Departamento de Química Orgánica e Inorgánica, Universidad de Oviedo, Facultad de Química, 33006 Oviedo (Spain).
Angew Chem Int Ed Engl. 2015 Mar 27;54(14):4212-6. doi: 10.1002/anie.201411647. Epub 2015 Feb 5.
By means of a combined experimental and theoretical approach, the electronic features and chemical behavior of metalla-N-heterocyclic carbenes (MNHCs, N-heterocyclic carbenes containing a metal atom within the heterocyclic skeleton) have been established and compared with those of classical NHCs. MNHCs are strongly basic (proton affinity and pK(a) values around 290 kcal mol(-1) and 36, respectively) with a narrow singlet-triplet gap (around 23 kcal mol(-1)). MNHCs can be generated from the corresponding metalla-imidazolium salts and trapped by addition of transition-metal complexes affording the corresponding heterodimetallic dicarbene derivatives, which can serve as carbene transfer agents.
通过结合实验和理论方法，确定了金属-N-杂环卡宾（MNHCs，杂环骨架内含有金属原子的 N-杂环卡宾）的电子特性和化学行为，并将其与经典 NHCs 进行了比较。MNHCs 具有很强的碱性（质子亲和能和 pK(a) 值约为 290 kcal/mol 和 36，分别），并且单重态-三重态能隙较窄（约为 23 kcal/mol）。MNHCs 可以从相应的金属咪唑鎓盐中生成，并通过添加过渡金属配合物捕获，得到相应的杂二价卡宾衍生物，这些衍生物可以作为卡宾转移试剂。
