Conformational isomerism of pyrimidine nucleosides isolated in the low temperature inert matrices
Abstract
For the first time, conformational structures of 2-deoxyuridine (dU) and thymidine (T) were investigated by using Fourier transform infrared (FTIR) matrix isolation spectroscopy. The FTIR spectra of dU and T in Ar matrices were obtained in the range 4000-1400 cm-1-1. The stability of conformers was estimated by the methods HF/3-21G (p), HF/6-31G (d, p), and MP2/6-31G (d, p). Ab initio calculations of the infrared spectra were performed by the methods HF/3-21G(p), HF/6-31G (d, p). The actual occupancy of conformational isomers in matrix samples was determined. It was shown that anti conformers of dU and T are dominant. The ribose rings of main anti conformers al1, a00 are in the С2''-endo conformation, but the ribose rings of low-occupying anti-conformers a22, a33 have the СЗ'-exo conformation, stabilized by intramolecular hydrogen bonds ОЗ'Н—05' and 05'Н—03' accordingly. Syn conformers of these nucleosides are stabilized by the intramolecular hydrogen bond 05'Н—02, and the dominant conformation of the ribose ring is С2'-endo.
Downloads
References
2. G.A. JefFrey. W. Saenger Hydrogen Bonding in Biological Structures / Springer- Verlag , Berlin, 1991, p. 563
3. S.N. Rao//'Nucleosides&Nucleotides, 1995, 14(6). p. 1179-1193
4. F. Seela, H. Debelak. H. Reuter, G. Kastner and I.A. Mikhailopulo //Tetrahedron 55. 1999. p. 1295-1308
5. N. Leulliot. M. Ghomi, G. Scalmani, G. Berthier. // J. Phys. Chem. A 1999, V. 103, p. 8716-8724.
6. N. Leulliot. M. Ghomi, H. Jobic. O. Bouloussa, V. Baumruk, C. Coulombeau // J.Phys.Chem. B 1999. 103, p. 10934-10944.
7. O.V. Shishkin, A. Pelmenschikov, D.M. Hovorun. J. Leszczynski //J. Mol.Struct. 526. 2000. p.329-341
8. Barnes A. J., // J.Mol. Struct. 113.(1984), p.161-174
9. S.A. Krasnokutski, A.Yu. Ivanov, V. Izvekov, G.G. Sheina and Yu.P. Blagoi // XXIV European Congress on Molecular Spectroscopy. Prague. Czech Repablic, 1998. p. 470.
10.S.A. Krasnokuski, A.Yu. Ivanov. V. Izvekov, G.G. Sheina, Yu.P. Blagoi //J. Mol.Struct. 482-483, (1998). p. 249-252.
11.A.Yu. Ivanov, A.M. Plokhotnichenko, E.D. Radchenko, G.G. Sheina, Yu.P. Blagoi, J.Mol. Struct. 372 (1995) p.91-100.
12.Yu. Ivanov, A.M. Plokhotnichenko, V. Izvekov. G.G. Sheina, Yu.P. Blagoi J. Mol.Struct. 408-409. 459 (1997).
13. M.W. Schmidt, K.K.Baldridge, J.A.Boats, S.T.Elbert, M.S.Gordon. J. H. Jensen. S. Koseki.,
N. Matsunaga, S.Su, T.L.Windus, M.Dupuis and J.A.Montgomeri. // J. of Computational Chemistry. Vol.14. No. l 1. (1993) p. 1347-1363
14.Alex A. Granovsky. http://classic.chem.msu.su/gran/gamess/index.html
15. Говорун Д.М., Міщук Я.Р., Кондратюк І.В., Желтовський М.В // Доповіді НАН України, 8. 1996. стор. 141-144
16. M.J. Nowak, L. Les and L. Adamowicz Trends in Physical Chemistry // 4, 1994, p. 137-168
17.M.J. Nowak, L. Lapinski, D.C. Bienko, D. Michalska // Spectrochimica acta A. 53. 1997, p. 855-865
18. Водородная связь. Под ред. Соколова Н.Д. / М., Наука, 1981, стр. 288
19. S.E. Barrows, F.J. Dulles, C.J. Cramer, A.D. French, D.G. Truhlar // Carb. Res. 276 (1995) p.219.
20.Kwiatkowski J.S., and Leszczynsky J. // Chem. Phys. Lett. 204.1993. p.430-434
21. M.J. Nowak , L.Lapinski, J. Fulara// Spectrochimica Acta, 45, A 2, (1989). p.229-242
22. Vranken H.., Smets J., Maes G., Lapinski L., Nowak M.J., and Adamovicz L. // Spectrochimica Acta, Vol 50A, N5, 1994. p. 875-889
23.Yamaguchi Y.. Frisch M., Gaw J., Schaefer III H.F., Binkley J.S. // J. Chem. Phys. 84 (4). 1986 p. 2262-2278
24. С. Глесстон. К. Лейдер. Г.Эйринг, Теория абсолютных скоростей реакций / М.: Издатинлит ,1948 - 321 с.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
