131618-88-7Relevant articles and documents
Zirconium(IV) and Hafnium(IV) Bisporphyrinate Double Deckers: Synthesis, Spectra, Redox Potentials, and Structure
Buchler, Johann W.,Cian, Andre De,Fischer, Jean,Hammerschmitt, Peter,Weiss, Raymond
, p. 1051 - 1058 (2007/10/02)
The synthesis of new zirconium and hafnium bisporphyrinate double deckers M(P)2 (M = Zr, Hf; P = OEP, TPP) is described.The complexes are characterized by UV/Vis/NIR and 1H-NMR spectroscopy and cyclic voltammetry.As compared with M = Ce, the redox potentials or the energies of the near-infrared absorption bands of the corresponding radical cations + are lower by ca. 0.2 V or higher by ca. 2000 cm-1, respectively.Hence, there is a stronger ?-? interaction between the porphyrin ligands as compared with the cerium analogues due to the smaller ionic radii of Zr(IV) and Hf(IV).X-ray crystallography of Zr(TPP)2 confirms the san dwich-like structure of the compound and the close proximity of the porphyrin ligands.