2-芳氧甲基苯并咪唑-1-乙酰肼的NMR谱的表征

利用酯3的肼解合成出了8个2-芳氧甲基苯并咪唑-1-乙酰肼(4). 其中4c、4d、4f和4g是新化合物. 利用元素分析、IR 和¹H NMR谱对目标化合物4进行了结构表征. 利用2D NMR谱(包括¹H-¹H COSY、HSQC、HMBC 和 NOESY) 对代表化合物4e进行了¹H 和¹³C NMR的归属及空间结构确定. 通过变温实验和溶剂实验(DMSO-d₆ 和CDCl₃)研究了化合物4e的互变异构. 实验结果表明,室温下,DMSO中,目标化合物4存在着酮式和亚胺醇式这两种异构体的互变,其中酮式占 88.2%~92.6%;而在CDCl₃中,仅以亚胺醇形式存在.     

One step synthesis of imidazole and benzimidazole acycloaromatic nucleoside analogs

A facile and rapid method for the synthesis of novel imidazole and benzimidazole aromatic acyclic nucleosides is described. Synchronous N-alkylation of imidazole or benzimidazole and potassium aryloxide with methylene iodide in the presence of triethylamine and a catalytic amount of tetrabutylammonium bromide (TBAB) in dry acetonitrile or acetone gave moderate yields of the acycloaromatic nucleoside analogs.     

Fluorene‐ and benzimidazole‐based blue light‐emitting copolymers: Synthesis,photophysical properties,and PLED applications

Blue light‐emitting materials are receiving considerable academic and industrial interest due to their potential applications in optoelectronic devices. In this study, blue light‐emitting copolymers based on 9,9′ ‐ dioctylfluorene and 2,2′‐(1,4‐phenylene)‐bis(benzimidazole) moieties were synthesized through palladium‐catalyzed Suzuki coupling reaction. While the copolymer consisting of unsubstituted benzimidazoles (PFBI0) is insoluble in common organic solvents, its counterpart with N‐octyl substituted benzimidazoles (PFBI8) enjoys good solubility in toluene, tetrahydrofuran, dichloromethane (DCM), and chloroform. The PFBI8 copolymer shows good thermal stability, whose glass transition temperature and onset decomposition temperature are 103 and 428 °C, respectively. Its solutions emit blue light efficiently, with the quantum yield up to 99% in chloroform. The electroluminescence (EL) device of PFBI8 with the configuration of indium‐tin oxide/poly(ethylenedioxythiophene):poly(styrene sulfonic acid)/PFBI8/1,3,5‐tris(1‐phenyl‐1H‐benzimidazole‐2‐yl)benzene/LiF/Al emits blue light with the maximum at 448 nm. Such unoptimized polymer light‐emitting diode (PLED) exhibits a maximum luminance of 1534 cd/m² with the current efficiency and power efficiency of 0.67 cd/A and 0.20 lm/W, respectively. The efficient blue emission and good EL performance make PFBI8 promising for optoelectronic applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

A concise synthesis of a highly substituted 6‐(1H‐benzimidazol‐1‐yl)‐5‐nitrosopyrimidin‐2‐amine: synthetic sequence and the molecular and supramolecular structures of one product and two intermediates

A concise and efficient synthesis of 6‐benzimidazolyl‐5‐nitrosopyrimidines has been developed using Schiff base‐type intermediates derived from N⁴‐(2‐aminophenyl)‐6‐methoxy‐5‐nitrosopyrimidine‐2,4‐diamine. 6‐Methoxy‐N⁴‐{2‐[(4‐methylbenzylidene)amino]phenyl}‐5‐nitrosopyrimidine‐2,4‐diamine, (I), and N⁴‐{2‐[(ethoxymethylidene)amino]phenyl}‐6‐methoxy‐5‐nitrosopyrimidine‐2,4‐diamine, (III), both crystallize from dimethyl sulfoxide solution as the 1:1 solvates C₁₉H₁₈N₆O₂·C₂H₆OS, (Ia), and C₁₄H₁₆N₆O₃·C₂H₆OS, (IIIa), respectively. The interatomic distances in these intermediates indicate significant electronic polarization within the substituted pyrimidine system. In each of (Ia) and (IIIa), intermolecular N—H…O hydrogen bonds generate centrosymmetric four‐molecule aggregates. Oxidative ring closure of intermediate (I), effected using ammonium hexanitratocerate(IV), produced 4‐methoxy‐6‐[2‐(4‐methylphenyl‐1H‐benzimidazol‐1‐yl]‐5‐nitrosopyrimidin‐2‐amine, C₁₉H₁₆N₆O₂, (II) [Cobo et al. (2018). Private communication (CCDC 1830889). CCDC, Cambridge, England], where the extent of electronic polarization is much less than in (Ia) and (IIIa). A combination of N—H…N and C—H…O hydrogen bonds links the molecules of (II) into complex sheets.     

