Single crystal X-ray studies and Hirshfeld surface analysis of ethoxy phenyl substituted chalcone derivatives

The single crystal X-ray of three chalcone derivatives, (2E)-3-(2-chlorophenyl) -1-(4-ethoxyphenyl) prop-2-en-1-one (I), (2E)-3-(3-chlorophenyl)-1-(4-ethoxyphenyl)prop-2-en-1-one (II) and (2E)-1-(4-ethoxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (III) was determined. The compound (I) crystallized in triclinic P−1 crystal system and in the asymmetric unit of the compound (I), two molecules were present. The conformational differences between molecule A and B indicated with the dihedral angles of 3.47 (2)° (A) and 8.12 (16)° (B), measured between chlorophenyl ring (C1A/B-C6A/B) and methoxy phenyl (C10A/B–C16A/B). Similarly the compound (II) crystallized in monoclinic P−1 crystal system and in the asymmetric unit of the compound (II), two molecules were present. The conformational differences between molecule A and B with the dihedral angles of 4.50 (11)° (A) and 3.94 (11)° (B) was measured between terminal phenyl rings. The compound (III) crystallized in monoclinic, P21/n, with a dihedral angle between two terminal phenyl rings is 13.18 (7)°, indicating the near planarity of the compound. The intramolecular hydrogen bond of the types C—H…O is observed in all compounds (I), (II) and (III). In the crystal structures (I), (II) and (III), C—H…π intermolecular interaction was found in all compounds. The intermolecular hydrogen bond of the type C—H…O was present in compounds (I) and (II). The Hirshfeld surface analysis was carried for compounds (I), (II) and (III). Intercontacts C C, C H, C O, H H and O H were common in all compounds which contributed more to the Hirshfeld surfaces. The electrostatic potential surfaces were drawn to understand electrophilic and nucleophilic regions on the molecule.