The crystal structures of six (2E)-3-aryl-1-(5-halogenothiophen-2-yl)prop-2-en-1-ones

Abstract

The structures of six chalcones containing 5-halogenothiophen-2-yl substituents are reported: (2E)-1-(5-chlorothiophen-2-yl)-3-(4-ethylphenyl)prop-2-en-1-one, C15H13ClOS, (I), and (2E)-1-(5-bromothiophen-2-yl)-3-(4-ethylphenyl)prop- 2-en-1-one, C15H13BrOS, (II), are isostructural in space group P1, while (2E)- 1-(5-chlorothiophen-2-yl)-3-(4-ethoxyphenyl)prop-2-en-1-one, C15H13ClO2S, (III) and (2E)-1-(5-bromothiophen-2-yl)-3-(4-ethoxyphenyl)prop-2-en-1-one C15H13BrO2S, (IV), are isostructural in space group P21/c. There are no hydrogen bonds of any kind in the structures of compounds (I) and (II), but in the structures of compounds (III) and (IV), the molecules are linked into C(7) chains by means of C-H⋯O hydrogen bonds. In the structure of (2E)-3-(4- bromophenyl)-1-(5-chlorothiophen-2-yl)prop-2-en-1-one, C13H8BrClOS, (V), there are again no hydrogen bonds nor π-π stacking interactions but in that of (2E)-1-(5-bromothiophen-2-yl)-3-(3-methoxyphenyl)prop-2-en-1-one, C14H11BrO2S, (VI), the molecules are linked into C(5) chains by C-H⋯O hydrogen bonds. In each of compounds (I)-(VI), the molecular skeletons are close to planarity, and there are short halogen⋯halogen contacts in the structures of compounds (II) and (V) and a short Br⋯O contact in the structure of compound (VI). Comparisons are made with the structures of some similar compounds.