A study of some haloferrate complexes and a potentiometric equilibrium study of the ferric chloride system

Several chloroferrate(III) and bromoferrate(III) salts of aliphatic and aromatic amines have been prepared and isolated. The chemical compositions, based on iron and chloride analyses, have been compared with theoretical compositions for the pure haloferrate complexes. Complex salts have been produced which gave a halide to iron ratio of 4:1, 5:1, 9:2 and 7:1. An explanation for these various ratios has been proposed. The melting range or decomposition temperature, the qualitative solubilities, densities and absorption spectra of the salts listed below have been determined by standard techniques. Chloroferrate(III) Salts[:] Methylammonium tetrachloroferrate[,] Tetramethylammonium tetrachloroferrate[,] Diethylammonium tetrachloroferrate[,] Triethylammonium tetrachloroferrate[,] Di-n-propylammonium tetrachloroferrate[,] Tri-n-propylammonium tetrachloroferrate[,] Diisopropylammonium tetrachloroferrate[,] Piperidinium tetrachloroferrate[,] 2-Picolinium tetrachloroferrate[,] 4-Picolinium tetrachloroferrate[,] 2,6-Lutidinium tetrachloroferrate[,] Quinolinium tetrachloroferrate[,] Isoquinolinium tetrachloroferrate[,] Ethylenediammonium pentachloroferrate[,] Bis(cyclohexylammonium) pentachloroferrate[,] Bis(anilinium) pentachloroferrate[,] Tris(diisobutylammonium) nonachlorodiferrate Tris(pyridinium) nonachlorodiferrate Tetrakis (methylammonium) heptachloroferrate[.] Bromoferrate(III) Salts[:] Tetramethylammonium tetrabromoferrate[,] Tetraethylammonium tetrabromoferrate[,] n-Hexylammonium tetrabromoferrate Cyclohexylammonium tetrabromoferrate[,] Quinolinium tetrabromoferrate[,] Bis(di-n-butylammonium) nonabromodiferrate[,] Tetrakis(methylammonium) heptabromoferrate[.] A study of the iron(III)-chloride ionic equilibria utilizing electromotive force measurements has been extended to higher ionic strengths than previously reported by this technique. Formation constants have been reported at constant acidity and ionic strength. Potential measurements were obtained using two platinum electrodes in conjunction with a salt bridge. All data collected from the electromotive force measurements were processed on a digital computer to solve the equations containing the equilibrium expressions