Analysis of Intermolecular Interactions in 2,3,5 Trisubstituted Pyrazoles Derivatives: Insights into Crystal Structures, Gaussian B3LYP/6-311G (d,p), PIXELC and Hirshfeld Surface

Abstract: Two derivatives of pyrazole have been synthesized with one of the systematic substitutions made on the ortho position of the phenyl ring attached to the pyrazole moiety and characterised via single crystal X-ray diffraction. The nature of the molecules appear as planar with the hydrogen bonding features analysed quantitatively. The derivatives are geometrically optimized and studied for its molecular confirmation at the B3LYP/6-311G (d,p). The structure overlay, molecular packing and intermolecular hydrogen bonding are studied quantitatively using Hirshfeld surface and 2D fingerprint plots. In both the compounds, packing of the molecules is derived via strong O–H···N and weak C–H···O, C–H···π interactions stabilizing the packing. Further, the structure overlay between the experimental structures and the geometrically optimized structures along with frequency analysis at the quantum chemical level shows the deviation in the central pyrazole moiety and the substituted phenyl ring with the RMSD value of 0.5051 and 0.6305 Å respectively. The lattice energy is calculated for both the compounds using PIXELC module in Coulomb–London–Pauli (CLP) package and is partitioned into corresponding coulombic, polarization, dispersion and repulsion contributions. Graphical Abstract: [Figure not available: see fulltext.]