Scandium fluoride

The only other route to scandium fluoride derivatives has been via C—F bond activation of fluoro-alkenes with [ScR(Cp )2] (R = H, Me) to give [ScF(Cp )2] [1], Very recent work has produced the first report of an organometallic yttrium fluoride. The reaction between [(CsH5)3Y] and Me3NHF results in the isolation of [ (C5H5)2YF(THF) 2] which has been fully characterised by elemental analysis, infra-red, mass and NMR spectroscopies and X-ray diffraction [8]. 

Pure scandium metal can be made by reacting scandium fluoride (SCF3) with another active metal, such as calcium or zinc ... 

Derivation Reduction of scandium fluoride with calcium or with zinc or magnesium alloy. Purification by distillation gives purity of 99+%. 

S2CI2 DISULFUR DICHLORIDE 1416 ScF3 SCANDIUM FLUORIDE 1457... 

S2CI2[g] DISULFUR DICHLORIDE (GAS) 1417 ScF3[g] SCANDIUM FLUORIDE (GAS) 1458... 

F3SC Scandium fluoride -f629.2 -f 666.6 92.0 -f247.0 -f234.0 300.6 67.8... 

Ksp for scandium fluoride (SCF3) at 298 Kis 4.2 x 10 . Write the chemical equation for the solubility equilibrium of scandium fluoride in water. What concentration of Sc5+ ions is required to cause a precipitate to form if the fluoride-ion concentration is 0.076M ... 

The relative number of cations and anions also helps determine the most stable structure type. All the structures in Figure 12.27 have equal numbers of cations and anions. These structure types can be realized only for ionic compounds in which the number of cations and anions are equal. When this is not the case, other crystal structures must result. As an example, consider NaF, Mgp2, and SCF3 ( FIGURE 12.28). Sodium fluoride has the sodium chloride structure with a coordination number of 6 for both cation and anion. Magnesium fluoride has a tetragonal crystal structure called the rutile structure. The cation coordination number is stiU 6, but the fluoride coordination number is now only 3. In the scandium fluoride structure, the cation coordination number is stiU 6 but the fluoride coordination number has dropped to 2. As the cation/anion ratio goes down, there are fewer cations to surround each anion, and so the anion coordination number must decrease. We can state this quantitatively with the relationship... 

Properties Wh. amorphous powd. sol. in hot acids less sol. in cold acids dens. 3.864 pH weakly alkaline sp. heat 0.153 Uses Preparation of scandium fluoride Manuf./Distrlb. Aldrich http //www.sigma-aldrich.com-, Atlantic Equip. Engrs. http //www.micronmetais.com-, Atomergic Chemetals, http //www.atomergic.com, Cerac http //www.cerac.com-, Fluka http //www.sigma-aldrich.com... 

Simmons, C.R., 1%1, The Mechanical Properties of Yttrium, Scandium, and the Rare Earth Metals, in Spedding, F.H., and A.H. Daane eds.. The Rare Earths (John Wiley and Sons, New York), pp. 428-452. a) Lithium-reduced scandium fluoride, distilled and arc-melted into buttons, b) Calcium reduced scandium fluoride in tantalum crucibles contain 2-5 w/o Ta. c) Arc-melted yttrium low value for 500 ppm O and 700ppm F, high value for 2500 ppm O, 3000 ppm F. (500 kg. load, 10 mm indenter.)... 

To a solution of scandium fluoride (0.03 mmol 10 mol%) in THF-H2O (0.22 mL) was added 36% aqueous solution of formaldehyde (1 1.5 mmol 5 equiv.) and dimethylsilyl enolate (2 0.3 mmol). The mixture was stirred for 40 h at room temperature to complete the reaction. The mixture was then diluted with water (10 mL), and the aqueous layer was extracted with dichloromethane (3 x 20 mL). The combined organic extracts were washed with brine, and dried over anhyd. sodium sulfate. After filtration, the solvent was removed in vacuo. The crude residue was purified by preparative TLC (elution with n-hexane-EtOAc) to furnish p-hydroxy ketone 3 with good yield (71-93%). All the compounds were characterized from comparison of their physical and spectral properties with those reported for authentic samples in literature. 

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