Ingenieurwissenschaften und zugeordnete Tätigkeiten
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Preparation of new bimetallic compounds, including double complex salts (DCSs), containing both a platinumgroup metal and a transition metal of the fourth period is of great interest since these compounds can act as precursors of bimetallic materials. One example of using such compounds is the preparation of ultrafine particles of solid solutions of metals or intermetallic compounds on various supports to fabricate highly efficient catalysts with a low content of noble
metals.
Compounds containing coordinated oxalate anions are important objects of synthetic chemistry and interesting precursors. For example, a lot of attention is given to salts with [M(C2O4)2]2– anions, where M = Co, Ni, Cu, Pt, Pd. On the one hand, the uniqueness of oxalate coordinated anions is due to the fact that they are easily obtained and are stable both in aqueous solutions and in the solid phase; on the other hand, they are thermally decomposed at relatively low temperatures, which makes them promising precursors for the fabrication of metallic and oxide materials.
Nitrogen-rich noble metal nitrides possess unique mechanical and catalytic properties, therefore their synthesis and characterization is of interest for fundamental solid state chemistry and materials science. In this study we have synthesized a singlesource precursor [Rh(NH3)6]3(N3)5Cl4 (Rh:N ratio 1:11). Its controlled decomposition in a laser-heated diamond anvil cell at 39 GPa resulted in a formation of rhodium pernitride, RhN2. According to the results of single-crystal X-ray diffraction RhN2 has arsenopyrite structure type crystal structure previously unknown for this compound (P21/c (no. 14).
Knowledge of the compressional and thermal behaviour of metals and alloys is of a high fundamental and applied value. In this work, we studied the behaviour of Ir, Rh, and their fcc-structured alloys, Ir0.42Rh0.58 and Ir0.26Os0.05Pt0.31Rh0.23Ru0.15, up to 70 GPa using the diamond anvil cell technique with synchrotron X-ray diffraction. We found that all these materials are structurally stable upon room-temperature hydrostatic compression in the whole pressure interval, as well as upon heating to 2273 K both at ambient and high pressure. Rh, Ir0.42Rh0.58 and Ir0.26Os0.05Pt0.31Rh0.23Ru0.15 were investigated under static compression for the first time. According to our data, the compressibility of Ir, Rh, fcc–Ir0.42Rh0.58, and fcc Ir0.26Os0.05Pt0.31Rh0.23Ru0.15, can be described with the 3rd order Birch-Murnaghan equation of state with the following parameters: V0 = 14.14(6) Å3·atom−1, B0 = 341(10) GPa, and B0' = 4.7(3); V0 = 13.73(7) Å3·atom−1, B0 = 301(9) GPa, and B0' = 3.1(2); V0 = 13.90(8) Å3·atom−1, B0 = 317(17) GPa, and B0' = 6.0(5); V0 = 14.16(9) Å3·atom−1, B0 = 300(22) GPa, B0' = 6(1), where V0 is the unit cell volume, B0 and B0' – are the bulk modulus and its pressure derivative.