Crystal structure and optical spectroscopic analyses of (E)-3-(1H-indol-2-yl)-1-(4-nitro­phen­yl)prop-2-en-1-one hemihydrate

The asymmetric unit of the title compound, 2C(17)H(12)N(2)O(3)·H(2)O comprises two mol­ecules of (E)-3-(1H-indol-2-yl)-1-(4-nitro­phen­yl)prop-2-en-1-one and a water mol­ecule. The main mol­ecule adopts an s-cis configuration with respect to the C=O and C=C bonds. The dihedral angle between the indole ring system and the nitro-substituted benzene ring is 37.64 (16)°. In the crystal, mol­ecules are linked by O—-H⋯O and N—H⋯O hydrogen bonds, forming chains along [010]. In addition, weak C—H⋯O, C—H⋯π and π–π inter­actions further link the structure into a three-dimensional network. The optimized structure was generated theoretically via a density functional theory (DFT) approach at the B3LYP/6–311 G++(d,p) basis level and the HOMO–LUMO behaviour was elucidated to determine the energy gap. The obtained values of 2.70 eV (experimental) and 2.80 eV (DFT) are desirable for optoelectronic applications. The inter­molecular inter­actions were qu­anti­fied and analysed using Hirshfeld surface analysis.