Research On Recognition Of Small Molecules Of Organic Objects By Bamboo Half-Melon Rings

The host-guest interactions of bambus[6]uril,dodeca?4-carboxybenzyl?bambus[6]uril and Semithiobambus[6]uril with quinoline,6-hydroxyisoquinoline,8-hydroxyquinoline and 8-hydroxyquinaldine hydrochloride salts have been investigated by means of ¹H NMR,fluorescence emission spectroscopy and molecular simulation.The study of the interactions between host 1and guests by NMR spectroscopy reveals that the guests can interact with host 1.The changes of fluorescence emissions of guests suggested the formation of host-guest complexes in a ratio of 1:1.The association constant of host 1 and guest 4 is?9.7±0.3?×10⁴ L?mol^-1,of host 1 with guest 5 is?2.8±0.2?×10⁶L·mol^-1,of host 1 with guest 6is?5.5±0.3?×10³L·mol^-1,and of host 1 with guest 7 is?5.7±0.1?×10³ L·mol^-1.The host-guest interaction between host 2 and guests was studied by ¹H NMR.The results showed that the guests can interact with host 2.The fluorescence spectra revealed that the interaction ratio is 1:2 of host 2 with guest 4,and K_a1is?7.0±0.2?×10⁴ L?mol^-1,K_a2is?9.4±0.4?×x10⁵ L?mol^-1.The rest of guests and host are formed a1:1 complex,the association constant of host 2 with guest 5 is?2.9±0.3?×10⁵L·mol^-1,of host 2 with guest 6 is?6.3±0.2?×10⁴ L·mol^-1,and of host 2 with guest 7is?8.2±0.4?×10³ L·mol^-1.Similarly,the host-guest interaction between host 3 and guests was studied by¹H NMR.The results showed that the guests can interact with host 3.And the association constant of host 3 with guest 4 is?6.5±0.1?×10⁴ L?mol^-1,of host 3 with guest 5 is?1.0±0.3?×10⁵,of host 3 with guest 6 is?1.3±0.2?×10⁵ L?mol^-1,and of host 3 with guest 7 is?1.9±0.2?×10⁵ L?mol^-1.In addition,we investigated the adsorption properties of Bambus[6]urils and HemiQ[6]by isothermal adsorption.The results show that the adsorption capacity of Bambus[6]urils is about twice that of Hemi Q[6],and all of the adsorption processes are physical adsorption,they are both have no adsorption properties for hydrogen.Additionally,the mechanism for the host-guest interactions and the adsorption properties of gases was illustrated by a semi-empirical PM6-D3H4 method.Whether it is the interaction between the host and guest or the adsorption of gas,the formation of hydrogen bonds is the main driving force.