organic compounds
Open access
In the title phosphonate, C19H21O9P, the dihedral angle between the benzene rings is 63.33 (3)°, and the P atom has a distorted tetrahedral geometry, with angles in the range 101.30 (6)–120.38 (6)°. No significant intermolecular interactions are observed in the crystal structure, and π–π interactions between symmetry-related benzene rings are beyond 4 Å.
organic compounds
Open access
In the title compound, C17H12F3NO4S, the heterocyclic thiazine ring adopts a half-chair conformation and the dihedral angle between the benzene rings is 43.28 (9)°. The α,β-unsaturated C=C group is inclined at an angle of 21.0 (3)° to the benzene ring of the benzothiazine moiety. In the crystal, inversion dimers linked by pairs of carboxylic acid O—HO hydrogen bonds generate R22(8) loops. Each of the F atoms accepts a Ca—HF (a = aromatic) hydrogen bond from an adjacent molecule, resulting in (001) sheets.