Crystal and molecular structures of Si-(iodomethyl)silatranes with methyl substituents in β-position relative to the nitrogen atom

Crystal and molecular structures of two silatranes, 1-iodomethyl-3-methyl- and 1-iodomethyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-silabicyclo[3.3.3]undecanes, were determined by X-ray analysis. Comparison of their structural and geometrical characteristics with those of other silatranes shows that the presence of methyl substituents β-positioned to nitrogen atoms increases the length of the dative Si←N bond, whereas the introduction of iodine into the axial position of the silatrane slightly decreases the length of the Si←N bond.