The Characteristics Of Disulfide-Centered Hydrogen Bonds

The disulfide-centered hydrogen bonds in the three different model systems of diethyl disulfide...H2O/H2CO/HCONH2 clusters were characterized by high-resolution Fourier transform microwave spectroscopy and quantum chemical computations. The global minimum energy structures for each cluster are experimentally observed and are characterized by one of the three different S-S...H-C/N/O disulfide-centered hydrogen bonds and two O...H-C hydrogen bonds. Non-covalent interaction and natural bond orbital analyses further confirm the experimental observations. The symmetry-adapted perturbation theory (SAPT) analysis reveals that electrostatic is dominant in diethyl disulfide...H2O/HCONH2 clusters being consistent with normal hydrogen bonds, whilst dispersion takes over in diethyl disulfide...H2CO cluster. Our study gives accurate structural parameters for the disulfide bond involved non-covalent clusters providing important benchmarking data for the theoretical evaluation of more complex systems.