Divalent tin and lead complexes of a bulky salen ligand: the syntheses and structures of [SalenBut,Me]Sn and [SalenBut,Me]Pb

Abstract

The divalent tin and lead complexes, [Salen^But,Me]Sn and [Salen^But,Me]Pb, have been synthesized by the reactions of [(Me₃Si)₂N]₂M (M = Sn, Pb) with the substituted Salen compound, [Salen^But,Me]H₂. [Salen^But,Me]Sn and [Salen^But,Me]Pb have been characterized by X-ray diffraction, which demonstrates that the complexes are structurally similar, with the metal atom located above the [N₂O₂] plane. Despite their similar structures, however, ¹H NMR spectroscopy demonstrates that the barrier for the formal transfer of the metal from one face of the ligand to the other is significantly greater for the tin derivative.