Cobalt thiosulfate

A sample of about l.2g, when dissolved in water and titrated with iodine, gave 35.8% thiosulfate or 54.7% cobalt thiosulfate which corresponds to an 8-hydrate (54.3% COS3O0). The product prepared as described decomposes slowly in boiling water to give cobalt sulfide. The color in a cold concentrated aqueous medium is deep blue— possibly Co(Co(S 0 ) ). 

Cesium is determined as the tetraphenylborate, total cobalt as the anthranilate, sulfate as barium sulfate, and cobalt(III) by addition of the alum to excess of potassium iodide solution followed by titration with thiosulfate- Anal. Calcd. -for CsCo(S04)2-12H20 Cs, 22.2 Co, 9.82 S04, 32.0. Found Cs, 22.2 Co, 9.83 S04, 32.3 Co(III), 9.80. 

Electrocatalysis in oxidation has apparently first been shown for ascorbic acid oxidation by Prussian blue [60] and later by nickel hexacyanoferrate [61]. More valuable for analytical applications was the discovery in the early 1990s of the oxidation of sulfite [62] and thiosulfate [18, 63] at nickel [62, 63] and also ferric, indium, and cobalt [18] hexacyanoferrates. More recently electrocatalytic activity in thiosulfate oxidation was shown also for zinc [23] hexacyanoferrate. Prussian blue-modified electrodes allowed sulfite determination in wine products [64], which is important for the wine industry. 

For cyanide and cyanogen, antidote should be administered as soon as possible. The Lilly Cyanide Antidote Kit contains amyl nitrite, sodium nitrite, and sodium thiosulfate. Cobalt edentate or 4-dimethylaminophenol are alternative antidotes for cyanide poisoning. Benzodiazepines or barbiturates may be required to control severe seizures. 

Note Destruction of cobaltic ammines, such as of hexammine by means of thiosulfate in acid soln was described by L.M. Orlova, ZavodLab 8, 502 (1939) CA 36, 6935 (1942), which is listed in Vol 1, p A286-R... 

Fig. 11. Dinuclear cobalt(III) complexes bridged by a peroxo linkage and either thiosulfate -) (56) or benzenethiolatef 1") (57).

L. M. Orlova, ZavodLab 8, 502(1939) CA36, 6935(1942)Destruction of cobaltic ammines can be achieved by treating with thiosulfate in acid soln 2[Co(NHs) l + 2Na,S,Os + 12HC1 - 2CoCl, + Na,S4Oe + 12 NH4Cl + 2 NaCl... 

To a solution of 70.0g of cobalt (II) sulfate 7-hydrate in 200 ml of water warmed to 50°C are added 0 .Og of barium thiosulfate 1-hydrate. The mixture is stirred at 50°C until the barium sulfate settles out completely and it is then... 

Ammonia is determined by the Kjeldahl method. Cobalt is determined by decomposing the salt with aqueous sodium hydroxide, dissolving the cobalt(III) oxide in acidified potassium iodide, and titrating the liberated iodine with thiosulfate. Anal. Calcd. for Co(NH3)3H20(C1)2C1 Co, 25.0 NH3, 21.6. Found Co, 24.6 NH3, 21.8. 

The configurations of the cis and trans forms of dinitro-bis(ethylenediamine)cobalt(III) ion were established by Werner,4 who resolved the cis form into its optical antipodes. The cis and trans isomers may also be distinguished chemically by utilization of the fact that a warm aqueous 3 % solution of the cis form yields precipitates when treated with concentrated solutions of potassium chromate, ammonium oxalate, or sodium thiosulfate a warm 10% solution of the trans form gives no precipitate with any of these reagents.3... 

