Photoionization of glycine-betaine: A permanent zwitterion

The electronic structure of permanent zwitterion, glycine-betaine (GBZW) has been studied using high-level ab initio method: equation-of-motion couple-cluster (EOM-CCSD) method. The photoelectron spectra of GBZW have been simulated in the valence and core ionization regions. The zwitterion shows remarkable stability with standard enthalpy of formation Delta H-f(o)(g) = -313.6 kJ/mol and 1st ionization energy which is 2 eV lower compared to the parent glycine. The results help understanding of molecular structure of ubiquitous zwitterions. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The electronic structure of permanent zwitterion glycine-betaine (GBZW) was studied using the high-level ab initio method: equation-of-motion couple-cluster (EOM-CCSD) method, and the photoelectron spectra of GBZW were simulated in the valence and core ionization regions. The zwitterion showed remarkable stability with a standard enthalpy of formation Delta H-f(o)(g) = -313.6 kJ/mol and a 1st ionization energy 2 eV lower compared to the parent glycine, which helps in understanding the molecular structure of ubiquitous zwitterions.