Cobalt dithionate

Dibromo-tetrammino-cobaltic Nitrate, [Co(NH3)4Br2] NOa, 1-, 2-dibromo-tetrammino-cobaltic sulphate,[Co(NH3)4Br2]2 S04, and 1-, 2-dibromo-tetrammino-cobaltic dithionate,... 

Thus, hydroxo-aquo-diethylenediamino-cobaltic dithionate, [Co ena (0H)(H2O)]S2O6, if heated, loses water, as in the ease of the corresponding tetrammino-salts, with formation of tetraethylenediamino-eobaltie dithionate,... 

The hexol cation in crystals of racemic tris[di-/i-hydroxobis(ethylene-diamine)cobalt]cobalt dithionate octahydrate (35) has the structure pre-... 

That is, a mixture of 1-, 2-diaquo-tetrammino-cobaltic chloride and 1-, 2-diehloro-tetranimino-cobaltic chloride is formed. The aquo-salt is readily soluble in water but the diehloro-salt sparingly so. The last named forms intense blue crystals which are contaminated with small quantities of the praseo-salt, from which it may be freed by transforming it into the dithionate. The dithionate is practically insoluble, but the chloride may be regenerated from it by rubbing it with ammonium chloride. The bromide, the iodide, and the nitrate have all been prepared. 

The dithionate, [Rh(NH3)5N03]S206.H20, is precipitated from a saturated solution of the nitrate or chloride on the addition of a solution of sodium dithionate. It crystallises in white silky needles resembling the corresponding cobalt salt, and is insoluble in water. 

Besides (carbonato)bis(ethylenediamine)cobalt(III) chloride and the corresponding bromide salt, the following complexes are described cis- and frara -dichlorobis(ethylenediamine)cobalt(III) chloride, cts-aquachlorobis(ethylenediamine)cobalt(III) sulfate, cis-bis(ethylenediamine)dinitrocobalt(III) nitrite, m-aquabis-(ethylenediamine)hydroxocobalt(III) dithionate, and cis-diaqua-bis(ethylenediamine)cobalt(III) bromide. 

Sodium diimidotrimetaphosphate, Na3P308(NH)2, formation and basic hydrolysis of, in preparation of pentasodium diimido-triphosphate, 6 105ra., 106 Sodium diimidotriphosphate, Na5P308(NH)2-6H20, 6 104 Sodium diphosphates, 3 98, 99, 100 Sodium dithionate, 2 170 Sodium (ethylenediaminetetra-acetato)cobaltate(III), 5 186 Sodium hexafluorophosphate, 3 111, 115... 

Meyer,1 who dissolved cobaltie hydroxide in sulphurous acid. At first a brown colour was produced, rapidly giving place to a rose-red tint which remained permanent even on boiling. The colour change is attributable to the formation of the unstable cobaltie sulphite which decomposes into cobaltous sulphite and dithionate respectively. Thus ... 

One and two-tenths grams (0.00275 mole) of (—)-cj5-bromoamminebis-(ethylenediamine)cobalt(III) dithionate from Sec. B is ground thoroughly with 4 ml of concentrated hydrochloric acid. The solution is allowed to stand in an ice bath for ca. 30 min, and the resulting deep red-violet crystals are collected by suction filtration. Additional product is obtained from the filtrate by addition of 12 ml of absolute ethanol. The combined crystals are dissolved in a minimum volume of water (ca. 4 ml), 2 ml of concentrated hydrochloric acid is added, and the solution is refrigerated overnight. The resulting crystals are collected by suction filtration, washed with absolute ethanol and ether, and then air-dried. The yield of (—)-chloride is 0.538 g (56.4%). For a 0.200% aqueous solution in a 2-dm tube, [aYc = —0.1886°, whence [or]p = —47.15° (Werner did not prepare the (—)-chloride, but he reported [aY = -t- 50.6° for the (+)-chloride the checkers report [a] = —50.6°). The checkers report =-155.2°. 

The corresponding macrobicyclic cobalt(II) [Co(sep)](ZnCl4) H20 complex was prepared by reduction of the [Co(sep)]Cl3 complex with zinc dust in aqueous HCl [95], A similar procedure was used for the synthesis of the dithionate [Co(sep)](S206) salt in the presence of Li2S206 [99], The optically active R- and S-isomers of cobalt sepulchrate were obtained from the optically active parent A-[Co(en)3]Cl3 and A-[Co(en)3]Cl3 complexes [94-95],... 

