Interplay of weak noncovalent interactions in (E)-4-chloro-N’-(thiophen-2-ylmethylene)benzohydrazide: Insights from Hirshfeld surface, PIXEL energy and QTAIM analyses

Abstract

A newly synthesized compound, (E)-4-chloro-N'-(thiophen-2-ylmethylene)benzohydrazide, has undergone characterization through NMR and single crystal X-ray diffraction techniques. By leveraging the Cambridge Structural Database (CSD), closely related structures to the title compound were identified and compared in terms of conformation to elucidate the substitution effect. Furthermore, Hirshfeld surface analysis and the assessment of the relative contribution of various intermolecular interactions shed light on the impact of substitutions introduced in hydrazide derivatives. The energetics of the molecular dimers observed in the title compound were delineated using CLP-PIXEL energy calculations. These dimers are formed from a range of noncovalent interactions, including a strong N-H center dot center dot center dot O=C hydrogen bond, N-H center dot center dot center dot N, and C-H center dot center dot center dot N/OS/pi interactions. Moreover, a a-hole interaction, such as a chalcogen bond, is observed in one of the molecular dimers, coexisting with other types of interactions to stabilize the molecular dimer. The nature of the chalcogen bond was characterized through a deformation electron density map. The dimensionality of the similarity between the title compound and its closely related structures from the CSD was calculated to comprehend the effect of substitution introduced in one of the aryl rings in hydrazide derivatives. Furthermore, topological analysis was conducted to examine the nature and strength of noncovalent interactions present in the title compound using the framework of the quantum theory of atoms in molecule (QTAIM).