A hexahomotrioxacalix[3]arene-based ditopic receptor for alkylammonium ions controlled by Ag⁺Ions

© 2018 by the authors. A receptor cone-1 based on a hexahomotrioxacalix[3]arene bearing three pyridyl groups was successfully synthesized, which has a C 3 -symmetric conformation and is capable of binding alkylammonium and metal ions simultaneously in a cooperative fashion. It can bind alkylammonium ions through the π-cavity formed by three aryl rings. This behaviour is consistent with the cone-in/cone-out conformational rearrangement needed to reorganize the cavity for endo-complexation. As a C 3 -symmetrical pyridyl-substituted calixarene, receptor cone-1 can also bind an Ag + ion, and the nitrogen atoms are turned towards the inside of the cavity and interact with Ag + . After complexation of tris(2-pyridylamide) derivative receptor cone-1 with Ag + , the original C 3 -symmetry was retained and higher complexation selectivity for n-BuNH 3 + versus t-BuNH 3 + was observed. Thus, it is believed that this receptor will have a role to play in the sensing, detection, and recognition of Ag + and n-BuNH 3 + ions.