Crystal Structure and Thermal Properties of Double-Complex Salts [M-1(NH3)(6)][M-2(C2O4)(3)] (M-1, M-2 = Co, Rh) and K-3[Rh(NH3)(6)][Rh(C2O4)(3)](2)& BULL;6H(2)O

Here, seven new double-complex salts, [M-1(NH3)(6)][M-2(C2O4)(3)] (M-1, M-2 = Co, Rh) and K-3[Rh(NH3)(6)][Rh(C2O4)(3)](2)& BULL;6H(2)O types, are synthesised. The crystal structure and composition of DCS (double-complex salts) are studied by SCXRD, XRD, CHN and IR methods. The complex salts of the [M-1(NH3)(6)][M-2(C2O4)(3)] (M-1, M-2 = Co, Rh) type can be crystallised both as a crystalline hydrate [M-1(NH3)(6)][M-2(C2O4)(3)]& BULL;3H(2)O (sp. gr. P-3) and as an anhydrous complex (sp. gr. P-1) depending on the synthesis conditions. The process of [Rh(NH3)(6)][Rh(C2O4)(3)] formation is significantly dependent on the synthesis temperature. At room temperature, a mixture is formed comprising [Rh(NH3)(6)][Rh(C2O4)(3)] and K-3[Rh(NH3)(6)][Rh(C2O4)(3)](2)& BULL;6H(2)O, while the [Rh(NH3)(6)][Rh(C2O4)(3)] target product crystallises at elevated temperatures. The thermal behaviour of double-complex salts is studied by the STA, EGA-MS, IR and XRD methods. The complete decomposition of complex salts in helium and hydrogen atmospheres resulting in metals or CoxRh1-x solid solutions is achieved at temperatures of 320-450 & DEG;C.

Automated summary

In this study, seven new double-complex salts (DCS) were synthesized and their crystal structure and composition were analyzed using SCXRD, XRD, CHN, and IR methods. The complex salts of [M-1(NH3)(6)][M-2(C2O4)(3)] (M-1, M-2 = Co, Rh) can crystallize as either a crystalline hydrate [M-1(NH3)(6)][M-2(C2O4)(3)]•3H(2)O or an anhydrous complex, depending on the synthesis conditions. The formation of [Rh(NH3)(6)][Rh(C2O4)(3)] is temperature-dependent, with a mixture of [Rh(NH3)(6)][Rh(C2O4)(3)] and K-3[Rh(NH3)(6)][Rh(C2O4)(3)](2)•6H(2)O observed at room temperature, and the target product [Rh(NH3)(6)][Rh(C2O4)(3)] crystallizing at elevated temperatures. The thermal decomposition of the double-complex salts leads to the formation of metals or CoxRh1-x solid solutions at temperatures of 320-450°C, as determined by STA, EGA-MS, IR, and XRD methods.