Intermolecular Interactions In Antipyrine-Like Derivatives 2-Halo-N-(1,5-Dimethyl-3-Oxo-2-Phenyl-2,3-Dihydro-1h-Pyrazol-4-Yl)Benzam Ides: X-Ray Structure, Hirshfeld Surface Analysis And Dft Calculations

The synthesis, X-ray structure characterization, Hirshfeld surface analysis and DFT calculations of two new antipyrine derivatives are reported herein. Particularly, 2-bromo-N-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)benzamide (1) and 2-chloro-N-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)benzamide (2) are synthesized in good yields and characterized spectroscopically. Both compounds are isostructural and crystallize in the monoclinic P2(1)/c space group. The crystal packing of both compounds is mainly stabilized by a combination of N-HMIDLINE HORIZONTAL ELLIPSISO and C-HMIDLINE HORIZONTAL ELLIPSISO hydrogen bonds. In addition, C-HMIDLINE HORIZONTAL ELLIPSIS pi and lone pairMIDLINE HORIZONTAL ELLIPSIS pi contacts were observed. Their solid-state structures have been analyzed through Hirshfeld surface analysis, including the evaluation of the different energy frameworks, indicating that the molecular sheets are primarily formed by hydrogen bonds and the stabilization is dominated via the electrostatic energy contribution. These studies are complemented with DFT calculations (B3LYP-D3/def2-TZVP), and a combination of QTAIM/NCIplot analyses disclosing that the H-bonding interactions are energetically relevant (ranging from 0.9 to 6.1 kcal mol(-1)), however the total binding energies of the different assemblies are dominated by a combination of pi-interactions (of the type C-HMIDLINE HORIZONTAL ELLIPSIS pi, pi MIDLINE HORIZONTAL ELLIPSIS pi, and lone pair halogenMIDLINE HORIZONTAL ELLIPSIS pi) that are able to stabilize cooperatively the assemblies up to 12 kcal mol(-1).