Vasu Anuji K, Khurana Raman, Mohanty Jyotirmayee, Kanvah Sriram
Department of Chemistry, Indian Institute of Technology Gandhinagar Palaj Gandhinagar 382 355 India
Radiation & Photochemistry Division, Bhabha Atomic Research Centre Mumbai 400085 India
RSC Adv. 2018 May 8;8(30):16738-16745. doi: 10.1039/c8ra03355b. eCollection 2018 May 3.
The interaction between red-emitting pyridinium derivative [4-((1,3)-4-(4-(dimethylamino)phenyl)buta-1,3-dien-1-yl)-1-methylpyridin-1-ium] (DABP) and cucurbit[7]uril was investigated using optical absorption, steady-state and time-resolved fluorescence and anisotropy measurements. The changes in the UV/Vis absorption, fluorescence spectral characteristics and lifetime, with a change in pH, reveal efficient binding of CB7 to the dye molecule. The cucurbit[7]uril encapsulated DABP brings ∼1.5 units upward p shift. The formation of supramolecular assemblies with 1 : 1 and 2 : 1 host-guest stoichiometries with CB7 at different pH conditions have been verified from H NMR, isothermal titration calorimetric studies and geometry optimization calculations. CB7-dye complexation and the ensuing morphological changes were revealed by SEM, AFM and optical microscopy images. This pH-responsive supramolecular assemblies of red-emitting DABP dye can find potential applications in biological imaging, optical pH-sensor and the construction of building blocks for the supramolecular architectures.
利用光吸收、稳态和时间分辨荧光以及各向异性测量，研究了发红光的吡啶鎓衍生物4-((1,3)-4-(4-(二甲基氨基)苯基)丁-1,3-二烯-1-基)-1-甲基吡啶-1-鎓与葫芦[7]脲之间的相互作用。紫外/可见吸收、荧光光谱特征和寿命随pH值的变化，揭示了CB7与染料分子的有效结合。葫芦[7]脲包封的DABP使p值向上移动约1.5个单位。通过核磁共振氢谱、等温滴定量热研究和几何优化计算，验证了在不同pH条件下与CB7形成1:1和2:1主客体化学计量比的超分子组装体。扫描电子显微镜、原子力显微镜和光学显微镜图像揭示了CB7-染料络合作用以及随之而来的形态变化。这种发红光的DABP染料的pH响应超分子组装体在生物成像、光学pH传感器以及超分子结构构建模块的构建方面具有潜在应用。
