Three-dimensional hydrogen-bonded magnesium(II) supramolecular motifs based on in situ generated alkanesulfonate (Me/Et/nPrSO3−) ligands: A combined experimental and computational study

Abstract

One-pot three-component Arbuzov-type reactions, involving in situ generation and complexation of alkanesulfonate ligands (RSO3−; R = Me, Et, nPr) to magnesium(II) ions, afford three new compounds of compositions, [Mg(OSO2Me)2(H2O)2]n (1), [Mg(H2O)6](O3SEt)2 (2), and [Mg(H2O)6](O3SnPr)2 (3). The compounds, 1–3, are characterized by single-crystal X-ray diffraction, spectroscopic (FT-IR, 1H, and 13C) techniques, elemental, and thermogravimetric analysis. Structural study of compound 1 reveals construction of a one-dimensional (1-D) polymeric chain by virtue of a bridging bidentate (µ2) mode of coordination of sulfonate ligands between the metal centers, while compounds, 2 and 3 exhibit formation of hexaaqua [Mg(H2O)6]2+ cationic moieties surrounded by corresponding ethane/n-propanesulfonate entities as the charge-balancing counter-anions. The 1-D linear chain (in 1) and cation–anion pair (in 2 and 3) further perpetuate to higher-order dimensionalities of 3-D supramolecular motifs by virtue of OH⋯O type hydrogen bonds. To the best of our knowledge, the paper reports the first in situ preparation of a homologous series of alkanesulfonates with an alkaline metal. Herein, the construction of supramolecular architectures was achieved by the flexible coordinative nature of sulfonate groups and its ability to facilitate hydrogen-bonding interactions by acting as prolific hydrogen atom acceptor. In addition, theoretical studies, using B3LYP method with the 6-311 g(d,p) basis set and atoms in molecules (AIM) tool, were carried out to understand the stability with electronic properties, and involved non-covalent interactions, respectively. Furthermore, Hirshfeld surface analysis has been carried to understand the subtle influence of non-covalent intermolecular contacts in the consolidation of the supramolecular motifs.