Cobalt complexes ethylenediamine

Dumond F., Marceau E., and Che M. 2007. A study of cobalt speciation in Co/Al203 catalysts prepared from solutions of cobalt-ethylenediamine complexes. J. Phys. Chem. C 111 4780-89. 

If hydrolysis plays a role in the sorption process, the slight differences for the Co/Mn ratio at the higher pH could be related to the relatively lower rates for hydrolysis of the cobalt ethylenediamine complex at low pH (27). 

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... 

FIG. 22. Preparation of a cyanocobalt(II)-chiral diamine catalyst solution. The cobalt species in solution may resemble the ethylenediamine complex (VI). 

It was her thesis work with Alfred Werner34 that was to enter her in the annals of the history of chemistry. Among the compounds she made was cis-bis(ethylenediamine)dinitro-cobalt(III) bromide. This was the very first synthesis of a chiral octahedral cobalt complex, though at the time the significance of her synthesis was overlooked.31(a) Werner was so impressed with her work that, for her last year, he took her on as his personal assistant, the first women to be chosen for this prestigious post.35 More important for the impoverished Humphrey, she at last had some income in very expensive Switzerland. 

Since the reviews have stressed the numerous stereochemical studies which have been conducted on the octahedral bis(ethylenediamine) complexes of cobalt(III), those results will be reiterated only briefly. 

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. 

R.F. Howe and J.H. Lunsford, Oxygen Adducts of Cobalt(n)-ethylenediamine Complexes in X- and Y-type Zeolites. J. Phys. Chem., 1975, 79, 1836-1842. 

Treatment of an aqueous solution of the cobalt(III) bis(ethylenediamine) complex of 1-aminocyclopropanecarboxylate 1 with ammonium sulfide followed by hydrochloric acid gave cobalt(II) sulfide and the hydrochloride salt of 1-aminocyclopropanecarboxylic acid (2). ... 

Figure 3.4 nickel ethylenediamine complex reacts with acetone to form a nirrin, the four planar positions of the JVz " " bonds templating the reaction. In evolutionary terms, such reactions permitted great strides forward, as simple molecules such as the two above immediately became corrins surrounding the cobalt of vitamin B12 chlorophyll if magnesium and haem if ferrous was at the centre (from R.W. Hay, in An Introduction to Bio-inorganic Chemistry , ed. D.R. Williams, by permission of the Publishers,... 

The cobalt (III) ammine complexes have been extensively studied by Wendlandt (170) and co-workers. Recently, the cobalt (III) ethylenediamine complexes have been investigated, by EGA (mass spectrometry) and other TA techniques. Several of these studies, as well as those by other investigaiors. will be discussed briefly. 

In addition to molybdic acid, there have been reports of several other catalytic systems that cause mechanistically relative transformations of aldoses involving a 1,2-shift of their carbon skeleton. They include the nickel(II)-ethylenediamine [43] and cobalt(II)-ethylenediamine complexes [44] as well as the calciiun(II), strontium(II),lanthanum(III) and neodymium(III) cations in both aqueous and alcoholic alkaline solutions [45,46]. Unlike the BiTik reaction, all these transformations exploit rather equimolar amounts of the catalysts so that they result in thermodynamic equilibria of the catalytic complexes with the epimeric aldoses. Moreover, due to steric restrictions, the aforementioned alkaline earth and rare earth cations, which form mononuclear tetradentate complexes with aldoses. 

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