Hexol is a cobalt compound that was first prepared by Alfred Werner in 1914 and represented the first non-carbon-containing chiral compound. The salt with the molecular formula of Co((OH)2Co(NH3)4)3(SO4)3 was prepared starting from cobalt sulfate.
Optical resolution of this compound was possible by treating the hexol chloride salt with the resolving agent silver d(+)-bromocamphorsulphonate in dilute acetic acid. The d-Hexol salt precipitated out from solution and the filtrate contained the l-hexol species. Werner also published a second achiral hexol (a minor byproduct from the production of Fremy's salt) that he incorrectly identified as a linear trimer.
In 2004 the second hexol was reinvestigated and found to be a hexameric species.