Synthesis And Cation Recognition Properties Of Calix[4]arene Schiff Base Derivatives

Calixarenes, macrocyclic compounds with versatile three-dimensional cavity, are ideal candidates for building blocks and/or molecular scaffolds in the design of new more sophisticated and special functional molecules. Schiff bases are very important ligands. They can complex with most of soft metal ions. In the thesis, by the incorporation of imino groups into the upper rim of the calix[4]arenes, thirty six new compounds were synthesized and characterized by IR, ¹H-NMR, ¹³C-NMR and MS. The recognization and complexation abilities were studied by UV-vis spectroscopy and fluorescence spectrometer.By condensation of aminocalixarene(4, 8) with substituent benzaldehyde, fifteen new calixrene derivatives with four or two imino groups at the upper rim were synthesized and characterized by IR, ¹H-NMR, ¹³C-NMR and MS. All the compounds adopt cone conformation. The CH=N in these compounds exist in E-configuration. Apart from compounds 12, 18, 21, all the other compounds show selective recogniton to Fe³⁺ and Cr³⁺.By condensation of aminocalixarene(4, 8, 26) with coumarin aldehyde, twelve new calixrene derivatives with four or two imino groups at the upper rim were synthesized and characterized by IR, ¹H-NMR, ¹³C-NMR and MS. Compounds 27³4 adopt cone conformation and compounds 35³8 adopt 1, 3-alternate conformation. The CH=N in these compounds exist in E-configuration. Other than compounds 29, 35³8, the other compounds show selective recognition to Fe³⁺ and Cr³⁺. The complexation ratio of these compounds and Fe³⁺ or Cr³⁺ is 1:1. The compound 30 shows the best complex properties to Fe³⁺ and Cr³⁺. The association constants for Fe³⁺ is 2.13×10⁶ M^-1, for Cr³⁺ is 1.65×10⁶ M^-1. Compounds 27, 28, 30, 31, 32, 33, 34 may be considered as potential fluorescent chemosensors for Fe³⁺ and Cr³⁺.By condensation of aminocalixarene (4, 8, 26) with benzoazole-vinyl-benzaldehy -de, nine new calixrene derivatives with four or two imino groups at the upper rim were synthesized and characterized by IR, ¹H-NMR, ¹³C-NMR and MS. Compounds 39⁴4 adopt cone conformation and compounds 45⁴7 adopt 1, 3-alternate conformation. The CH=N and CH=CH in these compounds exist in E-configuration. All the compounds show selective recognition to Fe³⁺ and Cr³⁺. The complexation ratio of these compounds and Fe³⁺ or Cr³⁺ is 1:1. Compound 41 shows the best complex properties to Fe³⁺, the association constants is 3.06×10⁶ M^-1. Compound 44 shows the best complex properties to Cr³⁺, the association constants is 1.65×10⁶ M^-1. Compounds 39⁴7 may be considered as potential fluorescent chemosensors for Fe³⁺ and Cr³⁺.