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The structures of three iodochalcones, functionalized with fluorine or a nitro group, have been investigated to explore the impact of different molecular electrostatic distributions on the halogen bonding within each crystal structure. The strongly withdrawing nitro group presented a switch of the halogen bond from a lateral to a linear motif. Surprisingly, this appears to be influenced by a net positive shift in charge distribution around the lateral edges of the σ‐hole, making the lateral I...I bonding motif less preferable. A channel of amphoteric I...I type II halogen bonds is observed for a chalcone molecule, which was not previously reported in chalcones, alongside an example of the common synthon involving extended linear chains of I...O2N donor–acceptor halogen bonds. This work shows that halogenated chalcones may be an interesting target for developing halogen bonding as a significant tool within crystal engineering, a thus far underexplored area for this common structural motif. [ABSTRACT FROM AUTHOR]

The structure of three functionalized chalcones (1,3-diarylprop-2-en-1-ones), containing combinations of nitro and dimethylamino functional groups, are presented, namely, 1-[4-(dimethylamino)phenyl]-3-(3-nitrophenyl)prop-2-en-1- one, C17H16N2O3, Gp8m, 3-[3-(dimethylamino)phenyl]-1-(3-nitrophenyl)prop- 2-en-1-one, C17H16N2O3, Hm7m and 1-(3-nitrophenyl)-3-phenylprop-2-en-1- one, C15H11NO3, Hm1-. Each of the molecules contains bonding motifs seen in previously solved crystal structures of functionalized chalcones, adding to the large dataset available for these small organic molecules. The structures of all three of the title compounds contain similar bonding motifs, resulting in twodimensional planes of molecules formed via C--H O hydrogen-bonding interactions involving the nitro- and ketone groups. The structure of Hm1- is very similar to the crystal structure of a previously solved isomer [Jing (2009). Acta Cryst. E65, o2510]. [ABSTRACT FROM AUTHOR]

Heterocyclic chalcones are a recently explored subgroup of chalcones that have sparked interest due to their significant antibacterial and antifungal capabilities. Herein, the structure and solubility of two such compounds, (E)‐1‐(1H‐pyrrol‐2‐yl)‐3‐(thiophen‐2‐yl)prop‐2‐en‐1‐one and (E)‐3‐phenyl‐1‐(1H‐pyrrol‐2‐yl)prop‐2‐en‐1‐one, are assessed. Single crystals of (E)‐1‐(1H‐pyrrol‐2‐yl)‐3‐(thiophen‐2‐yl)prop‐2‐en‐1‐one were grown, allowing structural comparisons between the heterocyclic chalcones and (2E)‐1,3‐diphenylprop‐2‐en‐1‐one, trivially known as trans‐chalcone. The two heterocyclic chalcones were found to be less soluble in all solvents tested and to have higher melting points than trans‐chalcone, probably due to their stronger intermolecular interactions arising from the functionalized rings. Interestingly, however, it was found that the addition of the thiophene ring in (E)‐1‐(1H‐pyrrol‐2‐yl)‐3‐(thiophen‐2‐yl)prop‐2‐en‐1‐one increased both the melting point and solubility of the sample compared with (E)‐3‐phenyl‐1‐(1H‐pyrrol‐2‐yl)prop‐2‐en‐1‐one. This observation may be key for the future crystal engineering of heterocyclic chalcones for pharmaceutical applications. [ABSTRACT FROM AUTHOR]