Molecular recognition. 1. Crystal structures of hexaazamacrocyclic amines containing p-xylylene spacers and their adducts with acids.

The macrocyclic amine, 1,5,9,18,22,26-hexaaza [11.11]-p-cyclophane (1) contains two dipropylenetriamine units which make the molecule highly basic. Owing to this basicity, 1 can be highly protonated in acidic media and can form supramolecular assemblies with different anions. Two new supramolecular structures arise from self-assembly of the salt of 1 with fumaric acid and of the N-methyl derivative of 1.