The structures of silanols and siloxanes

Although the stereochemistry of silicon in these compounds presents no points of special interest, the bond arrangement being the normal tetrahedral one, the siloxanes include some interesting ring systems. 

Linear polysiloxanes. Several studies have been made of the simplest member of this family, 0(SiH3)2. The most reliable estimate of the Si-O-Si bond angle may be compared with the much smaller value in the sulphur analogue 

Cyclic polysiloxanes. Particular interest attaches to the configurations of these molecules, for the related carbon compounds paraldehyde and metaldehyde have puckered rings. The true silicon analogue of paraldehyde, tri-methylcyclo-trisiloxane, has been prepared but its structure is not known. 

---