Each year, C&E News runs a poll for their “Molecule of the year“. I occasionally comment with some aspect of one of the molecules that catches my eye (I have already written about cyclo[18]carbon, another in the list). Here, it is the Incredible chloride cage, a cryptand-like container with an attomolar (1017 M-1) affinity for a chloride anion.[1] The essence of the binding is six short CH…Cl– and one slightly longer interactions to the same chloride (DOI: 10.5517/ccdc.csd.cc1ngqrl) and one further hydrogen bond to a water molecule; eight coordinated chloride anion!
References
- Y. Liu, W. Zhao, C. Chen, and A.H. Flood, "Chloride capture using a C–H hydrogen-bonding cage", Science, vol. 365, pp. 159-161, 2019. http://dx.doi.org/10.1126/science.aaw5145