Siloxide

Siloxides are <a href="/facts/Chemical_compound/37FXqqtv">chemical compounds</a> with the formula R3SiOM, where R is usually an organic group and M is usually a <a href="/facts/Metal/PT8hNX6R">metal</a> <a href="/facts/Cation/wrbwhF3z">cation</a>. Also called silanolates, they are derived by <a href="/facts/Deprotonation/SmUSh369">deprotonation</a> of <a href="/facts/Silanol/3f58wE1l">silanols</a>. They also arise by the degradation of <a href="/facts/Siloxane/6fbEIal7">siloxanes</a> by base:

R3SiOSiR3 + 2 NaOH → 2 R3SiONa + H2O
Cleavage of cyclic siloxanes affords siloxides:

(Me2SiO)3 + MeLi → Me3SiOSiMe2OSiMe2OLi
These anions function as <a href="/facts/Ligand/6etB3qeW">ligands</a> for metal ions, forming complexes similar to metal <a href="/facts/Alkoxide/RqG0rm1v">alkoxides</a>. <a href="/facts/Sodium_trimethylsiloxide/6vjXKwgk">Sodium trimethylsiloxide</a> is useful for generating metal complexes by <a href="/facts/Salt_metathesis_reaction/YpadY3lq">salt metathesis reactions</a>. A very bulky siloxide is <a href="/facts/Tert-butyl/fbTF0UkI">tert-butyl</a>3SiO−, sometimes called <a href="/facts/Silox/jA9yBzT0">silox</a>.
Siloxides are weaker net donors than <a href="/facts/Alkoxides/RqG0rm1v">alkoxides</a> because pπ-d donation has to compete with <a href="/facts/Back_bonding/un6buomN">backbonding</a> from the oxygen atom into the low-lying Si-C σ* orbitals.

Siloxide open-in-new

Siloxide