The first structurally characterised perchlorato-cobalt(III) complexes, involving the C-bonded macrobicyclic ligand 1,4,8,11-tetraazabicyclo[9.5.2]octadecane.
Two isomeric C-bonded complexes, sym-anti-[Co(L-C)(OH2)]2+ and sym-syn-[Co(L-C)(OH2)]2+ (L = 1,4,8,11-tetraazabicyclo[9.5.2]octadecane) when crystallised from aqueous NaClO4 remarkably yielded the corresponding perchlorato complexes, confirmed by the single crystal X-ray structures.