Crystal structure of 2-oxo-2H-chromen-7-yl 4-fluorobenzoate

Abstract

In the title compound, C16H9FO4, (I), the benzene ring is oriented at an acute angle of 59.03 (15)° relative to the coumarin plane (r.m.s deviation = 0.009 Å). This conformation of (I) is stabilized by an intramolecular C—H...O hydrogen bond, which closes a five-membering ring. In the crystal, molecules of (I) form infinite zigzag chains along the b-axis direction, linked by C—H...O hydrogen bonds. Furthermore, the crystal structure is supported by π–π stacking interactions between neighbouring pyrone and benzene or coumarin rings [centroid–centroid distances in the range 3.5758 (18)–3.6115 (16) Å], as well as C=O...π interactions [O...centroid distances in the range 3.266 (3)–3.567 (3) Å]. The theoretical data for (I) obtained from quantum chemical calculations are in good agreement with the observed structure, although the calculated C—O—C—C torsion angle between the coumarin fragment and the benzene ring (73.7°) is somewhat larger than the experimental value [63.4 (4)°]. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.

Keywords

• coumarin ester
• C—H...O hydrogen bonds
• π–π stacking interactions
• Hirshfeld surface analysis
• quantum chemical calculations
• crystal structure