Structure of dibromotetrakis(dimethyl sulfoxide)osmium(II)

Abstract

OsBr2(C2H6OS)4], M r = 662.52, tetragonal, I4/m, a = 9.178 (2), c= 11.126 (2)A, V= 937.2 (4) A 3, z = 2, D x = 2.35 g cm -3, 2(Mo Ka) = 0.71069A, /~= 114.66 cm -1, F(000)= 628, T= 296 K, R = 0.024 for 425 unique reflections. Crystals were prepared by warming a solution of bis(tetran-butylammonium) hexabromoosmate(IV) and dimethyl sulfoxide. The molecule has 4/m symmetry with the Os atom at the 4/m intersection, S and O atoms on the symmetry plane, and the trans-Br atoms on the fourfold axis. All Me2SO ligands are S-bonded to the Os atom. Principal distances and angles are Os-Br = 2.555 (1), Os-S = 2.351 (2), S-O =

Osmium-Promoted Oxidative Dimerization of Aminoarenes toN-Aryl-o-arenoquinone Diimines (L). Synthesis, Structure, Electrochemistry, and Reactivity of OsBr2L2

“…Moreover, the C−C bond lengths (average 1.349(26) Å) at positions that would have localized double bonds for the diimine form of the ligands are significantly shorter than the other C−C bond lengths (average 1.418(20) Å) in the same ring. Furthermore, each chelate is a good plane, with no atom deviating by more than 0.07 Å, which further confirms localized diimine character of the ligand L. The Os−Br lengths in our complex compare well with the corresponding Os−Br lengths in OsBr 2 (C 2 H 6 OS) 4 . The molecule approximates to overall C 2 symmetry.…”

Geometrical and Linkage Isomers of [OsCl2(dmso)4] − The Complete Picture

“…The synthesis of cis , fac ‐[OsCl 2 (dmso‐ S ) 3 (dmso‐ O )] and of trans ‐[OsCl 2 (dmso‐ S ) 4 ],15 together with the X‐ray crystallographic characterisation of trans ‐[OsBr 2 (dmso‐ S ) 4 ],16 were in perfect agreement with the previous reports on the analogous ruthenium species and suggested that Os II behaves essentially as does Ru II . This seemingly well‐defined belief was shaken, however, in 1998 by McDonagh et al who reported the X‐ray structural characterisation of the unprecedented all‐S‐bonded isomer cis ‐[OsCl 2 (dmso‐ S ) 4 ],17 which showed that the two metal ions can behave quite differently.…”

The Pivotal Role of Ru‐dmso Compounds in the Discovery of Well‐Behaved Precursors

“…It is however quite common that stereoisomers differ also in the binding modes of the dmso ligands (i.e., like 1 and 2 that, in addition to being stereoisomers, are also linkage isomers). In my long‐term experience in this field, besides the already mentioned case of the Os II complexes 5 and 6 , I came across only the following three examples of pure, spontaneous (at room temperature) and reversible S/O‐dmso linkage isomerization in ruthenium compounds.…”

“…in 2 ) but also on Ru III species, such as 3 and its neutral derivative mer,trans ‐[RuCl 3 (dmso‐S) 2 (dmso‐O)] ( 4 ) . The reason for the dmso‐O binding mode in 1 was to be found in the corresponding Os II species, that we and others also investigated . In that case cis,fac ‐[OsCl 2 (dmso) 4 ] ( 5 ), the homologue of 1 , slowly equilibrates in light‐protected chloroform or DMSO solutions with the all‐S‐bonded isomer cis ‐[OsCl 2 (dmso‐S) 4 ] ( 6 ) (Figure ), which is unknown for Ru II .…”