Synthesis of Well-Defined <i>N</i>-Heterocyclic Carbene Silver(I) Complexes

A series of N-heterocyclic carbene (NHC)AgCl complexes [NHC = SIMes (1), IPr (2), SIPr (3), IPrMe (4), IMe (5), ICy (6), IAd (7), IsB (8), IDD (9), and TPh (10)] have been synthesized through reaction of the imidazolium chloride salts with Ag2O or by direct metalation of the corresponding imidazol-2-ylidene carbene in the presence of AgCl. All silver(I) complexes [(SIMes)AgCl] (11), [(IPr)AgCl] (12), [(SIPr)AgCl] (13), [(IPrMe)AgCl] (14), [(IMe)AgCl] (15), [(ICy)AgCl] (16), [(IAd)AgCl] (17), [(IsB)AgCl] (18), [(IDD)AgCl] (19), and [(TPh)AgCl] (20) have been spectroscopically and structurally characterized. The structure of these silver complexes is dependent on the halide and the solvent used for the synthesis. Adjusting these parameters has led to the previously reported complex, [(IMes)2Ag]+[AgCl2]- (21), and to a new silver complex, [(IMes)2Ag]+2[Ag4I6]2- (22).一系列氮杂环卡宾（N-heterocyclic carbene, NHC）氯化银(I)配合物[NHC = SIMes (1)、IPr (2)、SIPr (3)、IPrMe (4)、IMe (5)、ICy (6)、IAd (7)、IsB (8)、IDD (9)及TPh (10)]，可通过氯化咪唑鎓盐与氧化银(I)（Ag₂O）反应，或在氯化银(AgCl)存在下对相应的咪唑-2-亚基卡宾进行直接金属化反应合成。所有银(I)配合物[(SIMes)AgCl] (11)、[(IPr)AgCl] (12)、[(SIPr)AgCl] (13)、[(IPrMe)AgCl] (14)、[(IMe)AgCl] (15)、[(ICy)AgCl] (16)、[(IAd)AgCl] (17)、[(IsB)AgCl] (18)、[(IDD)AgCl] (19)及[(TPh)AgCl] (20)，均已通过光谱学与结构学手段完成表征。此类银(I)配合物的结构取决于合成过程中所使用的卤化物与溶剂。通过调控上述参数，我们得到了已有文献报道的配合物[(IMes)₂Ag]⁺[AgCl₂]⁻ (21)，以及一种新型银配合物[(IMes)₂Ag]₂²⁺[Ag₄I₆]²⁻ (22)。