High oxygen pressures and the stabilization of six-coordinated Ir(VI) in an oxygen lattice |
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| Authors: | G Demazeau D Y Jung L Fournès J P Sanchez E Colineau A Blaise |
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| Institution: | 1. Laboratoire de Chimie du Solide du CNRS–Université BORDEAUX I 351 Cours de la Libération , TALENCE, Cedex, 33405, France;2. Laboratoire de Chimie du Solide du CNRS–Université BORDEAUX I 351 Cours de la Libération , TALENCE, Cedex, 33405, France;3. Centre d' Etudes Nucléaires de Grenoble–DRF.MC/SPS MS/LIH , GRENOBLE, Cedex, 38041, France |
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| Abstract: | Abstract During these last twenty five years a great efforts have been made in the Laboratoire de Chimie du Solide du CNRS in order to develop high oxygen pressure for the stabilization of unusual oxidation state of transition elements. The aims of such research works was to correlate the increase of the Mn+-O bond covalency versus the increase of the oxidation state n+ to the physicochemical properties of resulting oxides 1]. Iridium was an interesting element due to its position (5d) in the Periodic Table. In 1980 Ir(V) (d4) was stabilized in La2LiIrO6 in the perovskite structure 2]. Such a study had underlined the strong value of the spin-orbit coupling associated to Ir(V) 3]. The stabilization of Ir(VI) is interesting from two points of view : (i) its isotropic electronic configuration (d3), (ii) such a high oxidation state could lead to the strongest M-O bond in an oxygen lattice. Selecting, through a specific methodology, the most appropriate local structural and chemical factors and with the help of high oxygen pressure, Ir(V1) was stabilized in the perovskite Ba2CaIrO6. Structural, magnetic and Mössbauer studies have been carried out in order to characterize the physicochemical properties induced by this unusual oxidation state. |
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