Aqueous organometallic catalysis. Isotope exchange reactions in H2–D2O and D2–H2O systems catalyzed by water-soluble Rh- and Ru-phosphine complexes

The water-soluble complexes [{RuCl2(mTPPMS)2}2], [RuCl2(PTA)4], [RhCl(mTPPMS)3], [RhCl(mTPPTS)3], and [RhCl(PTA)3] (mTPPMS = sodium salt of meta-sulfonatophenyl-diphenylphosphine, mTPPTS = sodium salt oftris(meta-sulfonatophenyl)phosphine, and PTA = 1,3,5-triaza-7-phosphaadamantane) showed high catalytic activity (up to 1252 h−1) in the H–D isotope exchange reactions between H2 and D2O or D2 and H2O. The reactions took place at 20–70 °C, 0.1–2 MPa H2, and were strongly influenced by the pH. In the hydrogenation (with H2) of unsaturated acids in D2O, the relative rates of H–D exchange, hydrogenation and deuteration were determined by the individual substrates and catalysts: in the reaction of maleic acid catalyzed by [RhCl(mTPPMS)3] only hydrogenation took place with no deuteration and H–D exchange, whereas a similar reaction of itaconic acid was accompanied by a fast H–D exchange and the product methylsuccinic acid was highly deuterated.