96383-18-5Relevant articles and documents
Metal complexes with tetrapyrrole ligands. 46. Europium(III) bis(octaethylporphyrinate), a lanthanoid porphyrin sandwich with porphyrin rings in different oxidation states, and dieuropium(III) tris(octaethylporphyrinate)
Buchler, Johann W.,De Cian, André,Fischer, Jean,Kihn-Botulinski, Martina,Weiss, Raymond
, p. 339 - 345 (2008/10/08)
Reaction of tris(2,4-pentanedionato)europium(III) with octaethylporphyrin [H2(OEP)] in refluxing 1,2,4-trichlorobenzene (TCB) produces a mixture of double-decker europium(III) bis(octaethylporphyrinate) [Eu(OEP)2, 2] and triple-decker dieuropium(III) tris(octaethylporphyrinate) [Eu2(OEP)3, 4], which are separated by chromatography. 2 is characterized by UV/vis, near-IR, IR, 1H NMR, ESR, and mass spectra. Crystals of 2 (monoclinic, P21/n) are isomorphous with those of the known cerium(IV) sandwich Ce(OEP)2 (1). The presence of EuIII follows from the temperature dependence of the magnetic moment. The well-defined composition Eu(OEP)2 requires that one of the porphyrin rings is electron-deficient; i.e., the charge of the EuIII ion is compensated for by the normal porphyrinate dianion and a porphyrinate monoanion radical. The presence of a porphyrin radical is deduced from near-IR, IR, and NMR data, but the hole cannot be assigned to a specific ring on the time scales available. In refluxing TCB, 2 is transformed into 4 and H2(OEP). Reduction of 2 with sodium anthracenide furnishes the anion [Eu(OEP)2]-.
