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Unveiling the Sulfur–Sulfur Bridge: Accurate Structural and Energetic Characterization of a Homochalcogen Intermolecular Bond
Author(s) -
Obenchain Daniel A.,
Spada Lorenzo,
Alessandrini Silvia,
Rampino Sergio,
Herbers Sven,
Tasinato Nicola,
Mendolicchio Marco,
Kraus Peter,
Gauss Jürgen,
Puzzarini Cristina,
Grabow JensUwe,
Barone Vincenzo
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201810637
Subject(s) - chemistry , chalcogen , intermolecular force , van der waals force , rotational spectroscopy , computational chemistry , sulfur , natural bond orbital , chemical physics , molecule , density functional theory , crystallography , organic chemistry
By combining rotational spectroscopy in supersonic expansion with the capability of state‐of‐the‐art quantum‐chemical computations in accurately determining structural and energetic properties, the genuine nature of a sulfur–sulfur chalcogen bond between dimethyl sulfide and sulfur dioxide has been unveiled in a gas‐jet environment free from collision, solvent and matrix perturbations. A SAPT analysis pointed out that electrostatic S⋅⋅⋅S interactions play the dominant role in determining the stability of the complex, largely overcoming dispersion and C−H⋅⋅⋅O hydrogen‐bond contributions. Indeed, in agreement with the analysis of the quadrupole‐coupling constants and of the methyl internal rotation barrier, the NBO and NOCV/CD approaches show a marked charge transfer between the sulfur atoms. Based on the assignment of the rotational spectra for 7 isotopologues, an accurate semi‐experimental equilibrium structure for the heavy‐atom backbone of the molecular complex has been determined, which is characterized by a S⋅⋅⋅S distance (2.947(3) Å) well below the sum of van der Waals radii.