Fluoro complex rhenium

Again, fluoro and oxo complexes of rhenium predominate. The reaction of KF and ReFe in an inert PTFE vessel yields pink K2[ReFs], the anion of which has a square-prismatic structure hydrolysis converts it to K[ReOFs]. 

Attempts to prepare fluoro derivatives of (102) failed and resulted in the formation of the unusual /i-pyrazolyl fi-oxo dimer [ ReO HBF(pz)2-A,A 2(/i-pz)2(M-0)] (105)." An X-ray structural analysis shows that one pyrazolyl residue of each tridentate ligand has been substituted by fluoride. With the analogous complex containing hydridotris(3,5-dimethyl-l-pyrazolylborate), however, mixed Cl/F, I/F, or OSO2CF3/F derivatives of (102) are readily formed. The different reactivity of the hydridotris(pyrazolyl)borato rhenium complexes has been attributed to the greater steric protection of the boron atom afforded by the dimethyl-substituted ligand. 

Several oxo-bridged mixed fluoro-hydroxo-oxalato complexes of rhenium(V) that are prepared by boiling freshly precipitated Re02 with oxalic acid and 40% HF may actually be derivatives of the [Re203]4+ moiety. They have been formulated as containing the [Re20(C204)(0H)6F2]2- anion but remain inadequately characterized.396... 

Experiments in which introduction of bulky pseudofluorides to try to understand the way they might influence the chemistry of low-valent metals was described in Section 3.6 in respect of rhenium complexes. The same thinking has been applied in the case of osmium and the reaction of cf.v-[Os(CO)4Me2] with on the one hand, HF and on the other, HOTeF5 have resulted in methane elimination and the formation of m-[OsF2(CO)4] and c/.v-[Os(OTeF5)(CO)4Me] respectively [44]. This offers the promise that methane elimination from hydrides will be a useful route into other low-valent fluoro derivatives. 

FN20)ReC 2HH, Rhenium, (2,2 -bipyridine)-tricarbonylfluoro-, 26 82 FO2C7H, Benzoic acid, 3-fluoro-, rhodium complex, 27 292... 

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