The reaction of the organometallic acid [(h5-C5H4COOH)2CoIII]+ with HBr and HI. Preparation and characterization of [(h5-C5H4COOH)2CoIII]Br and [(h5-C5H4COOH)2CoIII]I and hydrogen bridges between cations.

The water sol. dicarboxylic cationic acid [(h5-C5H4COOH)2CoIII]+ (1) as its Cl- salt was treated thermally to produce the neutral zwitterion [(h5-C5H4COOH)(h5-C5H4COO)CoIII] (2). 2 Reacts with HBr in water soln. to yield the bromide salt of the dicarboxylic acid [(h5-C5H4-COOH)2CoIII]Br, 1Br. Prepn. of the iodide [(h5-C5H4COOH)2CoIII]I, 1I, was achieved by direct oxidn. of [(h5-C5H4Me)2CoIII]OH with KMnO4 immediately followed by reaction with HI. The crystal structures of 1Br and 1I were detd. by single crystal x-ray diffraction. The H bonding interactions between the acid cations and between the acid cation and the halide ions were studied.