Bis(trimethylsilyl)amine

Bis(trimethylsilyl)amine (also known as hexamethyldisilazane, or HMDS) a chemical reagent with molecular formula (CH3)3Si-NH-Si(CH3)3 which consists of ammonia substituted with two trimethylsilyl functional groups. It is a clear, colorless liquid that will hydrolize slowly upon exposure to water.

A bis(trimethylsilyl)amide (also known as hexamethyldisilazide) results from the deprotonation of the nitrogen atom of bis(trimethylsilyl)amines and are used as non-nucleophilic bases:

Examples of these bases are:
 * Lithium bis(trimethylsilyl)amide (LiHMDS)
 * Sodium bis(trimethylsilyl)amide (NaHMDS)
 * Potassium bis(trimethylsilyl)amide (KHMDS)

Uses in organic chemistry
One of the uses of HMDS is as a reagent in condensation reactions of heterocyclic compounds such as in the microwave synthesis of a derivative of xanthine :
 * [[Image:HMDS application.png|400px|HMDS application]]

Other uses
HMDS is often used in Photolithography as an adhesion promoter for Photoresist. Best results are obtained by applying HMDS from the gas phase on heated substrates.