Anomalous Viscosity of a Racemate: A Simple Experiment Demonstrating Chirally Induced Spin Selectivity.

It has been known for over a century that racemic solutions of hydrogen-bonded compounds are less viscous than their component enantiomers, but this fact has so far remained unexplained. Here we confirm it using enantiomers of lactic acid and compare it to molecular dynamics (MD) simulations of lactic acid viscosity. The effect is absent in classical MD. We suggest that the anomalous viscosity of racemates may be due to a recently discovered magnetic intermolecular force due to spin-dependent charge reorganization.