2-Oxo-2H-chromen-7-yl 4-tert-butylbenzoate

Abstract : In the title compound, C20H18O4, the benzoate ring is oriented at an acute angle of 33.10 (12)degrees with respect to the planar (r.m.s deviation = 0.016 angstrom) coumarin ring system. An intramolecular C-H center dot center dot center dot O hydrogen bond closes an S(6) ring motif. In the crystal, C-H center dot center dot center dot O contacts generate infinite C(6) chains along the b-axis direction. Also present are pi-pi stacking interactions between neighbouring pyrone and benzene rings [centroid-centroid distance = 3.7034 (18) A degrees] and C=O center dot center dot center dot pi interactions [O center dot center dot center dot centroid = 3.760 (3) angstrom]. The data obtained from quantum chemical calculations performed on the title compound are in good agreement with the observed structure, although the calculated C-O-C-C torsion angle between the coumarin ring system and the benzoate ring (129.1 degrees) is somewhat lower than the observed value [141 .3 (3)degrees]. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.