Studies On The Synthesis And Properties Of New Functional Materials Based On Polyhedral Oligomeric Silsesquioxanes

Cubic Polyhedral oligomeric silsesquioxane(POSS) is a class of inorganic/organic hybrid material, which could combine the advantages of inorganic materials and organic materials on the molecular level. The introduction of POSS unites can improve the performances of composite materials, such as mechanical properties, dielectric characteristics, thermal stability, permeability, and so on. Now, POSS has been an important constructing block to prepare the high performance nanomaterials.This thesis mainly contains two parts. The first part is the synthesis, characterization of the POSS-based functional materials (Chapter 2-5); while the second part presents the synthesis, characterization of a series of new cyanide ions fluorescent probe with the trifluoroacyl group. The main contents and results are described as following:Chapter 1 introduced the structure and characters of Polyhedral oligomeric silsesquioxane (POSS). We reviewed the recent progress of POSS in different research fields. The design strategies and main contents of this thesis are also outlined.In Chapter 2, four new cobalt complexes including POSS, POSS(Co)1, POSS(Co)2, POSS(Co)8, and POSS(Co)16, were synthesized. The four metal complexes were sealed in quartz tubes under vacuum, and submitted to different heating programs in an oven. The cobalt magnetic nanocomplexes were obtained. The remnant’s yield can reach to as high as 66%. Transmission electron microscopy (TEM) analysis revealed that the complexes consisted of the carbon nanotube and cobalt nanoparticle. The nanoparticles were coated by a film. The hysteresis loop shown that four nanomagentic complexes exhibit the ferromagnetism.In Chapter 3, we synthesized a new compound of POSS-silole. It demonstrated the property of aggregation-induced emission (AIE). We detected the fluorescent spectra of POSS-silole in the mixture solution of THF/H2O. The nanoaggregates of POSS-Siloe in the mixture solution of THF/water with 95% water content are applied as a probe to detect picric acid (PA) with the detection limit as low as 4μgmLIn Chapter 4, we synthesized the precursor POSS(N3)8, and studied the influence of the reaction temperature. Considering the stability of azide, we synthesized six POSS precursors bearing many alkynes. All precursors have been characterized by 1H NMR, 13C NMR,FIT-IR etc.In Chapter 5, We synthesized six compounds, POSS-Cz-1, POSS-Cz-2, POSS-Cz-4, POSS-Cz-8, POSS-Cz-16, and POSS-Cz-32, by using the "Click" chemistry reaction. These compounds have good thermal stability and electrochemical stability. The results exhibited that POSS-Cz-8 can suppress the aggregation of carbazole moietes effectively.In Chapter 6, we have successfully obtained two cyanide chemosensors, and proposed two different machanisms on the detection of cyanide ions:1. the nucleophilic addition reaction in the trifluoroacetamide derivative-based cyanide chemosensors; 2. the acid-base reaction present in the response of this kind of sensors towards some generally ignored anions, such as PO43-, CO32-, and S2-. Also, the internal rule of the acid-base reaction was utilized to develop two new pH sensors with good performance.