A team of researchers from the University of Basel, Switzerland, and their colleagues in Hamburg have reportedly succeeded in succeeded in seperating water molecules into two separate forms for the first time.
While the two forms have similar physical properties, they apparently exhibit different chemical reactivities.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two different forms (isomers) at the molecular level. The difference lies in the relative orientation of the nuclear spins of the two hydrogen atoms. Depending on whether the spins are aligned in the same or opposite direction, one refers to ortho- or para-water.
The researchers investigated how the two forms of water differ in terms of their chemical reactivity – their ability to undergo a chemical reaction. Both isomers have almost identical physical properties which makes their separation particularly challenging.
It was demonstrated that para-water reacts about 25% faster than ortho-water. This effect can be explained in terms of the nuclear spin also influencing the rotation of the water molecules. As a result, different attractive forces act between the reaction partners. Para-water is able to attract its reaction partner more strongly than the ortho-form, which leads to an increased chemical reactivity. Computer simulations have confirmed the experimental findings.