The reaction of a strong solution of aqueous ammonia with the sulfide concentrate in a strongly agitated pressure vessel at a temperature between 160 and 190°F under an oxygen partial pressure of about 10 psi, either as pure oxygen or as compressed air, fulfills the optimal conditions for the above requirements. The iron present in the concentrate is oxidized to hydrated ferric oxide which, together with the silicates is insoluble in aqueous ammonia. The copper, nickel, and cobalt form their amines, while the sulfides are oxidized to sulfates, thiosulfates, and polythionates. 

In the case of the octahedral robust complexes of cobalt (III) and chro-mium(III), substitution in the first sphere is hindered. This type of complex ion is, therefore, especially suitable for studying association in the second sphere. The hexammine and tris(ethylenediamine) cobalt(III) ions have especially been used for this kind of study. For the association of these ions with anions, such as sulfate and thiosulfate, the ion-pair constant is of the order of magnitude of 10 at 7 = 0, somewhat smaller for Coena" than for Co(NH3)6 21)y but strongly dependent on the ionic strength. Thus Posey and Taube 37) y from spectrophotometric measurements in the ultraviolet, obtain the following expression for the association constant of the ion pair [Co(NH3)6]S04 in solutions with y/Jvarying from 0.04 to 0.3 ... 

The rather polarizable thiosulfate ion has a much higher influence on the ultraviolet absorption of the cobalt(Ill)-ammine complexes than the much less polarizable sulfate ion 24) j but it is noteworthy that the stability of the ion pairs formed with the first mentioned ion is even smaller than those formed with the sulfate ion 18). This supports the electrostatic nature of the second-sphere association. 

The idea that the instantaneous equilibrium between the different conformations of dissymmetric complex ions could be influenced by ion-pair formation finds some support in recent experiments of Mason and coworkers with diastereoisomeric cobalt(III) complexes. Thus, Mason and Norman (31) have shown that the circular dichroism spectra of D-Co(d-pn)3" and L-Co(d-pn)3" (pn = propylenediamine) are differently changed by oxo-anions such as P04, S04 and 8203 . According to these authors the oxo-anion and D-Co(d-pn)3+ (or D-Coen3" ), but not L-Co(d-pn)3 should have a preferred mutual orientation in the ion pairs. At low concentrations the effect of sulfate and thiosulfate ions on the circular dichroism of D-Co(d-pn)3" is similar to that of phosphate but with these anions at concentrations > 0.2M the previous changes are reversed— probably due to breaking down the specific orientation of the ion pair in the denser ionic atmosphere. It is also interesting that Mason and Norman (32) have found that Co(NH3)6 associated with d-tartaric acid produces a pronounced Cotton effect. These results show that some... 

Pyrazolin-5-ones form complexes with both inorganic and organic compounds much more readily than do the 2-pyrazolin-5-ones. The most extensive series of complexes is that formed with a variety of metallic salts. Antipyrine (2,3-dimethyl-l-phenyl-3-pyrazolin-5-one) forms a series of complexes with salts of divalent, trivalent and tetra-valent metals. Two molecules of antipyrine form a complex with one molecule of copper, cadmium, cobalt and zinc salts.266,866,1116 Complexes prepared from metallic nitrates are usually hydrated.1322 There also exists a series of complexes in which three molecules of antipyrine form a complex with one or two molecules of metallic salts. Such complexes form with two molecules of simple ferric salts272 or with one of complex iron cyanides.608 Nitrates of thorium, lanthanum, cerium and samarium also give such complexes.841 This ratio also occurs in some antipyrine complexes with cadmium and zinc thiocyanate.266 A number of salts of rare earths and iron which have complex anions such as thiosulfate, thiocyanate, dithionic acid and complex iron cyanides form complexes in which six molecules of antipyrine are present.405,408 608,841,950 Stannic chloride forms salts containing three or four molecules of antipyrine and hydrochloric acid.46... 

Nitrite administration has been augmented by thiosulfate administration (intravenously) in the treatment of cyanide poisoning. Cobalt-containing compounds (e.g., cobalt chloride and cobalt ethylenediaminetetraacetate) have also been used to form complexes with cyanide, in... 

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