Crystal structures of three functionalized chalcones: 4′-dimethylamino-3-nitrochalcone, 3-dimethylamino-3′-nitrochalcone and 3′-nitrochalcone

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 two-dimensional 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].