Pyrene ionization potential

Cavalieri and coworkers, following earlier investigators , have championed the hypothesis that the covalent binding of polycyclic aromatic hydrocarbons to DNA is due to radical cations formed from them by the action of cytochrome P450 and/or peroxidase enzymes . They have reported that polycyclic aromatic hydrocarbons with ionization potentials below 7.35 eV can be oxidized to radical cations by peroxidases . Furthermore, the formation of a benzo[a]pyrene-DNA adduct consistent with oxidation of the... 

Hydrated electrons have also been exploited as kinetic probes in model biological systems for many years. In the first tunable laser study of ionization potentials (7 ) of aromatic molecules in model membranes, we observed a significant reduction in the threshold for pyrene in aqueous... 

These effects are not expected to correlate with only one parameter, such as the ionization potential, even if this is considered as the potential of an electron of the orbital which is affected in the reaction with the platinum complexes. The apparent linearity of the observed log k relation with the ionization potential might be connected to a considerable extent with the fact that the effect of C-H bond differences on the rate of H-D exchange in the case of platinum complexes is relatively small. When we go from the most inert alkanes of the methane series to the most active aromatic hydrocarbons (such as phenanthrene and pyrene), the rate differs by slightly more than two orders of magnitude, whereas the ionization potential changes by over 5 eV. This would have changed the reaction rate by a factor of approximately 10 at 120 °C if the latter were determined entirely by the energy of electron transfer from the hydrocarbon molecule. 

The ionization potential of pyrene is substantially lowered by incorporation into the hydrophobic bilayers of dihexadecylphosphate vesicles. Photoejected electrons leave the vesicle interior and are transferred to an acceptor. ... 

In a study of the biphotonic ionization of pyrene with a tunable laser, Wallace et al. [102] found that the ionization potential in SDS is lower than in the gas phase and in methyl alcohol. They applied the following expression for the ionization potential of a molecule in a medium ... 

The Rydberg state of pyrene in solution can be estimarea to be around 5 eV above the ground state according to the rule that the lowest Rydberg state has an energy level lower than the gas-phase ionization potential by 2.5 eV (33). 

This method was first applied to relative electron affinities of substituted nitro-benzenes. All but one of these has been measured by HPMS TCT studies. However, the Ea of s-butyl nitrobenzene has only been determined by collisional ionization and is still listed in the NIST tables as 2.17(20) eV. This value is referenced to a high value for nitrobenzene and should be about 1 eV lower [60]. The electron affinities of aromatic hydrocarbons have been reported using the collisional ionization method. The value for biphenylene is larger than that obtained from half-wave reduction potentials. The values for pyrene, anthracene, and c-CgHg are consistent with other reported values, but the values for benzanthracene, coronene, and benzo[ghi]perylene are significantly lower than the largest precise value and are attributed to excited states. 

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