Unveiling the underappreciated: The bonding features of C–H⋯S–S interactions observed from rotational spectroscopy

Abstract

The C–H⋯S–S interactions are fundamentally important to understand the stability of biomacromolecules and their binding with small molecules, but they are still underappreciated. Herein, we characterized the C–H⋯S–S interactions in model molecular complexes. The rotational spectra of the complexes of diethyl disulfide with CH2CH2 and CH2CHF were measured and analyzed. All the detected structures are mainly stabilized by a C–H⋯S–S hydrogen bond, providing stabilization energies of 2.3–7.2 kJ mol−1. Incidental C–H⋯π or C–H⋯F interactions enhance the stabilization of the complexes. London dispersion, which accounts for 54%–68% of the total attractions, is the main driving force of stabilization. The provided bonding features of C–H⋯S–S are crucial for understanding the stabilizing role of this type of interaction in diverse processes such as supramolecular recognition, protein stability, and enzyme activity.