Synthesis and Characterization of Tetravalent Cerium Complexes with p-Tert-butylcalix[ n ] arenes （ n = 4, 6, 8）
摘要
Three Ce4+ complexes Ce(p-tert-butylcalix［4］arene)*(dmf)4*H2O (complex A), Ce(p-tert-butylcalix［6］arene)2*(dmf)10 (complex B) and Ce(p-tert-butylcalix［8］arene)*(dmf)4 (complex C) were prepared from N,N-dimethylforamide (dmf) solution of Ce(NO3)3. Their thermal stability, optical properties and coordination features were investigated with thermogravimetric and differential thermal analysis, ultraviolet and visible spectrophotometer, fluorescence spectrophotometer, infrared spectroscopy, and 1H NMR spectrometer. In the solvents of C6H6, 1,2-dichloroethane and dmf, complexes A and B can exhibit a ligand to metal charge transfer transition lying in ca. 20000 cm-1 in the electronic spectra. Complex A displays a dimeric structure in C6D6 solution. Ce4+ ions in the complexes are coordinated by phenolic groups of the ligands, oxygen atoms of dmf molecules, and / or OH- ions.