Ebner Fabian, Wadepohl Hubert, Greb Lutz
Anorganisch-Chemisches Institut , Ruprecht-Karls-Universität Heidelberg , Im Neuenheimer Feld 275 , 69120 Heidelberg , Germany.
J Am Chem Soc. 2019 Nov 13;141(45):18009-18012. doi: 10.1021/jacs.9b10628. Epub 2019 Nov 4.
Tetracoordinate aluminum(III) anions are generally tetrahedral and non-Lewis acidic. Herein, we describe the first planar tetracoordinate aluminum anion. The anion is isolated in its free form, representing a new "anti-van't Hoff/Le Bel" case. Despite its negative charge, it remains Lewis acidic and permits the formation of various unique adducts, e.g., a dianionic p-block metal hydride. Turning an inert spectator anion into a Lewis acid by planarization verifies theoretical predictions made 40 years ago, ultimately connects "anti-van't Hoff/Le Bel" structure with reactivity, and pushes further the field of geometrically enhanced p-block element reactivity.
四配位铝（III）阴离子通常呈四面体结构且无路易斯酸性。在此，我们描述了首例平面四配位铝阴离子。该阴离子以游离形式被分离出来，代表了一种新的“反范特霍夫/勒贝尔”情况。尽管它带有负电荷，但仍具有路易斯酸性，并能形成各种独特的加合物，例如双阴离子p区金属氢化物。通过平面化将惰性旁观阴离子转变为路易斯酸，验证了40年前所做的理论预测，最终将“反范特霍夫/勒贝尔”结构与反应活性联系起来，并进一步推动了几何增强p区元素反应活性领域的发展。
