Intramolecular hydrogen bonds in a quercetin molecule: a study by the method of analysis of the electron density

1Protsenko, IO
1Institute of High Technology, Taras Shevchenko National University of Kyiv
Dopov. Nac. akad. nauk Ukr. 2014, 7:165-168
Section: Biophysics
Language: Ukrainian

Using the method of analysis of the electron density at the level of the theory DFT B3LYP/6-31++G(d,p), it is shown that each of twelve stable conformers of a quercetin molecule has three intramolecular H-bonds - two OH. . .O and one CH. . .O, whose energies lie within 3.16–6.09 kcal/mol. Moreover, the total energy of H-bonds in each conformer is a little bit higher than the value of 13 kcal/mol. For the most energetically favorable conformer, it is shown that the H-bond CH. . .O is quite flexible and is broken when the modified phenyl ring is turned relative to the plane of the molecule by an angle of more than 45 degrees.

Keywords: electron density, hydrogen bonds, quercetin molecule