Assignment of the lowest ionization potentials in pyridine and pyrazine by multiphoton ionization spectroscopy

Resonance enhanced multiphoton ionization spectroscopy for detection of azabenzenes in supersonic beam mass spectrometry

“…However, a more recent interpretation shows that this may be incorrect since interaction of the nonbonding electrons with the structure may also provide diffuse bands and electron bands are sometimes found to be sharp (18). Further, measurements of polarization ratios in MPI suggest that the lowest ionization potentials in pyridine and pyrazine are from nonbonding orbitals (37). Thus, the IP of these molecules in regard to which electron is being removed is still open to debate, but in either case the IP is too high for R2PI.…”

Femtosecond Photoelectron Imaging on Pyridine: Ultrafast Electronic Dephasing from the S1(nπ*) State and Rydberg State Energetics

“…Berg et al have analyzed the polarization dependence of the (2+1) REMPI of pyridine via the lowest 3s Rydberg state, which also suggested that the lowest cationic state is n -1 . 25 Recent ab initio molecular orbital calculations confirmed these conclusions. 26 When two-color excitation is employed via the S 1 state, observation of the Rydberg states is limited to the series converging to the n -1 cationic state, because the configuration mixing between the S 1 (nπ*) and the other (ππ*) state is small.…”

Collision Energy Resolved Penning Ionization Electron Spectroscopy of Azines: Anisotropic Interaction of Azines with He*(23S) Atoms and Assignments of Ionic States

“…Photoelectron spectra of azines have been extensively investigated, − but there are discrepancies concerning assignments of some bands. On the other hand, electronic structures of these azines also have been investigated theoretically. − ,− For the PIES measurement, Penning ionization of pyridine was observed with the Ne*( 3 P 2 ) atom, and assignment of π 1 band which shows highest IP among π bands was confirmed previously …”

“…Photoelectron spectra of azines have been extensively investigated, [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] but there are discrepancies concerning as-signments of some bands. On the other hand, electronic structures of these azines also have been investigated theoretically.…”