The Squaramides. A New Family of Host Molecules for Crystal Engineering

A host guest co-crystallization strategy for crystal engineering has been developed and a library of host molecules has been established. Each molecule possesses a hydrogen bond functionality that leads to the formation of a one-dimensional f -network with a characteristic repeat distance. The squaramides, diamides derived from squaric acid, represent a new entry into this library. They self assemble with repeat distances of about 6.1 Å. This structure of the squaramide derived from 4-aminomethylpyridine is reported along with two of its co-crystals.