Bis tetraethylammonium tetrabromocuprate II

Four and nine-tenths grams (0.025 mol) of sodium metaperiodate is dissolved in 75 ml. of water. Nine and eight- 

Cobalt is determined spectrophotometrically using the absorption spectrum of CoCU in 10 M hydrochloric acid. Iodine is determined by precipitation of silver iodide after reduction of the complex with sulfur dioxide. Titratable H is determined by a potentiometric pH titration. AnaL Calcd. for H3[Co4l3024Hi2] 3H20 Co, 22.04 I, 35.59 titratable H+, 0.282 ratio CorlrH = 1 0.75 0.75. Found Co, 22.0 I, 35.45 titratable H , 0.285 ratio Co.T H = 1 0.75 0.75. 

ReOX3-2P(C6H,)3 + (C6H6)3PO + 2H2O HRe04 + 2HX + 3P(C6Hs)3 + EtOH 

Submitted by N. P. Johnson, C. J. L. Lock. and G. Wilkinson Checked by James L. BooKEst and Richard J. Thompson t 

Complexes of rhenium (V) have generally been prepared by careful reduction of perrhenic acid or perrhenates or by oxidation of rhenium(IV) compounds. - These procedures involve some difficulties, as in the former case compounds of rhenium (IV) may be produced, and in the latter, complete oxidation to perrhenate may occur. 

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