Synthesis and Reactivity of Osmium(VI) Thiolate Complexes, [Os(N)(CH2SiMe3)2(μ-SR)]2 and [Os(N)(SCH2Ph)4]

• Published in: Organometallics Vol. 15; no. 24; pp. 5090 - 5096
• Main Authors: Shapley, Patricia A, Reinerth, William A
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.11.1996
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om960491p

Primary, secondary, and tertiary alkanethiolate complexes of osmium(VI) possessing bridging thiolate ligands have been prepared and characterized. The complexes [Os(N)(CH2SiMe3)2(μ-SR)]2 (R = CH2CH3, CMe3, CHMe2, CH2CHMe2, CH2Ph) are synthesized by the reaction of [Os(N)(CH2SiMe3)2Cl]2 with alkali metal thiolates. They are air- and water-stable and unreactive toward nucleophiles and electrophiles. Anionic tetrathiolate and tetraalkoxide complexes of osmium(VI) have also been prepared and characterized. Reaction of [PPh4][Os(N)Cl4] with NaSCH2Ph or LiOCH2Ph in refluxing THF produces [PPh4][Os(N)(SCH2Ph)4] or [PPh4][Os(N)(OCH2Ph)4]. Thermolysis of [PPh4][Os(N)(SCH2Ph)4] gives benzyl disulfide, probably via reductive elimination, while the tetraalkoxide complex produces benzaldehyde and benzyl alcohol upon heating in a β-hydrogen elimination reaction.