Institute of Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Dalton Trans. 2023 Jul 18;52(28):9553-9561. doi: 10.1039/d3dt01249b.
The anionic 1-methyl-3-(tris(pentafluoroethyl)difluorophosphorane)imidazoline-2-ylidenate 3 and the 1,3-bis(tris(pentafluoroethyl)difluorophosphorane)imidazoline-2-ylidenate dianion 4 were obtained in high yield by deprotonation of {(CF)PF}-methylimidazole 1 and the {(CF)PF}-imidazolate anion 2. Carbenes 3 and 4 are first examples for a novel class of NHCs carrying weakly coordinating anions (WCA-NHCs). First reactions of these new ligands with elemental selenium and chloro(phosphine)gold(I) complexes to result in an anionic selenium adduct (5) and WCA-NHC gold complexes (6 and 7) have been undertaken. The structural and spectroscopic properties of these NHC derivatives in conjunction with data from quantum chemical calculations provide an insight into the electronic and steric properties of the WCA-NHCs 3 and 4. Especially the combination of properties such as weakly coordinating periphery combined with the coordinative carbene center, negative charge, large buried volume (%), and strong σ-donor as well as efficient π-acceptor ability render NHCs 3 and 4 unique and promising new ligands.
阴离子 1-甲基-3-（三（五氟乙基）二氟膦基）咪唑啉-2-亚基 3 和 1,3-双（三（五氟乙基）二氟膦基）咪唑啉-2-亚基二阴离子 4 通过 {(CF)PF}-甲基咪唑 1 和 {(CF)PF}-咪唑盐阴离子 2 的去质子化得到高产率。卡宾 3 和 4 是首例新型 NHC 类带有弱配位阴离子（WCA-NHC）的化合物。这些新配体与元素硒和氯（膦）金（I）配合物的首次反应导致形成阴离子硒加合物（5）和 WCA-NHC 金配合物（6 和 7）。这些 NHC 衍生物的结构和光谱性质以及量子化学计算的数据提供了对 WCA-NHCs 3 和 4 的电子和空间性质的深入了解。特别是具有弱配位外围与配位卡宾中心、负电荷、大埋置体积（%）、强σ-供体以及高效π-受体相结合的特性使 NHCs 3 和 4 成为独特且有前途的新型配体。
