Unusual recognition of (n-Bu4N)2SO4 by a cyanuric acid based host via contact ion-pair interactions.

A tripodal neutral receptor selectively binds tetrabutylammonium sulfate where anion is encapsulated in the cavity and cations are in close contact with the anion via C-H...O interactions. This organic cation capped sulfate-bowl exists both in solid and solution states and the sulfate assisted cap can be opened and closed reversibly with a temperature key.