(Iminophosphoranyl)(thiophosphoranyl)methanide {CH(PPh2NSiMe3)(Ph2PS)}− as a Ligand in Rare-Earth-Element Chemistry

The (iminophosphoranyl)(thiophosphoranyl)methanide {CH(PPh2═NSiMe3)(PPh2═S)}− has been introduced as a ligand into the chemistry of yttrium and the lanthanides. First, the bimetallic potassium reagent [K{CH(PPh2═NSiMe3)(PPh2═S)}]2 was synthesized by deprotonation of [CH2(PPh2═NSiMe3)(PPh2═S)] with KH. [K{CH(PPh2═NSiMe3)(PPh2═S)}]2 forms a dimeric structure in the solid state. The potassium atoms are bridged by the sulfur atom of the ligand. Moreover, an η6 coordination of one phenyl ring is observed. The salt metathesis of [K{CH(PPh2═NSiMe3)(PPh2═S)}]2 with LnCl3 led to the dichloro complexes [{CH(PPh2═NSiMe3)(PPh2═S)}LnCl2(THF)] (Ln = Dy, Er). The bis(amido) compounds [{CH(PPh2═NSiMe3)(PPh2═S)}Ln{N(SiHMe2)2}2] (Ln = Y, Sm, Er, Lu) were obtained by amine elimination from [CH2(PPh2═NSiMe3)(PPh2═S)] and [Ln{N(SiHMe2)2}3(THF)2]. The amido complex [{CH(PPh2═NSiMe3)(PPh2═S)}Er{N(SiHMe2)2}2] could also be accessed by the reaction of [{CH(PPh2═NSiMe3)(PPh2═S)}ErCl2(THF)] with KN(SiHMe2)2.