Crystal Structure of S8 Molecule from Thiourea

Thiourea is an interesting ligand for metal complexes, which have attracted much attention of many researchers as potential applications from optical devices to cancer-treatment reagents.1 Such thiourea-based metal complexes have also been employed as precursors in preparing metal sulfide materials.2 For example, bismuth sulfide obtained from thiourea complexes is known to be as an important semiconductor.3 The formation of thiourea complexes of bismuth is used for the qualitative analysis of bismuth in undergraduate inorganic-chemistry courses.4 In the course of our study on bismuth complexes with thiourea, we isolated crystals of the S8 molecule instead of the bismuth complex, and determined the crystal structure (Fig. 1). Thiourea (229 mg, 3.0 mmol) and bismuth nitrate pentahydrate (242 mg, 0.5 mmol) were dissolved in N,N-dimethylformamide (8 cm3). The solution was left at room temperature for several days. The resulting pale-yellow crystals were filtered off. Yield, 17.2 mg (17.9%). A preliminary examination was made, and data were collected on a Bruker CCD X-ray diffractometer (SMART APEX) using graphite-monochromated Mo-Kα radiation. Crystal data and details concerning the data collection are given in Table 1. The integrated and scaled data were empirically corrected with TWINABS.5 The structure was solved as a 2-component twin with the only non-overlapping reflections of component 1 and refined using the hklf 5 routine with all reflections of component 1 (including the overlapping ones). Crystallographic data have been deposited with Cambridge Crystallographic Data Centre (Deposit number CCDC-1947735). Copies of the data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/ 2020 © The Japan Society for Analytical Chemistry