The influence of arylene and alkylene units on the structuring of urea-based bridged silsesquioxanes

Abstract

The influence of the intrinsic self-assembling properties of rigid or semirigid aromatic units as the main substructures combined with the effect of the alkylene side chains as linkers on the nanostructure of bridged silsesquioxanes was studied. The symmetry of the organic units was found to control the dimensionality of the hybrid nanostructure. Bis(silylated) aromatic units lead to lamellar hybrids, whereas tris(silylated) aromatic units tend to form hexagonal structures. The ordering of each type of structure depends directly on the conformation of the organic units, which determines the self-assembling of precursors through intermolecular interactions. The organic units (arylene, urea and trialkoxysilyl groups; hydrocarbon side chains) of organosilanes are shown to self-direct the nanostructuring of bridged silsesquioxanes. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.