Absorption and resonance Raman spectra of Eu sup III (porphyrin) sub 2 sup + complexes. Oxidation-induced enhancement of porphyrin-porphyrin. pi. pi. interaction

Journal Article · Wed Feb 06 23:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100156a053· OSTI ID:5212429

Perng, Jinghuei; Duchowski, J K; Bocian, D F ^[1]

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1. Carnegie Mellon Univ., Pittsburgh, PA (USA)

Absorption and resonance Raman spectra are reported for the lanthanide porphyrin sandwich complexes Eu{sup III}(OEP){sub 2}{sup +}, Eu{sup III}(TPnP){sub 2}{sup +}, and Eu{sup III}(TPP){sub 2}{sup +} (OEP = octaethylporphyrin, TPnP = meso-tetrapentylporphyrin and TPP = mesotetraphenylporphyrin). These cations contain two holes in the porphyrin {pi} system; consequently, they are electronically similar to solution cation dimers of the form (MOEP{sup +}){sub 2}. All three of the double-hole sandwich complexes exhibit spectral features characteristic of strong {pi}{pi} interactions. In particular, a near-infrared (near-IR)absorption band is observed at 861 nm (Eu{sup III}(OEP){sub 2}{sup +}), 867 nm (Eu{sup III}(TPnP){sub 2}{sup +}), and 1,025 nm (Eu{sup III}(TPP){sub 2}{sup +}). The energies of these near-IR bands are significantly higher than those of the corresponding single-hole complexes. The blue shift of the near-IR absorption maximum of all three double-hole sandwiches undergoes a substantial blue shift as the temperature is lowered from room temperature to 11 K.

• OSTI ID: 5212429
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:3; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

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ABSORPTION SPECTRA
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
COMPLEXES
EUROPIUM COMPLEXES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
MEDIUM TEMPERATURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHOTOSYNTHETIC REACTION CENTERS
PORPHYRINS
RAMAN SPECTRA
RARE EARTH COMPLEXES
SPECTRA
SYNTHESIS
ULTRALOW TEMPERATURE