Selective Encapsulation and Sequential Release of Guests Within a Self-Sorting Mixture of Three Tetrahedral Cages


  • This work was supported by the European Research Council, the Schlumberger Foundation, Faculty for the Future Fellowship (R.A.B.). We thank Diamond Light Source (UK) for synchrotron beamtime on I19 (MT7569), the EPSRC National Crystallography Service at the University of Southampton for the collection of crystallographic data, and Andrew Hogben, Jack K. Clegg and Sean Houghton for preliminary studies on cage 3.


A mixture of two triamines, one diamine, 2-formylpyridine and a ZnII salt was found to self-sort, cleanly producing a mixture of three different tetrahedral cages. Each cage bound one of three guests selectively. These guests could be released in a specific sequence following the addition of 4-methoxyaniline, which reacted with the cages, opening each in turn and releasing its guest. The system here described thus behaved in an organized way in three distinct contexts: cage formation, guest encapsulation, and guest release. Such behavior could be used in the context of a more complex system, where released guests serve as signals to other chemical actors.