Some reactions of tetrakis(tert-butylimido)osmium(VIII). X-Ray crystal structures of Os(NBut)O(O2CBut)2(NH2But)2·ButCO2H, (ButN)2 Os(µ-NBut)2Os(µ-NBut)X2(X = Cl or I) and [Os2(NBut)4(µ-NBut)2]I3

Abstract

Reaction of Os(NBu^t)₄ with carboxylic acids and halogens have been studied. Acetic and pivalic acids give different oxo carboxylate complexes, the acetate being Os(NBu^t)O(O₂CMe-O)(O₂CMe-OO′)(NH₂Bu^t)1 and the pivalate Os(NBu^t)O(O₂CBu^t-O)₂(NH₂Bu^t)₂2. The osmium(VI) compounds (Bu^tN)₂Os(µ-NBu^t)₂Os(NBu^t)X₂(X = 1, 3; or Cl, 5) have been obtained by interaction of Os(NBu^t)₄ with, respectively, I₂ and PPh₄I in 1,2-C₂H₄Cl₂; the iodine reaction also produces the paramagnetic mixed-valence diosmium(VI, VII) compound [Os₂(NBu^t)₄(µ-NBu^t)₂]I₃4. The X-ray crystal structures of compounds 2–5 have been determined: 2 is octahedral with trans-NH₂Bu^t and trans-carboxylate groups; 3 and 5 are isomorphous with tetrahedral and trigonal-bipyramidal osmium atoms, the latter having trans-halogens, a linear NBu^t and two NBu^t bridging groups. Compound 4 is similar to the dimeric compounds previously described and completes the series [Os(NBu^t)₂(µ-NBu^t)]₂^0,+,2+.