Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
Angew Chem Int Ed Engl. 2014 Aug 18;53(34):9082-5. doi: 10.1002/anie.201403888. Epub 2014 May 23.
The complexation of two equivalents of a cyclic (alkyl)(amino)carbene (CAAC) to tetrabromodiborane, followed by reduction with four equivalents of sodium naphthalide, led to the formation of the CAAC-stabilized linear diboracumulene (CAAC)2B2. The capacity of the CAAC ligand to facilitate B2 →CAAC donation of π-electron density resulted in important differences between this species and a previously reported complex featuring a B≡B triple bond stabilized by cyclic di(amino)carbenes, including a longer B-B bond and shorter B-C bonds. Frontier orbital analysis indicated sharing of valence electrons across the entire linear C-B-B-C unit in (CAAC)2B2, which is supported by natural population analysis and cyclic voltammetry.
两个当量的环状（烷基）（氨基）卡宾（CAAC）与四溴二硼烷络合，然后用四当量的萘钠还原，得到 CAAC 稳定的线性二硼烯（CAAC）2B2。CAAC 配体促进 B2→CAAC 提供π 电子密度的能力导致该物种与之前报道的由环状二（氨基）卡宾稳定的 B≡B 三键的配合物之间存在重要差异，包括更长的 B-B 键和更短的 B-C 键。前沿轨道分析表明，在（CAAC）2B2 的整个线性 C-B-B-C 单元中共享价电子，这得到自然键轨道分析和循环伏安法的支持。
