A borazaaromatic analogue of isophthalic acid

Abstract

A diboradiazaaromatic—2,7-di-tert-butyl-5,9-dihydroxy-5,9-dibora-4,10-diazapyrene-4,10-diium-5,9-diuide—which is a structural analogue of isophthalic acid has been designed and synthesised. This compound is capable of spontaneous dehydration in solution to form linear oligoanhydrides. These oligoanhydrides can be readily hydrolysed to the starting diboradiazaaromatic under appropriate conditions. This unusual reactivity is mirrored in the solid-state behaviour of 2,7-di-tert-butyl-5,9-dihydroxy-5,9-dibora-4,10-diazapyrene-4,10-diium-5,9-diuide. A complex network of hydrogen bonds present in the solid-state structure of the borazaaromatic serve to facilitate a facile solid-state dehydration reaction, once again forming oligoanhydrides of molecular weight greater than 3000 Da.