Osmium complexes fluoro

Fluoroborazines, 16 252 Fluorocarbons commercial, 3 338-339 tritium recoil experiments on, 5 182 Fluorochlorodisulfane, 16 303, 306 UV spectra of, 16 311 Fluoro complexes, osmium, 37 296-299 Fluorocyclodiphosphazane, dehydrohalogena-tion, 21 46... 

The chemistry of osmium fluorides and fluoro complexes differs sufficiently from that of the chloro, bromo and iodo species to warrant separate treatment here. The early review of Canterford and Colton is still useful for the general halide chemistry of the element.736... 

All four halide ions from octahedral complexes with the metal. Fluorides or fluoro complexes are known for osmium(VII) to osmium(IV) inclusive, with rather tenuous evidence for OsFj OsF is a rare example of seven coordination for the metal. The other halides prefer the IV and III states, though osmium(V) chloride and chloro complexes have recently been made and also [OsBr ]". Although [RuFs] " is well known there is no osmium analogue, in keeping with the general tendency of third-row elements to display higher oxidation states than their second-row partners. 

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. 

Iron, Ruthenium, and Osmium.—Cyclo-octafluorotetramethylenetetra-carbonyliron (100), formed in the thermal reaction of tetrafluoroethylene with iron carbonyls, was one of the earliest reported fluoro-organo-derivatives of a transition metal. It may be more efficiently synthesized in a photochemical reaction. Ligands displace carbon monoxide from complex (100) to form complexes of the types (101) [L = PPhj, AsPhj,... 

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