X-ray crystallographic and computational studies of quaternary ammonium chloride salt complexes with uranyl–salophen compounds

This study investigates salophen-UO2 complexes 1 and 2 assembled with four tetraalkylammonium chloride salts of various cation sizes: tetramethyl (TMA), dimethyl-dipropyl (DMDPA), dimethyl-dibutyl (DMDPA), and tetrabutylammonium (TBA). Single-crystal X-ray diffraction (SC-XRD) and computational analyses such as Hirshfeld surface and DFT analyses and interaction region indicator (IRI) representation provided a comprehensive view on how packing and the overall assembly of the complexes are affected by the size of the ammonium cation and on the interplay among different intermolecular forces responsible for the solid-state structures observed, with a particular focus on the role of cation-π interactions.