Design And Synthesis Of Self-folded Rotors Controlled By Ch/π Interactions

In the process of exploring microcosm,the organic chemists are trying to explore a nanometer world in order to achieve the level of nanometer devices,through using single molecular or supramolecular system to simulate and finally substitute many of the processes in macroscopical world.The molecular machine is widely noticed under such background.Inspired by the nature,many scientists have been trying to design artificial molecular machine via the organic synthesis method.As one kind of supramolecular system,the molecular machines based on weak interaction(e.g.hydrogen-bond, hydrophobic-hydrophobic interaction) are fragile because they can be easily disassembled with the change of external condition(e.g.change of solvent,change of pH).Meanwhile,such changes can bring some readable signal.In this thesis,first we made a summarization,including the basic conceptions, characters,the kinds of movement,the kinds of energy,etc,about the nature molecular machines and the artificial molecular machines,especially the molecular rotors drived by CH/πweak interaction.Secondly,we introduced a flexible group like the fan base and a rigid group like the fan leaves respectively on the two sidewalls of diethoxycarbonyl glycoluril(DEG) in order to study the factors which affect the rotation rate in the CH/πdriving molecular machines.Accordingly,we obtained a kind of semi-flexible molecular clips which was controlled by CH/πinteraction.All of the molecular structures were characterized by IR, HRMS,¹H NMR,¹³C NMR,respectively,and some structures were confirmed by X-ray.Finally,we analyzed the ¹H NMR and X-ray of all compounds from four aspects. Firstly,we discussed the influence on CH/πinteraction and the rotation rate by changing electron cloud density of the CH acceptor.Secondly,we discussed the influence on rotational speed by changing electron cloud density of the CH donor.Thirdly,we discussed the influence on molecular conformation by changing the distribution of electron cloud density of the CH acceptor.Lastly,we discussed the influence on CH/πinteraction by changing electron cloud density of the sp³ hybridized CH donor. Meanwhile,we obtained the conclusion that CH/πinteraction could be strengthened by increasing the acidity of CH donor and the alkalinity ofπacceptor,and the rotation speed of the molecular machines could be reduced by uneven distribution of electron cloud density of the CH acceptor.