Silicon-nitrogen bond properties

Most of the reactions and properties of 1-substituted imidazoles have been discussed earlier in this review. Apart from the utilization of the readily removable benzyl substituent in synthetic procedures leading to 2-substituted imidazoles, perhaps the mostexciting advances have stemmed from the reactions of the 1 -acylimidazoles (imidazolides) which are extremely reactive in such nucleophilic reactions as hydrolysis and alcoholysis.12 The use of such compounds as N,N -carbonyl-diimidazole in peptide synthesis is now commonplace. The silicon-nitrogen bond in N-trimethylsilylimidazoles is also extremely reactive, so reactive that it is attacked by a-halogenocarboxylic esters.361... 

The Raman spectrum of nanocrystalline silicon was used to determine the amounts of SiHs, SiH2 and SiH groups present/ IR measurements revealed vSiH bands in the initial stages of porous silicon formation on silicon surfaces vSiH and vSiN IR bands were used to probe hydrogen-bonding properties of nitrogen-doped silicon thin films Surface-IR observation of 5SiH modes showed the formation of Si-H units by decomposition of H2O on a clean Si(100)-(2 X 1) surface ... 

To date, chemical properties have been reported mainly for 59 and 61. Occupancy of the silicon 3p orbital by electrons from nitrogen greatly reduces the electrophilicity of these silylenes. This, together with probable aromatic stabilization, significantly mutes the behavior of 59 and 61 as silylenes. For example, 59 does not insert into Si—H bonds, or react with alkynes such as PhC=CPh367, Moreover, 59 shows no Lewis acidic behavior, even toward bases as strong as pyridine. 

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