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-(34-di­meth­oxy­phen­yl)prop-2-en-1-one

摘要

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).