N,N-dimethylformamide complex of aluminium(III) perchlorate

Hexakis(N,N-dimethylformamide-O)aluminium(III) triperchlorate, [A1{(CH₃)₂NCHO}₆](ClO₄)₃, has an octahedral coordination structure with the center of symmetry at the Al³⁺ ion. One of the anions is disordered and the other centers on the twofold axis. Each N,N-dimethylformamide (DMF) ligand coordinates via its O atom in the sp² lone-pair direction. Although the vicinity of the Al atom is crowded with six planar ligands, no serious steric hindrance is found in the coordination structure. The intramolecular bond lengths of the coordinated DMF show clear variations from those of non-coordinated DMF and are in accord with the sequence of metal-DMF interactions: Sb^V > Si^IV > Al^III > Ca^II.