A tetranuclear samarium(ii) inverse sandwich from direct reduction of toluene by a samarium(ii) siloxide

The dinuclear Sm-II complex, [Sm2L4(dme)] (L = OSi(OtBu)(3)), is easily obtained from the protonolysis reaction of [Sm{N(SiMe3)(2)}(thf)(2)] with HOSi(OtBu)(3). This complex reacts slowly with toluene, resulting in the isolation of the triple-decker arene-bridged Sm-II complex, [{Sm2L3}(2)(-(6):(6)-C7H8)], in 44% yield. This reactivity provides the first example of unambiguous arene reduction by an isolated Sm-II species. In contrast, reduction of [SmL3](2) afforded the inverse sandwich complex, [{KSmL3}(2)(-(6):(6)-C7H8)].