Benchmark ab initio proton affinity of glycine

Saved in:
Bibliographic Details
Main Authors: Nacsa András Bence
Czakó Gábor
Format: Article
Published: 2021
Series:PHYSICAL CHEMISTRY CHEMICAL PHYSICS 23 No. 16
Subjects:
AAA
Online access:http://publicatio.bibl.u-szeged.hu/22657
DOI:10.1039/d1cp00376c
MTMT:31991485
Description
Summary:A systematic conformational search reveals three N- (amino) and eight O- (carbonyl) protonated glycine conformers with benchmark equilibrium(adiabatic) relative energies in the 0.00-7.51(0.00-7.37) and 25.91-31.61(24.45-30.28) kcal mol(-1) ranges, respectively. Benchmark ab initio structures of the glycine conformers and its protonated species are obtained at the CCSD(T)-F12b/aug-cc-pVTZ level of theory and the relative energy computations consider basis-set effects up to aug-cc-pVQZ with CCSD(T)-F12b, electron correlation up to CCSDT(Q), core correlation corrections, scalar relativistic effects, and zero-point energy contributions. The best predictions for Boltzmann-averaged 0(298.15) K proton affinities and [298.15 K gas-phase basicities] of glycine are 211.00(212.43)[204.75] and 186.38(187.64)[180.21] kcal mol(-1) for N- and O-protonation, respectively, in excellent agreement with experiments.
Physical Description:9663-9671
ISSN:1463-9076