A combined experimental and computational study of a supramolecular assembly based on cationic zinc(II)-ethanesulfonate

Abstract

Abstract Studies based on the role of non-covalent interactions in physical, chemical, and biological phenomena in supramolecular assemblies have gained considerable interest. Herein, we report a supramolecular assembly, [Zn(phen)2(H2O)2](EtSO3)2·2H2O (1) afforded by the reaction of a preformed zincate salt, [Et4N]2[Zn(OSO2Et)4] and 1,10-phenanthroline (phen). Compound 1 has been characterized by FTIR, 1H/13C NMR, elemental analysis, and single-crystal X-ray crystallography. Crystal structure of 1 reveals two different stacking modes (π … π) between the aromatic rings of phen ligands of dicationic moieties, [Zn(phen)2(H2O)2]2+ leading to the formation of one-dimensional (1D) supramolecular motifs. Furthermore, the ability of the ethanesulfonate group to act as prolific H-bond acceptor (O–H⋯O/C–H⋯O type hydrogen bonds) between the water dimer/tetramer, and aromatic phen rings perpetuates 1D cationic units into a 3D supramolecular motif. Density functional theory (DFT) calculations were carried out to understand the relative importance of such interactions by evaluating their individual bonding energies. Additionally, the 3D Hirshfeld surfaces analysis and 2D fingerplots suggested that the assembly is dominated by H⋯H and O⋯H supramolecular contacts. Remarkably, the interplay of secondary interactions between cationic moieties, weakly-coordinating ethanesulfonate anions, and water dimer/tetramers forming a 3D supramolecular assembly has not been reported in the literature earlier.