Electron diffraction study of the molecular structure of trisilylarsine

The molecular structure of gaseous trisilylarsine has been determined by the sector-microphotometer method of electron diffraction. The heavy-atom skeleton is found to be pyramidal; the As–Si distance is 2·355 ± 0·001 Å and the Si–As–Si angle 93·79 ± 0·17°. The Si–H distance is 1·488 ± 0·011 Å.