Lanthanide metal(III) heteroleptic alkyls: synthesis of [LnR3(µ-Me)Li(pmdeta)][Ln = La or Sm, R ={CH(SiMe3)2}, pmdeta =N,N,N′,N″,N″-pentamethyldiethylenetriamine] and X-ray structure of the samarium complex

Abstract

The first ‘mixed’ lanthanide metal(III) alkyls [LnR₃(µ-Me)Li(pmdeta)][Ln = La or Sm, R = CH(SiMe₃)₂, pmdeta =N,N,N′,N″,N″-pentamethyldiethylenetriamine] were prepared from [LnR₃], LiMe, and pmdeta; crystalline [SmR₃(µ-Me)Li(pmdeta)] has approximately tetrahedral environments for Sm and Li, an almost linear Sm–Me–Li unit [Sm–Me–Li 174(2)°], and short Sm–Me [2.33(3)Å] but long Li–Me [2.42(6)Å] distances.