Adet Nicolas, Specklin David, Gourlaouen Christophe, Damiens Thibault, Jacques Béatrice, Wehmschulte Rudolf J, Dagorne Samuel
Institut de Chimie de Strasbourg, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67000, Strasbourg, France.
Chemistry Program, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL, 32901-6975, USA.
Angew Chem Int Ed Engl. 2021 Jan 25;60(4):2084-2088. doi: 10.1002/anie.202012287. Epub 2020 Nov 24.
The employment of the hexyl-substituted anion [HexCB Cl ] allowed the synthesis of a Zn species, Zn[HexCB Cl ] , 3, in which the Zn cation is only weakly coordinated to two carborate counterions and that is soluble in low polarity organic solvents such as bromobenzene. DOSY NMR studies show the facile displacement of at least one of the counterions, and this near nakedness of the cation results in high catalytic activity in the hydrosilylation of 1-hexene and 1-methyl-1cyclohexene. Fluoride ion affinity (FIA) calculations reveal a solution Lewis acidity of 3 (FIA=262.1 kJ mol ) that is higher than that of the landmark Lewis acid B(C F ) (FIA=220.5 kJ mol ). This high Lewis acidity leads to a high activity in catalytic CO and Ph CO reduction by Et SiH and hydrogenation of 1,1-diphenylethylene using 1,4-cyclohexadiene as the hydrogen source. Compound 3 was characterized by multinuclear NMR spectroscopy, mass spectrometry, single crystal X-ray diffraction, and DFT studies.
使用己基取代的阴离子[HexCB Cl ]能够合成一种锌物种Zn[HexCB Cl ] （3），其中锌阳离子仅与两个碳酸根抗衡离子形成弱配位，并且可溶于低极性有机溶剂，如溴苯。扩散排序核磁共振（DOSY NMR）研究表明，至少有一个抗衡离子容易被取代，阳离子的这种近乎裸露状态导致其在1-己烯和1-甲基-1-环己烯的硅氢化反应中具有高催化活性。氟离子亲和能（FIA）计算显示，3的溶液路易斯酸度为262.1 kJ mol ，高于标志性路易斯酸B(C F ) （220.5 kJ mol ）。这种高路易斯酸度导致其在通过Et SiH催化还原CO和Ph CO以及使用1,4-环己二烯作为氢源氢化1,1-二苯乙烯的反应中具有高活性。化合物3通过多核核磁共振光谱、质谱、单晶X射线衍射和密度泛函理论（DFT）研究进行了表征。
