Crystal and molecular structure of 5-benzylidene-2-thiohydantoin: The S…S intermolecular interactions between two C [dbnd]S groups

Abstract

The crystal structure of 5-benzylidene-2-thiohydantoin, C 10H 8N 2OS, the precursor of annelated arylidene-2-thiohydantoin derivatives with the micromolar affinity to the benzodiazepine receptor, has been determined at 293 K and 120 K. The title molecule in Z-configuration is planar within experimental error. Among two bonds between N1/N3 and C2(sp 2), N3 C2 is evidently longer than the N1 C2 one. In the structure determined at 120 K difference equals 0.019 Å. For that reason, in the cycloaddition reaction N3 nitrogen was privileged and the products of 2,3-substitution were obtained at a significantly higher yield than the 1,2-substitution ones. The chain of molecules joined by N H…O hydrogen bonds created the main structure motive in the crystal. Hydrogen bond of N H…S and intermolecular interactions of S…S were noticed between two chains. With respect to the center of symmetry, sulfur atoms are 3.414(1) Å and 3.3745(8) Å apart at ambient and low temperatures, respectively. The related S…S contacts, shorter than the sum of van der Waals’ radii, were identified in many species deposited in CSD, all with cyclic and/or non-cyclic arrangements of C S. The statistical analysis of the geometrical distribution for such contacts suggests that there is a maximum of probability for collinear C S…S C orientations. Additionally, if NH is located in close proximity of C S substituent, this contact is self-assembled with N H…S weak hydrogen bonds.