Synthesis And Studies On CH/π Interaction In Crystal Srtucture Of Half Flexible Clip Molecules Based On Diethoxycarbonyl Glycoluril

A weak interaction was found and termed as CH/Ï€interaction when people studied the conformational problems of a series of compounds bearing an aliphatic group on one side of the molecule and a phenyl group sited at the other terminus. With the rising of study on supramolecular chemistry and self-assembly, intermolecular weak interactions such as van der Wall, hydrogen bonds were paid enough attention. So was the CH/Ï€weak interaction. Studies showed that CH/Ï€interaction which can be observed in solutions and crystals is the extreme of hydrogen bonds occurring between soft acids and soft bases. With the consideration of its flexibility and its unique properties that could't be affected by water, CH/Ï€interaction will play an important role which could not be substituted in biochemical process. In this thesis, it is reviewed the definition, development, molecular recognition and current situations of CH/Ï€interaction.In glycoluril's and glycoluril derivatives' structures, there are rigid angles between the two fused imidazole rings, and the bonds show particular vector, so glycoluril are widely used to construct artificial receptors as building units. There are four NH groups in the glucoluril molecule, so it can be decorated extensively. In order to abtain a self-folded rotor which is controlled by CH/Ï€interaction, we introduce a rigid aromatic group and a flexible aromatic group respectively on the two sides of diethoxylcarbonyl glycoluril(DEG), since it has good solubility in organic solvent, which avoid the problem of infusibility or poor solubility. We changed the acidity of donor CH group and the basity of acceptorÏ€by introducing different electronic substituents on the side walls, then we can examine the substituents effects on CH/Ï€interaction in HNMR and crystal.At the same time, we synthesized a series of half flexible molecules in which aliphatic groups are the flexible side walls. And we examined the crystal packing influence by different flexible sidewalls.We synthesized seventeen new compounds which were characterized by corresponding spectra, including IR, ¹H NMR, ¹³C NMR and MS. The structures of fourteen compounds were confirmed by X-ray crystal structure.