Wydział Chemii

Piotr Durlak

Maria Jerzykiewicz

Irmina Ćwieląg-Piasecka

2019

Magnetic Resonance in Chemistry

57

S95-S100

10.1002/mrc.4822

Naukowa

Angielski

Artykuł

The presented results attempt to approximate the proper structure of the radical formed as a result of the oxidation of 1,2,3‐propanetriol. To fulfil the aim unstable radical originated in 1,2,3‐propanetriol was trapped by PBN. Resulted spin adduct was measured using EPR spectroscopy and the isotropic hyperfine coupling constants a_iso(¹⁴N) and a_iso(¹H) were obtained by simulation of the EPR spectrum. The next step consisted of conducting a comparative analysis of EPR parameters, based on the calculations conducted at the DFT and MP2 methods level in open‐shell formalism including solvent effects. For comparison, calculations were also carried out at the level of combined methods (UB3LYP/QCISD and UMP2/QCISD) in terms of the ONIOM formalism. Comparison of the experimental EPR data of the isotropic hyperfine coupling constants a_iso(¹⁴N) and a_iso(¹H) with the calculated parameters indicate that oxidation of 1,2,3‐propanetriol leads to a carbon centred radical where unpaired electron is situated on the second (middle) carbon of 1,2,3‐propanetriol. What is important, this conclusion could be made regardless of the chosen calculation method. However, it could be stated that for calculation of the isotropic hyperfine coupling constants a_iso(¹⁴N) and a_iso(¹H) of PBN/gly• adducts, UMP2 polarisable conductor calculation model with two ethanol molecules is explicitly defined.

DFT, EPR, radical, spin trapping

https://doi.org/10.1002/mrc.4822

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