Syntheses And Properties Of Novel Calixarene Aza-derivatives And Polymers

Calixarenee are macrocylic compounds generally formed by condensation of aldehydes and substituted phenols. Because calixarenes have a calix-shaped, hydrophobic cavity and several reactable positions, they have attracted considerable attentions. And they are broadly used as building blocks to construct well preorganized host molecules which have widely applying potential in the field of molecular recognition, enzyme mimics, etc. So they are considered as the third host molecule after crown ethers and cyclodextrins in supramolecular chemistry. The design, syntheses, properties of novel calix[6]-crown-g-cellulose chelating resins and calix[4]arene derivatives containing polyaza groups are described.Firstly, a series of novel calix[6]-crown-g-cellulose chelating resins are synthesized. The chelating resins not only keep high adsorption capacities but also exhibit excellent adsorption selectivity to Na⁺ and Ag⁺ due to the synergetic effect of cellulose derivatives and calixarene polymers.Secondly, a series of novel ringopening or bridged calix[4]arene derivatives containing polyaza groups are synthesized. It is found that the extraction percentage of these new calix[4]arene derivatives for soft cations are higher than that of calixarene derivatives only containing amide groups or Shiff-base groups, and they exhibit a good extraction selectivity towards Cs⁺ and Ni²⁺. Amino acids extracting experiments showed that the novel compounds exhibite outstanding extractabilities towards amino acids, especially towards aromatic amino acids. Ringopening or bridged calix[4]arene derivatives containing polyaza groups show similar extractabilities with a good selectivity toward tryptophane. Their UV/vis spectra show a red shift upon the addition of the transition or heavy metal ions. From the fluorescence spectra of the bridged calix[4]crown containing polyaza groups, it is found that the fluorescence intensity of emission spectrum changes upon the addition of the metal ions, while it could form a complex with copper ion to cause its peak of fluorescence emission spectrum shift. On the other hand, the addition of these metal ions causes the ringopening calix[4]arene derivatives' fluorescence quenching.