Three isomeric forms of hydroxyphenyl-2-oxazoline: 2-(2-hydroxyphenyl)-2-oxazoline, 2-(3-hydroxyphenyl)-2-oxazoline and 2-(4-hydroxyphenyl)-2-oxazoline
Journal article, 2005

Crystal structures are reported for three isomeric compounds, namely 2-(2-hydroxyphenyl)-2-oxazoline, (I), 2-(3-hydroxyphenyl)-2-oxazoline, (II), and 2-(4-hydroxyphenyl)-2-oxazoline, (III), all C9H9NO2 [systematic names: 2-(4,5-dihydro-1,3-oxazol-2-yl)phenol, (I), 3-(4,5-dihydro-1,3-oxazol-2-yl)phenol, (II), and 4-(4,5-dihydro-1,3-oxazol-2-yl)phenol, (III)]. In these compounds, the deviation from coplanarity of the oxazoline and benzene rings is dependent on the position of the hydroxy group on the benzene ring. The coplanar arrangement in (I) is stabilized by a strong intramolecular O-H...N hydrogen bond. Surprisingly, the 2-oxazoline ring in molecule B of (II) adopts a 3T4 (C2TC3) conformation, while the 2-oxazoline ring in molecule A, as well as that in (I) and (III), is nearly planar, as expected. Tetramers of molecules of (II) are formed and they are bound together via weak C-H...N hydrogen bonds. In (III), strong intermolecular O-H...N hydrogen bonds and weak intramolecular C-H...O hydrogen bonds lead to the formation of an infinite chain of molecules perpendicular to the b direction. This paper also reports a theoretical investigation of hydrogen bonds, based on density functional theory (DFT) employing periodic boundary conditions.

conformation

hydrogen bonds

X-ray structure

density functional theory

Author

Vratislav Langer

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Miroslav Koós

Dalma Gyepesová

Mariana Sládkovicová

Jozef Luston

Juraj Kronek

Acta Crystallographica Section C: Crystal Structure Communications

0108-2701 (ISSN) 1600-5759 (eISSN)

Vol. C61 10 o602-o606

Subject Categories

Chemical Sciences

More information

Created

10/6/2017