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Title: Hole localization or delocalization an optical, Raman, and redox study of lanthanide porphyrin-phthalocyanine sandwich-type heterocomplexes

Journal Article · · Journal of Physical Chemistry; (United States)
DOI:https://doi.org/10.1021/j100085a004· OSTI ID:6970766
;  [1]; ; ;  [2]
  1. CEA-CNRS URA, Gif-sur-Yvette (France)
  2. Universite Louis-Pasteur, Strasbourg (France)

A systematic electrochemical, redox, optical absorption, and resonance Raman spectroscopic study of 22 gadolinium and cerium double- and triple-decker tetraphenylporphyrin-phthalocyanine (TPP-Pc) complexes is reported. The work is aimed at elucidating the extent of the localization or delocalization among the chromophore ligands in the mixed complexes, where there exists a charge imbalance between the metal centers and the dianion Pc/TPP ligands, as well as in different oxidation states for these types of complexes. For mixed double- and triple-decker complexes, [vert bar]Pc(M)TPP[vert bar] and [vert bar]TPP(M)TPP[vert bar] (where M = Gd[sup III], Ce[sup IV]), in which the metal cannot be oxidized, it appears that the ligand preferentially oxidized is the Pc moiety. This perfentially localized hole in the phthalocyanine results in new near-infrared transitions which show maxima around 1200-1300 nm for the double-decker complexes and shifts to 1800-2300 nm for the triple-decker derivatives. In this case, the removal of an electron from a complex redox orbital which is rich in Pc character is easily identified by the accompanying changes in the optical absorption characteristic of a Pc[sup [sm bullet][minus]] species and is also seen in FT Raman spectra (excited at 1064 nm) by a significant (>15 cm[sup [minus]1]) upshift of a redox-sensitive Raman band at ca. 1500 cm[sup [minus]1]. 33 refs., 13 figs., 2 tabs.

OSTI ID:
6970766
Journal Information:
Journal of Physical Chemistry; (United States), Vol. 98:34; ISSN 0022-3654
Country of Publication:
United States
Language:
English