Anionic Head Containing Oxacalix[2]arene[2]triazines: Synthesis and Anion−π-Directed Self-Assembly in Solution and Solid State

A series of oxacalix[2]­arene[2]­triazines bearing one anionic head such as carboxylate, sulfonate, sulfate, and phosphate were synthesized. With the anionic head and complementary V-shape electron-deficient cavity, these macrocycles can serve as dual building units, and their anion−π directed self-assembly was investigated. The formation of oligomeric aggregates in solution was revealed by nuclear magnetic resonance, dynamic light scattering, and mass spectroscopy. Crystal structures further confirmed chainlike assembly formation directed by anion−π interactions.