Title: Cupric Ferrocyanide
CAS Registry Number: 13601-13-3
CAS Name: Hexakis(cyano-C)ferrate(4-) copper(2+) (1:2)
Additional Names: hexacyanoferrate(4-) dicopper(2+); cupric hexacyanoferrate(II); Hatchett's brown; C.I. Pigment Brown 9
Molecular Formula: C6Cu2FeN6
Molecular Weight: 339.04
Percent Composition: C 21.26%, Cu 37.49%, Fe 16.47%, N 24.79%
Line Formula: Cu2Fe(CN)6
Literature References: Prepd by addition of K4Fe(CN)6 to an aqueous soln of a sol cupric salt: Weiser et al., J. Phys. Chem. 42, 945 (1938); 46, 99 (1942).
Properties: Reddish-brown powder or cubic crystals; ppts as a colloid or gel. Practically insol in water, dil acids, most organic solvents. Sol in NH4OH, solns of alkali cyanides.
Use: As pigment; in photographic toning baths; to lower electric resistance of soil and electrode-to-soil contacts.