Structure of Imidazolium-N-phthalolylglycinate Salt Hydrate: Combined Experimental and Quantum Chemical Calculations Studies

Abstract

An organic supramolecular salt hydrate (imidazolium:N-phthalolylglycinate:H2O; IM+-NPG−-HYD) has been examined for its charge-transfer (CT) characteristics. Accordingly, IM+−NPG−−HYD has been characterized thoroughly using various spectroscopic techniques. Combined experimental and quantum chemical studies, along with wave function analysis, were performed to study the non-covalent interactions and their role in CT in the supramolecular salt hydrate. Notably, IM+−NPG−−HYD crystalizes in two configurations (A and B), both of which are held together via non-covalent interactions to result in a three-dimensional CT supramolecular assembly. The through-space CT occurs from NPG− (donor) to IM+ (acceptor), and this was mediated via non-covalent forces. We demonstrated the role of π−π stacking interactions (mixed-stacking donor-acceptor interactions) in the presence of charge-assisted hydrogen bonds in the regulation of CT properties in the self-assembly of the IM+−NPG−−HYD salt hydrate.

Keywords

• crystal structure
• charge transfer
• salt hydrate
• hirshfeld surface
• dft
• qtaim
• nbo