The interaction of the free ligand with cobalt(II) perchlorate in the presence of AgC104 as a precipitant in the nitromethane-methanol mixture made it possible to isolate the [Co(diME l,3pnsar-S6)](C104)3 clathrochelate. The reduction of this clathrochelate with sodium dithionate led to the formation of a cobalt (II) complex that readily produced a free sarcophagine [147],... 

Methods for the preparation and purification of salts of the dimeric complex ions di-/i-hydroxo-bis[tetraamminechromium(III)] and di-p-hydroxo-bis [bis-(ethylenediamine)chromium(III)] and of the two corresponding cobalt(III) species are presented. The two ammine complex dimers are isolated as bromide and perchlorate salts. The two ethylenediamine complexes are isolated as dithionate, bromide, chloride, and perchlorate salts. All four dimers have been obtained by heating the corresponding cis-aquahydroxo complexes as the dithionate salts. 

In the literature cis-[tetraammineaquahydroxocobalt(Ill)] sulfate has been prepared from cis-[tetraamminediaquacobalt(IIl)] sulfate, which is prepared from [tetraammine(carbonato)cobalt(lII)] sulfate. In the method described here cis-[tetraammineaquahydroxocobalt(III)] dithionate is prepared in this manner from [tetraammine(carbonato)cobalt(III)] sulfate by way of the cis-diaqua salt, which is isolated only as a crude product. [Tetraammine(carbonato)-cobalt(III)] sulfate is easily obtained in higli yield from cobalt(Il) sulfate. ... 

K. DI-ai-HYDROXO-BIS[BIS(ETHYLENEDIAMINE)COBALT(III)] DITHIONATE, BROMIDE, CHLORIDE, AND PERCHLORATE... 

Di-/Li-hydroxo-bis[bis(ethylenediamine)cobalt(III)] dithionate may be obtained analogously to the chromium(III) salt from cis- [aquabis(ethylenediamine)hydrox-ocobalt(III)] dithionate, either by heating at 110° or by refluxing in acetic anhydride. The formation of the bridged cation of cobalt(III) is much slower than that of chromium(III). In contrast to the chromium(III) complex there is no evidence that the bridged cobalt(III) complex can be formed by aqueous hydrolysis. 

In the procedure given below, di-/a-hydroxo-bis[bis(ethylenediamine)cobalt-(III)] dithionate is obtained quantitatively from ds-[aquabis(ethylenediamine)-hydroxocobalt(III)] dithionate by refluxing in acetic anhydride. The ds-[aqua-bis(ethylenediamine)hydroxocobalt(III)] dithionate is obtained from carbo-natobis(ethylenediamine)cobalt(III) chloride. ... 

Crude ds-[aquabis(ethylenediamine)hydroxocobalt(III)] dithionate (40.0 g, 0.107 mole) is added to 400 mL of acetic anhydride. The suspension is refluxed for 3 hours. The crude di-/i-hydroxo-bis[bis(ethylenediamine)cobalt(III)] dithionate is isolated analogously to the chromium(III) complex as mentioned in Section 15-J. Yield is 34.0 g (89%) of a crude, almost pure product. 

The crude dithionate (10.0 g, 0.0141 mole) is added to 40 mLof a saturated solution of ammonium chloride and the suspension is stirred at room temperature for 1 hour. Red crystals of the chloride salt separate. The sample is filtered, washed with three 7-mL portions of ice-cold 50% v/v ethanol-water, and sucked as dry as possible. The sample is dissolved in 75 mL of 0.005 M hydrochloric acid at room temperature and filtered. Then 45 mL of a saturated solution of ammonium chloride is added with stirring and cooling in an ice bath. After cooling for 1 hour, the sample is filtered, washed with three 5-mL portions of 50% v/v ethanol-water, and dried over 5.4 Af sulfuric acid. This yields 5.4 g (62%) of the crude, almost pure di-/x-hydroxo-bis[bis(ethylenediamine)cobalt(III)] chloride pentahydrate. The pure salt is obtained by dissolution of 2.00 g of the crude chloride salt in 20 mL of 0.005 M hydrochloric acid and reprecipitation by addition of 12 mL of a saturated solution of ammonium chloride as above. Yield 1.75 g (88%). Anal. Calcd. for [(en)2Co(0H)2Co(en)2]CL -5H20 Co, 18.89 C, 15.39 N, 17.96 H, 7.11 Cl, 22.72. Found Co, 19.01 C, 15.39 N, 17.90 H, 6.71 Cl, 22.85. 

