Sol-Gel Synthesis of Water-Soluble Polysilsesquioxanes with Regular Structures

This paper deals with our recent works on the preparation of polysilsesquioxanes with regularly controlled molecular and higher-ordered structures. Such preparations were achieved by the sol-gel reactions of organotrialkoxysilanes containing amino groups under acidic conditions; the resulting products formed ladder-like and hexagonal stacking structures. Self-organization of a salt (an ion pair) prepared from an amino group in the organotrialkoxysilane and an inorganic acid used as a catalyst is a key factor for the formation of such regular structures. We also report on control of the conformation of the polysilsesquioxanes by introduction of a chiral moiety.