker than those involving off-axis interactions. Magnetic measurements were also made on [Cr(en)2(ox)][Cr(en)(ox)2]·2H2O. The structure of this compound has been previously reported.