2-(4-N-methylpyridinium)-5-(dicyanomethanido)thiophene

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡啶及其衍生物
• 英文名称: 2-(4-N-methylpyridinium)-5-(dicyanomethanido)thiophene
• 英文别名: 2-[5-(1-Methylpyridin-4-ylidene)thiophen-2-ylidene]propanedinitrile；2-[5-(1-methylpyridin-4-ylidene)thiophen-2-ylidene]propanedinitrile
• 化学式: C₁₃H₉N₃S
• 分子量: 239.301
• InChiKey: UJQVPVYFFRVVFL-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  17
• 可旋转键数：
  0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.08
• 拓扑面积：
  76.1
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  4-溴吡啶 在 (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride 、 四(三苯基膦)钯 溴 、 sodium hydride 作用下， 以 乙醚 、 二氯甲烷 、 丙酮 为溶剂， 反应 19.33h， 生成 2-(4-N-methylpyridinium)-5-(dicyanomethanido)thiophene
  参考文献：
  名称：

  Facile, Regioselective Synthesis of Highly Solvatochromic Thiophene-Spaced N-Alkylpyridinium Dicyanomethanides for Second-Harmonic Generation

  摘要：

  The facile and clean synthesis of a navel class of highly solvatochromic chromophores 1 is reported. Compounds 1 are push-pull systems containing a negatively charged dicyanomethanide as a donor group and a positively charged N-alkylpyridinium as an acceptor group. The terminal polar functions are spaced by a thiophene-based moiety containing one or two heterocyclic rings and none, one, or two ethylene bridges. Chromophores 1 have been obtained through a general synthetic scheme involving, as the last step, the 100% regioselective alkylation of the precursor bidentate anions 2, where two competing nucleophilic sites, one neutral at the pyridic nitrogen and one anionic at the carbanionic carbon of the dicyanomethanide group, are present. The unprecedented highly regioselective attack of the alkylating agent onto the neutral pyridic nitrogen rather than the highly charged carbanionic carbon has been also confirmed in the case of the intermolecular competition. Multinuclear (C-13 and N-15) NMR spectroscopy has been used to investigate the structure and the extent of intramolecular charge transfer in 1, which are shown to exist in the ground state as highly charge-separated zwitterionic systems. Experimental results are discussed and compared with semiempirical (PM3) computations. The solvatochromic response of compounds 1, among the highest ever reported in the literature for similar systems, candidates this class of compounds as very attractive active components of nonlinear optical materials.

  DOI：

  10.1021/jo970059x

文献信息

• Twisted Thiophene-Based Chromophores with Enhanced Intramolecular Charge Transfer for Cooperative Amplification of Third-Order Optical Nonlinearity
  作者：Natasha B. Teran、Guang S. He、Alexander Baev、Yanrong Shi、Mark T. Swihart、Paras N. Prasad、Tobin J. Marks、John R. Reynolds

  DOI：10.1021/jacs.5b12457

  日期：2016.6.8

  electron-rich thiophene-containing donor-acceptor chromophores with condensed π-systems and sterically regulated inter-aryl twist angles. These structures couple two key mechanisms underlying optical nonlinearity, namely, (i) intramolecular charge transfer, greatly enhanced by increased electron density and reduced aromaticity at chromophore thiophene rings and (ii) a twisted chromophore geometry, producing a manifold

  利用多个光学非线性源之间的协同合作，我们报告了一系列具有稠合 π 系统和空间调节芳基间扭曲角的富电子含噻吩供体-受体发色团的设计、合成和非线性光学特性。这些结构耦合了光学非线性背后的两个关键机制，即（i）分子内电荷转移，通过增加电子密度和减少发色团噻吩环的芳香性而大大增强；（ii）扭曲的发色团几何形状，产生多种紧密排列的激发态基态和激发态之间的偶极矩变化几乎是未扭曲系统的两倍。光谱、电化学和非线性 Z 扫描测量，结合量子化学计算，阐明分子结构与非线性折射率增强机制之间的关系。实验和计算共同揭示了对溶剂极性有强烈反应的基态结构，导致显着的负溶剂致变色 (Δλ ≈ 10(2) nm) 和在固态和极性溶剂中占主导地位的两性离子/芳族结构。在凝聚的 π 系统中获得低于 2.0 eV 的基激发态能隙，扭曲系统与未扭曲系统的能隙较低。扭曲结构中第二超极化率的实部远大于虚部，最高扭曲角发色团给出|Re(γ)/Im(γ)|