A reference scale of cucurbituril 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 <106 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 cucurbituril (CB7) comprising binding affinities in the range from 103 to 1015 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.
- This article is part of the themed collection: Supramolecular chemistry in OBC