| Popis: |
Proton NMR spectra for 'jellyfish' type porphyrinatocobalt(II) and zinc(II) complexes were measured. Upon complexing with cobalt(II), 1H NMR spectra of the porphyrin ligands suggest the deformations of the cavity structures, while such deformations were not observed in the case of Zn(II) complexes. Proton NMR spectra for the various axial base adducts of the Zn(II) complexes were measured in both toluene-d8 and CDCl3, and the equilibrium constants for axial base bindings to the Zn(II) complexes were also measured spectrophotometrically. The Zn(II) complexes having fence structures show significant changes in the 1H NMR spectra upon binding with bulky axial bases such as piperidine. These observations suggest that the porphyrin rings can be deformed by the binding of axial bases, and they can be explained in terms of unfavorable steric repulsions between the fence structures and the bound axial bases. Temperature dependence of 1,2-dimethylimidazole (diMeIm) adducts of the Zn(II) complexes were measured. Solution behaviours of diMeIm bound to Zn(II) complexes and of the porphyrin ligands are also discussed. |
