Caesium chloride, effect

Vandecasteele et al. [745] studied signal suppression in ICP-MS of beryllium, aluminium, zinc, rubidium, indium, and lead in multielement solutions, and in the presence of increasing amounts of sodium chloride (up to 9 g/1). The suppression effects were the same for all of the analyte elements under consideration, and it was therefore possible to use one particular element, 115indium, as an internal standard to correct for the suppressive matrix effect, which significantly improved experimental precision. To study the causes of matrix effect, 0.154 M solutions of ammonium chloride, sodium chloride, and caesium chloride were compared. Ammonium chloride exhibited the least suppressive effect, and caesium chloride the most. The results had implications for trace element determinations in seawater (35 g sodium chloride per litre). 

According to J. Wagner, the viscosity of normal soln. of rubidium chloride at 25° is 0"9846 and of caesium chloride, 0"9775, under similar conditions. W. H. Green measured the viscosity and fluidity of aq. soln. of lithium chloride at 17"92° and 25° he found at 25° for 0 6175A, 5"325N, and 12 345A/r-soln. the respective values 0"009724, 0 019319, and 0"09589 when the value for water is 0"008955. R. Cohen measured the effect of press, on the viscosity of soln. of... 

The heat of solution is -4-68 Cal.,2 and the heat of formation 109-86 Cal.3 A saturated solution boils at 119-9° C. under 760 mm. pressure.4 Caesium chloride resembles the rubidium salt in forming a number of complex polyhalides.5 It is a useful agent in photomicrography, since it forms well-defined double salts with many metals among them—silver, gold, platinum, mercury, lead, copper, and many others.8 It has a decided toxic effect. 

Molecular weights,—The composition of the alkali chlorides has been established by analyses. These salts contain alkali, R, and chlorine, Cl, in the proportion 1 1. Consequently, the mol. formulae are represented by RnCl . The difficult volatility of sodium chloride—contrasted with say mercuric chloride—suggests a complex molecule. W. Nernst 7 found the vapour density of both sodium and potassium chlorides, at 2000 , corresponded with the respective formula NaCl and KCl for the vapours of these salts. L. Riigheimer found that the effect of sodium chloride on the b.p. of bismuth trichloride corresponded with the simple formula NaCl and E. Beckmann obtained a similar result from the effect of sodium, potassium, rubidium, and caesium chlorides on the f.p. of mercuric chloride. 

The occurrence of the NH4+ ion in the highly symmetrical sodium chloride and caesium chloride structures is seemingly inconsistent with its tetrahedral configuration and can be explained only on the assumption that the ion effectively acquires spherical symmetry by free rotation under the influence of the energy of thermal agitation. We shall encounter many other examples of structures in which ions or molecules are in free rotation, either at all temperatures or above a certain transition temperature all are examples of yet a further type of defect structure. 

This rule arises immediately from the fact that an edge or a face common to two anion polyhedra necessitates the close approach of two cations, and a corresponding increase in the potential energy of the system as compared with the state in which only corners are shared and the cations are as far apart as possible. It is readily seen that the effect will be the more marked the higher the cation charge and the lower the co-ordination, as may be illustrated by a comparison of the caesium chloride, sodium chloride and zincblende structures. In caesium chloride each cation is surrounded by anions at the corners of a cube, and these cubes share faces in sodium chloride the anions lie at the corners of octahedra, which share edges and, finally, in the zincblende structure the anions are disposed at the corners of tetrahedra and these... 

We have already seen ( 8.06) that all the ammonium halides, except the fluoride, have either the caesium chloride or the sodium chloride structure and that the NH4+ ion is in free rotation and behaves as a sphere of effective radius 1-48 A. (They are, in fact, all dimorphous with a transformation from the former to the latter structure as the temperature is raised.)... 

Bonds to Halogens.— Two lines with markedly different temperature coefficients are observed in the C1 n.q.r. spectra of solid bismuth trichloride, probably as a result of volume effects associated with different intermolecular bonding. The Raman spectra of the solid and molten trichloride are markedly different, and the latter is best interpreted in terms of the presence of discrete molecules with symmetry. Addition of varying amounts of potassium or caesium chlorides gives BiCl and BiCl, with C v and Oj symmetry, respectively, but AICI4 ions are not produced when aluminium chloride is added, and the melt consists of BiCl3 and AI2CI8. 

The use of a buffer solution containing caesium chloride as a spectroscopic buffer and aluminium nitrate as a physical buffer largely eliminates the potential interferences otherwise caused by alkali metals in flame photometry. Since it is easily ionizable, the caesium chloride has the effect of almost totally suppressing the ionization of the K, Na and Li atoms which are also present and exert a mutual influence on excitation. To this must be added the spectroscopic buffer action of caesium which has a smoothing effect on operational fluctuations of the burner. 

Polyakova, L.P., Kononova, Z.A., Polyakov, E.G., and Kremenetsky, V.G. (1996) Effect of caesium chloride on the difiusion coefficient value of tantalum complexes in NaCl-KCl-K2TaF7 melts, Zh. PriklKhim. (Russ.), 69, 1307-1313. 

Table 2. Electronic origins (all in cm-1) at very low temperatures in crystalline caesium and rubidium uranyl chloride, caesium uranyl nitrate and sodium uranyl acetate. The quantum number Q characterizing many-electron states in linear chromophores (subject to perceptible relativistic effects) may correspond to two energy levels because of the 4 or 6 ligating atoms in the equatorial plane...

Preparation.—The main source of rubidium compounds is the residual mother-liquor obtained in the extraction of potassium chloride from carnallite. The solution contains rubidium-carnallite, RbCl,MgCI2, a substance transformed by addition of aluminium sulphate into rubidium-alum, RbAl(S04)8,12H20. Separation from the potassium and caesium salts also present is effected by fractional crystallization of the alum,8 of the chloroplatinate 8 Rb2PtCl8, of rubidium-iron-alum,4 and of the double chloride with stannous chloride5 or with antimony trichloride.6... 

Under conditions mentionned in Table 21, tetramethylammonium chloride is more effective than caesium fluoride to improve the Halex reaction on DCNB at 130°C (refs. 65 - 67). However, a synergistic effect is observed when combining these two catalysts (Table 22). 

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