Protonation effect on the electronic properties of 2-pyridone monomer, dimer and its water clusters: a theoretical study.
The CC2 (second order approximate coupled cluster method) has been applied to investigate protonation effect on electronic transition energies of 2-pyridone (2PY), 2-pyridone dimer, and micro-solvated 2-pyridone (0-2 water molecules). The PE profiles of protonated 2-pyridone (2PYH(+)) as well as monohydrated 2PYH(+) at the different electronic states have been investigated. The (1)πσ∗ state in protonated species (2PYH(+)) is a barrier free and dissociative state along the O-H stretching coordinate. In this reaction coordinate, the lowest lying (1)πσ∗ predissociates the bound S1((1)ππ∗) state, connecting the latter to a conical intersection with the S0 state. These conical intersections lead the (1)ππ∗ state to proceed as predissociative state and finally direct the excited system to the ground state. Furthermore, in presence of water molecule, the (1)πσ∗ state still remains dissociative but the conical intersection between (1)πσ∗ and ground state disappears. In addition, according to the CC2 calculation results, it has been predicted that protonation significantly blue shifts the S1-S0 electronic transition of monomer, dimer, and microhydrated 2-pyridone.
Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran.
Behnaz
B
Saed
Department of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran.
Reza
R
Omidyan
D019281:Dimerization; D004583:Electrons; D008958:Models, Molecular; D011522:Protons; D011728:Pyridones / Q000737:chemistry*; D011789:Quantum Theory; D014867:Water / Q000737:chemistry*
D011522:Protons; D011728:Pyridones; D014867:Water; C017679:2-hydroxypyridine