Wydział Chemii

Xing Nie

Yong Yang

Tianlv Xu

Małgorzata Biczysko

Steven R. Kirk

Samantha Jenkins

2022

International Journal of Quantum Chemistry

122

e26917/1-e26917/11

10.1002/qua.26917

Naukowa

Angielski

Artykuł

The effect of a deuterium (D) or tritium (T) isotope bonded to the alpha carbon of glycine is determined without the need to apply external forces, for example, electric fields or using normal mode analysis. Isotopic effects were accounted for using the mass-dependent diagonal Born-Oppenheimer energy correction (DBOC) at the CCSD level of theory. We calculated the stress tensor trajectories of the dominant C-N bond within next generation quantum theory of atoms in molecules (NG-QTAIM).S-character chirality was discovered using the stress tensor trajectories, instead of the Cahn–Ingold–Prelog (CIP) rules, for ordinary glycine. The S-character chirality was preserved after the substitution of the H on the alpha carbon for a D isotope but transformed to R-character chirality after replacement with the T isotope. This rever-sal of the chirality depending on the presence of a single D or T isotope bound to the alpha carbon adds to the debate on the nature of the extraterrestrial origins of chiral-ity in simple amino acids. We demonstrate that NG-QTAIM is a promising tool for understanding isotopic induced electronic charge density changes, useful in analysis of infrared (IR) or circular dichroism (CD) spectra explaining changes in mode couplings and bands intensities or sign.

chirality, DBOC, glyine, isotopomers, next generation QTAIM

http://dx.doi.org/10.1002/qua.26917

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