Lock-and-Key Principle on a Microscopic Scale: The Case of the Propylene Oxide⋅⋅⋅Ethanol Complex


  • This research was funded by the University of Alberta, the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation (New Opportunity), and an Alberta Ingenuity New Faculty Grant. We thank Z. Su for helpful discussions and W. Jäger for the instrument time on the microwave spectrometer. N.B. thanks the German Academic Exchange Service (DAAD) and Alberta Ingenuity for postdoctoral fellowships.


original image

Molecular recognition: The binding between propylene oxide (PO) and ethanol resembles the lock-and-key principle, with (R)-PO as a rigid lock and G−, G+, and T conformers of EtOH as different keys (see picture; C yellow, O red). Six hydrogen-bonded PO⋅⋅⋅EtOH conformers were studied using rotational spectroscopy and ab initio calculations, revealing which EtOH key fits best into the PO lock.