Synthesis And Hosts-guest Complexation Of Copillar[5]arens

Pillar[n]arenes,a novel class of hosts molecules,have shown excellent host-guest binding properties with different guests including neutral molecules and anion-cation guests such as halohydrocarbon,alkanes,pyridinium salts,bipyridinium salts and ammonium salts.Since the pillar[n]arenes were firstly reported by Japanese scientists Ogoshi et al in 2008,their derivatives have attracted more attention because of their applications in host-guest recognition chemistry,self-assemble chemistry,biomaterials chemistry and fluorescence material chemistry.In the recent years,the functionalized pillar[5]arenes have become the central topic of many studies owing to their easy functionalization and different self-assembly behavior.In this thesis,a series of functionalized copillar[5]arenes were successfully synthesized and their host-guest properties were studied.(1)In this thesis,1,4-bis-(methoxy)pillar[5]arene 1 was successfully synthesized by 1,4-dimethoxy benzene and paraformaldehyde with Lewis acid FeC13 as catalyst.Then,monohydroxylated pillar[5]arene 2 was synthesized by means of demethylation reaction.Finally,three types of copillar[5]arenes such as dehydroabietacyl-copillar[5]arenes(5a～5d),phenyl-copillar[5]arenes(5e～5h)and naphthyl-copillar[5]arenes(5i～51)were prepared by Williamson reaction of compound 2 with the corresponding bromoalkane derivatives 3 or 4.The synthesized four intermediates 3a～3d and twelve target products 5a～51 are all new compounds that have not been reported in literature.The synthetic conditions of the target products were investigated preliminarily,and the novel compounds were characterized and analyzed by means of infrared spectroscopy,nuclear magnetic resonance,and mass spectrometry techniques.(2)The host-guest complexation between three types of copillar[5]arenes 5a～51 bearing the substituents with different side chain lengh and two types of guests was investigated in CDCl3 by 1H NMR.For symmetrical guests,1,4-dibromobutane(DBB)could thread in the cavity of copillar[5]arenes to form inclusion complexes.Compared with the full symmetrical pillar[5]arene 1,all these mono-functionalization copillar[5]arenes had stronger binding abilities with DBB,except 5e and 5j.But for unsymmetrical guests,copillar[5]arene showed weak interaction with sec-butylaminehydrochioride(SBA)and terminal one haloalkane such as n-butyl chloride(NBC),n-butyl bromide(NBB),n-butyl iodid(NBI)and their binding models were different.Furthermore,copillar[5]arene could not complex with sec-butyl iodide(SBI),sec-butyl bromide(SBB),1,2-dibromopropane(DBP)and 1,2-dichloropropane(DCP)at all.These results indicated that the modified group of copillar[5]arene and the symmetry of guest played an important role in the complexation model and selectivity.(3)Four novel fimctionalized pillar[5]arenes including trimer 6a,dimer 6b,6c,and monomer 6d were designed and synthesized by esterification reactions of compound 2 with 1,3,5-benzenetricarbonyl trichloride and benzoyl chloride,respectively.The products were characterized and analyzed by means of FT-IR,MS and nuclear magnetic resonance techniques.Finally,the host-guest complexation properties of the novel compounds 6a,6c and 6d with 1,4-butanediaminedihydrochloride(DB-HCl)and tris(2-aminoethyl)aninete-trahydrochloride(TA-HCl)were examined preliminarily in CHCl3/CH3OH(v/v=9:1)by UV-visible spectra titration.Compound 6a displayed excellent complex properties with DB-HCl and TA-HCl.The result indicated that this trimer 6a have potential advantage and good cooperaction between the three cavities of pillar[5]arene in host-guest system.