7687. Potassium Tetraiodocadmate

Nomenclature

CAS number: 584-10-1
Dipotassium tetraiodocadmate(2-); cadmium potassium iodide; potassium cadmium iodide; potassium iodocadmate; Marme's reagent.
CdI4K2; mol wt 698.23.
Cd 16.10%, I 72.70%, K 11.20%.
K2[CdI4].

Description and references

Dihydrate prepd from aq solns of stoichiometric amounts of CdI2 and KI; must be recrystallized from water at low temps: Croft, Philos. Mag. 21, 355 (1842); J. Prakt. Chem. 58, 399 (1856); Hittorf, Pogg. Ann. 106, 525 (1859); Eder, Photogr. Mitt. 13, 67 (1867); Rimbach, Ber. 38, 1562 (1905).

Derivative

Dihydrate.

Properties

Large, water-clear, somewhat distorted octahedra. Deliquesc upon standing in air. Turns yellow with age. d421 3.359. One part (w/w) dissolves at 15° in 0.73 part water, in 1.4 part alcohol, in 24.5 parts ether, in 4.5 parts of a 1:1 alcohol-ether mixture; also sol in ethyl acetate.

Use

In testing for alkaloids, amines, imines, heterocyclic nitrogens, peroxides in ether. In chelatometric quantitative organic analysis: Chim. Anal. (Paris) 43, 449 (1961).