Steric and Electronic Parameters of a Bulky yet Flexible N‑Heterocyclic Carbene: 1,3-Bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene (IPent)

The free N-heterocyclic carbene IPent (1; IPent = 1,3-bis­(2,6-bis­(1-ethylpropyl)­phenyl)­imidazol-2-ylidene) was prepared from the corresponding imidazolium chloride salt (2). The steric and electronic parameters of 1 were determined by synthesis of the gold­(I) chloride complex [Au­(IPent)­Cl] (3) and the nickel–carbonyl complex [Ni­(IPent)­(CO)3] (4), respectively. 3 and 4 were fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction studies on single crystals.

游离态氮杂环卡宾（N-heterocyclic carbene）IPent（1；IPent = 1,3-双(2,6-双(1-乙基丙基)苯基)咪唑-2-亚基）由相应的氯化咪唑鎓盐（2）制备得到。分别通过合成氯化金(I)配合物[Au(IPent)Cl]（3）与羰基镍配合物[Ni(IPent)(CO)₃]（4），测定了化合物1的空间位阻与电子参数。通过核磁共振波谱法、元素分析以及单晶X射线衍射分析，对3和4完成了全面表征。