Supramolecular assembly and structural analysis of substituted 2-ferrocenylquinazolin-4-(3H)-one derivatives

• The 6-aryl-substituted 2-ferrocenylquinazolin-4-(3 H )-ones were synthesized and described • The XRD, DFT, Hirschfeld, and RDG-NCI calculations were used to examine intramolecular interactions. • Their crystal structures indicate that intermolecular N–H⋯O hydrogen bonds, C–H⋯π interactions, and π⋯π stacking are the principal determinants of crystal packing. • 4a and 4b had substitutional disorder at C7, indicating that the Suzuki cross-coupling reaction was not quite complete The synthesis of the 6-aryl-substituted 2-Ferrocenylquinazolin-4-(3 H )-ones was achieved using the Suzuki-cross coupling of the 6-iodo-2-ferrocenylquinazolin-4(3 H )-one derivative. The structures of the compounds were determined using 1 H-NMR, 13 C-NMR, IR, XRD, and mass spectrometry. The crystal structures of compounds 3, 4a , and 4b have been elucidated using experimental and theoretical methods. They have been found to crystallise in the monoclinic (space group P2\c), monoclinic (space group P21\n), and triclinic (space group P2-1) crystal systems, respectively. The compounds were found to be stabilised by N—H⋯O intermolecular hydrogen bonds and π⋯π interactions. The HOMO-LUMO energy gap and molecular electrostatic potential maps have been computed to help determine the reactive sites of the molecule. The Hirshfeld surface analysis and 2-D fingerprint plots help explore the nature and percentage contribution of intermolecular interactions. The highest contribution to the total Hirshfeld surface area is for compound 3, which is the H⋯H contacts (41.1%), compound 4a is the H⋯H contact (46.1%), while the contribution of F⋯H/H⋯F contacts is the highest in 4b at 32.6%. The strength and nature of interactions present in the molecules have been characterized by RDG-based NCI analysis.