Abstract
In the title compound, C29H21O3P, a coumarin-substitued ylid, the P atom is linked to three benzene rings and a planar coumarin moiety via a methylenecarbonyl group. The bond lengths in the P=C-C=O fragment clearly indicate a delocalized system involving the olefinic and carbonyl bonds. The molecular structure is stabilized by an intramolecular C-H center dot center dot center dot O interaction that results in an S7 graph-set ring motif. In the crystal, molecules are linked into a three-dimensional framework by C-H center dot center dot center dot O hydrogen bonds.