Studies On The Selective Synthesis & Properties Of C-shaped And S-shaped Topological Isomers

Topological isomers are brand-new phenomena in molecular structures, which can bring new subjects to Molecular Structural Theory. The studies on the spectrum properties, structure analysis, translation, and selective synthesis are based on synthesis of diverse topological isomers in one pot. According to our investigation, few reports focus on the synthesis of multiple topological isomers in one pot.In this thesis, six topological isomers based on diethoxycarbonyl glycoluril were synthesized in one pot, whose chemical configurations were characterized by means of ¹H NMR, ¹³C NMR, IR, UV and SEM. It was found that the topological configuration of C-shaped and 5-shaped molecules could be identified by ¹H NMR, and the topological isomers of S-shaped cis (SC) and trans ((±) ST), C-shaped cis (CC) and trans ((±) CT) could be identified by ¹³C NMR. There is little difference in IR, UV and SEM of six topological isomers. What's more, the X-ray structures of all the six topological isomers were obtained, which further confirmed our analysis of classical means were correct. In addition, we synthesized a series of compounds with the similar structure under similar conditions. These compounds constitute a chemical library based on diverse topological structures to screen new drugs, which has significance in the preparation of pharmaceuticals. Little attention has been paid to the bioactivity of the topological isomers in previous work. So we investigate the preliminary bioassays of the six topological isomers. The results showed that the six isomers exhibited obvious difference in herbicidal activity. At the dosage of 100mg litre^-1, CC showed 100% inhibitory rate not only to the root of the rape but also to the root of barnyard grass, what's more, CC showed excellent herbicidal activity to the stalk of the rape and the stalk of barnyard grass, inhibitory rate is 100% and 94.2% respectively. However, besides (±) ST showed good herbicide activity to the root of the rape (inhibitory rate 93.5%), other isomers (SC, (±) CT) showed general herbicidal activity. There is little difference in antifungal activity.With the emphasis on the research for atom-efficient transformations of easily available starting materials into complex organic molecules, nowadays how to selectively synthesize one of the desired well-defined 3D molecular structures becomes a new bottleneck to chemists. Here we investigate the effect of reaction time, temperature and the 3D structure of the building block on the topological selective formation of multi-topological isomers. A modified synthetic method in which the desired C-shaped molecules could be selectively obtained under high pressure in short reaction time or elevating the reaction temperature is presented.The C-shaped molecules, also referred as molecular clips, have many applications in molecular recognition, assembly etc. After C-shaped molecules are synthesized selectively, we studied the binding properties for neutral guest molecules. The complexes were characterized through ¹H NMR, IR and Dilution titration. Their unique binding behavior towards hydroquinone, which is different from Nolte's clips (high affinity for resorcinol), has been investigated in details. There exists hydrogen bonds andÏ€-Ï€stacking interactions in binding process similar to Notle's clips. But compared with Notle's clips, our molecular clips possess four oxygen atoms as binding sites. According to the calculated distances of the oxygen atoms, we assumed that our molecular clips might bind hydroquinone through bifurcated hydrogen bonds. Job-plot analyses are performed to determine the stoichiometry of the complexes and provide good evidence of a 1:1 stoichiometry for the complexes.