Complexation of Michler’s Ketone by Trimeric Perfluoro-Ortho-Phenylenemercury: Synthesis, Structure and Spectroscopic Properties of a New Supramolecular Adduct

Abstract

Trimeric perfluoro-ortho-phenylenemercury (o-(C6F4Hg)3) has been identified as one of the simplest Lewis acidic host molecules due to its proximity of Hg(II) atoms, electron-withdrawing properties and inherent accessibility to electrophilic sites on the molecule’s surface. Owing to these concerted effects, the molecule is capable of forming supramolecular complexes with a variety of neutral and anionic substrates, among them organic carbonyls such as aldehydes and ketones. In this communication, we highlight the structural and spectroscopic properties of the complex formed between (o-C6F4Hg)3 and Michler’s Ketone (4,4′-Bis(dimethylamino)benzophenone or MK). The complex crystallizes in the triclinic space group $$ P\bar{1} $$ with a = 11.690(2) A, b = 12.011(2) A, c = 13.617(5) A, α = 101.30(2)°, β = 98.44(2)°, and γ = 107.15(2)° and contains non-covalent Hg–Hg, Hg–C and Hg–O interactions. IR spectroscopy measurements were also completed and reveal a moderate shifting of the carbonyl stretching frequency between [(o-C6F4Hg)3·μ3-MK] and free Michler’s Ketone, due presumably to the Hg–O interactions. Herein we present the structure and infrared spectroscopic properties of the supramolecular complex [(o-C6F4Hg)3·μ3-MK] which combines the Lewis Acid trimeric perfluoro-ortho-phenylenemercury ((o-C6F4Hg)3) with Michler’s Ketone.