Wills Siobhan S, Bailly Corinne, Chetcuti Michael J
School of Chemistry, University of New South Wales (UNSW), Sydney, NSW 2052, Australia.
Fédération de Chimie Le Bel UAR2042, BP20296, 1 rue Blaise Pascal, 67008 Strasbourg, France.
Molecules. 2024 Sep 21;29(18):4493. doi: 10.3390/molecules29184493.
While hundreds of complexes of the general formula [Ni(η-CH)(NHC)(X)] exist (NHC = a N-heterocyclic carbene, X = Cl, Br, I), none is yet known with X = F. We attempted to prepare such a species by reacting nickelocene with imidazolium fluorides. Three imidazolium fluorides (ImH) F [Im = (,'-(R)-imidazolium: , IMe, R = Me; , IMes, R = 2,4,6-trimethylphenyl; , IPr, R = 2,6-diisopropylphenyl)] were prepared and characterized by spectroscopic methods. In addition, the salts [(IMesH) F] and [(IPrH) F] were subjected single-crystal X-ray diffraction experiments. The reactions of these imidazolium fluorides with nickelocene did not lead to [Ni(η-CH)(NHC)(F)] species. Instead, the reaction of [(IMeH) F] and [(IMesH) F] with nickelocene led to the salt [Ni(η-CH)(IMe)] F and to the square planar complex [NiF(IMes)] respectively. Both complexes were characterized spectroscopically and by single crystal X-ray diffraction. All four X-ray diffraction studies reveal hydrogen bonding and hydrogen interactions with the F atom or anion, and in some cases with solvent molecules of crystallization, and these phenomena are all discussed. Complex , in particular, exhibited a wide range of interesting H-bonded interactions in the solid state. Complexes and were tested as catalysts for Suzuki-Miyaura coupling but were not promising: complex was inactive, and while did indeed catalyze the reaction, it gave widely diverging results owing to its instability in solution.
虽然存在数百种通式为[Ni(η-CH)(NHC)(X)]的配合物（NHC = N-杂环卡宾，X = Cl、Br、I），但尚未发现X = F的此类配合物。我们尝试通过二茂镍与咪唑鎓氟化物反应来制备这样的物种。制备了三种咪唑鎓氟化物(ImH)F [Im = (,'-(R)-咪唑鎓：, IMe, R = 甲基；, IMes, R = 2,4,6-三甲基苯基；, IPr, R = 2,6-二异丙基苯基)]，并通过光谱方法对其进行了表征。此外，对盐[(IMesH)F]和[(IPrH)F]进行了单晶X射线衍射实验。这些咪唑鎓氟化物与二茂镍的反应并未生成[Ni(η-CH)(NHC)(F)]物种。相反，[(IMeH)F]和[(IMesH)F]与二茂镍的反应分别生成了盐[Ni(η-CH)(IMe)]F和平面正方形配合物[NiF(IMes)]。通过光谱和单晶X射线衍射对这两种配合物进行了表征。所有四项X射线衍射研究均揭示了与F原子或阴离子以及在某些情况下与结晶溶剂分子的氢键和氢相互作用，并对这些现象进行了讨论。特别是配合物，在固态中表现出广泛的有趣氢键相互作用。对配合物和作为铃木-宫浦偶联反应的催化剂进行了测试，但结果并不理想：配合物无活性，而虽然确实催化了该反应，但由于其在溶液中的不稳定性，结果差异很大。
