Synthesis Of Cucurbit[6] Uril And Perhydroxycb[6] And Investgation On Their Supramolecular Structures

In recent years cucurbit[6]uril has been a new research hotspot in supramolecular chemistry after crown ether,calixarene and cyclodextrin,etc.Cucurbit[6]uril(CB6)is a pumpkin-shaped macrocyclic compound synthesized by acid-catalyzed condensation of glycoluril and formaldehyde.It has very good application prospect in molecular recognition and assembly,molecular catalysis,drug sustained-release,etc.,due to its rigid outwall,highly polar and symmetrical carbonyl openings and hollow cavity with hydrophobicity.Our lab has researched the Supramolecular Self-assembly for several years.We raised and used the anion-exchange strategy,which leads to a hybrid assembly of the CB6-alkali metal coordination polymer incorporating the transition metal complex competing with CB6 self-recognition.Constructed and reported novel helical hybrid assembly supramolecular structure which was formed by negatively charged transition Cu(II)complex with iodo-aromatic moieties and positively charged CB6-alkali metal complex in aqueous solution.Discussed the iodine-assisted asymmetric shape-matching interactions between the convex outer walls of CB6 and the aromatic moieties of asymmetric Cu(II)complexes,suggested that iodo substituent may exert a profound effect on its covalently bound aromatic moiety in specific asymmetric recognition to a given structural environment through selective shape-matching interaction.On the basis of the research achievement has been made,I optimized the synthesis and separation of CB6 and HOCB6 and characterized by NMR,IR.Synthesized CB6-K template complexes,then used the cation-exchange strategy,synthesized two kinds of new supramolecular compound with different anion successfully,and got the single crystal:[(NH3CH2CH2CH2CH2CH2CH2NH3)2(CB6)2Cl4]·6H2O(compoundl)[(NH3CH2CH2CH2CH2CH2CH2NH3)2(CB6)2(NO3)4]· 6H2O(compound2)XRD was used to get the crystal structure,and the results showed that the CB6-K single crystal belongs to hexagonal system,P63/mmc space group,a=19.850(3)A,c=10.360(2)A,V=3535.2(10)A3,Z=1,F(000)=1568,Dcalc=1.417 g/cm3,?=0.397 mm-1,Rall=0.1166.Compound 1 single crystal belongs to monoclinic system,P21/n space group,a=12.0800(24)A,b=16.5900(33)A,c=14.4000(29)A,V=2882.24(445)A3,Z=1,Dcalc=1.4288 g/cm3,Rall=0.0757.Compound 2 single crystal belongs to monoclinic system,P21/n space group,a=12.130(2)A,b=16.110(3)A,c=14.300(3)A,V=2792.35(90)A3,Z=1,Dcalc=1.5380 g/cm3,Rall=0.075.On this basis,I researched the unique supramolecular shape matching recognition characteristics between hexamethylenediamine ion and CB6 and the reason why hexamethylenediamine ion has the highest binding constant with CB6 compared to other diamine ions.Then I analysized and compared the crystal structures of two compounds with different anions,discuss the influence on supermolecular structures by anions.The results of this paper have important value of science to new type of hybrid supramolecular constructed by CB6 and it has reference meaning to the synthesis and characters of CB6 and its derivatives.