organic compounds
The title compound, C20H19NO5S2, crystallizes as an almost 2:1 mixture of two molecular orientations (described as Orient-A and Orient-B). The consequences of these two orientations is the formation of three types of N—HO hydrogen-bonded dimers in which the (Orient-A + Orient-A) dimers are likely to be the most stable, while the mixed (Orient-A + Orient-B) dimers are more frequent. Extra interactions in the form of C—HO and C—Hπ interactions act to further stabilize these dimers and probably allow the less energetically favourable (Orient-A + Orient-B) and (Orient-B + Orient-B) hydrogen-bonded dimers to exist by preventing their conversion to (Orient-A + Orient-A)-only hydrogen-bonded dimers during the crystal-growth process.
organic compounds
The title compounds, namely (2Z)-1-(4-bromophenyl)-2-(pyrrolidin-2-ylidene)ethanone, C12H12BrNO, (I), (2Z)-1-(4-bromophenyl)-2-(piperidin-2-ylidene)ethanone, C13H14BrNO, (II), and (2Z)-2-(azepan-2-ylidene)-1-(4-bromophenyl)ethanone, C14H16BrNO, (III), are characterized by bifurcated intra- and intermolecular hydrogen bonding between the secondary amine and carbonyl groups. The former establishes a six-membered hydrogen-bonded ring, while the latter leads to the formation of centrosymmetric dimers. Weak C—HBr interactions link the individual molecules into chains that run along the [011], [101] and [101] directions in (I)–(III), respectively. Additional weak BrO, C—Hπ and C—HO interactions further stabilize the crystal structures.