Analyse des malates de cuivre et d'uranyle par potentiométrie, polarimétrie et spectrophotométrie

Abstract

The stability and optical constants of the copper malates [CuH2Mal]+, [CuHMal], [CuH2Mal2]2−, [CuMal]−, [Cu2Mal2]2− and [CuH−1,Mal]2− have been fitted by a pit-mapping method, which also gives their confidence limits, from potentiometric, visible spectroscopic and polarimetric measurements.In the case of the uranyle malates, the presence of polynuclear species, detectable in the potentiometric study, have been confirmed by nmr spectrocopy. The constants of [UO2HMal], [UO2Mal]−, [(U02),Mal2]2−, [(UO2)3MaI5]9− and [(UO2)3H−2Mal5]11− have been determined, first by a pit-mapping method, then, by the graphical method of Lefebvre. All the values are given at 25 °C for an ionic strength of 0.5 in NaNO3.