Electronic effects in the UV spectra of Si-substituted heterylthiomethylsilanes

Ultraviolet and IR absorption spectroscopy were used to evaluate the mutual effect of the organosilicon substituent and the heterocyclic fragment in 8 -quinolyl-, 2-benzothiazolyl-, 2-benzoxazolylthiomethylsilanes and the corr esponding silatranes. The UV absorption bands of compounds containing a for mally unconjugated silatranyl group Si(OCH2CH2)(3)N suffer a considerable b athochomic shift compared with respective bands of their analogs with a fou r-coordinate silicon atom. This shift is explained by the superelectron-don or inductive effect of the silatranylmethyl group containing a five-coordin ate silicon atom.