research communications Acta Cryst. (2023). E79 https://doi.org/10.1107/S2056989023001895 1 of 5 Received 25 October 2022 Accepted 1 March 2023 Edited by A. S. Batsanov, University of Durham, United Kingdom Keywords: crystal structure; condensation; crystal packing; density functional theory; Hirshfeld surface analysis; hydrogen bonding. CCDC reference: 2153643 Supporting information: this article has supporting information at journals.iucr.org/e Crystal structure, Hirshfeld surface analysis and DFT study of (5E,5 0 E,6Z,6 0 Z)-6,6 0 -[ethane-1,2-diyl- bis(azanylylidene)]bis{5-[2-(4-fluorophenyl)- hydrazono]-3,3-dimethylcyclohexanone} 2.5-hydrate Malahat Musrat Kurbanova, a Md. Serajul Haque Faizi, b Emine Berrin Cinar, c Asif Jamal, b Mustafa C ¸emberci, c Arzu Sadigova, a Rizvan Askerov, a Necmi Dege d and Tahera Nabi e * a Baku State University, Organic Chemistry Department, Z. Khalilov 23, Baku, AZ, 1148, Azerbaijan, b PG Department of Chemistry, Langat Singh College, B. R. A. Bihar University, Muzaffarpur, Bihar-842001, India, c Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, Samsun, 55200, Tu ¨ rkiye, d Department of Physics, Faculty of Sciences, Ondokuz Mayıs University, Samsun, 55200, Tu ¨ rkiye, and e Faculty of Chemistry, Karte-e-chahar, Kabul, Afghanistan. *Correspondence e-mail: tahera.nabi@ku.edu.af The title compound, C 30 H 34 F 2 N 6 O 2 2.5H 2 O, was obtained by condensation of 2-[2-(4-fluorophenyl)hydrazono]-5,5-dimethylcyclohexan-1,3-dione with ethyl- enediamine in ethanol and crystallized as a 1:2.5 hydrate in space group C2/c. The two independent molecules, with approximate crystallographic C 2 symmetries, have different conformations and packing environments, are stabilized by intramolecular N—HN hydrogen bonds and linked by O— HO hydrogen bonds involving the water molecules. A Hirshfeld surface analysis showed that HH contacts make by far the largest (48–50%) contribution to the crystal packing. From DFT calculations, the LUMO–HOMO energy gap of the molecule is 0.827 eV. 1. Chemical context Diketones are versatile starting materials in the synthesis of organic and coordination compounds (Mahmudov et al. , 2017), used as shift reagents (Hinckley, 1969), chemical and photo- chemical catalysts or as biologically active derivatives to treat inflammatory diseases. -Diketones can be isolated from natural sources such as bacteria, plants or fungi, and can also be obtained synthetically (Shokova et al., 2015). More recently, 1,2-bis(3,5-difluorophenyl)ethane-1,2-dione has been used to synthesize various polymers for use as photovoltaics (Cai et al., 2019) or gas chromatography stationary phases (Liu et al., 2019). Non-covalent interactions, such as halogen, hydrogen, chalcogen, pnicogen, aerogen, tetrel and icosagen bonds, as well as –cation, –anion, n–, – * stacking and hydrophobic contacts may organize or arrange the confor- mation and aggregation of molecules, their stabilization and particular properties (Desiraju 1995; Akbari Afkhami et al., 2017; Hazra et al., 2018; Gurbanov et al. , 2018; Kvyatkovskaya et al., 2017; Jlassi et al., 2014). Herein we report the synthesis, crystal structure and density functional theory (DFT) calcu- lation of the title compound (II), obtained by the condensa- tion reaction between ethylenediamine and 2-[2-(4-fluoro- phenyl)hydrazone]-5,5-dimethylcyclohexan-1,3-dione (I) in a 2:1 ratio, in the presence of catalytic hydrochloric acid. A ISSN 2056-9890 Published under a CC BY 4.0 licence