- Co-ordination Chemistry of Higher Oxidation States. Part 22. trans-Dioxo-osmium(VI) Complexes of Diamines, Diphosphines, and Diarsines
-
The reactions of tertiary arsines and diarsines with a mixture of OsO4, concentrated HCl, and ethanol at low temperatures produce the dioxo-osmium(VI) complexes (L=AsEt3, AsMe2Ph, or AsPh3) and .The corresponding reactions at higher temperatures lead to mixtures containing OsIV complexes and chloro complexes of OsIII and OsIV.The diphosphine complexes are prepared similarly, but are very difficult to obtain pure, and the bromo complexes (L-L)= diphosphine or diarsine> are obtained from OsO4, concentrated HBr, EtOH, and L-L.NNN'N'-Tetramethylenediamine (tmen) produces , and has been characterised as a minor by-product in the case of X=Cl.Bis-ligand complexes have been characterised by i.r., u.v.-visible, (1)H, and (31)P n.m.r. spectroscopy and microanalysis.Decomposition in solution is suggested to involve oxygen-atom transfer from the OsO2(2+) group to the neutral ligand.The properties and stabilities of the complexes are discussed and the ease of oxidation of the neutral ligands is suggested to be a major factor determining relative stabilities.
- Harbron, Stephen K.,Levason, William
-
p. 633 - 638
(2007/10/02)
-