Redetermination of (E)-3-(anthracen-9-yl)-1-(2-hy­droxy­phen­yl)prop-2-en-1-one1

The redetermined structure of title chalcone derivative, C23H16O2, corrects errors in the title, scheme and synthesis in the previous report of the same structure [Jasinski et al. (2011 ▶). Acta Cryst. E67, o795]. There are two independent mol­ecules in the asymmetric unit with slight differences in bond lengths and angles. The dihedral angle between the benzene ring and the anthracene ring system is 73.30 (4)° in one mol­ecule and 73.18 (4)° in the other. Both mol­ecules feature an intra­molecular O—H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, mol­ecules are arranged into sheets lying parallel to the ac plane and further stacked along the b axis by π–π inter­actions with centroid–centroid distances in the range 3.6421 (6)–3.7607 (6) Å. The crystal structure is further stabilized by C—H⋯π inter­actions. There are also C⋯O [3.2159 (15) Å] short contacts

(E)-3-(Anthracen-9-yl)-1-(2-bromo­phen­yl)prop-2-en-1-one

The mol­ecule of the title chalcone, C23H15BrO, is not planar and exists in the E configuration with respect to the central C=C bond. The dihedral angle between the benzene and anthracene rings is 83.58 (6)°. The prop-2-en-1-one bridge makes dihedral angles of 63.00 (7) and 42.62 (16)° with the benzene and anthracene rings, respectively. In the crystal, mol­ecules are linked into dimers by weak C—H⋯O inter­actions. These dimers are arranged parallel to the bc plane and are further stacked along the a axis by π–π inter­actions with a centroid–centroid distance of 3.7561 (9) Å. The crystal structure is further stabilized by C—H⋯π inter­actions

(Z)-3-(Anthracen-9-yl)-1-(2-ethoxyphenyl)prop-2-en-1-oneThis paper is dedicated to the late His Royal Highness Prince Mahidol of Songkla for his contributions to the development of medical education in Thailand on the occasion of Mahidol Day which falls on the 24th September.

The molecule of the title chalcone, C25H20O2, consisting of 2-ethoxyphenyl and anthracene rings bridged by a prop-2-en-1-one unit, is twisted and exists in the Z configuration with respect to the central C=C bond. The dihedral angle between the benzene and anthracene rings is 78.17 (9)°. The propene unit makes dihedral angles of 44.5 (2) and 81.1 (2)° with the benzene and anthracene rings, respectively. The ethoxy substituent is almost coplanar with the attached benzene ring [C—O—C—C torsion angle = 178.57 (19)°]. In the crystal, molecules are linked into chains along the a axis by weak C—H...O interactions. The crystal structure is further stabilized by C—H...π interactions