Abstract Ferrocene-ferricinium bromide-MEK complex, (I), ferrocene-tris[ferricinium tetrabromoferrate(III) hydrate], (II), were prepared as new compounds and compared with ferricinium tetrabromoferrate(III). The complexes were prepared by crystallization from ferrocene rich polar solutions. (I) decomposed at 217°, (II) melted reversibly at 187°, while ferricinium tetrabromoferrate(III) decomposed at 244°. When placed in water FcH +FeBr 4 4 dissolves completely, but both (I) and (II) yield insoluble ferrocene. The amount of ferrocene thus obtained from (II) agreed with the calculated amount of ferrocene in the complex. IR and visible spectrum comparisons were inconclusive in detection of ferrocene in the compounds. The compounds were further characterized by their X-ray powder patterns and optical microscopic observations.