Photoionization of ferrocene

Ferrocene/ferrocenium, cobaltocene/cobaltocenium and nickelocene/nickelocenium: from gas phase ionization energy to one-electron reduction potential in solvated medium

“…The F12a and F12b implementations differ in the way of approximating the matrix elements of the first-order Hamiltonian 72 and are supposed to give very similar results. Indeed, both the IE(Cp 2 Fe) values of 6.810 (F12a) and 6.790 (F12b) eV compare favorably with several experimental IEs: 6.747 ± 0.009 eV obtained from the photoionization efficiency measurement, 8 6.81 ± 0.07 eV obtained from thermochemical measurements in charge-transfer equilibria at 298 K, 9 and 6.64 ± 0.07 eV (153.1 ± 1.5 kcal mol −1 ) determined from Fourier transform ion cyclotron resonance mass spectrometry in which gas-phase electron-transfer equilibrium reactions were studied between Cp 2 Fe and other reference compounds with a known IE value at 350 K. 10 After correcting the free energy contribution and temperature effect, the latter two values of 6.81 ± 0.07 eV (at 298 K) 9 and 6.64 ± 0.07 (at 350 K) 10 eV are converted to 0 K IE values of 6.87 ± 0.07 eV and 6.72 ± 0.07 eV, respectively. All the correlation terms are identical for and , and only the latter ionization transition is presented in Table 2.…”

“…0 K IE = 7.17 eV is obtained by correcting 7.11 eV (685.633 kJ mol −1 , ωB97X-D value at 298 K) with the free energy contribution and temperature effect.hFrom ref. 8. Obtained by the photoionization efficiency measurement.iFrom ref.…”

Dissociative Intramolecular Charge Transfer after Local Two-Photon Ionization of Ferrocene Derivatives with Aromatic Chromophores

“…While resonance-enhanced two-photon ionization with typical photon energies hv ≤ 6.2 eV failed to produce parent ions, one-photon vacuum ultraviolet (VUV) ionization of ferrocene leads to intact parent (ferrocene) ions. Determination of the IE of ferrocene by one-photon VUV ionization or electron impact yielded slightly different values of 6.75 eV, 6.72 eV (adiabatic) and 6.86 eV (vertical), and 6.99 eV . In our work, the value of 6.75 eV for the adiabatic ionization energy (AIE) is adopted.…”

“…In a series of multiphoton dissociation (MPD)/multiphoton ionization (MPI) studies of ferrocene − with nanosecond (ns) laser pulses at different wavelengths in the visible and near UV (UV/VIS) it has been shown that the cyclopentadienyl (cp) ligands are lost prior to ionization, and as a consequence, no intact ferrocene cations can be observed in the mass spectra. In the intensive laser radiation field the central iron atom loses its cp rings in one or more MP steps, and the uncaged iron atom can be ionized and detected by a MPI process when the laser wavelength is close to an atomic resonance.…”

Ultrafast Dissociation Dynamics of Ferrocene and [3]-Ferrocenophan

“…While resonance-enhanced multiphoton ionization with typical photon energies h ν ≤ 6.2 eV failed to produce parent ions, one-photon vacuum ultraviolet (VUV) ionization of ferrocene has led to intact ferrocene ions. − Determination of the ionization energy (IE) of ferrocene by one-photon VUV or electron impact ionization yielded slightly differing values in the range between 6.61 and 7.15 eV. ,− With increasing photon energy new dissociation channels are opened. − E.g., the appearance energy for the ferrocene fragment Fe(Cp) + lies between 11.6 and 14.38 eV. In this energy range three other fragments of the ferrocene cation appear: The Fe + , Fe(Cp)C 3 H 3 + , and (Cp) 2 + ion.…”