The blue complex formed by reaction of hexaammineruthenium(II) dichloride and hydrochloric acid bas been characterized by analytical, spectroscopic, electrochemical, and chemical methods as a chlorobridged ruthenium(II)–ruthenium(III) dimer, [Ru2(NH3)6Cl4H2O]Cl. With hydrobromic acid the analogous complex [Ru2(NH3)6Br4H2O]Br is formed. Reactions of the complexes with ammonia and hydrohalic acids are reported.

Palladium metal has been precipitated in a gel formed by the crosslinking polymerization of 2-hydroxyethylmethacrylate. The metal particles were found to have an average size of 14 nm. The dried polymer gel contained 1.38% Pd; it was cmshed and sieved to give gel particles ca 200 p. m in size. When the gel containing Pd was swollen by a solvent, catalytic activity toward the quantitative hydrogenation of nitrobenezene to aniline was observed. A detailed study of the kinetics of this hydrogenation revealed that at 101 kPa pressure and 31"C, resistance to the reaction was approximately equally divided between extra-particle mass transfer and the chemical activity of the Pd. The high activity of this novel catalyst is attributed to the large surface of the Pd and the extensive swelling of the gel by the reaction medium.ydrogenation catalysts of the platinum group