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synopais The kinetics and mechanisms of propadiene polymerization under the influence of [Rh(C0)&1]~, Rh(CO)2P(C&5)3C1, Rh(C0)3Cl are reported. The reaction rates are firsborder in Rh(CO)eP(C&,),Cl and Rh(C0)SCl and half-order in [Rh(C0)2Cl]*. They are second-order in the substrate for Rh(CO)3C1 and [Rh(CO)1C1]2 and first-order for Rh(C0)2P(C&)&l.The data are interpreted in terms of a common intermediate mechanism. The formation of this common intermediate is the rate-determining step. A solvent effect is also discussed.

The polymerization of propadiene to 1,2‐polyallene by various Rh(I) based catalysts is described and discussed. Also the interrelations between these Rh(I) complexes are discussed and an overall reaction scheme is given. A mechanism is put forward in which the formation of a common intermediate from propadiene and different Rh(I) complexes is the rate determining step. It is found that the activity decreases in the order: cis‐Rh(CO)2P(C6H5)3Cl > [Rh(CO)2Cl]2 > Rh(CO)3Cl. The complexes Rh[P(C6H5)3]2(CO)Cl and Rh[P(C6H5)3]3Cl proved to be inactive in the polymerization of propadiene.

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Patients suffering from primary hyperoxaluria show elevated plasma concentrations of oxalic acid and glyoxylic acid. The in vitro adsorption of these compounds into activated charcoal, a series of neutral and ion exchange resins and onto hydrous zirconium oxide has been investigated. Hydrous zirconium oxide was the most effective sorbent studied for the removal of both oxalic acid and glyoxylic acid. In batch experiments, the zirconium oxide was capable of binding 5.5 mu mol oxalic acid and 8 mu mol glyoxylic acid per gram sorbent using 0.5 gram sorbent and 50 ml of solutions with initial concentrations of 100 mu mol . L-1 and an ionic composition resembling that of plasma. Recirculation of 2 L of the same solutions through 12 gram of a mixture of hydrous zirconium oxide and alumina for 6 hours at a flow rate of 12 ml . min-1, resulted in a final concentration of 70 mu mol . L-1 of oxalic acid and 50 mu mol . L-/ of glyoxylic acid.