1,1,3,3-TETRACHLORODISILAZANE

The new compound 1 can be prepared by the reaction of calciumoctamminedichloride, CaCl2(NH3)8, with trichlorosilane, HSiCl3. IR, Raman, H-1 and Si-29 NMR spectra show a planar Si2NH framework, probably C2-symmetry of the whole molecule and a symmetrical distribution of the four chlorine atoms. In 1 we have got a compound with Bronsted and Lewis acidity, which reacts with three equivalents of pyridine to HSiCl2(py)2-NH(py)-HSiCl2. This addition compound exhibits a fourfold and a sixfold coordinated silicon atom as is shown by a Si-29-solid-NMR spectrum. By thermal decomposition of 1 the new compound 1,3,5-trichloro-2,4,6-tris(dichlorosilyl)-cyclo-1,3,5-trisil-2,4,6-triazane, Si6Cl9H6N3, 4, is formed. With piperidine, 1 reacts by substitution of all four chlorine atoms to compound 5, whereas with diazomethane the NH-functionality is converted to a NCH3 group in 6. Attempts of lithiation lead mainly to a substitution of the chlorine atoms by alkyl groups