Correlation between the molecular structures and thermodynamic parameters of chiral recognition on Host-Guest complexation

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In the cases of many complexations of crown ethers with amines, there is a linear relationship between 1n K and 1/T, which is called the van't Hoff relationship. Based on the van't Hoff relationship, the enthalpy and the entropy can be obtained quantitatively. In addition to an ordinary adopted molecular design based on qualitative host-guest complimentarity judged by a steric hindrance and a fittability between the size of cavity and that of substrate, novel criteria based on the enthalpy and entropy were thought to be contribute to create the precise molecular design of host. Here I extended this idea to a chiral recognition phenomena. I carried out this research as following three steps.(1) The syntheses of optically active artificial hosts and guests, which are correlated by the structural similarity.(2) Measurements of binding constants in the complexation between series of hosts and chiral amines.(3) Investigation of molecular recognition mechanism thinking the thermodynamic parameters.Novel six hosts and both enantiomers of 3 chiral amines were prepared, the measurements of binding constants in the complexation between part of the host-guest combinations were carried out. And the results are published under the consideration of thermodynamic parameters.