Su ve Benzen Çözeltilerinde 5,5-Dimetil-1-Pirolin N-Oksit’in Bazı Radikal Ürünlerinin Teorik İnce Yapı Çiftlenim Sabitleri

Abstract

Su ve benzen çözeltilerinde 5,5-dimetil-1-pirolin N-oksit (DMPO)’nun bazı radikal ürünlerinin temel hal optimize yapıları, 6-31G (d,p), 6-311++G (d,p), LanL2DZ, LanL2MB ve SDD setlerinde Yoğunluk Fonksiyon Teori (DFT/B3LYP, DFT/B3PW91 ve DFT/PBEPBE) ve Hartree Fock (HF) metotları kullanılarak hesaplandı. Tuzaklanmış radikaller olarak,  H, OH, O(CH₂)(CH₃) ve OC(CH₃)₃ kullanıldı. Tuzaklanan radikallerin hesaplanan izotropik ince yapı çiftlenim sabitlerinin, deneysel veriler uyum içinde olduğu görüldü. Azot radikalinin β protonundan kaynaklı aşırı ince yapı çiftlenim sabitinin, azota bağlı oksijen çekirdeğindeki zıt spin yoğunluğundan etkilendiği görüldü. Elde edilen bütün teorik sonuçlardan, kullanılan radikaller için ince yapı hesaplamalarında, DFT(B3LYP)/LANL2MB setinin diğer setlere kıyasla deneysel veriler ile daha uyumlu sonuçlar verdiği tespit edildi. Ayrıca çalışma, bütün radikal ürünleri için teorik geometrik parametreler, bağlanma enerjileri, atomik spin yoğunlukları ve hiper konjugatif etkileşim enerjileri ile zenginleştirildi.

Keywords

• Aşırı ince yapı sabiti,DMPO,radikal,ESR,DFT

Theoretical Hyperfine Coupling Constants of Some Radical Adducts to 5,5-Dimethyl-1-Pyrroline N-Oxide in Water and Benzene Solutions

Abstract

The ground state optimized structures of some radical adducts of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) in water and benzene solutions have been determined by using Density Functional Theory (DFT/B3LYP, DFT/B3PW91 ve DFT/PBEPBE) ve Hartree Fock (HF) methods with 6-31G (d,p), 6-311++G (d,p), LanL2DZ, LanL2MB and SDD levels. As trapped radicals, H, OH, O(CH₂)(CH₃) and OC(CH₃)₃ have been used. The calculated isotropic hyperfine coupling constants of all the trapped radicals have been seen to be agree with the corresponding experimental data. The hyperfine coupling constant due to the β proton of nitroxide radical is concluded to be effected with the opposite spin density of oxygen nucleus bonded to the nitrogen. From all the calculated data it was obtained that on the hyperfine calculations the DFT (B3LYP) LANL2MB level is superior relative to the other levels for the used radicals. Also, the study has been enriched by the computational of the geometrical parameters, binding energies, atomic spin densities and hyper conjugative interaction energies for all the radical adducts.

Keywords

• Hyperfine constant,DMPO,radical,ESR,DFT

References

1. Morton J.R., 1964. Electron spin resonance spectra of oriented radicals, Chemical Reviews, 64 (4): 453−471.
2. Feller D., Davidson E.R., 1984. Ab initio configuration interaction calculations of the hyperfine structure in small radicals, Journal of Chemical Physics, 80: 1006−1018.
3. Makarova K., Łastawska K., Wagner D., Wawer I., 2014. ESR study of spin trapping in Fenton media in the presence of taxifolin, Journal of Molecular Structure, 1067: 27–36.
4. Buettner G.R., 1987. Spin trapping: ESR parameters of spin adducts, Free Radical Biology & Medicine, 3(4): 259−303.
5. Dikalov S.I., Mason R.P., 2001. Spin trapping of polyunsaturated fatty acid-derived peroxyl radicals. Reassignment to alkoxy radical adducts, Free Radical Biology & Medicine, 30: 187−197.
6. Makarova, K., Rokhina, E.V., Golovina, E.A., Van As, H., Virkutyte J., 2012. Combination of Neural Networks and DFT Calculations for the Comprehensive Analysis of FDMPO Radical Adducts from Fast Isotropic Electron Spin Resonance Spectra, The Journal of Physical Chemistry A, 116(1): 443−451.
7. Ucun F., Aydın S.G.,2014. Calculated optimized structures and hyperfine coupling constants of some radical adducts of α-phenyl-N-tert-buthyl nitrone in water and benzene solutions, Journal of Organometallic Chemistry, 759: 27−32.
8. Miertus S., Scrocco E.,Tomasi J., 1981. Electrostatic interaction of a solute with a continuum A direct utilization of AB initio molecular potentials for the prevision of solvent effects, Chemical Physics 55(1): 117−129.

