Guest-induced capsular assembly of calix[5]arenes

Novel dimeric capsules are generated from the non-covalent assembly of cone calix[5]arenes and alkyldiammonium ions[H₃N- (CH₂)_n-NH₃]² featuring an appropriate length of the spacer joining the two charged end groups. ¹H NMR spectroscopy and electrospray ionisation mass spectrometry provide evidence that in the capsule a single ditopic guest holds together a pair of calix[5]arene units, which are oriented rim-to-rim to form a closed cavity encapsulating the shape-complementary dication.