Synthesis and Reactivity of Bis(phospholyl)neodymium(III) and -samarium(III) Chlorides and Alkyl Derivatives

The reaction of 2,3,4,5-tetramethylphospholylpotassium [C4Me4PK] with [LnCl3(THF)x] (Ln = Nd, Sm) in a 2:1 ratio gave unsolvated ate complexes of the formula [(C4Me4P)2LnCl2K]. Crystallisation of the samarium complex from ether afforded a polymeric ether solvate: {[(η5-C4Me4P)Sm(μ3-Cl)2(μ:η5,η1-C4Me4P)K(Et2O)]∞}, which was characterised by X-ray crystallography. Reaction of [(C4Me4P)2LnCl2K] with [LiCH(SiMe3)2] in toluene gave the alkyl complexes [(C4Me4P)2LnCH(SiMe3)2]; these complexes were most efficiently prepared from [LnCl3(THF)x], [KC4Me4P] and [LiCH(SiMe3)2] in a one-pot procedure. Reaction of [(C4Me4P)2LnCH(SiMe3)2] with molecular hydrogen gave [(C4Me4P)2NdH], when Ln = Nd, whereas, when Ln = Sm, reduction occurred and the already known [(C4Me4P)2Sm] was isolated instead.