Selective formation of heterodimeric resorcinarene capsules

C2V-symmetrical resorcinarene tetraesters form in CDCl3 dimeric capsules encapsulating one Me4N+ cation. The homodimeric capsules of the tetra(3,4,5-trimethoxybenzoate) and tetrabenzoate or tetrafuroylate disproportionate in solution to give quantitatively the heterodimers. The higher stability of the heterodimer is, most probably, caused by π–π attractions between the π-basic trimethoxyphenyl rings of and relatively more π-accepting phenyl or furyl fragments of or .