COMPOUNDS OF GERMANIUM AND TIN .22. REACTIONS OF A SILYLENE WITH A GERMYLENE AND A STANNYLENE - FORMATION OF A DIGERMENE WITH AN UNUSUAL ARRANGEMENT OF THE SUBSTITUENTS AND OF A STANNANE

The reaction of the diaminosilylene :Si(tBuNCH(2)CH(2)NtEu) (5) with t he diaminogermylene :Ge(tBuNCH(2)CH(2)NtBu) is thought to proceed via a germasilene --> silylgermylene re arrangement and dimerisation to fu rnish the (Z)-1,2-diamino-1,2-disilyldigermene (Z)-9. The X-ray struct ure analysis of (Z)-9 reveals a long Ge=Ge bond length of 245 pm and a large trans-bent angle of 42 degrees. Air-oxidation of (Z)-9 takes pl ace with retention of configuration at the germanium atoms to provide the corresponding substituted (Z)-2,4-digerma-1,3-dioxetane (Z)-10. Tr eatment of 5 with the stannylene :Sn[N(SiMe3)(2)](2) gives, as a final product, the hydridodisilyl-stannane 12. The structures of (Z)-10 and 12 were also determined. by X-ray crystallography.