The molecular structure and conformation of hexamethyldisilazane, NH(Si(CH 3) 3) 2, as determined by gas phase electron diffraction

Abstract

The structure and conformation of gaseous hexamethyldisilazane, NH(SiMe 3) 2, have been determined by gas phase electron diffraction at a nozzle temperature of 293 K. The SiMe, groups are found to be close to staggered with respect to each other when viewed along the Si…Si vector; one SiMe, group is twisted 13(4)° while the other SiMe, group is twisted 37(3)° in the opposite direction away from the reference position where SiC bonds eclipse the NH bond. The methyl groups are twisted 19(6)° (mean value) away from their staggered reference positions. Principal bond length and valence angles are: NSi 1.738(5) Å, SiC 1.876(1) Å, SiNSi 131.3(1.5)°, NSiC 110.7(0.5)° (mean value) and SiCH 111.2(0.8)°.