The hexol cation exists as two optical isomers that are mirror images of each other, depending on the arrangement of the bonds between the central cobalt atom and the three bidentate peripheral units [Co(NH)(HO)]. It belongs to the D point group.  The nature of chirality can be compared to that of the ferrioxalate anion .
In a historic set of experiments, a salt of hexol with an optically active anion — specifically, its -(+)-bromocamphorsulfonate – was resolved into separate salts of the two cation isomers by fractional crystallisation.  A more efficient resolution involves the bis(tartrato)diantimonate(III) anion.  The hexol hexacation has a high specific rotation of 2640°.