A series of (E)-1-(4-alkyloxyphenyl)-3-(hydroxyphenyl)-prop-2-en-1-one have been successfully synthesised via Claisen-Schmidt condensation. The synthesised chalcone derivatives consisted of hydroxyl groups at either ortho, meta or para position and differed in the length of the alkyl groups, C (n) H(2) (n) (+1,) where n = 6, 10, 12 and 14. The structures of all compounds were defined by elemental analysis, IR, (1)H- and (13)C-NMR. The antimicrobial studies were carried out against wild-type Escherichia coli American Type Culture Collection 8739 to evaluate the effect of the hydroxyl and the alkyl groups of the synthesised chalcones. All the synthesised compounds have shown significant antimicrobial activities. The optimum inhibition was dependent on the position of the hydroxyl group as well as the length of the alkyl chains.
In the title compound, C(29)H(40)O(3), the enone moiety adopts an s-cis conformation. The dihedral angle between the benzene rings is 4.33 (5)° The least-squares mean line through the tetra-decyl side chain forms a dihedral angle of 83.99 (7)° with the normal to the attached benzene ring. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds involving the keto and the hy-droxy O atoms form ribbons along [-41-1]. The crystal structure also features C-H⋯π inter-actions.
In the title compound, C(21)H(24)O(3), the enone moiety adopts an s-cis conformation and the dihedral angle between the benzene rings is 12.89 (6)°. The hex-yloxy tail adopts an extended conformation. In the crystal, inversion dimers are linked by pairs of O-H⋯O hydrogen bonds and pairs of C-H⋯O inter-actions, forming two R(2) (2)(7) and one R(2) (2)(10) loops. The dimers are then arranged into sheets lying parallel to (201) and weak C-H⋯π inter-actions consolidate the packing.
In the title compound, C(25)H(32)O(3), the enone group adopts an s-cis conformation. The alk-oxy chain is in an all-trans conformation. The dihedral angle between the benzene rings is 7.86 (5)°. In the crystal, mol-ecules are connected by pairs of O-H⋯O hydrogen bonds, forming inversion dimers and giving R(2) (2)(10) rings. Within these dimers, weak C-H⋯O hydrogen bonds form two R(2) (2)(7) rings. In the crystal, the approximately planar mol-ecules [largest deviation for an atom being 0.4737 (12) Å for the terminal C atom of the alk-oxy chain] are arranged in sheets parallel to (20-1). Weak C-H⋯π inter-actions are also observed.