Abstract The study was designed to synthesize bromide-bridged mercury(II) symmetric and non-symmetric N-heterocyclic carbene complexes. The preparation of benzimidazolium salts (4–6) was accomplished by symmetrical and non-symmetrical substitution on benzimidazole. The salts were subjected to an in-situ process for metallation to get [Hg(II)-NHC] complexes [(HgBr-NHC)(µ2Br)2] (7–9) by reacting benzimidazolium salts (4–6) with mercury(II) acetate at room temperature. Compounds were characterized by elemental analyses, FT-IR and NMR spectroscopy. Single crystals of 7 and 8 were analyzed by X-ray crystallographic technique which showed tetrahedral dinuclear complexes with two bridging bromides. An attempt to explore the feasibility of redox transmetallation approach (RTM) for synthesis of ytterbium complexes was also carried out by reacting 7–9 with ytterbium powder under inert atmosphere. The products were metallic mercury, benzimidazolium salts, and ytterbium bromide instead of ytterbium complexes. Graphical Abstract

中文翻译：

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溴化物桥连汞 (II) N-杂环卡宾配合物的原位合成方法

摘要 本研究旨在合成溴桥汞(II) 对称和非对称N-杂环卡宾配合物。苯并咪唑鎓盐（4-6）的制备是通过苯并咪唑上的对称和非对称取代来完成的。通过使苯并咪唑鎓盐 (4-6) 与汞反应，对盐进行原位金属化过程以得到 [Hg(II)-NHC] 配合物 [(HgBr-NHC)(µ2Br)2] (7-9) (II) 室温下的醋酸盐。通过元素分析、FT-IR和NMR光谱表征化合物。7 和 8 的单晶通过 X 射线晶体学技术分析，显示出具有两个桥接溴化物的四面体双核配合物。还通过在惰性气氛下使 7-9 与镱粉反应来探索氧化还原金属转移法 (RTM) 合成镱配合物的可行性。产品是金属汞、苯并咪唑鎓盐和溴化镱而不是镱配合物。图形概要