N,S- and N,O-Substituted Stannylenes: Preparation and X-ray Diffraction Studies

The reaction of 2 equiv of Sn[N(SiMe3)2]2 with 1,2-benzodithiol gave the unstable N,S-substituted bis-stannylene 1, which decomposes in solution to yield Sn[N(SiMe3)2]2 and the S-heterocyclic stannylene 2. An X-ray diffraction analysis with crystals of 1 revealed the presence of two three-coordinated tin atoms with an S,S,N donor set and strong intramolecular Sn−S interactions. The related reaction of 3 equiv of Sn[N(SiMe3)2]2 with 2 equiv of 1,2-benzodiol gave the tris-stannylene 3 with two different types of SnII atoms. An X-ray diffraction analysis with crystals of 3 shows the central tin(II) atom to be coordinated by four oxygen donors while two additional peripheral tin(II) atoms are three-coordinated by a mixed O,O,N donor set. The central O4Sn core in 3 is strongly pyramidalized. In contrast to bis-stannylene 1 tris-stannylene 3 is stable both in the solid state and in solution.