The influence of intermolecular interactions on the SiH bond vibration in silatrane and its c-substituents

Spectra of the silatrane HSi(OCHRCH₂)₃N and its 3,7,10-trimethyl- and -trifluoromethyl derivatives have been studied. The dependences of frequency and integral intensity of the SiH vibration on solvent polarity and temperature have been established. It has been shown that interaction of silatrane molecules with the solvent is universal in character. The phenomenon of the changing SiH vibration is explained by the possible formation of a three-centered orbital bending the atoms of hydrogen, silicon and nitrogen. In contrast to triethoxysilane, a dependence between v(SiH) and Σσ1 values of substituents in the cycle has been observed for silatranes.