Crystal structures of three 1-[4-(4-bromobutoxy)phenyl] chalcone derivatives: (E)-1-[4-(4-bromobutoxy)phenyl]-3-phenylprop-2-en-1-one, (E)-1-[4-(4-bromobutoxy)phenyl]-3-(4-methoxyphenyl)prop-2-en-1-one and (E)-1-[4-(4-bromobutoxy)phenyl]-3-(3,4-dimethoxyphenyl)prop-2-en-1-one

Abstract

The crystal structures of three chalcones with a bromo-substituted butoxy side chain, viz. (E)-1-[4-(4-bromobutoxy)phenyl]-3-phenylprop-2-en-1-one, C19H19BrO2, (I), (E)-1-[4-(4-bromobutoxy)phenyl]-3-(4-methoxyphenyl)prop-2-en-1-one, C20H21BrO3, (II), and (E)-1-[4-(4-bromobutoxy)phenyl]-3-(3,4-dimethoxyphenyl)prop-2-en-1-one, C21H23BrO4, (III), are reported. In all molecules, the conformation of the keto group with respect to the olefinic bond is s-cis. Molecules of (I) and (II) are nearly planar, while molecule (III) is not planar. In the crystal of compounds (I) and (II), molecules are linked into chains parallel to the c axis by C - H⋯π interactions. In the crystal of compound (III), molecules are linked by a pairs of C - H⋯O hydrogen bonds, forming inversion dimers. Weak C - Br⋯π interactions are also observed in (III).