Synergism of primary and secondary interactions in a crystalline hydrogen peroxide complex with tin.

Medvedev, Alexander G; Egorov, Pavel A; Mikhaylov, Alexey A; Belyaev, Evgeny S; Kirakosyan, Gayane A; Gorbunova, Yulia G; Filippov, Oleg A; Belkova, Natalia V et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Despite the significance of H<sub>2</sub>O<sub>2</sub>-metal adducts in catalysis, materials science and biotechnology, the nature of the interactions between H<sub>2</sub>O<sub>2</sub> and metal cations remains elusive and debatable. This is primarily due to the extremely weak coordinating ability of H<sub>2</sub>O<sub>2</sub>, which poses challenges in characterizing and understanding the specific nature of these interactions. Herein, we present an approach to obtain H<sub>2</sub>O<sub>2</sub>-metal complexes that employs neat H<sub>2</sub>O<sub>2</sub> as both solvent and ligand. SnCl<sub>4</sub> effectively binds H<sub>2</sub>O<sub>2</sub>, forming a SnCl<sub>4</sub>(H<sub>2</sub>O<sub>2</sub>)<sub>2</sub> complex, as confirmed by <sup>119</sup>Sn and <sup>17</sup>O NMR spectroscopy. Crystalline adducts, SnCl<sub>4</sub>(H<sub>2</sub>O<sub>2</sub>)<sub>2</sub>·H<sub>2</sub>O<sub>2</sub>·18-crown-6 and 2[SnCl<sub>4</sub>(H<sub>2</sub>O<sub>2</sub>)(H<sub>2</sub>O)]·18-crown-6, are isolated and characterized by X-ray diffraction, providing the complete characterization of the hydrogen bonding of H<sub>2</sub>O<sub>2</sub> ligands including geometric parameters and energy values. DFT analysis reveals the synergy between a coordinative bond of H<sub>2</sub>O<sub>2</sub> with metal cation and its hydrogen bonding with a second coordination sphere. This synergism of primary and secondary interactions might be a key to understanding H<sub>2</sub>O<sub>2</sub> reactivity in biological systems.