Bis(benzimidazolium)methane salts: a potential guest for dibenzo-24-crown-8 towards [2]pseudorotaxanes

We investigated the threading of bis(benzimidazolium) methane moieties with DB24C8 at 35 °C (room temperature) and found a high degree of association. The presence of threaded complexes was determined by ¹H NMR and also supported by high resolution mass spectrometry and B3LYP/6-31G**++calculations. A 2D NMR study was done to elucidate the host-guest geometry and the molecular interactions present. The variable temperature NMR experiment was done over a temperature range of 243-323 K. The threading was stable and visible even at 323 K. Acid-base equilibrium established the reversibility of the process. DFT optimized structures establish that two H-bonded links are present between O₁?O_4′ and O₃?O_2′ across the dibenzo axis of the crown.     

选择性氧化剂-苯并咪唑重铬酸复合物的合成与表征

首次用两种方法合成了苯并咪唑重铬酸复合物(BIDC)。用元素分析、分光光度法、红外光谱、核磁谱和热分析等方法研究了该复合物的组成和性质。     

Synthesis of Cyclohexyl and Isopropyl Ketones from Benzimidazole Methiodide Salt and Grignard Reagents

The reaction of 2-alkyl-l, 3-dimethylbenzimidazolinm salts with Grignard reagents gave addition products which were hy-drelyzed to give ketones. A new method for the preparation of cyclohexyl ketones and isopropyl ketones is provided.     

Benzimidazolium-Decorated Metalloporphyrin Molecule and Polymer: a Reliable Preparation Method and Application in Catalyzing the Cycloaddition Reaction of CO2 and Epoxides

Due to the synergistic effect of central metal and halide anion, cationic metalloporphyrins and derivatives exhibit outstanding catalytic activities for the cycloaddition reaction of epoxides and carbon dioxide. Herein, a generic strategy was developed to synthesize the benzimidazolium-containing metalloporphyrin molecule and polymer. To demonstrate the method feasibility, we firstly synthesized the molecule 1_H , in which the benzimidazole groups were in-site constructed by the cyclization of 5,10,15,20-(4-carboxyphenyl)-porphyrin ( H₂TCPP ) with o-diaminobenzene ( PEA ). After post-synthetic ionization and metallization, I⁻ and Zn²⁺ were introduced as the nucleophile and Lewis acid, respectively. The structure of 1_ZnIL was confirmed by single crystal X-ray diffraction analysis. By using the similar conditions of model reaction, H₂TCPP was copolymerized with 1,2,4,5-tetraaminobenzene ( BTA ) to prepare the polymer P-1_ZnIL . The prepared cationic molecule 1_ZnIL and polymer P-1_ZnIL showed comparable activities in catalyzing the cycloaddition of carbon dioxide with epoxides to cyclic carbonates compared to the reported bifunctional catalysts based on metalloporphyrins.     

Synthesis of the β‐keto acids from benzimidazolium iodides and ethyl malonate

The reaction of benzimidazole methiodide with ethyl malonate in the existence of base was studied, and a new convenient synthetic method of the β‐keto acid was provided.     

基于蒽-苯并咪唑鎓的荧光传感器对H2PO4-的高选择性识别

设计合成了基于蒽-苯并咪唑鎓的受体分子1和2,通过荧光发射光谱研究了受体分子1和2对F^-、Cl^-、Br^-、I^-、AcO^-、HSO₄^-、H₂PO₄^-、NO₃^-、ClO₄^-等阴离子的识别性能。 研究发现,在受体分子1和2的乙腈溶液(5.0×10^-6 mol/L)中加入10倍化学计量的H₂PO₄^-时,受体分子1的荧光猝灭百分数为13%,受体分子2的荧光猝灭百分数高达94%,表明受体分子2在构型上与H₂PO₄^-更匹配,可作为H₂PO₄^-的荧光关闭型(turn-off)探针。 受体分子2与H₂PO₄^-的结合比为1:1,结合常数为(3.70±0.16)×10⁴ L/mol,检出限为3.77×10^-6 mol/L。