Synthesis, characterization, and crystal structure of two α,β-unsaturated ketones with N-heterocycle

Abstract

Two α,β-unsaturated ketones: C₂₂H₁₆N₂O (1), (E)-3-(4-(1H-benzo[d]imidazol-1-yl)phenyl)-1-phenylprop-2-en-1-one and C₁₉H₁₆N₂O₂ (2), (E)-3-(4-(1H-pyrazol-1-yl)phenyl)-1-(4-methoxyphenyl)prop-2-en-1-one were synthesized and characterized by X-ray diffraction analyses, EA, ¹H NMR-, and IR-spectra. In the crystal structure of 1, molecules are linked through intermolecular hydrogen bonds, C-H⋯π and π⋯π interactions forming a 3-D network, while in the crystal structures of 2, molecules are assembled by the C-H⋯O, C-H⋯N hydrogen bonds and C-H⋯π interactions into an infinite 3-D supramolecular structure. A particularly interesting feature of the packing in the structure of 2, is the extensive contribution of C-H⋯π interactions, involving two hydrogen atoms from each of the methyl groups of the methoxy substituents.