Supramolecules from cobaloximes

This short review describes the use of organocobaloximes in the self-assembly of supramolecular systems by means of functionalized aromatic boronic or diboronic acids. With the former, the cyclization is achieved by the coordination of the nitrogen donor of the boronic acid to one of the Co axial positions, with simultaneous insertion of the boron in the hydrogen bond of the other cobaloxime unit. Cyclic supramolecular species of different nuclearity, depending either on the kind of boronic acid or on the side substituents of the cobaloxime, can be obtained. The use of diboronic acids, which link two organonaquocobaloxime units, allows the formation of cyclic oligomers only in the presence of suitable guests. (C) 2008 Elsevier B. V. All rights reserved.