Cyclic Organopolysilanes

All organocyclopolysilanes are solid at room temperature. Aryl compounds have high melting points  

Octaorganocyclotetrasilanes, e.g. octamethyltetrasiletane [493] (m.p. 105-106 C) are easily decomposed by oxygen, halogens and even moisture. Organocyclohexa-silanes are very stable however, dodecamethylcyclohexasilane can be converted to 1,2,3,4,5.6-hexachlorohexamethyltyclohexasilane [494] (Eq. 3.268)  

Dodecaphenylcyclohexasilane [490] does not react at all with halogen in boiling benzene or with methyllithium. It can be attacked only be metallic lithium. 

Alkali metal or 1, w-dili-thium organo-polysilane 

5 mole silane + 1.1 mole alloy + Ig naphthalene 20 h reflux in 300 ml TMF 

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Cyclic organopolysilanes are cleaved by Li (or Na) metal in THF to give a,a>-dilithio or disodio reagents ... 

The proton NMR spectral data of organopolysilanes have often been published incidental to preparative studies (51, 54, 62, 74, 108, 119, 177, 187, 190). Only recently has a systematic investigation to determine the chemical shifts and coupling constants in linear and cyclic permethylated polysilanes, and to study the effects of substituents on the NMR properties of methyl derivatives of disilane and trisilane been reported (see Table V-VII) (206). 

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