669052-63-5Relevant academic research and scientific papers
Osmium mediated decarbonylation of aldehydes and ketones. Synthesis, structure and reactivities of some osmium carbonyl complexes
Gupta, Parna,Basuli, Falguni,Peng, Shie-Ming,Lee, Gene-Hsiang,Bhattacharya, Samaresh
, p. 2406 - 2415 (2007/10/03)
Reaction of [Os(PPh3)3Br2] with salicylaldehyde or 2-hydroxyacetophenone or 2-hydroxynaphthaldehyde in the presence of a base results in the decarbonylation of these phenolic ligands affording an osmium carbonyl complex, viz. [Os(PPh3) 2(CO)2Br2]. The same [Os(PPh3) 2(CO)2Br2] complex has also been obtained from the reaction of [Os(PPh3)3Br2] with benzaldehyde, acetophenone and 1-naphthaldehyde in the absence of any base. Reaction of [Os(PPh3)3Br2] with formaldehyde in the presence of a base affords another carbonyl complex, viz. [Os(PPh 3)2(CO)2(HCOO)2]. Structure of both the carbonyl complexes has been determined by X-ray crystallography. Reaction of the carbonyl complexes has been carried out with three bidentate ligands, viz. tetrachlorocatechol (H2ClCat), quinolin-8-ol (Hq) and 2,2′-bipyridine (bpy), which results in the formation of [Os(PPh 3)2(CO)2(Cl4Cat)], [Os(PPh 3)2(CO)(q)(H)] and [Os(PPh3) 2(CO)(bpy)(H)]+ complexes respectively. Structure of [Os(PPh3)2(CO)2(Cl4Cat)] has also been determined by X-ray crystallography. All the complexes are diamagnetic and show intense charge-transfer transitions in the visible and/or ultraviolet region. Cyclic voltammetry of all the complexes in dichloromethane solution shows an osmium(II)-osmium(III) oxidation within 0.56-1.15 V vs SCE. The [Os(PPh3)2(CO)(q)(H)] complex also shows an osmium(III)-osmium(IV) oxidation at 1.15 V vs SCE and in the [Os(PPh 3)2(CO)(bpy)(H)]+ complex, a reduction of the coordinated 2,2′-bipyridine ligand is observed at -1.21 V vs SCE.
