engleski

Threading of Conformationally Stable Calix[6]arene Wheels Substituted at the Methylene Bridges

Calix[6]arenes disubstituted at the methylene bridges, which are stable in the cone or 1, 2, 3- alternate conformation, form pseudorotaxanes with dialkylammonium axles. The cone-wheel based pseudorotaxanes are 10-100 times more stable than those obtained with the native conformationally- mobile calix[6]arene wheel, as a consequence of their higher degree of preorganization. The threading of conformationally stable 1, 2, 3- alternate-calix[6]arenes is unprecedented in the literature. Therefore, very peculiar NMR features are here evidenced for this threading process involving the less symmetrical 1, 2, 3-alternate calix[6]arene conformation, which implies a peculiar rototranslation motion of the axle.

calix[6]arene ; threading ; pseudorotaxane

nije evidentirano