A Stable Cyclic (R2SnAu)3 Anion Having In‐Plane σ‐Möbius Aromaticity. Issue 5 (17th December 2019)

• Record Type: Journal Article
• Authors: Wang, Liliang; Xu, Jian; Kira, Mitsuo; Yan, Liping; Xiao, Xu‐Qiong; Li, Zhifang
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 5(2020)
• Page Start: 1980
• Page End: 1984
• Publication Date: 2019-12-17
• Subjects: gold complexes -- low-valent compounds -- stannylenes -- σ-Hückel aromaticity -- σ-Möbius aromaticity; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201910731
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A cyclic (R2 SnAu)3 anion (3 −, R2 Sn=2, 2, 5, 5‐tetrakis(trimethylsilyl)‐1‐stannacyclopentane‐1, 1‐diyl) has been synthesized as a stable blue salt with K + (THF)6 through the reaction of stable dialkylstannylene 1 with R′3 PAuCl (R′=Et, Ph) followed by the reduction with KC8 . Crystallographic and NMR analysis shows that the six‐membered (SnAu)3 ring of 3 − is planar and highly symmetric with an equal distance of six Au−Sn bonds. A UV/Vis spectrum of 3 − in hexane reveals an intense absorption maximum at 598 nm. While cyclic Au3 − with four valence electrons is known as unstable anti‐aromatic anion, 3 − with three divalent tin ligands is stable σ aromatic anion with an unprecedented Möbius orbital array as predicted by the perturbation MO and CCSD analysis of 3 − . Abstract : A cyclic (R2 SnAu)3 anion has been synthesized as a stable blue salt with K + (THF)6 by reaction of a dialkylstannylene with R′3 PAuCl (R′=Et, Ph) and reduction with KC8 . The six‐membered (SnAu)3 ring is planar and highly symmetric. Whereas cyclic Au3 − with four valence electrons is an unstable anti‐aromatic anion, the (R2 SnAu)3 anion with three divalent tin ligands is a stable σ aromatic anion with an unprecedented Möbius orbital array.