Rubidium derivatives

Of these the first-named is readily obtained by adding a solution of caesium chloride to one of sodium heptanitroso ferro-sulphide, when the caesium derivative is precipitated as an insoluble black crystalline powder. The rubidium derivative, obtained in an analogous manner, presents a similar appearance. The thallium salt is likewise difficultly soluble in water, and is obtained by double decomposition with thallium sulphate and the potassium derivative. 

During their flame spectrometry experiments on mineral waters in 1860, the German chemists Gustav Kirchhoff and Robert Bunsen determined the existence of cesium from the characteristic two blue lines in the spectrum. Likewise, extracts of the mineral lepidolite exhibited two dark red spectral lines from which the presence of Rb was inferred. Thus, cesium derives from the Latin caesius, meaning heavenly blue, whereas rubidium derives from rubidus, the Latin word used to describe a very dark red color. Bunsen was able to isolate pure Rb but not Cs, later purified by C. Setterberg. 

Metal atoms or ions can be trapped endohedrally the tris-potassium or tris-rubidium derivative is the organic superconductor with the highest critical temperature obtained so far. 

Values of the distance of closest approach derived from experimental values of the activity coefficients are given in column 2 of Table 40. It will be seen that for the lithium and sodium salts the value is greater than the crystal-lattice spacing (given in column 4) by rather more than 1 angstrom, as is expected. For the salts of cesium, rubidium, and potassium, on the other hand, the distance of closest approach... 

Only a few group 1 and 2 metal derivatives of selenolates have been structurally characterized. They are prepared with the same methods used for the thiolates.155,158 At present there are no crystal structures of lithium terphenyl selenolates. However, the potassium and rubidium salts, which are dimeric, have been structurally characterized.155 They are isomorphous, both to each other and to the closely related thiolate analogues.1533 Currently, there are no reported terphenylselenolates reported for the alkaline-earth metals. 

Rubidium - the atomic number is 37 and the chemical symbol is Rb. The name derives from the Latin rubidus for deepest red because of the two deep red lines in its spectra. It was discovered in the mineral lepidolite by the German chemist Robert Wilhelm Bunsen and the German physicist Gustav-Robert Kirchoff in 1861. Bimsen isolated rubidium in 1863. 

Pt(II) compound reactivation, 37 201 Pt(IV) compound reduction, 37 201 rate-determining step, 37 199-201 tetrachloride, 4 187-188 tetracyanide anions, as one-dimensional electrical conductors, 26 235-268 anion-deficient structures anhydrous compounds, 26 252-254 dimerization, 26 249-251 hydrated derivatives, 26 245-252 physics, 26 260-263 with potassium bromide, 26 248-249 with rubidium chloride, 26 249-250 cation-deficient compounds, 26 244, 254-256... 

In the rubidium-strontium age dating method, radioactive 87Rb isotope with a natural isotope abundance of 27.85 % and a half-life of 4.8 x 1010 a is fundamental to the 3 decay to the isobar 87 Sr. The equation for the Rb-Sr method can be derived from Equation (8.9) ... 

Rubidium fluoride offers no advantage over cesium fluoride in fluorine replacement reactions. For example, in the reaction of / -(nitrophenyl)dimethylsulfonium methyl sulfonate (21) with cesium and rubidium fluoride, rubidium fluoride afforded the fluoro derivative 22 in 51 % yield as well as the side product 23. In contrast cesium fluoride gives 66% yield of 22 and only 20% of the side product 23.180... 

The compounds MC=CCH3 (M = Na, K) were described earlier.1 The rubidium and cesium derivatives have now been obtained by the reaction of the metals with propyne in liquid ammonia, and their crystal structures studied by X-ray powder diffraction. The compounds are isostructural with those isolated previously, and the c/a ratio in the tetragonal unit cell decreases linearly with the increasing ionic radii of the alkali metals ions.120... 

Metal-arene interactions are also apparent in the triazinido derivative [Rb(THF)2NCPh = NClBu2N = < Ph]4,99, which crystallizes as cyclic tetrainers with S4 symmetry. Each rubidium (Fig. 60) is coordinated by one nitrogen and one ortho carbon (Rb-C 335.2(3)-338.0(3) pm) from two triazinido ligands and other short Rb-C contacts of 345.0(3)-357.3(3) pm contribute to the metal-ligand bonding.153... 

BORONCOMPOUNDS - BORON HYDRIDES, HETEROBORANES AND THEIRMETALLA DERIVATIVES] (Vol 4) Rubidium trioxide [12137-26-7]... 

Fig. 9. Radial probability density distribution, derived from quantum-mechanical predictions. Ibr rubidium, along with Bohr planetary model for the same atom...

---