Dichlorobis ethylenediamine cobalt III Nitrate

Submitted by JACK ZEKTZER Checked by ROBERT E. HERMER  

A previously published procedure for the preparation of tra s-[CoCl2(en)2] Cl gave an overall yield of 35% based on cobalt(II) chloride. The procedure must be followed exactly to avoid contamination of the product with [Co(en)3] CI3. The procedures of Springborg and Schaffer give yields of 75% but require 3-4 days for the crystallization of the product. The procedure set forth below gives overall yields of 70% and only requires 3-4 hours beginning with [Co(en)2(N02)2] -NO3, or a total of 12 hours beginning with Co(N03)2 61120. 

The absorption spectral data agree well with those reported for the chloride salt. The nitrate salt is sparingly soluble in water (0.346 g in 100 mL of water at 7°) and can be recrystallized from hot water. The chloride salt is much more soluble in water. 

IL Biltz and W. Biltz (adapted from the German by W. T. Hall and A. A. Blanchard), Laboratory Methods of Inorganic Chemistry, John Wiley Inc., New York, 1928, p. 179. 

Palmer, Experimental Inorganic Chemistry, Cambridge University Press, Cambridge, England, 1970, p. 537. 

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With 2- for two Cl and 0 for two en, the metal must be cobalt(III). The word nitrate follows a space dichlorobis(ethylenediamine)cobalt(III) nitrate. 

Disodium cw-bis(ethylenediamine)disuIfitocobaltate(III) nitrate and also the perchlorate have not been reported before and are recommended as sources of the cfs-bis(ethylenediamine)disulfito-cobaltate(III) ion, which has been prepared by Baldwin1 by proceeding through a difficult series of complex salts. The m-azidobis(ethylenediamine)sulfitocobalt(III) is also newly reported it can be converted into a relatively pure sodium ran.y-bis(ethylenediamine)disulfitocobaltate(III), which has previously been made from dichlorobis(ethylenediamine)cobalt(III) chloride1 and tetraammine(carbonato)cobalt(III) chloride.2... 

Several preparations of salts of the czs-dinitrobis(ethyl-enediamine)cobalt(III) ion have been reported in the literature. The most usual is that of Werner/ modified by Holtzclaw, Sheetz, and McCarty, beginning with potassium hexanitrocobaltate(III). However, this method makes use of a starting material which is difficult to prepare in high purity and to dry thoroughly, involves critical temperature control, and produces a yield of about 15%. The following procedure, which utilizes ethylenedi-amine)cobalt(III) chloride as the starting material, provides a 60% yield of cfs-dinitrobis(ethylenediamine)cobalt-(III) nitrite. The nitrite is then easily converted to the nitrate. 

Write formulas for the following compounds, using brackets to enclose the complex ion portion (a) tri-amminebromoplatinum(II) nitrate (h) dichlorobis(ethylenediamine)cobalt(Il) monohydrate, (c) penta-amminesulfatocobalt(III) bromide, (d) potassium hexafluoroplatinate(IV), (e) tetraaquadibromochro-mium(lll) chloride, (/) ammonium heptafluorozirconate(lV). 

C6H24NeNi06, Trisethylenediaminenickel nitrate, 24, 605 C6H25ClaCoN202, trans-Dichlorobis(l-propylenediamine)cobalt(III) chloride hydrochloride dihydrate, 27, 833 CgH26AU2N6O12S4, Ethylenediammonium bis-cis-(ethylenediamine-disulf itoauratedll)), 41B, 941... 

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