Die Nitridhalogenide UNCl, UNBr und UNJ wurden durch Erhitzen der Tetrahalogenide im Ammoniakstrom, ferner durch Umsetzung der Tetrahalogenide mit Urannitrid hergestellt und durch Analyse sowie durch ihre chemischen und physikalischen Eigenschaften charakterisiert. Die Verbindungen sind dem BiOCl (EO1) isotyp, sie schließen sich strukturell den entsprechenden Thoriumverbindungen an.

. Can. J. Chem. 63, 3357 ( 1985). The possible formation of organo-metal-phosphate complexes (0-M-P) in aqueous solutions is examined by potentiometric titration analysis. The complex-forming solutions contain A?+-ions or Few-ions, organic acids (salicylic, phthalic, oxalic, and citric acids) and phosphate ions. The titrations are done within the precipitation-free pH-region from 2 to 4.5 (approximately) at 25°C under nitrogen at an ionic strength of 0.2 M KC1. ' The calibration of the electrode pair (glass-electrode, calomel-reference electrode) and the determination of the formation constants are facilitated by analyzing the pertinent curves with the ACBA-(Arena et 01.) and MINIQUAD-(Cans et 01.) computer programs. The results suggest (i) that 0-M-P complexes are readily formed, and that the power of selected organic acids to form ternary mixed-ligand complexes with A1"-ions and phosphate ions decreases in the order salycilate > citrate > oxalate > phthalate. Also, Fe"-ions are found to be more strongly bound by salicylate and phosphate ions than ~l'+-ions. The effect of 0-M-P formation on the chemical speciation of Al in buffered aqueous solutions containing mineral nutrients for the growth of biological organisms is demonstrated for a special case study. Dans une etude d'un cas spCcial, on a pu demontrer I'influence de la formation du complexe 0-M-P sur la speciation chimique de I'aluminium dans des solutions aqueuses tamponees contenant des sels mintraux facilitant la croissance d'organismes biologiques.[Traduit par le journal]

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