Highly directional co-assembly of 2,6-pyridinedicarboxylic acid and 4-hydroxypyridine based on low molecular weight gelators

The highly directional interactions among complex gelators of 2,6-pyridinedicarboxylic acid and 4-hydroxypyridine are investigated, which lead to the formation of ordered one-dimensional fibers with diameters of 500   nm   ~   2   μm. By scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, and X-ray powder diffraction (XRD), the co-assembly of the complex into straight fibers under the function of multiple directional hydrogen bonds and π–π stackings is proved. The strong and directional interactions lead to rich dynamic behavior and high degrees of internal order among the complex gelators. The ordered one-dimensional co-assemblies possess useful functions in templated synthesis, molecular recognition , enzyme immobilization, and other biochemistry fields.