Construction And Application Of Symmetrical Tetramethyl Six-membered Cucurbit Ring And Metal Ion Framework Driven By Exo-wall Interactio

Porous materials,such as inorganic zeolites,metal-organic frameworks or coordination networks and covalent organic frameworks,find widespread applications in heterogeneous catalysis,adsorption,ion exchange processes.In recent years,there has been a trend of constructing supramolecular organic frameworks with framework structural characteristics based on weak intermolecular interactions,including hydrogen bonds,ion-dipole interactions,C-H???πinteractions,and/orπ???πinteractions.Because the driving force of their synthetic process stems from weak supramolecular interactions,supramolecular organic frameworks are generally easy to synthesize and show good reversibility.However,it is precisely because of their weak supramolecular interactions that supramolecular organic frameworks usually lack sufficient strength and stability.Using a selection of organic building blocks with rigid structures to construct supramolecular organic frameworks could be an effective method to overcome this shortcoming.Cucurbit[n]urils（Q[n]s）may be particularly suitable as such organic building blocks due to their rigid hydrophobic cavity and two identical carbonyl-fringed portals.According to the structure of Q[n]s and their surface electrostatic potential,the main characteristics of Q[n]s can be found:1)Q[n]s have a rigid structure,and the internal cavity surface electrostatic potential is nearly neutral,,which can selectively accommodate guest molecules with matching size and shape,showing a unique molecular recognition function,forming a unique Q[n]-based host-guest chemistry.2)The portal carbonyl oxygen atoms have a negative electrostatic potential,and can coordinate with metal ions to form the Q[n]-based coordination chemistry.3)The electrostatic potential of outer surface of Q[n]s is positive,and can interact with the portal carbonyl oxygen atoms with negative electrostatic potential of adjacent Q[n]molecules,anions and organic aromatic compounds to form the chemistry of outer surface interaction of Q[n]s.In this thesis,based on the outer surface interaction of TMe Q[6],mainly including self-induced and polychlorinated metal anion-induced out surface interaction of Q[n]s（OSIQs）,different TMe Q[6]-based supramolecular frameworks were constructed with polychlorinated metal anions of Cd,Au and Pt,respectively.In the catalytic application of these supramolecular framework materials,TMe Q[6]molecules are generally used as stabilizers,carriers and modifiers to disperse loaded metal nanoparticles on the surface of TMe Q[6]molecules,thus improving the catalytic efficiency.The main contents are as follows:1)The outer surface interaction of Q[n]s（OSIQ）is an important driving force in the construction of Q[n]-based supramolecular frameworks.Using the self-induced-and anion-induced OSIQ derived from[Cd_xCl_y]^n-anions formed by Cd²⁺cations in a HCl medium,four different TMe Q[6]-[Cd_xCl_y]^n--based supramolecular frameworks are constructed.Three of the most common TMe Q[6]-[Cd_xCl_y]^n--based supramolecular frameworks are selected for further vulcanization and three different Cd S/TMe Q[6]-based framework catalysts with different structures and properties are obtained.The catalytic activities of these three Cd S/TMe Q[6]-based framework catalysts are investigated by the coupling photocatalytic reaction of aminobenzyl,and the results showed that the catalytic activities of the three catalysts are all higher than that of pure Cd S.Therefore,this work establishes that it is possible to establish a method to synthesize the Q[n]-based framework supported catalysts by first synthesizing TMe Q[6]-[Cd_xCl_y]^n--based supramolecular frameworks and then forming Q[n]-based framework supported catalysts by sulfurization or reduction.2)In HCl medium,four kinds of TMe Q[6]/[Au Cl₄]^--based supramolecular frameworks were constructed based on the self-induced and anion-induced OSIQs formed between TMe Q[6]molecules and[Au Cl4]^-anions.X-ray single crystal diffraction and X-ray powder diffraction were used to characterize the structures of the two of these TMe Q[6]/[Au Cl₄]^--based supramolecular frameworks with higher yield.The catalytic hydrogenation of p-nitrophenol（4-NP）to p-aminophenol（4-AP）was investigated on these two frameworks,and the reaction progress was measured by UV-vis technique.In the catalytic reduction process,Na BH₄was used as a reducing agent as a hydrogen source to continuously provide hydrogen for the reaction instead of traditional hydrogen.The experimental results show that this process may be an efficient,green and clean catalytic method.3)In HCl medium,two kinds of TMe Q[6]/[Pt Cl₆]^4--based supramolecular frameworks were constructed based on the self-induced and anion-induced OSIQs formed between TMe Q[6]molecules and[Pt Cl₆]^2-anions.X-ray single crystal diffraction and X-ray powder diffraction were used to characterize the structures of these two TMe Q[6]/[Pt Cl₆]^4--based supramolecular frameworks.The catalytic hydrogenation of p-nitrophenol（4-NP）to p-aminophenol（4-AP）was investigated on these two frameworks,and the reaction progress was measured by UV-vis technique.In the catalytic reduction process,Na BH₄was used as a reducing agent as a hydrogen source to continuously provide hydrogen for the reaction instead of traditional hydrogen.Compared with the above frameworks constructed by TMe Q[6]and[Au Cl₄]^-,the catalytic performances are lower.