Formation of the charge-transfer and constrained complexes of cobalt(II) tetraphenylporphyrin in rigid solution. [Gamma radiation]

Journal Article · Thu Dec 11 04:00:00 EST 1980 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100462a025· OSTI ID:6696309

Konishi, S; Hoshino, M; Imamura, M

The electronic absorption spectrum of solutions in 2-methyltetrahydrofuran (MTHF) of equimolar amounts of cobalt(II) tetraphenylporphyrin (Co/sup II/TPP) and tetracyanoquinodimethane (TCNQ) is very different from the sum of the spectra of solutions of the separate components. In addition, the ESR spectrum of the equimolar solution of the two solutes exhibited only one narrow signal at 77 K with a g value of 2.004 and no signal due to Co/sup II/TPP. The absorption spectrum of the TCNQ anion and another new absorption band appear in the spectrum of the solution of the two solutes after ..gamma.. irradiation at 77 K, and the intensities of absorption of the doublet at 553 and 592 nm of the original solution decrease. The ESR spectrum of the irradiated solution of the two components yielded an anisotropic signal with a hyperfine structure attributable to the cobalt nucleus but different from that of Co/sup II/TPP. After being warmed up and then brought back to 77 K, the irradiated solution gave absorption and ESR spectra identical with those of Co/sup II/TPP in the absence of TCNQ. These spectroscopic data have been interpreted in terms of the formation of a charge-transfer complex CT complex) between Co/sup II/TPP and TCNQ followed by the formation through electron capture during irradiation of a constrained complex in which Co/sup II/TPP is forced to retain the TCNQ anion in the axial position due to the rigidity of the solvent matrix.

• Research Organization: Inst. of Physical and Chemical Research, Saitama, Japan
• OSTI ID: 6696309
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 84:25; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ABSORPTION SPECTROSCOPY
AROMATICS
AZINES
CAPTURE
CARBOXYLIC ACIDS
CHARGE EXCHANGE
CHEMICAL RADIATION EFFECTS
CHEMISTRY
COBALT COMPLEXES
COMPLEXES
ELECTROMAGNETIC RADIATION
ELECTRON CAPTURE
ELECTRON SPIN RESONANCE
FURANS
G VALUE
GAMMA RADIATION
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYPERFINE STRUCTURE
IONIZING RADIATIONS
LOW TEMPERATURE
MAGNETIC RESONANCE
MTHF
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PORPHYRINS
PYRIDINES
QUINOLINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RESONANCE
SPECTROSCOPY
TETRAHYDROFURAN
TRANSITION ELEMENT COMPLEXES