In chemistry, boron sulfides refers to a large family of compounds with boron-sulfur bonds. They are colorless solids that are prone toward hydrolysis, reflecting their tendency to form boron oxides. With regards to structures, boron generally assumes the oxidation state III and sulfur is -II. Sulfide is typically two-coordinate and boron is three coordinate.
Binary boron sulfides
Structure of one form of BS2
The parent boron sulfide is B2S3. According to X-ray crystallography, this material is polymeric, with 3-coordinate B and 2-coordinate S. It features both four- and six-membered rings. Two sulfur-rich phases are also known, polymeric (BS2)n and molecular (BS2)8. The latter two feature some S-S bonds.
Tertiary phases
From a structural perspective, the simplest members are derivatives of trigonal planar [BS3], exemplified by Li3BS3. Other motifs include the following anions: [B2S4] and [B3S6], which also exist as alkali metal salts.
References
- Conrad, Olaf; Jansen, Christoph; Krebs, Bernt (1998). "Boron-Sulfur and Boron-Selenium Compounds—From Unique Molecular Structural Principles to Novel Polymeric Materials". Angewandte Chemie International Edition. 37 (23): 3208–3218. doi:10.1002/(SICI)1521-3773(19981217)37:23<3208::AID-ANIE3208>3.0.CO;2-5. PMID 29711432.