Me3Si2N

Me3Si2N refers to hexamethyldisilazane (HMDS), a small organosilicon compound with the formula (Me3Si)2NH. In this molecule, two trimethylsilyl groups attach to a single nitrogen atom, giving a volatile, colorless liquid that is widely used in organic synthesis and surface chemistry.

HMDS functions primarily as a silylating agent. It transfers trimethylsilyl groups to alcohols and amines to form their corresponding trimethylsilyl derivatives, enabling protection of reactive hydroxyl and amino functionalities and facilitating subsequent reactions. It also acts as a moisture scavenger and dehydration agent in synthetic workups, helping to drive reactions by removing water.

Beyond synthesis, HMDS is employed in materials science and electronics. It is used to pretreat oxide surfaces to render them hydrophobic, improving adhesion of photoresists in microfabrication. HMDS serves as a chemical handle for introducing Si–N linkages in silicone and silazane polymers and can function as a precursor in the preparation of silicon-containing materials.

Preparation and handling are moisture sensitive. HMDS is typically prepared by condensation or metathesis routes involving chlorosilanes and ammonia or related reagents, and is purified by distillation under inert atmosphere. It hydrolyzes in the presence of water, releasing ammonia and silanol byproducts, so it is stored and handled under anhydrous conditions and appropriate precautions.

See also: hexamethyldisilazane, trimethylsilyl group, silylation, silazanes.