Environment-controlled switching between cyclic hexamer and helical conformations of a water chloride cluster: An old compound viewed in a new perspective

On extrusion of a water molecule from the nano-channels created by the packing of [cis-α-(trien)CoCl2]Cl · 3H2O, an unprecedented dehydration transition occurs that cause the guest water–chloride hexameric clusters to rearrange into a helical modification. The reverse process is achieved by the introduction of an additional water molecule.