The inertness of the dinuclear complexes is greatest in slightly acidic solutions, which therefore have been employed for the reprecipitation reactions. Apparently the chromium systems are much more labile toward bridge breaking than are the cobalt systems. In aqueous solution the meso-[(en)2Cr(OH)2Ci(en)2] cation (I) enters into a rapidly established (t 1 min. at room temperature) equilibrium with the mono-ju-hydroxo complex [(OHXen)2Cr(OH)Cr(en)2-(HaO)] (n) The equilibrium constant K = [II]/[I] is 0.83 in 1 Af NaC104 at 0°. The salts (dithionate, bromide, chloride, and perchlorate) of the di-p-hydroxo cation are less soluble than the respective salts of the mono-/i-hydroxo cation. It is therefore possible to precipitate the pure salts of the di-/i-hydroxo cation from the equilibrium mixture following the procedure given above. 

As examples of series of related reactions, compensation effects have been described [53] for the thermal decompositions of [CoXj (aromatic amine)2] type complexes (7 reactions) and also for a series of cobalt (III) and chromium (III) complexes (22 compounds studied in which two compensation trends were identified). Later work [54] examined the dehydrations and deamminations of dioximine complexes (two compensation trends identified), and [Co(NCS)2(ammine)2]-type complexes (three compensation trends identified). The systems involving larger entropy changes required less energy for activation [53]. Separate compensation plots for the dehydrations and the decompositions of eleven alkali and alkaline-earth metal dithionates were described by Zsako et al. [55]. 

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... 

N.m.r. line-broadening and shift effects have been investigated for CoL [L = (12)] in H2O, MeOH, and DMT. " Crystalline and molecular susceptibilities and their orientations of cobalt(ii) phthalocyanine [Co(pc)], bis(pentane-2,4-dithionate)cobalt(ii) [Co(pdt)2], and the analogous copper(ii) complexes have been reported. E.s.r. has been used to show that addition of DMF or DMSO to aqueous solutions of cobalt(ii)tetraphenylporphyrintetrasulphonate [Co(tpps)] results in a... 

In addition to the cis and trans dibromo complexes, the syntheses of c/s-aqua-bromobis(l,2-ethanediamine)cobalt(III) dibromide monohydrate and trans-aquabromobis(l,2-ethanediamine)cobalt(III) dithionate monohydrate are described. It is of historical interest that of the hundreds of cis/trans isomeric pairs of diacidobis(l,2-ethanediamine)cobalt(III) complexes known to Werner,3 the trans isomers in the classical aquahalo series eluded him. The procedures described here for their isolation are a modification of much later works, 8 in which the more soluble trans complexes were obtained pure as their sulfate salts by fractional crystallization of cis/trans mixtures. The syntheses of cis-[Co(en)2(OH2)Cl]S04-2H201-9 and ds-[Co(en)2(0H2)Cl]Br2"H209 are described in previous volumes of this series. The preparation of frans-aquachloro-bis(l, 2-ethanediamine)cobalt(III) dithionate monohydrate is given here to complete the series. 

E. frons-AQUABROMOBIS( 1,2-ETHANEDIAMINE)COBALT(III) DITHIONATE MONOHYDRATE... 

BrCoN407S2C4His - H20, Cobalt(m), aqua-bromobis(l,2-ethanediamine)-, dithionate, trans-, monohydrate, 21 124 Br2N4PdCi2H30, Palladium(D), [Af V-bis[2-(di-methylamino)ethyl]-iV -dimethyl-1,2-ethanediamine]bromo-, bromide, 21 131... 

C1CoN407S2C4H,8 HjO, Cobalt(HI), aquachlo-robis( 1,2-ethanediamine)-, dithionate, trans-, monohydrate, 21 125 ClF8nCl2H2, Thallium(III), chlorobis(2,3,4,6-tetrafluorophenyl-), chlorobis(2,3,5,6-tetra-fluorophenyl)-, 21 73... 

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