Molecule 'handedness' determines the strength of a coupling between nuclear spins

Chirality -- a geometric property that allows molecules to exist in two distinct forms that are chemically identical but are 3D mirror images of each other, like a right and left hand -- has a powerful effect on nuclear spin state but was thought to have no effect on coupling between spins. A study found chirality, or handedness, does in fact determine the strength of a coupling between nuclear spins. Findings could lead to better methods of probing electrons and spin in chemical and biological systems.