Organosilicon compound

A silicon–oxygen framework with ideal fully condensed composition $(\mathrm{RSi}{\mathrm{O}}_{3/2}{)}_{\mathrm{n}}$. Each silicon has one organic substituent and three siloxane bridges. Incompletely condensed cages retain silanol groups.

A corner-deficient cage ${\mathrm{R}}_7\mathrm{S}{\mathrm{i}}_7{\mathrm{O}}_9(\mathrm{OH}{)}_3$. Removing one silicon corner from a T8 cage leaves three silanol-bearing silicon sites, three further sites adjacent to those, and a unique opposite site: symmetry classes 3:3:1.

A cage ${\mathrm{R}}_{10}\mathrm{S}{\mathrm{i}}_{10}{\mathrm{O}}_{15}$ with a common pentagonal-prismatic silicon skeleton and an oxygen bridge on each edge.

A cage ${\mathrm{R}}_8\mathrm{S}{\mathrm{i}}_8{\mathrm{O}}_{12}$ represented by a cube of eight silicon vertices with one bridging oxygen on each of twelve edges.

A compound containing a silicon–oxygen double bond, ${\mathrm{R}}_2\mathrm{Si}=\mathrm{O}$. Ordinary small-substituent silanones are highly reactive; oligomerization to siloxane linkages is favoured over persistence as freely dissolved monomers.

An Si–O–Si linkage, or a compound containing such linkages. Cyclic and polymeric siloxanes have strongly polar bonds and flexible bond angles; their bonding should not be reduced to a dominant oxygen-2p/silicon-3d pi interaction.

The substituent $\mathrm{Si}(\mathrm{C}{\mathrm{H}}_3{)}_3$, often abbreviated $\mathrm{SiM}{\mathrm{e}}_3$. Its steric and electronic effects should be separated when interpreting regioselectivity.

An Si–OH group or a compound containing it. Condensation of two silanol groups can form an Si–O–Si bond and water.

A coordination ligand containing deprotonated silanol oxygen, $\mathrm{Si}-{\mathrm{O}}^{-}$, which binds a metal through oxygen. Three silanol groups on a corner-deficient silsesquioxane can give a facial tridentate trianionic donor set.

An organosilicon compound containing Si–Cl bonds. Hydrolysis can produce silanols, whose condensation builds siloxane linkages.