Pseudorotaxanes and rotaxanes from macrocyclic rings incorporating acridinone, 9-phenylacridinium and 9-phenyl-9-methoxy-acridane moieties

N-Substituted Acridinium as a Multi-Responsive Recognition Unit in Supramolecular Chemistry

The N-substituted acridinium motif is an electron-deficient unit with appealing multi-responsive properties which have been exploited in the field of supramolecular chemistry. This building block reversibly alters its shape, with its chemical and optical properties in response to a chemical or redox signal. In this Review, we discuss selected examples where the switchable properties of 9-aryl-N-methyl-acridinium lead to actuators, multi-input and multi-output systems, host or guest systems, and to interlocked systems with controllable motion.

Supramolecular networks of 10-(2-hydroxyethyl)acridin-9(10H)-one and 10-(2-chloroethyl)acridin-9(10H)-one

Both 10-(2-hydroxyethyl)acridin-9(10H)-one, C15H13NO2, and 10-(2-chloroethyl)acridin-9(10H)-one, C15H12ClNO, have monoclinic (P21/c) symmetry and supramolecular three-dimensional networks. But the differences in the intermolecular interactions displayed by the hydroxy group and the chlorine substituent lead to stronger intermolecular π-stacking interactions and hydrogen bonding, and hence a significantly higher melting point for the former.