Investigation of solution effect on the EPR spectrum of alanine radicals based on density functional theory

Janbazi, M; Taghipour Azar, Y; Ziaie, F

doi:10.29252/ijpr.18.1.139

Investigation of solution effect on the EPR spectrum of alanine radicals based on density functional theory

Authors

M Janbazi

Y Taghipour Azar

F Ziaie

https://doi.org/10.29252/ijpr.18.1.139

Abstract

In this study, based on Density Functional Theory (DFT), the effect of solution on the g-tensor, hyperfine coupling constant of atoms and finally the EPR spectrum of alanine free radicals induced by ionizing radiation such as electron and gamma was investigated using implicit models such as COSMO, and explicit models such as introducing hydrogen bonds to the cluster structures. The obtained results confirmed a good consistency between the g-tensor and hyperfine coupling constant of atoms and the experimental data in the solution as well as qualitatively in the crystal by the introduction of the hydrogen bond of the water molecule to the cluster models. The use of different clusters in constituting hydrogen bonds between water molecule and radicals indicated that in the first shell, four, seven and six water molecules were needed for R1, R2 and R3 radicals, respectively. Moreover, the effect of solution on EPR spectrum was analyzed in a manner that the identity of the radical remained unchanged.

Keywords

Alanine

density functional theory

g-tensor

Hyperfine coupling constant

EPR spectrum

COSMO model

Hydrogen bond

1. N Maltar-Strmečki, and R Boris. Applied Radiation and Isotopes 63, 3 (2005) 375.
2. V Nagy, J M Puhl, and M F Desrosiers, Radiat. Phys. Chem. 57 (2000) 19.
3. M Brustolon, “Electron Paramagnetic Resonance: A Practitioner's Toolkit”, John Wiley and Sons (2009).
4. O F Sleptchonok, V Nagy, and M F Desrosiers, Radiat. Phys. Chem. 57 (2000) 115133.
5. ASTM E1261-00 “Standard Guide for Selection and Calibration of Dosimetry Systems for Radiation Processing American Society for Testing and Materials”, West Conshohocken, PA, USA (2000).
6. E Sagstuen et al., The Journal of Physical Chemistry A 101. 50 (1997) 9763.
7. E Sagstuen, A Sanderud, and O H Eli Radiation Research 162. 2 (2004) 112.
8. For an example of a reference work, see R G Parr, and W Yang, “Density-Functional Theory of Atoms and Molecules”, Oxford University Press: New York (1989).
9. P Lahorte et al., The Journal of Physical Chemistry A 103, 33 (1999) 6650.
10. S Ban, Fuqiang, Wetmore, and J Russell, Boyd. The Journal of Physical Chemistry A 103, 21 (1999) 4303.
11. E Pauwels, et al., The Journal of Physical Chemistry A 105. 38 (2001) 8794.
12. R Declerck, et al., Physical Review B 74, 24 (2006) 245103.
13. E Pauwels, et al., Physical Chemistry Chemical Physics 12, 31 (2010) 8733.
14. EPauwels, et al., Physical Chemistry Chemical Physics 16, 6 (2014) 2475.
15. A Klamt, and G J G J Schüürmann. Journal of the Chemical Society, Perkin Transactions 25 (1993) 799.
16. S Sinnecker et al., The Journal of Physical Chemistry A 110, 6 (2006) 2235.
17. E Sagstuen, et al., The Journal of Physical Chemistry A 101, 50 (1997) 9763.
18. H Taniguchi, et al., The Journal of Physical Chemistry 72, 6 (1968) 1926.
19. P Smith, et al., Canadian Journal of Chemistry 48, 3 (1970) 480.
20. M Witwicki, J Jezierska, and A Ozarowski. Chemical Physics Letters 473, 1 (2009) 160.
21. J R Asher, and Martin Kaupp. Chem. Phys. Chem 8, 1 (2007) 69.
22. M Witwicki, and Julia Jezierska. Chemical Physics Letters 493, 4 (2010) 364.
23. M Kaupp, et al., Journal of the American Chemical Society 124, 11 (2002) 2709.
24. R Declerck et al., Physical Review B 74, 24 (2006) 245103.
25. J Tomasi, B Mennucci, and R Cammi. Chemical reviews 105, 8 (2005) 2999