Syntheses and structures of (N',N'-dimethylhydrazido)silanes.

The hydrazidosilanes Ph(2)Si(NHNMe(2))(2) (1), Me(2)Si(NHNMe(2))(2) (2), PhSi(NHNMe(2))(3) (3), MeSi(NHNMe(2))(3) (4), PhClSi(NHNMe(2))(2) (5), MeClSi(NHNMe(2))(2) (6), Me(2)ClSi(NHNMe(2)) (7), MeClHSi(NHNMe(2)) (8), MeHSi(NHNMe(2))(2) (9), Me(2)HSi(NHNMe(2)) (10), Me(2)NN[HSi(NHNMe(2))(2)](2) (11) and Si(NHNMe(2))(4) (12) have been prepared by the reaction of the corresponding chlorosilanes with N,N-dimethylhydrazine. Some of the compounds containing Si-Cl and N-H functions simultaneously (6,7,8 ) are very reactive and tend to polymerise and could only be characterised by spectroscopic methods ((1)H, (13)C, (29)Si NMR, IR, MS). All other compounds could additionally be characterised by elemental analyses.

Highly asymmetric coordination of trimethylsilyl groups to tetrazole and triazole rings: an experimental and computational study in gaseous and crystalline phases.

1-Trimethylsilyltetrazole, 1, has been synthesised from chlorotrimethylsilane and tetrazole in the presence of triethylamine as an auxiliary base. The structure of this compound has been determined in the crystalline phase by X-ray diffraction of a crystal grown in situ. The gas-phase structures of 1 and 1-trimethylsilyl-1,2,4-triazole, 2, have been determined by gas-phase electron diffraction (GED).