He Tianyi, Bruening Meaghan A, Espinosa Matthew, Agapie Theodor
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Angew Chem Int Ed Engl. 2025 Jan 21;64(4):e202417136. doi: 10.1002/anie.202417136. Epub 2024 Nov 25.
Weakly-coordinating anions (WCAs) are employed in a wide range of applications, but limitations remain, including high reactivity, limited redox window, complicated synthesis, high cost, low solublity, and low structural tunabililty. Herein, we report a new class of WCA based on alkyl or aryl (R) substituted silicates bearing fluorinated pinacolate ligands, "[Si ]". Anions bearing a variety of R groups were prepared, enabling facile tuning of sterics and solubility. A range of cations employed in chemical reactivity has been supported by these anions, including ether-free alkali cations, Ag, PhC, Fc, [Ni(COD)]. [Pd(dppe)(NCMe)Me] has been generated by salt metathesis or protonation of a metal-alkyl bond, showcasing the ability of the [Si ] anions to support applications in coordination chemistry and catalysis. Electrochemical studies on the [BuN] variant show an exceptionally wide stability window for the [Si ] anion of 7.5 V in MeCN. CV experiments demonstrate reversible Mg deposition and stripping.
弱配位阴离子（WCAs）被广泛应用于众多领域，但仍存在一些局限性，包括高反应活性、有限的氧化还原窗口、合成复杂、成本高、溶解度低以及结构可调节性低等问题。在此，我们报道了一类基于带有氟化频哪醇配体的烷基或芳基（R）取代硅酸盐的新型WCA，即“[Si ]”。制备了带有各种R基团的阴离子，可以轻松调节空间位阻和溶解度。这些阴离子支持了一系列用于化学反应的阳离子，包括无醚碱金属阳离子、Ag、PhC、Fc、[Ni(COD)]。通过盐复分解反应或金属烷基键的质子化生成了[Pd(dppe)(NCMe)Me]，展示了[Si ]阴离子在配位化学和催化领域的应用能力。对[BuN]变体的电化学研究表明，在乙腈中，[Si ]阴离子具有7.5 V的异常宽的稳定性窗口。循环伏安实验证明了镁的可逆沉积和剥离。
