EPR spectroscopy of transformations of iridium(III) and iridium(IV) hydroxo complexes in alkaline media. Pankratov D.A., Komozin P.N., Kiselev Yu.M. //Russian Journal of Inorganic Chemistry. 2011. V.56. №11. P.1794-1799.
Processes that occur in strong alkaline solutions of iridium(III) and iridium(IV) hydroxo complexes have been studied by EPR and electronic absorption spectroscopy. It has been demonstrated that dissolution of iridium compounds in alkaline solutions should be accompanied by a series of complicated transformations involving oxygen, which lead to the formation of several binuclear iridium(III, III), (III, IV), and (IV, IV) dioxygen complexes.
Most research into the chemistry of platinum metals has focused on their complexes. However, the chemistry of their hydroxo complexes is still one of the least studied fields. There are both objective (experimental complexity of operation in alkaline and strong alkaline media, tendency to polymerization of many hydroxo compounds, and others) and subjective reasons for this situation. In particular, it is believed that the chemistry of platinum metal hydroxo complexes is insufficiently diverse. Nevertheless, we previously showed the possibility of the existence of platinum(IV) hydroxo complexes as mono- and binuclear as mono- (superoxo-) and bi- (hydroxo- and superoxo-) bridging superoxo complexes of different composition forming under oxidative conditions in strong alkaline media.
Mössbauer Diagnostics of the Isomorphic Substitution of Iron for Aluminum in Triclinic Iron Vanadate. Pankratov D.A., Yur’ev A.I. //Bulletin of the Russian Academy of Sciences. Physics. 2013. V.77. №6. P.759-764.
Mössbauer spectroscopy and X-ray powder diffractometry (XRD) phase analysis are used to study mixed vanadates with the composition AlxFe3– xV3O12, where x is 0, 0.3, 1.0, 1.5, 2.0, 2.7 and 3.0. Mössbauer spectroscopy is used to study the distribution of trivalent cations over different crystallographic positions. It is shown that the distribution of aluminum atoms differs from those expected from statistic and thermodynamic models.
Materials based on iron and vanadium compounds, which include material doped by transition or nontransition metals, are widely used as catalysts and sensor materials. Apart from solid solutions, two individual compounds form in the iron(III) oxide–vanadium(V) oxide system in particular: Fe2V4O13 and FeVO4. In turn, iron ortovanadate FeVO4 crystallizes depending on the conditions in an orthorhombic or triclinic system. In addition to its use in catalysis, triclinic iron vanadate has recently attracted attention due to its interesting magnetic properties. The type of iron vanadate formed at normal pressures is a multiferroic, and antiferromagnetic ordering is observed in it at temperatures below 22 K.