Synthesis and PMR spectra of organocyclotetrasilazanes

1. New organocyclotetrasilazanes with an assigned arrangement of the organic substituents in the ring have been obtained by the heterofunctional condensation of tetraorganodiaminodisilazanes with tetraorganodichlorodisilazanes. The condensation is accompanied by rearrangements with narrowing of the silazane ring. 2. Assignments of the signals of the methyl protons in the PMR spectra of the organocyclotetrasilazanes have been made. An analysis of the spectra has been carried out, and the nonadditivity of the chemical shifts of the protons of the methyl groups in different stereoisomers of these compounds has been demonstrated.