The Heaviest Bottleable Metallylone: Synthesis of a Monatomic, Zero‐Valent Lead Complex (“Plumbylone”)

Abstract

AbstractThe elusive plumbylone {[SiII(Xant)SiII]Pb0}3stabilized by the bis(silylene)xanthene chelating ligand1, [SiII(Xant)SiII=PhC(NtBu)2Si(Xant)Si(NtBu)2CPh], and its isolable carbonyl iron complex {[SiII(Xant)SiII]Pb0Fe(CO)4}4are reported. The compounds3and4were obtained stepwise via reduction of the lead(II) dibromide complex {[SiII(Xant)SiII]PbBr2}2, prepared from the bis(silylene)xanthene1and PbBr2, employing potassium naphthalenide and K2Fe(CO)4, respectively. While the genuine plumbylone3is rather labile even at −60 °C, its Pb0→Fe(CO)4complex4turned out to be relatively stable and bottleable. However, solutions of4decompose readily to elemental Pb and {[SiII(Xant)SiII]Fe(CO)3}5at 80 °C. Reaction of4with [Rh(CO)2Cl]2leads to the formation of the unusual dimeric [(OC)2RhPb(Cl)Fe(CO)4] complex6with trimetallic Rh−Pb−Fe bonds. The molecular and electronic structures of3and4were established by Density Functional Theory (DFT) calculations.