Self-Assembly And Recognition Of Chiral Bisbenzocoumarind

The chiral self-assembly and chiral recognition are of great significance in many scientific fields.In this paper,the self-assembly of bisbenzocoumarin(DB)in different polar solvents and its recognition with three chiral small molecules were investigated.In addition,the self-assembly and chiral resolution of racemic [5]helicene(BNC)were also explored.The main research contents are as follows:1.The self-assembly of DB and their recognition with three kinds of small chiral molecules by spectroscopical and morphological methods were studied.The results showed that low in solvent polarity could facilitate the aggregation of DB The DB enantiomers were influenced by different effects from the solution,although the molecules all inclined to aggregate via H-type mode.In addition,the chiral recognition of DB enantiomers to three organic small molecules(PE,DACH,and Ala)was further investigated by circular dichroism(CD),and the results showed that DB was most effectively recognized with PE.The method of simulation chemistry was used to assist in understanding the recognition mechanism.It is supposed that the increased DB dihedral angle was caused by the non-covalent interaction between DB and three small chiral molecules.This work highlights the fundamental understanding of self-assembly of chiral bisbenzocoumarins and the chiral recognition to small molecules thereof.2.The chiral resolution of racemic was studied.The self-assembly of BNC was controlled by changing the concentration,solvent and temperature.The chiral resolution of racemic helicene was further investigated,and the chiral resolution of 9,10-bis((5-bromopentyl)oxy)naphtho[1,2,3,4-ghi]perylene(BNP)and BNC was compared under the conditions of changing concentration,temperature and adding other molecules respectively.It was found that the addition of chiral resolution molecules induced the change of self-assembly mode,but no CD signal was found in CD spectra measured.The results showed that the chiral separation of BNC was not achieved,because the presence of C6 alkyl chains make the BNC easier to racemize.The effect of chiral molecules with different configurations on the chiral resolution of racemic BNC was investigated by adding cyclohexamediamine enantiomers(cis-/tran-DACH).The results show that the DACH enantiomers have different effects on BNC,but they all produce weak CD signals.The chiral separation of BNC is difficult is the existence of C6 alkyl chains.This study provides the research basis for the chiral resolution of racemic helicene.