9. Cammi R., Tomasi J., 1995. Remarks on the use of the apparent surface charges (ASC) methods in solvation problems: Iterative versus matrix-inversion procedures and the renormalization of the apparent charges, Journal of Computational Chemistry, 16(12): 1449−1458.
10. Frisch M.J., Trucks G.W., Schlegel H.B., Scuseria G.E., Robb M.A., Cheeseman J.R., Montgomery Jr J.A., Vreven T., Kudin K.N., Burant J.C., Millam J.M., Iyengar S.S., Tomasi J., Barone V., Mennucci B., Cossi M., Scalmani G., Rega N., Petersson G.A., Nakatsuji H., Hada M., Ehara M., Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai H., Klene M., Li X., Knox J.E., Hratchian H.P., Cross J.B., Adamo C., Jaramillo J., Gomperts R., Stratmann R.E., Yazyev O., Austin A.J., Cammi R., Pomelli C., Ochterski J.W., Ayala P.Y., Morokuma K., Voth G.A., Salvador P., Dannenberg J.J., Zakrzewski V.G., Dapprich S., Daniels A.D., Strain M.C., Farkas O., Malick D.K., Rabuck A.D., Raghavachari K., Foresman J.B., Ortiz J.V., Cui Q., Baboul A.G., Clifford S., Cioslowski J., Stefanov B.B., Liu G., Liashenko A., Piskorz P., Komaromi I., Martin R.L., Fox D.J., Keith T., Al-Laham M.A., Peng C.Y., Nanayakkara A., Challacombe M., Gill P.M.W., Johnson B., Chen W., Wong M.W., Gonzalez C., Pople J.A., 2003. GAUSSIAN 03, Revision C.02, Gaussian Inc., Pittsburgh, PA.
11. Frisch A., Nielsen A.B., Holder A.J., 2001. Gauss View User Manual, Gaussian Inc.,Pittsburg, PA.
12. Boys S.F., Bernardi F., 1970. The calculation of small molecular interactions by the differences of separate total energies. Some procedures with reduced errors, Molecular Physics, 19(4): 553−566.
13. Glandening E.D., Reed A.E., Carpenter J.E., Wienhold F., 1992. NBO Version 3.1, Gaussian Inc., Pittsburgh, PA.
14. Carpenter J. E., Weinhold F., 1988. Analysis of the geometry of the hydroxymethyl radical by the different hybrids for different spins natural bond orbital procedure, Journal of Molecular. Structure (Theochem) 46: 41-62.
15. Reed A.E., Weinstock R. B., Weinhold F., 1985. Natural population analysis, Journal of Chemical. Physics, 83: 735-46.
16. Ludwig P., Layloff T., Adams R.N., 1964. Solvent Effects on Hyperfine Coupling Constants in Electron Paramagnetic Resonance Spectra, Journal of the American Chemical Society, 86(21): 4568-4573.
17. Snehalatha M., Ravikumar C., Joe I.H., Sekar N., Jayakumar V.S., 2009. Spectroscopic analysis and DFT calculations of a food additive Carmoisine, Spectrochimica Acta - Part A, 72(3): 654-662.
18. Choo J., Kim S., Joo H., Kwon Y., 2002. Molecular structures of (trifluoromethyl) iodine dihalides CF3IX2 (X=F, Cl): Ab initio and DFT calculations, Journal of. Molecular Structure (Theochem), 587: 1-8.