C-H...O, C-H...pi and pi-pi interactions in three benzofuran-2-yl ketone derivatives

Acta Crystallogr C. 2005 Jul;61(Pt 7):o438-41. doi: 10.1107/S0108270105016185. Epub 2005 Jun 22.

Abstract

The molecules of 2-benzoyl-1-benzofuran, C15H10O2, (I), interact through double C-H...O hydrogen bonds, forming dimers that are further linked by C-H...O, C-H...pi and pi-pi interactions, resulting in a three-dimensional supramolecular network. The dihedral angle between the benzoyl and benzofuran fragments in (I) is 46.15 (3) degrees . The molecules of bis(5-bromo-1-benzofuran-2-yl) ketone, C17H8Br2O3, (II), exhibit C2 symmetry, with the carbonyl group (C=O) lying along the twofold rotation axis, and are linked by a combination of C-H...O and C-H...pi interactions and Br...Br contacts to form sheets. The stability of the molecular packing in 3-mesityl-3-methylcyclobutyl 3-methylnaphtho[1,2-b]furan-2-yl ketone, C28H28O2, (III), arises from C-H...pi and pi-pi stacking interactions. The fused naphthofuran moiety in (III) is essentially planar and makes a dihedral angle of 81.61 (3) degrees with the mean plane of the trimethylbenzene ring.