A new one‐dimensional CdII coordination polymer with a two‐dimensional layered structure incorporating 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole and benzene‐1,2‐dicarboxylate ligands

The N‐heterocyclic ligand 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole (imb) has a rich variety of coordination modes and can lead to polymers with intriguing structures and interesting properties. In the coordination polymer catena‐poly[[cadmium(II)‐bis[μ‐benzene‐1,2‐dicarboxylato‐κ⁴O¹,O^1′:O²,O^2′]‐cadmium(II)‐bis{μ‐2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole}‐κ²N²:N³;κ²N³:N²] dimethylformamide disolvate], {[Cd(C₈H₄O₄)(C₁₁H₁₀N₄)]·C₃H₇NO}_n, (I), each Cd^II ion exhibits an irregular octahedral CdO₄N₂ coordination geometry and is coordinated by four O atoms from two symmetry‐related benzene‐1,2‐dicarboxylate (1,2‐bdic²⁻) ligands and two N atoms from two symmetry‐related imb ligands. Two Cd^II ions are connected by two benzene‐1,2‐dicarboxylate ligands to generate a binuclear [Cd₂(1,2‐bdic)₂] unit. The binuclear units are further connected into a one‐dimensional chain by pairs of bridging imb ligands. These one‐dimensional chains are further connected through N—H…O hydrogen bonds and π–π interactions, leading to a two‐dimensional layered structure. The dimethylformamide solvent molecules are organized in dimeric pairs via weak interactions. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.     

Acid‐Base Switchable [2]‐ and [3]Rotaxane Molecular Shuttles with Benzimidazolium and Bis(pyridinium) Recognition Sites

For the purpose of developing higher level mechanically interlocked molecules (MIMs), such as molecular switches and machines, a new rotaxane system was designed in which both the 1,2‐bis(pyridinium)ethane and benzimidazolium recognition templating motifs were combined. These two very different recognition sites were successfully incorporated into [2]rotaxane and [3]rotaxane molecular shuttles which were fully characterized by ¹H NMR, 2D EXSY, single‐crystal X‐ray diffraction and VT NMR analysis. By utilizing benzimidazolium as both a recognition site and stoppering group it was possible to create not only an acid/base switchable [2]rotaxane molecular shuttle (energy barrier 20.9 kcal?mol^?1) but also a [3]rotaxane molecular shuttle that displays unique dynamic behavior involving the simultaneous motion of two macrocyclic wheels on a single dumbbell. This study provides new insights into the design of switchable molecular shuttles. Due to the unique properties of benzimidazoles, such as fluorescence and metal coordination, this new type of molecular shuttle may find further applications in developing functional molecular machines and materials.     

超分子化合物[2-(4-pyridyl)benzimidazoleH2].[SnCl6]的水热合成及晶体结构

通过水热法合成了一个新的超分子化合物[PyBImH2]?[SnCl6] (PyBIm=2-(4-吡啶基)苯并咪唑), 并用元素分析、红外光谱、荧光光谱及X射线单晶衍射对其进行了分析测试。化合物属于正交晶系,Pbcn空间群,晶胞参数：a = 7.1468(3),b = 15.0493(6),c = 16.1195(8) ?,V = 1733.72(13) ?₃,Z = 4,Dc = 2.025 g/cm₃,Mr = 528.63,μ(MoKα) = 2.395 mm_-1,F(000) = 1024,R₁= 0.0264,wR₂ = 0.0665。Sn₄₊与6个氯离子配位,形成八面体的配位几何。配位阴离子[SnCl₆]_2-与[2-(4-吡啶基)苯并咪唑阳离子通过氢键及π-π 堆积作用形成三维超分子结构。     

苯并咪唑及其衍生物合成与应用研究进展

苯并咪唑及其衍生物具有良好的生物活性, 而且是一种重要的药物中间体. 由于它们具有良好的生物活性和反应活性, 一直都是研究的热点. 从该类化合物的合成与应用两个方面综述了近年来该领域的重要研究成果.     

甲基酮香料的仿生合成新方法研究

四氢叶酸辅酶在生物体内的作用是转移不同氧化态的一碳单元, 当一碳单元处于甲酸氧化态时, 活性部位是具有五元环状结构的咪唑啉环. 模拟四氢叶酸辅酶转移一碳单元的反应, 以苯并咪唑甲基碘盐作为四氢叶酸辅酶甲酸氧化态模型, 以格利雅试剂甲基碘化镁作为接收一碳单元的亲核试剂, 将甲酸氧化态的一碳单元转移给甲基碘化镁, 成功合成了三种重要的甲基酮香料甲基己基酮、甲基壬基酮和甲基十一烷基酮, 其结构用元素分析, 1H NMR, IR和MS等方法进行了表征, 并对反应机理和反应条件进行了讨论, 为甲基酮香料提供了一种仿生合成新方法.     

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-（2-Pyridyl）benzimidazoleH2]2＋ ·[SbCls]2-}2

A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.