A shapeshifting organic molecule dynamically adjusts its equilibrium population of discrete structural isomers in response to an analyte. By incorporating a single 13C-label into the bullvalene core, these changes can be read by a single 13C NMR experiment. The shapeshifting nature and 13C nucleus together act as a reporting element that generates a reproducible pattern from small changes in the chemical shifts and intensities of the carbon peaks.
