Ionization of vitamin C in gas phase: Theoretical study.
In this work, the gas phase ionization energies and photoelectron spectra of four important conformers of vitamin C were calculated. Symmetry adapted cluster/configuration interaction methodology employing the single and double excitation operators (SAC-CI SD-R) along with D95++(d,p) basis set were used for the calculations. Thermochemistry calculations were also performed on all possible conformers of vitamin C to find the relative stability of conformers in the gas phase. The calculated ionization bands of each conformer were assigned by calculating the contribution of natural bonding orbital (NBO) in the calculated canonical molecular orbitals involved in the ionization. SAC-CI calculations showed that the first ionization band of vitamin C is related to the π electrons of CC bond of the ring of molecule although, there is the lone electron pairs of oxygen atoms and π electrons of CO bond in the molecule.
Department of Engineering, Ardakan University, Ardakan 89518-95491, Iran. Electronic address: F.abyar@ardakan.ac.ir.
Fatemeh
F
Abyar
Chemistry Department, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address: farrokhphossein@gmail.com.
Hossein
H
Farrokhpour
D001205:Ascorbic Acid / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D007477:Ions; D008958:Models, Molecular; D008962:Models, Theoretical
D005740:Gases; D007477:Ions; D001205:Ascorbic Acid
Ionization energy; NBO; Photoelectron spectrum; SAC-CIR-SD-; Vitamin C