THE PRESENT STATE OF THE CHEMISTRY OF CYCLOSILANES

Abstract

In this review, an overlook of the present state of the chemistry of cyclosilanes is given. Cyclosilanes with organic substituents are old and well-known compounds. Starting with the first investigations by Kipping a small review of the background introduces these cyclic compounds.

In the last decades, developments in this field have become faster. West showed in excellent investigations the important behavior of these compounds to form radical anions by adding electrons and we were able to synthesize the first inorganic substituted cyclosilanes such as halogenated cycles, but also the basic compounds Si₅H₁₀ and Si₆H₁₂. The properties of the cyclic silanes were reinvestigated in view of all the new derivatives and also of possible industrial applications. New results in UV-spectroscopy in connection with results of PE-spectroscopy show that these groups of compounds are chromophores. Similar results were found some years ago on polymeric compounds containing such silicon cycles, but in view of new results and in connection with the formation of radical anions, the picture now becomes clearer. After discussion of these new results, the review completes the overlook with a presentation of larger ring systems and cyclic silanes with other additional atoms.