Rhenium. Part XVI. Ammine and pyridine compounds of zinc and cadmium containing coordinated perrhenate

Studies on the Chemistry of Tetraamminezinc(II) Dipermanganate ([Zn(NH3)4](MnO4)2): Low‐Temperature Synthesis of the Manganese Zinc Oxide (ZnMn2O4) Catalyst Precursor

“…Based on these considerations and the quantum-chemical calculations (G94// B3LYP/6-311G and DFT//BLYP/TZVP), the other two bands at 388 and 381 cm À1 do [7] was formed). The thermo-gas titrimetric investigation indicated that 2 mol of NH 3 were released in the first decomposition step, and no further NH 3 formation in the second or third step was observed.…”

“…Since the thermal-decomposition temperature of the NH 4 2 was prepared in this way [7], the higher redox activity of MnO À 4 may be one of the reasons for this redox reaction. On the other hand, this redox reaction provided a possibility for the preparation of ZnMn 2 O 4 -type materials.…”

Studies on the Chemistry of [Cd(NH3)4](MnO4)2. A Low Temperature Synthesis Route of the CdMn2O4+x Type NOx and CH3SH Sensor Precursors

“…This assumption is verified by the fact that the deammoniation temperature of the complex [Cd(NH 3 ) 4 ] 2+ cation starts at 100 °C as it was observed in the case of the redox inactive compound 4 7. Since the [Cd(NH 3 ) 2 (MnO 4 ) 2 ] intermediate probably contains coordinated permanganate (based on the analogy with the [Cd(NH 3 ) 2 (ReO 4 ) 2 ] perrhenate complex7), no further deammoniation can be expected but a redox reaction of the coordinated ammonia and permanganate ions. The DSC at low heating rate (1 °C) shows two exothermic peaks during the first decomposition step, confirming the presence of a dominant (92 °C) and of a smaller secondary (100 °C) processes.…”

“…These experiments lead to the formation of long needle‐like single crystals of ammonium permanganate embedded in a brown amorphous matrix. Note that in spite of the existence of water‐insoluble [Cd(NH 3 ) 2 (ReO 4 ) 2 ] complex containing coordinated perrhenate ions7 formed during partial deammoniation of [Cd(NH 3 ) 4 ](ReO 4 ) 2 , due to reaction (2), the preparation of the analogous permanganate complex, diammine‐cadmium(II) bis(permanganate) ([Cd(NH 3 ) 2 (MnO 4 ) 2 ]) was not successful.…”

“…Due to this reaction, the [diamminecadmium(II)]bis(permanganate) complex cannot be isolated by partial deammoniation of complex 1 . Since the [diamminecadmium(II)] bis(perrhenate) can be prepared by the thermal deammoniation reaction of 4 ,7 the lack of this reaction may be attributed to the higher redox activity of the permanganate relating to the perrhenate. On the other hand, this redox reaction provides a possibility for the preparation of CdMn 2 O 4 type materials, whereas the analogous [tetraamminemetal] perrhenates, when the metal is cadmium, zinc, and copper ( 4 , 5 , and 6 , respectively) decompose with the formation of NH 4 ReO 4 and M (ReO 4 ) 2 · x H 2 O compounds, which indicates the presence of redox reactions 17–19.…”