An Unusual Reaction of (β-Dimethylaminoethoxy)triethyltin with Phenyltin Trichloride. The First X-ray Structural Evidence of the Existence of Complexes R2SnXY·R2SnXY (R = Alkyl, Aryl; X, Y = Hal, OR, X ≠ Y) Both as Unsymmetrical Adducts [R2SnX2·R2SnY2] and Symmetrical Dimers [R2SnXY]2

The substituent exchange reaction of PhSnCl3 with [Et3Sn(OCH2CH2NMe2)] gives rise unexpectedly to the unsymmetrical adduct [Ph2SnCl2·Ph2Sn(OCH2CH2NMe2)2] (2). It has been unambiguously proved for the first time that compounds of the RSnX3 type are able to undergo the hydrocarbon substituent redistribution reaction. The analogous tin complexes [Et2SnCl2·Et2Sn(OMe)2] (5) and [Bu2Sn(OAc)2·Bu2Sn(OMe)2] (6), which have ligands other than β‐dimethylaminoethoxy and could be considered as “organotin analogs of Grignard reagents” have symmetrical dimeric structures, i.e., can be formulated as [Bu2Sn(OMe)(OAc)]2 and [Et2Sn(OMe)Cl]2, respectively. Both types of structures, viz., unsymmetrical adduct (2) and symmetrical dimer (5, 6), have been characterized by X‐ray diffraction analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)