Abstract The use of simple calix [4] arenes for chemical conversion of NO 2/N 2 O 4 gases is demonstrated in solution and in the solid state. Upon reacting with these gases, calixarenes 1 encapsulate nitrosonium (NO+) cations within their cavities with the formation of stable calixarene–NO+ complexes 2. These complexes act as encapsulated nitrosating reagents; cavity effects control their reactivity and selectivity. Complexes 2 were effectively used for ...
