Hydrogen bonds of anti-HIV active aminophenols

Abstract

Analysis of IR-Fourier spectra from solutions and crystals of antiviral sulfo-containing aminophenols has shown that various types of intramolecular and intermolecular interactions can occur in molecules of these compounds. Three types of intramolecular hydrogen bonds (O-H⋅⋅⋅N, O-H⋅⋅⋅O=S=O, and N-H⋅⋅⋅O=S=O) are formed in CCl 4 solutions of the sulfo-containing aminophenols. The formation of intermolecular H-bonds involving the NH-and OH-groups and the preservation of the intramolecular O-H⋅⋅⋅O=S=O H-bond are characteristic of the anti-HIV active aminophenol crystals. Spectral attributes are determined in order to distinguish between the anti-HIV active and inactive sulfo-containing aminophenols.

Electronic structure and spectroscopic properties of anti-HIV active aminophenols

“…The study of the IR spec tra of 10 -3 M CCl 4 solutions of all eight sulphone con taining aminophenols has shown that the absorption bands with the frequencies of their maxima ν max = 3638, 3425, and 3250 cm -1 are caused by stretching vibrations of free and associated OH groups, while bands with ν max = 3510 and 3360 cm -1 occur due to free and coupled vibrations N-H [7,14].…”

“…Aminophenol compounds were synthesized according to techniques described in [7]. The correct ness of the chemical structure of synthesized ami nophenol derivatives was confirmed by data of mass spectrometry, NMR, and elemental analysis.…”

“…The geometry of aminophenol molecules was optimized based on the density functional theory using the ADF software package [12]. The IR spectra of aminophenol molecules yield useful information for choosing the most probable conformer of the mol ecule [4][5][6][7]. An analysis of these spectra showed that all o aminophenol molecules that contain hydroxyl group are characterized by the presence of hydrogen bonds of the О-Н…N type [4,5].…”

Infrared spectra and structure of molecular complexes of aromatic acids

“…Conditions for the formation of intramolecular HBs are created in phenols with several OH groups and electronegative atoms such as N and O located in the ortho-position to one of the hydroxyls [8][9][10][11][12]. Therefore, the AB with ν max = 3464 cm -1 in the IR spectrum of BA I in CCl 4 (Table 1) were observed in the IR spectrum of BA I crystal (Fig.…”

“…As a rule, vibrations of free OH groups in spectra of phenols appear in the range 3640-3600 cm -1 [12,13]. It is noteworthy that phenol hydroxyls are not involved in IeI that form HBs at concentrations ≤3⋅10 -3 M in neutral solvents [8][9][10][11][12].…”