From small structural modifications to adjustment of structurally dependent properties: 1-methyl-3,5-bis[(E)-2-thienylidene]-4-piperidone and 3,5-bis[(E)-5-bromo-2-thienylidene]-1-methyl-4-piperidone.

The molecules of the title compounds, C(16)H(15)NOS(2), (I), and C(16)H(13)Br(2)NOS(2), (II), are E,E-isomers and consist of an extensive conjugated system, which determines their molecular geometries. Compound (I) crystallizes in the monoclinic space group P2(1)/c. It has one thiophene ring disordered over two positions, with a minor component contribution of 0.