Identification of an iridium-containing compound with a formal oxidation state of +9 :--
[IrO4]+ , i.e., The valence electron configuration of iridium in IrO4 is 5d1, with a formal oxidation state of +8. Removal of the remaining d electron from IrO4 would lead to the iridium tetroxide cation ([IrO4]+), which was recently predicted to be stable and in which iridium is in a formal oxidation state of +9 .
Guanjun Wang, Mingfei Zhou & Sebastian Riedel
v Nature 514, pages475–477 (23 October 2014)
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At a glance :--
One of the most important classifications in chemistry and within the periodic table is the concepts of formal oxidation States. The preparation and characterization of chemical compounds containing element with unusal oxidation States is of the great interest to Chemists, They use their Chemist Thinking Power. The highest experimentally known formal oxidation state of any Chemical is at present +8. Although higher oxidation States have been postulated. Some compounds with oxidation state +8 include several Xenon compounds (i.e., XeO4 and XeO3F2) and mostly common species RuO4 and OsO4 are also familiar to this category.
Iridium, which has 9 valence electrons, is predicted to have the greatest chance of being oxidized beyond the +8 oxidation state. In recent matrix-isolation experiments, the IrO4 molecule was characterized as an isolated molecule in rare-gas matrices. The valence electron configuration of iridium is IrO4 is 5d¹, with a formal oxidation State of +8. Removal of the remaining d electron from IrO4 would lead to the iridium tetroxide cation, IrO4+, which was recently predicted to be stable. And in which iridium is in a formal oxidation state of 9. There has been some speculation about the formation of [IrO4]+ species. But these experimental observation have not been structurally confirmed.
Here we report the formation of [IrO4]+ and it's identification by infrared photo dissociation spectroscopy. Quantum Chemical calculation were carried out at the highest level of theory that is available today. And the predicted Iridium tetroxide cation, with a Tetrahedral symmetrical structure and a d° electron configuration, is the most stable of all possible [IrO4]+ isomers.
One of the most important classifications in chemistry and within the periodic table is the concepts of formal oxidation States. The preparation and characterization of chemical compounds containing element with unusal oxidation States is of the great interest to Chemists, They use their Chemist Thinking Power. The highest experimentally known formal oxidation state of any Chemical is at present +8. Although higher oxidation States have been postulated. Some compounds with oxidation state +8 include several Xenon compounds (i.e., XeO4 and XeO3F2) and mostly common species RuO4 and OsO4 are also familiar to this category.
Iridium, which has 9 valence electrons, is predicted to have the greatest chance of being oxidized beyond the +8 oxidation state. In recent matrix-isolation experiments, the IrO4 molecule was characterized as an isolated molecule in rare-gas matrices. The valence electron configuration of iridium is IrO4 is 5d¹, with a formal oxidation State of +8. Removal of the remaining d electron from IrO4 would lead to the iridium tetroxide cation, IrO4+, which was recently predicted to be stable. And in which iridium is in a formal oxidation state of 9. There has been some speculation about the formation of [IrO4]+ species. But these experimental observation have not been structurally confirmed.
Here we report the formation of [IrO4]+ and it's identification by infrared photo dissociation spectroscopy. Quantum Chemical calculation were carried out at the highest level of theory that is available today. And the predicted Iridium tetroxide cation, with a Tetrahedral symmetrical structure and a d° electron configuration, is the most stable of all possible [IrO4]+ isomers.
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