Dinitrogen complexes of osmium(III) haloammines

Determination of electron paramagnetic resonance parameters for osmium(III) low-spin systems using graphical solutions

“…( 6) must be solved to determine a, b, c and k. In the past, most workers assumed that they should try all six permutations in assigning the experimental g values to the three equations in eqn. (6) and since they could not measure the sign of g in EPR, they would, in principle, have 48 di †erent solutions, although many solutions give the same answer. Most of the solutions may be rejected on the grounds that they give a k value outside the range 0È1, or are solutions appropriate to the two excitedstate Kramers doublets, or they give unreasonable values for the parameters, D or V .…”

“…Osmium(III) species are less studied in the iron group, probably due to the difficulties inherent in the synthesis of osmium complexes. 4,6,7 This accounts for the relatively limited number of EPR studies of osmium(III) complexes. As observed for ruthenium chemistry, amines are very useful ligands for Os, allowing for the development of a very convenient synthetic route to obtain the metal centre in a well deÐned environment.…”

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species NxHy

“…[96,[106][107][108] The dinitrogen compounds are relatively unstable in contrast to its lighter group 8 homologues [109] and their formation did not proceed via reactions with N 2 , but rather as a result of N···N coupling of osmium nitrides [104] , dissociation of azides [97] or the diazotization of an osmium ammine species by nitrous acid. [94,101] Consequently, there is hardly any system known that is capable of binding a more extended series of intermediate species to one scaffold.…”

From Electron Transfer Reactions to the Effects of Backbonding

“…The compound [OsiNH^O.jSCFg)]-(03SCF3)2 was also prepared from [OsiNH^N^] 2 * as precursor, but with Br2 as oxidant in neat CF3SO3H medium (76). An exploration of some aspects of Os(IV) complexes with bis-and tris-halo ligands was carried out (75,77); Os(IV) is an oxidation state that is readily accessible when the complex is stabi lized by good σ-and π-donor ligands.…”