title: An extensive n, π, σ-electron delocalized Si(4) ring.
abstract: The tetrasilacyclobutadiene [LSi(μ-SiL')2 SiL] (L=PhC(NtBu)2 , L'=2,6-iPr2 C6 H3 NSiMe3 ) consists of an aromatic silicon-containing four-membered ring in which two π, two σ, and two lone-pair electrons are cyclically delocalized. The electron delocalization was illustrated by theoretical studies and reactivity with elemental sulfur to form the allylic zwitterionic cyclic compound [(LSi)2 (μ-SiL')(μ-Si(S)L')] with 2π-electron delocalization along the Si3 skeleton.
authors.affiliation: Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore).
authors.forename: Shu-Hua
authors.initials: SH
authors.lastname: Zhang
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Xi
authors.forename: Kok Hwa
authors.initials: KH
authors.lastname: Lim
authors.forename: Cheuk-Wai
authors.initials: CW
authors.lastname: So
keywords: N ligands; aromatic systems; cyclobutadiene; silicon; sulfur