Sequential protonation of meso-(p-(dimethylamino)phenyl)porphyrins. Charge-transfer excited states producing hyperporphyrins

Journal Article · Wed Dec 15 23:00:00 EST 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100152a025· OSTI ID:5188069

Ojadi, E C.A. ^[1]; Linschitz, H; Droupadi, P R; Wang, W ^[2]; Gouterman, M ^[3]; Walter, R I ^[4]; Lindsey, J S; Wagner, R W ^[5]

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1. Brandeis Univ., Waltham, MA (United States) Univ. of Massachusetts, Dartmouth, MA (United States)
2. Brandeis Univ., Waltham, MA (United States)
3. Univ. of Washington, Seattle, WA (United States)
4. Univ. of Illinois, Chicago, IL (United States)
5. Carnegie-Mellon Univ., Pittsburgh, PA (United States)

Successive protonation by trifluoroacetic acid of meso-tetraphenylporphyrin derivatives bearing one, two, or four p-dimethylamino groups gives rise to new types of spectra. With one free amino group, the spectrum of the centrally protonated porphyrin shows a strong far-red band, a broad, flat absorption in the visible, and a less intense Soret band. With two or more free amino groups, the Soret band of the centrally protonated porphyrin is further split into two components. Complete protonation, including the peripheral amino groups, in all cases restores the spectral structure of the unsubstituted tetraphenylporphyrin dication. The spectra of the dianions of tetraanilino- and tetraphenylporphyrins are also similar. These results, and the related behavior of p-oxyphenylporphyrins and protonated Schiff base porphyrins, lead to a general interpretation of hyperporphyrin spectra in terms of charge-transfer excited states, involving charge movement either into or out of the porphyrin ring. 26 refs., 4 figs., 2 tabs.

• DOE Contract Number: FG02-89ER14027
• OSTI ID: 5188069
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:50; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
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Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ABSORPTION SPECTRA
AMINES
CARBOXYLIC ACIDS
CHARGE TRANSPORT
CHEMICAL REACTIONS
ENERGY LEVELS
EXCITED STATES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGENATION
IMINES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHOTOSYNTHETIC REACTION CENTERS
PORPHYRINS
SCHIFF BASES
SPECTRA
SYNTHESIS