Structural and spectroscopic analyses of a ternary supramolecular complex [(o-C6F4Hg)3(o-Me2TTF)·CH3CN]: elucidating and validating non-covalent interactions in the solid state

Abstract

Given the presence of Hg(II) ions, heightened electron-withdrawing properties, and the presence of readily accessible electrophilic sites on its molecular surface, trimeric perfluoro-ortho-phenylene mercury (o-C6F4Hg)3 has been classified throughout the literature as one of the most powerful Lewis acids. Due to this fact, numerous supramolecular complexes containing both neutral and anionic substrates have been synthesized. In this paper, we highlight the structural and spectroscopic properties of a complex containing (o-C6F4Hg)3 and o-3,4-dimethyltetrathiafulvalene (o-Me2TTF). The supramolecular complex [(o-C6F4Hg)3(o-Me2TTF)·CH3CN] (1) is based upon an alternating stack structure of the two compounds held together by non-covalent Hg⋯S interactions. Fluorine atoms are found accepting C–H⋯F hydrogen bonds from hydrogens bonded to both sp2- and sp3-hybridized carbons, producing a 3-D supramolecular assembly. Infrared spectroscopic measurements confirmed the presence of both Hg⋯S and Hg⋯N supramolecular interactions within 1 due to a shift in respective vibrational frequencies.