Sterically demanding and chiral N,N'-disubstituted N-heterocyclic germylenes and stannylenes.

The N,N'-dimesitylene substituted o-phenylenediamine 1 reacts with Sn[N(SiMe(3))(2)](2) under formation of the monomeric N-heterocyclic stannylene 2, while the chiral N,N'-substituted o-phenylenediamine 3 reacts with E[N(SiMe(3))(2)](2) (E = Ge, Sn) under formation of the chiral germylene 4 and the chiral stannylene 5, respectively. X-Ray diffraction studies with both stannylenes demonstrated that the metal centers in these compounds are sufficiently sterically protected to prevent interaction between the tin center and the nitrogen donors of adjacent molecules.