TEM and SEM observations of super-structures constructed in organogel systems from a combination of boronic-acid-appended bola-amphiphiles with chiral diols

Two bola-amphiphilic alpha, omega -diboronic acids separated by a (CH2)(11) or (CH2)(12) group were synthesized. Complexation with chiral diols readil y gave new amphiphiles end-capped with the chiral substituents. Some of the se acted as good gelators of organic solvents. Transmission electron micros cope and scanning electron microscope observations established that a varie ty of super-structures are created in the organogels, depending on the solv ents and the structure of the chiral end-cap groups. In most cases, the fib rous aggregates, the network structure which is the driving-force for gelat ion, showed a helical higher-order structure reflecting the chirality of th e end-cap groups. The results indicate that the combinatorial approach util izing boronic acid functions and diol compounds is useful in creating a var iety of new super-structures in the gel phase.