A reference scale of cucurbit[7]uril binding affinities

The accurate determination of ultra-high binding affinities in supramolecular host-guest chemistry is a challenging endeavour because direct binding titrations are generally limited to affinities <10(6) M-1 due to sensitivity constraints of common titration methods. To determine higher affinities, competitive titrations are usually performed, in which one compound with a well established binding affinity serves as a reference. Herein, we propose a reference scale for such competitive titrations with the host cucurbit[7]uril (CB7) comprising binding affinities in the range from 10(3) to 10(15) M-1. The suggested reference compounds are commercially available and will aid in the future determination of CB7 binding affinities for stimuli-responsive host-guest systems.

Automated summary

Accurately determining ultra-high binding affinities in supramolecular host-guest chemistry is challenging due to sensitivity constraints of common titration methods. Competitive titrations with well-established reference compounds can provide a reference scale for determining high binding affinities, such as with the host cucurbit[7]uril (CB7) in the range from 10^3 to 10^15 M^-1. These commercially available reference compounds will aid in future research on stimuli-responsive host-guest systems.