Sniffing out camphor: the fine balance between hydrogen bonding and London dispersion in the chirality recognition with alpha-fenchol

This work was financially supported by the Deutsche Forschungsgemeinschaft (SCHN1280/4-2 project number 271359857 and Su 121/5-2 project number 271107160) in the context of the priority program SPP 1807 "Control of London dispersion interactions in molecular chemistry". We acknowledge the use of the GWDG computer cluster. M.M.Q.M. thanks Fundacion Alfonso Martin Escudero for a postdoctoral grant and Ministerio de Ciencia, Innovacion y Universidades for a Juan de la Cierva formacion contract (fellowship FJC2018-035709-I funded by MCIN/AEI/10.13039/501100011033). Helpful discussions with M. A. Suhm are acknowledged.Binary complexes between the chiral monoterpenoids camphor and a-fenchol were explored with vibrational and rotational jet spectroscopy as well as density functional theory in order to explore how chirality can influence the binding preferences in gas-phase complexes. The global minimum structures of the two diastereomers were assigned. It is found that chirality recognition leads to different compromises in the fine balance between intermolecular interactions. While one isomer features a stronger hydrogen bond, the other one is more tightly arranged and stabilized by larger London dispersion interactions. These new spectroscopic results help understand the influence of chirality in molecular aggregation and unveil the kind of interactions involved between a chiral alcohol and a chiral ketone with large dispersion contributions.German Research Foundation (DFG) SCHN1280/4-2 271359857 Su 121/5-2 271107160 SPP 1807Fundacion Alfonso Martin EscuderoSpanish Government FJC2018-035709-