title: A two-and-a-half-layer sandwich: potassium salt of anionic (η(4)-tetrasilacyclobutadiene)(η(5)-cyclopentadienyl)ruthenium.
abstract: An anionic ruthenium sandwich complex featuring the tetrasilacyclobutadiene ligand, [η(4)-tetrakis(di-tert-butylmethylsilyl)tetrasilacyclobutadiene](η(5)-pentamethylcyclopentadienyl)ruthenium was synthesized and isolated as its potassium salt [(η(4)-R(4)Si(4))RuCp*](-)·[K(+)(thf)(2)] (R = SiMet-Bu(2), Cp* = η(5)-Me(5)C(5)), 1(-)·[K(+)(thf)(2)], by the reaction of the tetrasilacyclobutadiene dianion dipotassium salt [R(4)Si(4)](2-)·[K(+)(thf)(2)](2) with 0.25 equiv. of [Cp*RuCl](4) in THF. In its crystalline form, 1(-)·[K(+)(thf)(2)] features a nearly square-planar tetrasilacyclobutadiene ligand.
authors.affiliation: Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Vladimir Ya
authors.initials: VY
authors.lastname: Lee
authors.forename: Kazunori
authors.initials: K
authors.lastname: Takanashi
authors.forename: Akira
authors.initials: A
authors.lastname: Sekiguchi