Ligand substitution in hexahalorhenate(IV) complexes: Synthesis, crystal structures and magnetic properties of NBu4[ReX5(DMF)] (XÂ =Â Cl and Br)

By heating, the hexahalorhenate(IV) anions [ReCl6]2− and [ReBr6]2− undergo a solvolysis reaction in N,N-dimethylformamide (DMF), allowing the isolation of two isostructural compounds of formula NBu4[ReX5(DMF)], being X = Cl (1) and Br (2). Magnetic measurements show that these novel octahedral Re(IV) complexes exhibit a large zero-field splitting.