Protonation-Induced Structural and Spectroscopic Variations in Molecular Species: A Computational Study on N2, H2, CO, CS, and PH3


  • John Pual Shinggu Federal University Wukari
  • Emmanuel E. Etim Federal University Wukari
  • Alfred I. Onen Federal University Wukari


Proton affinity, Spectroscopic properties, Computational methods, Bond lengths, Bond angles


Communication in Physical Sciences, 2023, 9(4): 408-433

Authors: John Pual Shinggu, Emmanuel E. Etim* and Alfred I. Onen

Received: 23 April 2023/Accepted 02 August 2023

This research presents computational studies on the influence of protonation on the structural and spectroscopic properties of molecules, with a focus on N2, CO, H2, CS, and PH3. Computational calculations were performed using various methods and levels of theories, including G4, MP2/6-311*, MP2/CC-pvdz, CCSD/CC-pvdz, and W2U. Calculations of thethe proton affinity (PA) and the examination of the effects of protonation on the bond lengths, bond angles, vibrational frequencies, dipole moment, and rotational constants of various molecules were also performed. The results of the calculation displayed a significant variation in molecular geometries, vibrational frequencies, dipole moments, and proton affinity protonation. Protonation was observed to be a precursor to the e formation of charged species and therefore highlighted, their potential as reactive intermediates in chemical reactions. The computational methods employed in this study clearly show that adopted methods can effectively be employed to describe the protonation-induced structural and spectroscopic variations in the molecules. These findings contribute to a better understanding of protonation processes in diatomic molecules and have implications for various fields, including chemistry, spectroscopy, and theoretical studies.


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Author Biographies

John Pual Shinggu, Federal University Wukari

Department of Chemical Sciences

Emmanuel E. Etim, Federal University Wukari

Department of Chemical Sciences

Alfred I. Onen, Federal University Wukari

Department of Chemical Sciences


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