Indium-chromium complexes

TRIS(0-ETHYL DITHIOCARBONATO) COMPLEXES OF TRIPOSITIVE CHROMIUM, INDIUM, AND COBALT... 

Tris(0-ethyl dithiocarbonato)chromium(III) is obtained as a dark blue crystalline powder which decomposes at 100 to 140°. The indium(III) ethylxanthate complex forms small colorless crystals which decompose at 130 to 150°.16,17 The cobalt (III) ethylxanthate complex is isolated as a dark green crystalline powder whose decomposition temperature determined by use of a thermal balance is 135 to 137° (lit. value, 117° 2 118 to 119°8). These compounds decompose slowly in air and more rapidly when heated in solution. The tripositive chromium, indium, and cobalt complexes are insoluble in water but are soluble in many organic solvents (Table T). 

Methods for the preparation of tris(0-ethyl dithiocarbonato) complexes of chromium(III), indium(III), and cobalt(III) are presented and serve to illustrate procedures applicable to the preparation of O-alkyl dithiocarbonato, alkyl trithiocarbonato, iV,A7-dialkyldithiocarbamato, and 0,0 -dialkyl dithiophosphato complexes of several metals. 

TABLE I Solubilities of Tris(0-ethyl dithiocarbonato) Complexes of Chromium(III), Indium(III), and Cobalt(III) in Organic Solvents at 25°... 

X-ray powder diagrams obtained by the Guinier method show the tris (O-ethyl dithiocarbonato) complexes of chro-mium(III), indium(III), cobalt(III), iron(III), arsenic(III), and antimony(III) to be isomorphous. Carrai and Gottardi have determined the structure of the arsenic(III)18 and anti-mony(III)19 complexes. Crystallographic data for the cobalt(III) and chromium(III) ethylxanthate complexes are given by Derenzini20 and Franzini and Schiaffino,21 respectively. 

Allyl complexes with boron, 9, 194 with chromium(III), 5, 373 copper-catalyzed substitution, 9, 518 with gallium, 9, 723, 9, 735 with indium... 

The trimethylsilylated silicic acids formed in this instance are soluble in conventional organic solvents, and their volatility is sufficiently high for them to be analysed by gas chromatography. Carzo and Hoebbel [411] carried out a comprehensive study of the chromatographic retention of various trimethylsilylated silicic acids on different stationary phases Apiezon L and silicone OV-1 and OV-17. The analysis of metals in the form of volatile complexes continues to attract attention, and have been described for analysing sodium [412], potassium [412], radium [413], caesium [413], barium [414], calcium [414], strontium [415], beryllium [416, 417], magnesium [418], zinc [419, 420], nickel [419], mercury [421], copper [422, 423], silver [424, 425], cadmium [421], indium [426, 427], g ium [428], scandium [217], cobalt [421], thallium [426], hafnium [429, 430], lead [431, 432], titanium [430], vanadium [433], chromium [434-436], manganese [426], iron [437], yttrium [438], platinum [439,440], palladium [439, 441, 442], zirconium [430], molybdenum [443], ruthenium [444], rhodium [445], rare earths [446—449], thorium [221, 450, 451] and uranium [221, 452]. The literature on GC analysis of metal chelates was reviewed by Sokolov [458]. 

In aqueous solution, these effects have been clearly observed in the case of the chromium (III) and indium systems. As the indium system has been the object of Raman investigations (2, 3) with conflicting results, it is of special interest that we find three new peaks at 1136 K, 1050 K and 975 K, i.e. corresponding to a sulphato complex of C3V symmetry. The 1050 K absorption cannot be caused by HSO as this ion has an absorption band at 1200 K too, which was not observed. For solutions of other systems of such a composition that the first complex should dominate only a broadening of the z/ -band was observed, together with a very feeble v absorption. These systems included the sodium and the cerium ones. 

Gilbert TW, Newman L, Klotz P (1968) Mixed-metal hydroxycarboxylic complexes. The chromium(III) inhibition of the solvent extraction of indium(III). Anal Chem 40 2123-2130... 

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