Electronic and MCD (magnetic circular dichroism) spectra of dilutetium(III) tris(phthalocyanate), Lu 2 (Pc) 3 (Pc = phthalocyanine), its one-electron oxidation product [Lu 2 (Pc) 3 ] +, and its two-electron oxidation product [Lu 2 (Pc) 3 ] 2+ are reported. Lu 2 (Pc) 3 was prepared by a new synthetic route in which PcLu(CH 3 COO)(H 2 O) 2 is used as the starting material. This new route enabled a purification of the triple-decker compound to a level necessary for spectroscopic measurements. Each of the two chemical oxidation steps occurred keeping isosbestic points. The first oxidation product [Lu 2 (Pc) 3 ] + shows a relatively intense band in the near-IR region. This is assigned to the LUMO-to-SOMO (singly occupied orbital) transition. The band has a transition moment perpendicular to the Pc planes. A single intense band was observed in the Q-band region in [Lu 2 (Pc) 3 ] + in contrast to the two bands in Lu 2 (Pc) 3 . Between the Q band and the near-IR band, several weak bands are observed. Among them, two bands show clear MCD A -term dispersions. In the region between the Q band and the B band, [Lu 2 (Pc) 3 ] + shows a characteristic band for Pc π radicals. Its MCD pattern suggests the presence of a negative A term. The second oxidation product [Lu 2 (Pc) 3 ] 2+ displays an intense band with two distinct vibronic bands in the near-IR region. None of the bands in the region shows an A -term contribution in MCD. The Q band remains single. There is only one band which shows an MCD A term between the near-IR band and the Q band. Semiempirical quantum chemical calculations were carried out for the ground and excited states of [Lu 2 (Pc) 3 ] + and [Lu 2 (Pc) 3 ] 2+ . Band assignments are discussed using the theoretical excitation energies, oscillator strengths, and MCD A terms.
No takes yet. Share an insight, caveat, or question.
Ishikawa et al. (1999) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: