Thioureidocalix[6]arenes Pseudorotaxanes

Abstract Heteroditopic calix[6]arenes are extensively exploited as synthetic receptors and molecular components of supramolecular threaded interlocked structures. We describe the synthesis two novel calix[6]arene macrocycles, upper rim which is functionalized with either or three phenylthioureido groups. These moieties excellent hydrogen‐bond donors largely affect conformation macrocycle, both in solution solid state. Alternate conformers observed solution, they give rise to chains Moreover, because this conformational freedom, also recognition properties toward formation pseudorotaxanes bipyridinium‐based axles strongly affected. The number units macrocyclic host nature counterions bipyridinium guest determine stability complexes. NMR, UV‐Vis electrochemical measurements revealed that very stable 1 : inclusion complexes formed between triphenylthioureido a tosylate counterions, whereas no complex diphenylthioureido macrocycle hexafluorophosphate salt.