Construction And Properties Of Framework Materials Based On Six-membered Melon Rings

The mixture of cucurbit[n]uril was synthesized by paraformaldehyde and glycoside as raw materials,then the Q[5],Q[6],Q[7]and Q[8]was obtained by filtration,deacidification,recrystallization and column chromatography.Utilizing the characteristic that the number of glycoside units is odd,the solubility is good,and the even number is poor,for Q[6]were recrystallized,and different crystal materials were obtained under different media,concentrations,temperatures,and induction reagents.Using the Q[6]-Cd Cl₂-HCl system,by changing its component ratio,acid concentration,reaction temperature and other conditions,three different structures of QSFs(1-3)were obtained.The experimental results not only confirmed the structure-directing effect of the polychloroxamic acid anions produced during the preparation process,but also proved the diversity of QSFs obtained by anion-induced OSIQs.X-ray analysis shows that two of the three main OSIQs,namely the auto-induced and anion-induced OSIQs formed between adjacent Q[6]molecules and Q[6]molecules and the anion of polychloroximate,are responsible for The main driving force for the formation of the three QSFs(1-3).The driving force includes the dipole interaction formed between the portal carbonyl oxygen atoms Q[6]and the methine bridge between the methylene group and the portal carbonyl carbon atom adjacent to the Q[6]molecules,and the ion-dipole interaction.The methine formed between bridging the methylene group,the carbonyl carbon atom molecule of the port six-membered citrullus ring and its adjacent polychlorinated salt anion.In addition,because the polychloride cadmium salt anion has an affinity with the outer surface of the Q[6]molecule,the inner walls of the channels of these frameworks are decorated with the port carbonyl oxygen atoms of the Q[6]molecule.This provides an important basis for further research on the functional characteristics of these QSFs.Using the interaction of Q[6]and 4-pyrrolidinylpyridine(Bu PC4),a new supramolecular host-guest inclusion complex was successfully constructed,the driving force of which is hydrogen bonding and ion-dipole interaction.The inclusion complex was characterized in detail by a series of modern analytical methods,including NMR spectroscopy,electronic absorption,MS and ITC analysis.In particular,the action form of this host-guest inclusion compound is clearly revealed on the basis of single crystal X-ray diffraction analysis.The results show that the alkyl chain of the guest Bu PC4 is located in the cavity of the Q[6],while other groups,including the tetrahydropyrrole and pyridyl moieties of the guest Bu PC4,remain outside the cavity.Through NMR and UV spectroscopy,MALDI-TOF mass spectroscopy,X-ray crystallography and isothermal titration,the supramolecular host and guest involving 4-pyrrolidinopyridine(Bu PC4)and Cucurbit[6]uril were studied.The results show that the alkyl chain of the guest Bu PC4 is located in the cavity of the main body of Q[6],while the other part of the guest Bu PC4 remains outside the cavity of the Cucurbit[6]uril.