One-electron-transfer reactions of molybdenum(V) and manganese(III) porphyrins with solvated electrons and solvent radicals in 2-methyltetrahydrofuran. [Pulsed electrons; Gamma radiation]

Journal Article · Wed Mar 21 04:00:00 EST 1990 · Inorganic Chemistry; (USA)

DOI:https://doi.org/10.1021/ic00331a004· OSTI ID:6814229

Suzuki, T; Imamura, T; Sumiyoshi, T; Katayama, M; Fujimoto, M ^[1]

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1. Hokkaido Univ., Sapporo (Japan)

The reactions of the six-coordinate molybdenum(V) tetraphenylporphyrins Mo{sup V}O(TPP)X (X = Br, Cl, F, NCS, N{sub 3}, OCH{sub 3}, OC(CH{sub 3}){sub 3}) with solvated electrons and solvent radicals were studied pulse-radiolytically, focusing on effects of the axial ligand X on the rates. Electron-pulse irradiation of the 2-methyltetrahydrofuran (MeTHF) solution dissolving Mo{sub V}O(TPP)X, which possess neutral charge and are almost all the same size, causes the reduction of the central molybdenum atom, yielding Mo{sup IV}O(TPP) at room temperature. The constrained complexes (Mo{sup IV}O(TPP)X){sup {minus}}, formed at 77 K by {gamma}-irradiation, are not stable intermediates in the reactions at room temperature. The reduction proceeds by an outer-sphere mechanism competitively between the reactions with the solvated electron and with the MeTHF neutral radical (MeTHF{center dot}). The second-order rate constants of the reactions with the solvated electron and with MeTHF{center dot} are in the range of 10{sup 10} and 10{sup 9}-10{sup 8} M{sup {minus}1} s{sup {minus}1}, respectively, and depend on the axial ligand X. The orders of the constants are NCS > Br > Cl for the reductions by the solvated electron and NCS > Br > Cl{approx} N{sub 3} > F > OCH{sub 3} > OC(CH{sub 3}){sub 3} for the reductions by MeTHF{center dot}. The effects of the axial ligand on the redox potentials of Mo{sup V}O(TPP)X were also studied electrochemically. 55 refs., 10 figs., 3 tabs.

• OSTI ID: 6814229
• Journal Information: Inorganic Chemistry; (USA), Journal Name: Inorganic Chemistry; (USA) Vol. 29:6; ISSN 0020-1669; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
FURANS
GAMMA RADIATION
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
IONIZING RADIATIONS
IRRADIATION
LEPTONS
MANGANESE COMPLEXES
MOLYBDENUM COMPLEXES
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PORPHYRINS
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADIOLYSIS
REDOX REACTIONS
TETRAHYDROFURAN
TRANSITION ELEMENT COMPLEXES