Oxalato salts

The isomeric dichloro-chlorides on hydration pass into the diaquo-salts, [Cr en2(H20)2]R3, and by the removal of water from these the corresponding dichloro-chlorides remain. The configuration is established by the behaviour of the salts towards potassium oxalate. The cis-salts react easily with potassium oxalate, giving the oxalato-deriva-tive, [Cr ensC204]R, whereas trans-salts are not acted upon by the oxalate. Further, the oxalato-salt formed gives, on treatment with... 

The following scheme, given by Pfeiffer,1 shows the relationship between aeido-aquo-salts, oxalato-salts, and diaeido-salts —... 

Ox alato - tetr ammino - chromic Salts, [Cr(NH3)4(C204)]R.—In the oxalato-salts the oxalate radicle occupies two co-ordinate positions in... 

The corresponding- diethylenediamino-series, [Cr en2(C204)]X, are of interest, as through these the cis- and traws-diaeido-diethylene-diamino-ehromic salts are distinguished. Pfeiffer showed that only those salts with acidic groups in the cis-position were likely to form ring compounds when replaced by one oxalato-radicle hence the diacido-salts formed from the oxalato-salts by treatment with halogen acids are m-salts. 

From these salts and from other series of salts where ring formation takes place, such as the oxalato-salts and the diol-dicobaltic salts, the configuration of the cis-salts has been deduced. 

Oxalates, determination of, in rare earth oxalates, 2 60 Oxalato salts, tri-, 1 35 Oxides, reduction of refractory metal, to metal powders with calcium, 6 47... 

There is a wide range of diketonates, such as Ru(acac)3, with octahedral coordination [133b] (they do not seem, however, to be oxidized to the +4 state this is possible with osmium) similarly several salts of the tris(oxalato) complex Ru(C204)3 have been isolated. 

Chromium, tris(hexafluoroacetylacetonato) optical isomerism, 1, 28 Chromium, tris(oxalato)-raceinization solid state, 1,466 strychnine salt... 

Among these new borates, particular attention should be paid to a salt based on oxalato ligands, which has aroused intense interest recently in the lithium ion research and development community. This salt was invented by Lischka et al. and independently synthesized and investigated by Xu and Angell, who also gave it the popular name LiBOB. Following these extensive physical characterizations, a rather comprehensive electrochemical evaluation was conducted on this salt by Xu et 155,324,488,489 found that the solutions of LiBOB in mixed carbonate solvents met the complete set of stringent requirements for electrolyte solute intended for lithium ion cell applications (1) it is anodically stable on the surface of composite cathode materials up to 4.3 V, (2) it can form a protective SEI on the... 

The salt K3[Cr(C204)] 3H20 is soluble in water. The crystals are dichroic, being green-blue by transmitted light and magenta by reflection. The infrared spectra of this and other tris(oxalato) complexes have been recorded and analyzed.17... 

Also, on replacement of oxalato- or carbonato-group by nitro-, chloro-, or bromo-radicles, brown salts are obtained with acid and sodium nitrite, and violet salts on treatment with concentrated hydrochloric or hydro-bromic acid. The brown nitro-compounds are therefore given a formula with the nitro-groups in the 1-, 2-, or eis-position, and the violet halogen salts the formula with halogen in the m-position. The cis-form may be transformed into the /ra -modification by intramolecular rearrangement. Concentrated hydrochloric acid converts carbonato-tctrammino-cobaltie salts first into violo-salts, and on standing, or on rise of temperature, these pass into the prasco- or I-, 6-salts. 

After the resolution of 1-2-chloro-ammino-diethylenediamino-cobaltie chloride many analogous resolutions of optically active compounds of octahedral symmetry were carried out, and active isomers of substances containing central cobalt, chromium, platinum, rhodium, iron atoms are known. The asymmetry is not confined to ammines alone, but is found in salts of complex type for example, potassium tri-oxalato-chromium, [Cr(Ca04)3]K3, exists in two optically active forms. These forms were separated by Werner2 by means of the base strychnine. More than forty series of compounds possessing octahedral symmetry have been proved to exist in optically active forms, so that the spatial configuration for co-ordination number six is firmly established. 

The bromide, [Cr(XH3)4(C204)]Br. H20, and the chloride, [Cr(NH3)4 (C204)]C1, are obtained from the nitrate by treating with concentrated hydrobromic and hydrochloric acid respectively. They crystallise in orange-coloured leaflets. If chloro-aquo-tetraminino-chromic chloride be treated with ammonium oxalate and hydrobromic acid successively, Cleve s triammino-chromium oxalate is formed and not oxalato-tetram-mino-salt.2... 

The series is prepared by treating blue potassium chromi-oxalate, [Cr(C204)3]Ks, with aqueous 10 per cent, ethylenediamine until a red salt begins to separate from the dark violet solution. On cooling the mixture the double salt, oxalato-diethylenediamino-ehromium dioxalato-ethylenediamino-chromate, [Cr en2C204][Cr en(C204)2], is obtained in... 

Tetrammino-salts arc also known in which a divalent acidic radicle takes the place of two monovalent acidic radicles in the diacido-tetram-mino-series, giving rise to efs-compounds such as the earbonato-tetram-mino- and the oxalato-tctrammino-cobaltic salts. 

Oxalato-tetrammino-cobaltic Salts, [Co(NH3)4(C204)]R.—These salts are analogous to the carbonato-salts, and were first described by Jorgensen in 1894. 

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