Carboxylate and carboxylic acid recognition by tin(IV) porphyrins

The scope of carboxylate binding by tin(IV) porphyrins and the solution geometries of the resulting complexes have been explored using 1H NMR spectroscopy; ring current induced shifts and competition experiments indicate the operation of an attractive anthracene–porphyrin interaction; outer sphere carboxylic acid complexes of dihydroxy tin(IV) porphyrins have been characterised, apparently for the first time.