Rigid, Biconical Hydrogen-Bonded Dimers That Strongly Encapsulate Cationic Guests In Solution And The Solid State

The octol of a new rigid, tetraarylene-bridged cavitand was investigated for self-assembly behaviour in solution. H-1 and DOSY NMR spectroscopic experiments show that the cavitand readily dimerizes through an unusual seam of interdigitated hydrogen-bonds that is resistant to disruption by polar co-solvents. The well-defined cavity encapsulates small cationic guests, but not their neutral counterparts, restricting the conformation of sequestered tetraethylammonium in solution and the solid state.