Fluorescent Conjugated Molecules Based On Pyrene And Boron-Nitride Fused Aromatic Ring Motifs:Design,Synthesis And Applications

The fluorescent conjugated molecules widely used in optoelectronic devices and biosensors,due to their excellent optical and electronical properties.Designing and fine-tuning the structures of fluorescent conjugated molecules at the molecular level is critical to improve their photophysical properties,electrochemical properties and crystal structure of materials,which provides scientific and theoretical basis for the development of new materials.This thesis focuses on the design,synthesis and application of novel fluorescent conjugated molecules based on pyrene or boron-nitride fused aromatic ring motifs.The main research progress can be summarized as follows:1.A novel class of amphiphilic dendrons with a pyrene functional group at the focal point was designed and synthesized.The self-assembly and DNA condensation behaviors of these pyrene-functionalized amphiphilic dendrons were investigated in detail.Anisotropic 1D nanostructures were formed owing to their amphiphilic nature and the synergic effect of non-covalent interactions.Furthermore,these pyrene-functionalized dendrons showed excellent DNA condensation abilities.And the condensation efficiency of these pyrene based supramolecular nanostructures towards DNA could be conveniently controlled by the generation of dendrons,which will make them potentially applicable in many fields of medicinal science and biotechnology.2.Via Bischler-Napieralski cyclization and cyclecondensation reaction as the key step,a series of pyrene-fused azaacene derivatives were designed and successfully synthesized.The regulation of photophysical properties and single crystal structure is achieved by adjusting the symmetry of the molecular structure and the degree of the?-conjugated system.Besides,their photon transport properties and acid responsive behavior were studied,which will be helpful for opening up the future applications of azaacene derivatives in optical waveguide devices and chemical sensors.3.A series of novel D-A-D type BN-embedded phenacenes were designed and synthesized,via N-directed borylation as the key step.Their crystal structures,and photophysical and electrical properties were systematically studied,which were found to be highly dependent on the incorporated BN units and fused aromatic rings with varied electron density.In solid states,the D–A–D type molecules exhibited excellent mechanochromic luminescence(MCL)behavior.In solution,these molecules showed the F~-responsive property with high selectivity and sensitivity.The dual-responsive properties of these compounds highlight the widespread applications of BN containing conjugated materials in optical sensors4.To further expand the types of BN-doped polycyclic aromatic hydrocarbons(PAHs),through the intermolecular dehydration between boronic acid and diamines,a series of NBN-doped star shaped truxenes cored PAHs were designed and synthesized.Through a reasonable design of boronic acid groups,different substituent groups of triphenylamine(TPA)and tetraphenylethylene(TPE)are introduced at the periphery of the truxenes structure.We therefore obtained NBN-TPA and NBN-TPE with excellent film-forming property or Aggregation-induced emission(AIE)characteristics,respectively,and demonstrated their potential applications in the detection of explosive sensors.