Fluorido

Treatment of 2,3-epoxy -2-methyl -4 butanone with boron iri-fluorido etherate in benzene (Kq. 471) gives a good yidd of 2,2-dimethyl-S-oxobutyraidehyde.6 7 This product can only be formed by niigr.it ion of an acyl group. When rearrangement waa conducted at 230 over alumina, methyl isopropyl ketone was isolated, not 4-methyJpenUi>< 2,3-dione as claimed previously.71 Deformylation appears U occur readily on the surface of the alumina catalyst. 

FMe2S iS iMe2S iMe3 fluorido- licF-heptamethyltrisilicon(2 Si—Si) (additive),... 

F fluorine F, fluorine) ), monofluorine —F, fluoro fluorine (general) F+, fluorine) 1+) fluoride (general) F, fluoride) 1—) fluoride F , fluorido(l—) fluorido... 

Cesium fluoride-C alcium (lw idc, 256 Cesium fluorido-Tetraalkoxysilanes. 69 Cctyhrimcthytammonium permanganate. 69 Chloral, 69... 

Suggest why (a) high coordination numbers are not usual for first row fi -block metals, (b) in early d-block metal complexes the combination of a high oxidation state and high coordination number is common, and (c) in first row rf-block metal complexes, high oxidation states are stabilized by fluorido or oxido ligands. 

The high coordination numbers exhibited in some apparently simple compounds of Zr(IV) and Hf(IV) extend to their complexes (e.g. see Fig. 19.10), hard fluorido and oxygen-donor ligands being favoured, e.g. ... 

Suggest why the high oxidation state compounds of Os are dominated by those containing oxido, nitrido and fluorido ligands. 

The motivation of this contribution is to point out that some data on the potassium fluorido-tantalates treated up to now need to be updated, deeply analysed, new data added and some of them revised. Finally a new sight on the system can be generated. 

Even a portion of fluorido-oxido-tantalates with different counter cations was investigated here, the focus being given to a more detailed investigation of the selected compounds - KjTaOF and K3Ta02F4 - based on X-ray single crystal analysis. X-ray powder diffraction, secondary ionised mass spectroscopy (SIMS) and XPS spectroscopy. The available structural data for both compounds are summarised in Table 3.3.1. 

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