以锡为中心的自由基和阳离子：稳定且游离。

Tin-centered radical and cation: stable and free.

作者信息

Sekiguchi Akira, Fukawa Tomohide, Lee Vladimir Ya, Nakamoto Masaaki

机构信息

Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.

出版信息

J Am Chem Soc. 2003 Aug 6;125(31):9250-1. doi: 10.1021/ja030156+.

DOI:10.1021/ja030156+

PMID:12889927

Abstract

The first stable stannyl radical (tBu2MeSi)3Sn* (1) has been synthesized by the reaction of tBu2MeSiNa with SnCl2-dioxane in diethyl ether. The X-ray crystal structure and electron paramagnetic resonance (EPR) data of this radical show that 1 has a planar geometry, being a pi-radical in both the solid and the liquid states. One-electron oxidation of 1 with Ph3C+.B(C6F5)4- in benzene quantitatively produced the corresponding cation (tBu2MeSi)3Sn+.B(C6F5)4- (2), representing the stable free stannylium ion that has been fully characterized by X-ray analysis and NMR data. Being free, 2 features a record downfield shifted resonance for stannylium ions: +2653 ppm.

摘要

首个稳定的锡自由基（tBu2MeSi）3Sn*（1）是通过tBu2MeSiNa与SnCl2 - 二氧六环在乙醚中反应合成的。该自由基的X射线晶体结构和电子顺磁共振（EPR）数据表明，1具有平面几何结构，在固态和液态时均为π自由基。在苯中用Ph3C+.B(C6F5)4-对1进行单电子氧化定量生成了相应的阳离子（tBu2MeSi）3Sn+.B(C6F5)4-（2），这是已通过X射线分析和NMR数据充分表征的稳定自由锡鎓离子。作为自由离子，2具有锡鎓离子记录中向低场位移的共振：+2653 ppm。