Silicon-nitrogen bond, polarity

Insertion of the Si=N bond into polar bonds is the most used reaction for the characterization of very reactive and transient silanimines. Especially, the reaction with alcohols is often the first reaction to be carried out with silicon-nitrogen multiple bond systems. Other reagents used for insertion reactions are amines, water and alkoxysilanes (equation 269)300,303,306,311,351-353. The insertion into E—X bonds (E = Si, Ge, Sn X = Cl, OR, NR2, N3) has been shown earlier in this review for the insertion into the Si—N bond of silyl azides310,351. A reaction reported is the insertion of 678 into the C—H... 

The structures of compounds 55a,c and 56a,c were established by means of NMR spectroscopy and mass spectrometry. Due to the different polarity of the C=N and C=P triple bonds, the silicon ring atom in 55a,c is bound to the nitrogen atom, and in 56a,c to the carbon atom of the C=P moiety. The molecular structure of 55a was further determined by single-crystal X-ray diffraction analysis (Fig. 16).14 The four-membered SiNAsC framework is slightly puckered (folding angle N—Si—C/Si—C—As 7°), and... 

According to the polarity of the Si=N bond Lewis bases (Lb) are added to the silicon atom while Lewis acids (La) react with the nitrogen atom (Scheme 3). 

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