TY - JOUR
T1 - Theoretical and Experimental Photoelectron Spectroscopy Characterization of the Ground State of Thymine Cation
AU - Majdi, Youssef
AU - Hochlaf, Majdi
AU - Pan, Yi
AU - Lau, Kai-Chung
AU - Poisson, Lionel
AU - Garcia, Gustavo A.
AU - Nahon, Laurent
AU - Al-Mogren, Muneerah Mogren
AU - Schwell, Martin
PY - 2015/6/11
Y1 - 2015/6/11
N2 - We report on the vibronic structure of the ground state X2A' of the thymine cation, which has been measured using a threshold photoelectron photoion coincidence technique and vacuum ultraviolet synchrotron radiation. The threshold photoelectron spectrum, recorded over ∼0.7 eV above the ionization potential (i.e., covering the whole ground state of the cation) shows rich vibrational structure that has been assigned with the help of calculated anharmonic modes of the ground electronic cation state at the PBE0/aug-cc-pVDZ level of theory. The adiabatic ionization energy has been experimentally determined as AIE = 8.913 ± 0.005 eV, in very good agreement with previous high resolution results. The corresponding theoretical value of AIE = 8.917 eV has been calculated in this work with the explicitly correlated method/basis set (R)CCSD(T)-F12/cc-pVTZ-F12, which validates the theoretical approach and benchmarks its accuracy for future studies of medium-sized biological molecules.
AB - We report on the vibronic structure of the ground state X2A' of the thymine cation, which has been measured using a threshold photoelectron photoion coincidence technique and vacuum ultraviolet synchrotron radiation. The threshold photoelectron spectrum, recorded over ∼0.7 eV above the ionization potential (i.e., covering the whole ground state of the cation) shows rich vibrational structure that has been assigned with the help of calculated anharmonic modes of the ground electronic cation state at the PBE0/aug-cc-pVDZ level of theory. The adiabatic ionization energy has been experimentally determined as AIE = 8.913 ± 0.005 eV, in very good agreement with previous high resolution results. The corresponding theoretical value of AIE = 8.917 eV has been calculated in this work with the explicitly correlated method/basis set (R)CCSD(T)-F12/cc-pVTZ-F12, which validates the theoretical approach and benchmarks its accuracy for future studies of medium-sized biological molecules.
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U2 - 10.1021/jp510716c
DO - 10.1021/jp510716c
M3 - RGC 21 - Publication in refereed journal
SN - 1089-5639
VL - 119
SP - 5951
EP - 5958
JO - The Journal of Physical Chemistry A
JF - The Journal of Physical Chemistry A
IS - 23
ER -