Synthesis Of O-Carborane-based Materials And Molecular Machines And Their Photoelectric Properties

Inspired by the functional of molecular machines in nature,the artificial molecular machines are successfully created.The artificial olecular machines possess a functional of their precise control at the micro levels,which has great application value in the fields of molecular devices,nanomotors,medical care,and smart materials.In 2016,three outstanding scientists were awarded the Nobel Prize in Chemistry for their contributions in the field of molecular machines.Their achievements are fully recognized,most of all,which provides valuable information for the exploitation of the artificial molecular machines.Therefore,numerious related researchers are engaged in the molecular machines.It can be believed that the corresponding research will play a significant role in artificial intelligence in the 21 st century.The key challenge is how to monitor the molecular movements at the nanometer level.Therefore,it is difficult to characterize such weak changes,whether it is direct observation or indirect measurement.Therefore,the visualization of molecular machines is the first problem to be solved;a large number of studies have found that introducing molecular machines to the macroscopic level that can be applied is the second challenge.The experience of molecular self-assembly to construct ordered aggregates is integrated into the design and amplification of molecular machines.This thesis uses the three-dimensional space advantage of carborane molecules and other different groups to construct and design molecular machine molecules,and explores the rotational behavior of intramolecular modules under the stimulation of different external environments.Use circularly polarized light spectroscopy,fluorescence spectroscopy,scanning electron microscopy and other different monitoring methods to characterize the dynamic changes of molecular machines.The main research contents and innovations of this graduation thesis are as follows:(1)The main research content of the first system: The first system designed and prepared carborane-modified binaphthol molecules,and explored the rotation of carborane in solution under different external stimuli,and used fluorescence spectroscopy to monitor the molecules Changes in the microscopic conformation of the machine.The use of binaphthol to effectively lock the molecular conformation and the differentiation of carborane structure affects the molecular stacking mode in the compound structure,realizes the control of the circular polarization factor,and provides a dynamic support for understanding the circular polarization.In addition,the study of self-assembly morphology provides strong support for the experimental conclusions.(2)The main research content of the second system: This chapter designs a new type of AIE molecular machine with triazine,borane,and carbazole as the main compound groups,and carborane as the connection hub to connect with carbazole and triazine respectively.Since the two dihedral angles between the carborane group and the connected benzene ring in the three-dimensional structure will produce a stimulus response change,there is a charge transfer direction in the molecule between the carborane group and the carbazole group.Controllability.Explore the dynamic detection of the intramolecular rotation of the compound through fluorescence ultraviolet spectroscopy when different external stimuli are input.Studies have found that carborane molecules can produce ordered aggregates of different compositions and configurations by inhibiting the rotation of each molecule in the substituent unit.The microscopic morphology has been observed to self-assemble the molecules to form a regular fiber structure in a poor solvent.The compound shows a good AIE effect.Prove its good organic photoelectric properties.(3)The main research content of the third system: Taking the dumbbell structure as the design inspiration,design the three-dimensional structure of the o-carborane modified by spirofluorene as the stator,and construct the molecular motor material with the flexible benzene ring rotor in the middle.The external environmental factors drive the rotation of the rotor,regulate the intramolecular charge transfer method,and realize the effective regulation of fluorescence.Experiments have shown that when the benzene ring is used as the center,its adjacent axis is highly rotatable.When the environment such as the ratio of poor solvents and the polarity of the solvent changes,it can respond to these changes accordingly,thereby affecting To its optical physical properties.And use the fluorescence spectrometer and scanning electron microscope to observe the dynamic changes of the molecular machine in the microscopic appearance,and realize the dynamic control of its optical performance.The successful preparation of molecular motors with luminescent properties and the study of their dynamic responses also provide new ideas and samples for subsequent combined research and application in the field of organic optoelectronics and molecular motors.