The Preparation Of Supramolecular Gel Of The Benzimidazole Derivatives And Study Of Its Luminescent Properties

Supramolecular gels, as one kind of soft materials, have attracted considerable attention in recent years because of its unique structures and wide applications in Materials science, liquid-crystalline materials, smart material, nanoscale inorganic materials, drug delivery, enzyme immobilizations, biosensors, and luminescent materials. A series of novel hydrazide/ acylhydrazone-functionalized benzimidazole derivative (gelators) are synthesized in this work. The gelation process and luminescent capability of these gels was studied. In addition, the luminous performance of these gels was optimized by implanting metal ions into them.This dissertation consists of five chapters:1. A brief review of supramolecular gels and the subject of this thesis.2. A dual-responsive supramolecular hydrogel (Gl-gel) was prepared with a simple hydrazide-functionalized benzimidazole ligand (Gl). The green luminescence of Tb@Gl-gel is enhanced due to the coordination effect between Gl and Tb3+. In addition, Tb@Gl-gel shows different luminescence in the semisolid state (gel) and in the solid state (xerogel). Remarkable reversible sol-gel transitions induced by temperature or pH were observed for these gels. The research content of this chapter will have some instruction meaning for the preparation of supramolecular gels with multiple response performance.3. A simple dual luminescent acylhydrazone-functionalized benzimidazole derivative (G2) blended with ethylene glycol affording a thermal-responsive green-light-emitting supramolecular gel (G2-gel). This G2-gel can convert to a blue-light-emitting metal-gel (Cd@G2-gel) via strongly increasing the luminescence of benzimidazole moiety upon addition of one equivalent Cd2+. The results may give some information for the design of luminous gels.4. A two-stage-assembly functional gelator containing shiff-base and benzimidazole moieties has been synthesized, and it shows excellent thermal-responsive gelation behavior in DMSO-ethylene glycol mixtures. This G3-gel can emit blue light under ultraviolet by naked eyes based on the AIE theory. After Cd2+ was implanted into G3-gel above, this gelator and Cd2+ can assembling a Cd@G3-gel, which can emits brilliant blue light due to the strongly AIEE effect depend on the multiple hydrogen-bonding and coordination effect between G3 and Cd2+.5. According to the key techniques for design of gelators above, we have developed a new gelator (G4), in which two benzimidazole derivatives was linked by one flexible alkyl chain. G4 was blended with mixed solvent of DMSO/glycol can affording a thermal-responsive blue-light-emitting supramolecular gel (G4-gel). We have achieved the collapsed gel after Y3+ was implanted into G4-gel above. However, the complex of G4-Y3+ has gelation behavior in mixed solvent of DMF/water. The complex of G4-Y3+ is noncrystalline material by X-ray powder diffraction analysis.