Recurrent π-π stacking motifs in three new 4,5-dihydropyrazolyl-thiazole-coumarin hybrids: X-ray characterization, Hirshfeld surface analysis and DFT calculations

Abstract

The synthesis and X-ray characterization of three new 4,5-dihydropyrazolylthiazole-coumarin hybrids (1-3) are reported herein, namely 3-(2-(3,5-bis(4-chlorophenyl)-4,5-dihydropyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one (1), 3-(2-(5-(4-chlorophenyl)-4,5-dihydro-3-phenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one (2) and 3-(2-(3-(4-chlorophenyl)-4,5-dihydro-5-p-tolylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one (3). A detailed structural analysis of the noncovalent interactions and their evaluation using Hirshfeld surface analysis is also reported, evidencing the importance of C-H⋯O and π-π interactions. Finally, DFT calculations along with the molecular electrostatic potential (MEP) and NCIplot index analysis have been used to evaluate those interactions energetically and to investigate the relative importance of two different π-stacking modes that are recurrent binding motifs in the solid state architecture of the three complexes.