Does isotopic substitution affect the reduction potential of aromatic molecules?

Goodnow, Timothy T.; Kaifer, Ángel E.

doi:10.1021/j100382a067

Cited by 21 publications

(26 citation statements)

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“…This technique obviously relies upon the detailed analysis of the EPR spectral patterns of the individual anion radicals involved, including those of any significant isotopic isomeric impurities. 2,4,5,7,9,. The potassium reduction of our synthesized 2,4,5,7,9,10-d 6 -pyrene (pyrene ) PY) in THF yields an anion radical solution that exhibits the expected EPR pattern from the desired 2,4,5,7,9,10-d 6 -PY •-, but this anion radical only accounts for 74.6% of the spectral intensity.…”

Section: Resultsmentioning

confidence: 84%

“…MS (m/ z): M + ) 208.1196 (C 16 H 4 D 6 requires 208.1159). 1,2,3,6,7,5,9,10-tetrahydropyrene (2e). 4,5,9,10-Tetrahydropyrene (2a) (10.0 g; 48.4 mmol) was deuteriated 3 times with PPA-d (90 g) in the manner described for pyrene.…”

Section: Methodsmentioning

confidence: 99%

“…On the benzylic positions approximately 10% deuterium is incorporated. IR 1, 3,6,5,9,. Compound 2e (2.06 g; 9.7 mmol) was treated with Br 2 (3.5 g; 22 mmol) and FeCl 3 ‚6H 2 O (270 mg; 1.0 mmol) in water (75 mL).…”

Section: Methodsmentioning

confidence: 99%

“…1b, 5 The endothermicity has been explained in terms of the extra electron being added to an antibonding π*-orbital, which reduces the total bonding. 1a, 4 In agreement with the general rule that "the lighter isotope prefers the looser species", the equilibrium of reaction 1 lies to the left.…”

Section: Introductionmentioning

confidence: 99%

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Relative Solution Electron Affinities of Selectively Deuteriated Pyrenes: Correlations between Voltammetric, Electron Paramagnetic Resonance, and Semiempirical PM3 Data

Hammerich¹,

Nielsen²,

Zuilhof³

et al. 1996

J. Phys. Chem.

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The equilibrium isotope effects (EIE) for the one-electron transfer between pyrene and seven regioselectively deuteriated pyrene isotopic isomers in dimethylformamide with 0.1 M tetrabutylammonium hexafluorophosphate were measured electrochemically. These data correlate linearly with the free energies (∆G°) obtained in tetrahydrofuran using electron paramagnetic resonance (EPR) techniques. However, the slope of the resulting line is not unity, and it indicates that the EIE in the DMF system is only two-thirds of that in the THF system. PM3 calculated ∆G°'s, which would correspond to the gas phase electron transfers, also correlate linearly with both sets of experimental data, but the predicted magnitudes of the EIE's are smaller than those observed experimentally by either technique. The nonunity slopes probably reflect slight differences in ion solvation and/or ion association parameters between the anion radicals of the isotopic isomers. No general relationship between the EIE and the charge on the hydrogen/deuterium substituted carbon atom was found.

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Section: Resultsmentioning

confidence: 84%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Relative Solution Electron Affinities of Selectively Deuteriated Pyrenes: Correlations between Voltammetric, Electron Paramagnetic Resonance, and Semiempirical PM3 Data

Hammerich¹,

Nielsen²,

Zuilhof³

et al. 1996

J. Phys. Chem.

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“…They found that the equilibrium constants for the electron exchange [equation (1)] deviated significantly from unity, and suggested that these EIEs might be used as a basis of isotope separations. Although some of their results, especially those dealing with 15 N/ 14 N and 13 C/ 12 C isotope effects, have led to some controversy, 2 the results are supported by independent cyclic voltammetric data 3,4 and theoretical calculations. 5 Stevenson and co-workers 6-8 also pointed out that the EIE is strongly dependent upon the charge and spin density in the area of isotope substitution, which, in turn, is dependent upon the specific anion radical-counter ion and anion radical-solvent interactions.…”

Section: Introductionmentioning

confidence: 99%

14n/15n Isotope Effect on the Electron Transfer Process Between Phenothiazine and Its Radical Cation

Lü

et al. 1997

J. Phys. Org. Chem.

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Synthesis, Electrochemical and Photochemical Studies on π‐Extended Mono‐β‐Functionalized Porphyrin Dyads

et al. 2019

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A series of π‐conjugated mono‐β‐functionalized donor−acceptor porphyrin dyads (1–4) with various donor groups (phenyl, naphthyl, anthracenyl and pyrenyl) and their metal complexes (M=Zn(1 a–4 a), Cu(1 b–4 b), Co(1 c–4 c) and Ni(1 d–4 d)) were synthesized and characterized by various spectroscopic and electrochemical techniques. A modified one‐step Horner‐Wadsworth‐Emmons reaction was performed on monoformyl porphyrin to get ethenyl‐linked mono‐β‐porphyrin dyads in good to excellent yields (70–90 %). Red‐shifted absorption and emission spectra were observed as compared to unsubstituted pristine tetraphenylporphyrins due to π‐extended donors. Time‐resolved fluorescence studies confirmed the effective intramolecular Förster energy transfer from the donor moiety to the porphyrin core in anthracene‐ and pyrene‐appended porphyrin dyads. DFT and TD‐DFT optimization signified that the orientation of the donor and acceptor plays a vital role in energy transfer as co‐planarity of the donor with the porphyrin core increases the energy transfer efficiency. The distribution of electron density on HOMOs and LUMOs indicated an excitation energy transfer (EET) mechanism from the donor moiety to the porphyrin acceptor core. All porphyrin dyads exhibited a cathodic shift in their oxidation potential suggesting facile oxidation of the porphyrin core due to π‐extension and the presence of electron‐donating moieties. Finally, femtosecond transient absorption spectral studies were performed to secure evidence of excitation transfer and kinetic information of the energy transfer event in the dyads.

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Does isotopic substitution affect the reduction potential of aromatic molecules?

Cited by 21 publications

References 0 publications

Relative Solution Electron Affinities of Selectively Deuteriated Pyrenes: Correlations between Voltammetric, Electron Paramagnetic Resonance, and Semiempirical PM3 Data

Relative Solution Electron Affinities of Selectively Deuteriated Pyrenes: Correlations between Voltammetric, Electron Paramagnetic Resonance, and Semiempirical PM3 Data

14n/15n Isotope Effect on the Electron Transfer Process Between Phenothiazine and Its Radical Cation

Synthesis, Electrochemical and Photochemical Studies on π‐Extended Mono‐β‐Functionalized Porphyrin Dyads

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