Ott Lisa Starkey, Cline Morgan L, Deetlefs Maggel, Seddon Kenneth R, Finke Richard G
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
J Am Chem Soc. 2005 Apr 27;127(16):5758-9. doi: 10.1021/ja0423320.
The mystery of how 1,3-substituted imidazolium-based ionic liquids (ILs) can provide high stabilization for transition-metal(0) nanoclusters, that is, in the absence of the usual strongly coordinating anions, has been probed. 2H NMR product and kinetic studies of 1,3-substituted imidazolium ILs under D2 reveal that nanocluster-catalyzed H/D exchange occurs at the 2- (as well as at the 4-, 5-, and 8-) C-H positions of the imidazolium cation. The results (i) provide compelling evidence that N-heterocyclic carbene formation and ligation of nanoclusters is occurring in ILs; and (ii) argue that N-heterocyclic carbenes merit further investigation as heretofore unappreciated stabilizers of transition-metal nanoclusters.
1,3-二取代咪唑基离子液体（ILs）如何在不存在通常的强配位阴离子的情况下为过渡金属（0）纳米团簇提供高度稳定性这一谜团已被探究。在D2条件下对1,3-二取代咪唑基离子液体进行的2H NMR产物和动力学研究表明，纳米团簇催化的H/D交换发生在咪唑阳离子的2-（以及4-、5-和8-）C-H位置。结果（i）提供了令人信服的证据，表明在离子液体中发生了N-杂环卡宾的形成以及纳米团簇的配位；（ii）表明N-杂环卡宾作为过渡金属纳米团簇迄今未被重视的稳定剂值得进一步研究。
