Flexibly Coordinating Tris(arylamido)stannates as Ligands: A [Rh]+/[Sn]- Zwitterion as an Intermediate in the Formation of Rh−Sn Complexes

Reaction of the lithium stannate MeSi{SiMe2N(3,5-xyl)}3SnLi(OEt2) (1) with 1/2 molar equiv of [RhCl(COD)]2 gave the zwitterionic heterodinuclear complex [MeSi{SiMe2N(3,5-xyl)}2Sn{SiMe2N(η6-3,5-xyl)}Rh(COD)] (2), in which one of the peripheral N-bonded 3,5-xylyl groups acts as an η6-aryl ligand to which the {Rh(COD)}+ cation is bonded. Reaction of the 18-electron complex 2 with nucleophiles leads to an attack at the late transition element, which moves over to the tin atom to form the Rh−Sn-bonded 16-electron complexes [MeSi{SiMe2N(3,5-xyl)}3SnRh(L)(COD)] (L = Ph3P (3), (PhO)3P (4), CyNC (5)).