Zheng Xiongfei, Zulkifly Ili, Heilmann Andreas, McManus Caitilín, Aldridge Simon
Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK.
Angew Chem Int Ed Engl. 2021 Jul 19;60(30):16416-16419. doi: 10.1002/anie.202106413. Epub 2021 Jun 22.
We report two BNB-type frustrated Lewis pairs which feature an acceptor-donor-acceptor functionalized cavity, and which differ in the nature of the B-bound fluoroaryl group (C F vs. C H (CF ) -3,5, Ar ). These receptor systems are capable of capturing gaseous CO, and in the case of the -BAr system this can be shown to occur in reversible fashion at/above room temperature. For both systems, the binding event is accompanied by migration of one of the aryl substituents to the electrophilic carbon of the CO guest. Experiments utilizing an additional equivalent of P Bu allow the initially formed (non-migrated) CO adduct to be identified and trapped (via demethylation), while also establishing the reversibility of the B-to-C migration process. When partnered with the slightly less Lewis acidic -BAr substituent, this reversibility allows for release of the captured carbon monoxide in the temperature range 40-70 °C, and the possibility for CO sensing, making use of the associated colourless to orange/red colour change.
我们报道了两种具有受体 - 给体 - 受体官能化空腔的BNB型受阻路易斯对，它们在与硼相连的氟芳基的性质上有所不同（CF 与C H (CF ) -3,5, Ar ）。这些受体系统能够捕获气态CO，并且对于 -BAr 系统而言，在室温及以上温度下，这种捕获能够以可逆方式发生。对于这两种系统，结合事件都伴随着芳基取代基之一迁移至CO客体的亲电碳上。利用额外当量的P Bu 进行的实验使得最初形成的（未迁移的）CO加合物能够被识别并捕获（通过去甲基化），同时也证实了硼到碳迁移过程的可逆性。当与路易斯酸性稍弱的 -BAr 取代基结合时，这种可逆性使得在40 - 70 °C的温度范围内能够释放捕获的一氧化碳，并且利用相关的无色至橙色/红色的颜色变化实现CO传感成为可能。
