Synthesis, structural elucidation, spectroscopic, Hirshfeld surface analysis and theoretical simulation of a new adeninium orthoperiodate (1−) bis(hydrate) organic–inorganic hybrid crystals

Abstract

One novel organic-inorganic hybrid supramolecular compound named Adeninium orthoperiodate (1−) bis(hydrate) (I) has been synthesized and characterized by FT-IR spectroscopy and single-crystal X-ray diffraction complemented with a quantum chemical study performed with DFT method at the B3LYP/3–21G level. The title compound crystallized in the monoclinic centrosymmetric P 21/n space group. In the molecular arrangement, the different entities are held together through the interplay of intermolecular O···HN/O and NH···O hydrogen bonds, that found to be effective in stabilizing the three-dimensional crystal packing. The hydrogen bonds network of (I) contains an interesting cyclic homosynthon of R22(10) graph set notation involving the adeninium Hoogsteen sites (N6—H1N···N7). The role of such interactions is known to be predominant in the stabilization of the usual 1H,9H tautomer. The different intermolecular interactions of (I) were quantified and analysed using Hirshfeld surface analysis, enrichment ratio (E) and fingerprint plots. The obtained results indicate that the main contributions are ascribed to O···H and H···H interactions. Scanning electron microscopy (SEM) was used to provide an extremely enlarged image of the sample morphology of (I), as well as information on its chemical composition using an energy dispersive X-ray spectrometer (EDS) detector, which confirms that the compound was successfully synthesized. The complementary theoretical achievements were found in a good agreement with respect to the experimental data. Moreover, a natural bond orbital (NBO) analysis was performed to evaluate the nature of bonding and the strength of the intra and inter-molecular interactions. Furthermore, the calculations of HOMO and LUMO energies were carried out to investigate the charge transfer within the molecular structure. The molecular electrostatic potential maps were used to detect the possible electrophilic and nucleophilic sites in (I).