Potassium-zinc comparison

Chemistry of the Vanous Oxidation States of I ransition Metals S8U The Chemistry of Elements Potassium-Zinc Comparison by Electron Configuration 582... 

The Chemistry of Elements Potassium—Zinc Comparison by Electron Configuration... 

A highly fluorinated bis(pyrazolyl)borate ligand, dihydridobis(3,5-bis(trifluoromethyl)pyrazo-lyl)borate has been synthesized. The zinc triflate complex was prepared from the potassium salt of the ligand and exhibits distorted tetrahedral coordination which allows comparison of the amount of distortion, in relation to the electronic properties of substituents, with the methylated analog.165... 

Jones and Isaac 16 ) compared atomic absorption spectroscopy and spark emission spectroscopy for the determination of several elements in plant tissue. By comparing results statistically using a t-test, no significant differences were found for calcium, manganese, iron, copper, zinc, and aluminium, but significant differences were found for potassium and magnesium at the 0.01 % level. Breck162) made a similar comparison study for 15 elements. 

A synthetic route to ( )-0,f>-dimethyltubocurarine iodide (CXXV), via the racemate of 0,0-dimethylbebeerine (CXXIII), was announced in 1959 by Tolkachev and his collaborators (94). It started by the condensation of 3-methoxy-4-hydroxyphenethylamine with 4-benzyloxy-phenylacetic acid to give the amide CXXVI. Reaction of the potassium salt of the latter with the methyl ester of 3-bromo-4-methoxyphenyl-acetic acid in the presence of copper powder gave compound CXXVII. This on condensation with 3-methoxy-4-hydroxy-5-bromophenethyl-amine afforded compound CXXVIII, which was methylated to CXXIX. The latter compound was cyclized with phosphorous oxychloride to the dihydroisoquinoline derivative CXXX. Debenzylation of CXXX followed by intramolecular Ullmann condensation yielded compound CXXXI. The latter was converted to racemic dimethylbebeerine (CXXIII) by reduction with zinc dust in acetic acid followed by methyla-tion. Finally, treatment of ( + )-CXXIII with methyl iodide furnished the dimethyl ether of ( + )-tubocurarine iodide, identified by comparison of its UV-spectrum with that of the dimethyl ether of natural tubo-curarine iodide and by melting-point determination of a mixture of the two specimens. 

Serum sodium, potassium, chloride, and bicarbonate values were all within the normal range in a series of 44 patients studied by Reinberg et al. (R6). Also, according to Sidi et al. (S12), serum phosphorus, calcium, and magnesium are normal. Zinc has already been discussed, and Molokhia and Portnoy (M15) will undoubtedly soon have comparison values of copper and manganese in the serum of psoriatics versus normals. 

Comparison of the stability constants for (at left) a linear and a cyclic polyether binding to potassium ion and (at right) a linear and cyclic polyamine binding to zinc ion, illustrating the macrocyclic effect in action. 

Chloride was very mobile sodium, ammonium, potassium, and magnesium were moderately mobile and zinc, cadmium, iron and in most cases also manganese were only partly mobile. In particular, the heavy metals zinc and cadmium showed very restricted mobility in the anaerobic zone of even very coarse aquifer materials. Comparison of inorganic groundwater... 

Zinc chloride also showed a catalytic effect (Figure 13) but was not as effective as the potassium catalyst. Kinetic analysis of the rate data gave average values for b of 0.37 and 0.35 at 500 and 1000 psi, respectively, and average values for K of 0.0015 and 0.0039 (Table IV). Figure 13 also shows a direct comparison of relative effectiveness of the zinc and potassium salt catalysts. 

The precipitation of metal calces by metals or alkalis was a special case of reversible operations in a number of respects. Fire, previously an omnipresent tool in chemical operations, played no role in precipitation. As, in this case, fire was no longer a cause of chemical transformations chemists could pay close attention to the relation-ships of substances. In addition, metals were pure substances with similar observable properties, but clear differences in terms of their reactions and relationships with other substances. Comparisons of their reactions resulted in the creation of a specific order of precipitations of metals with metals or with alkalis from acidic solutions. Glaser gave the following hierarchy of precipitation in aqua fortis silver by means of copper, copper by means of iron, iron by means of zinc, and zinc (zinc hydroxide) by means of fixed niter (potassium carbonate). Putting it in Glaser s words ... 

Gallium, Mendeleev s eka-aluminum, was discovered by Paul Emile Lecoq de Boisbaudran in 1875,5 years after the Russian chemist left a blank in his table for it and predicted a number of its properties. De Boisbaudran identified the element in a sample of zinc ore by using the still-new field of spectroscopy that Bunsen and Kirchhoff had employed to detect the fingerprints of elements such as cesium and rubidium (see p. 325). Within a month he had completed a series of conversions ending in the electrolysis of an aqueous solution of the hydroxide and potash (potassium carbonate). He isolated enough of the easily liquefied metal (mp = 29.78° C) to measure its properties and even present some to the French Academy of Sciences. A comparison of the properties of gallium and those predicted for eka-aluminum is given in Table 14.1. 

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