Study On Synthesis And Recognition Properties Of Functionalized P-tert-Butyldihomooxacalix[4]arene Derivatives

As the third generation host molecule after cyclodextrin and crown ether,calixarene has been regarded as one of the fundamental macrocyclic building blocks in the field of supramolecular chemistry.In the recent years,the research and applications about calix[4]arene have achieved rapid developments and many functionalized calixarene derivatives have been successfully synthesized.The functionalized calixarene derivatives have empty cavity to host various cations,anions,and neutral molecules.Therefore,the functionalized calixarene derivatives were widely applied in biology,catalysis,isolation,chemical sensor,etc.By using CH2OCH2 unit replacing the methylene bridge of the traditional calixarenes,oxacalixarene not only extended the cavity size,but also increased the flexibility of conformation.On the other hand,the oxygen atom provided more complexing site.In this paper,p-tert-butyldihomooxacalhx[4]arene which was a special macrocyclic molecule in the calixarene family was chosen for the study.Series of dihomooxacaIix[4]arene functionalized derivatives were successfully synthesized and their complexing properties for metal ions and anions were studied by the spectroscopic methods.The main contents are summarized as follows:In the first part,the synthetic methods and recent developments of the dihomooxacalix[4]arene functionalized derivatives were briefly summarized.The applications of dihomooxacalix[4]arene derivatives in various fields were also discussed and our resrach aim of the chemical modification of dihomooxaca!ix[4]arene was introduced.In the second part,p-tert-butyldihomooxacalix[4]arene functionalized amines were prepared by alkylation and hydrazinolysis.Then,p-tert-butyIdihomooxacalix[4]arene functionalized thioureas were obtained by the reaction of p-tert-butyldihomooxacalix[4]arene alkoxy-bridged amines with mono-or di-isothiocyanante.The structures of the obtained compounds were characterized by NMR,IR,ESI-MS spectroscopies.The conformation of the compounds in solution was investigated by the variable-temperature 1H NMR and the recognition propertity of the compounds toward anions was studied by IH NMR titration,UV-spectrum and fluorescence spectrum.The results indicated that p-tert-butyldihomooxacalhx[4]arene functionalized thioureas showed multiple interactions with added F’ including N-H…F,O-H… F hydrogen bonds and "through-space" C-H…F interaction between F.Also,the conformation of the compounds in solution or in the presence of anions was not stable.In the third part,novel p-ferr-butyldihomooxacalix[4]arene mono-Schiff base or terpyridine derivatives were conveniently synthesized by condensation reaction of p-tert-butyldihomooxacalix[4]arene O-alkoxy-substituted benzaldehydes with N’-(2-hydroxybenzylidene)hydrazinecarbohydrazide and 2-acetylpridine.Additionally,the pillar[5]arene alkoxy-bridged terpyridines were also prepared according to the similar method.The structures of the obtained compounds were characterized by NMR,IR,ESI-MS spectroscopies.The recognition properties of the obtained compounds to the metal ions and anions were investigated by UV_spectrum and fluorescence spectrum.The results showed that the p-tert-butyIdihomooxacalix[4]arene mono-Schiff base can form stable complexes with Cu2+and Zn2+ and prefer F-and H2PO4-than other anions.But,the recognition properties of the terpyride with Cu2+ was the strongest.2D NOESY spectra indicated that pillar[5]arene alkoxy-bridged terpyridines formed unique[1]rotaxane strctures in solution.In the fourth part,the novel hand-in-hand bis p-tert-butyldihomooxacalix[4]arene)derivatives were synthesized by condensation p-tert0utyldihomooxacalix[4]arene Oalkoxy-substituted benzaldehydes with N,N’-alkylenebis(hydrazinecarbothioamides).The structures of the obtained compounds were characterized by NMR,IR,ESI-MS spectroscopies.Then,the recognition properties of the obtained acylhydrazone derivatives to the metal ions were investigated by UV-spectrum and fluorescence spectrum.Similarly,the interaction of the preparated thiosemicai;bazone derivatives to the anions were studied by UV-spectrum and fluorescence spectrum and the conformation in solution was investigated by the variable-temperature 1H NMR.The results showed that the formation of complex did not affect the electron transition process of acylhydrazone.At the same time,the recognition properties of bisthiourea with F-was the strongest and the ability was F->Cl->Br->I-.