Cyclische Diazastannylene. - XXX : Symmetrisch und asymmetrisch substituierte German- und Stannandiyle mit Amid-, Alkoholat- und Thiolat-Liganden. - Teil I

Abstract

Symmetrically and unsymmetrically substituted germane- and stannanediyls as well as chelated bis(amino)- or aminooxogermanium- and -tinmonohalides have been obtained from cyclic bis(amino)germane- and stannanediyls by treatment with tert-butylamine, tert-butanol and tert-butylmercaptane. The following compounds have been synthesized: GeX2 (X=OtBu (5), StBu (6)), Sn(StBu)2 (9), GeXCl (X=N(H)tBu (21), OtBu (22)), SnXCl (X=N(H)tBu (23), OtBu (24), StBu (25), OMe (28)) and Sn(OtBu)Br (27). In the series of the chelates Me2Si(NtBu)(NHtBu)GeCl (13), Me2Si(NtBu)(OtBu)SnX (X=Cl (18), OMe (19)) and the bischelate [Me2Si(NtBu)(OtBu)]2Sn (20) have been prepared. When 18 is allowed to react with aluminiumtrimethyl Me2Si(NtBu)(OtBu)AlClMe is formed, a compound with a center of chirality at the aluminium atom. X-ray structure determinations have been performed on single crystals of 6, 8, 9, 13, 22 and 24. 6, 8, 22 and 24 form molecular dimers with c.n. of 3 at the Ge or Sn atoms, resp. While the tBu-S ligands are syn with respect to the central Ge2S2 ring in 6 (symmetry approaching C2v), the tBu-O ligands are anti to the central Sn2O2 ring in 8 (symmetry Ci). 9 forms a coordination polymer with all Sn atoms in a psi-tetrahedral environment. The germanium atom in 13 is coordinated by a chlorine, a lambda3-and lambda4-nitrogen atom, the two nitrogen atoms being connected by as dimethylsilyl group. the hydrogen and chlorine atom of 13 are found at the same side of the four-membered chelate ring. The two unsymmetrically substituted, homologous compounds Ge(OtBu)Cl (22) and Sn(OtBu)Cl (24) are found to form dimers via O->Ge resp. O->Sn bonds. While the chlorine atoms in 22 are syn with respect to the four-membered ring, they are anti in the case of molecule 24.