Names | |
---|---|
Systematic IUPAC name
Polonium trioxide | |
Identifiers | |
Properties | |
PoO3 | |
Molar mass | 256.98 g/mol |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Polonium trioxide (also known as polonium(VI) oxide) is a chemical compound with the formula Po O3. It is one of three oxides of polonium, the other two being polonium monoxide (PoO) and polonium dioxide (PoO2). It is an interchalcogen that has so far only been detected in trace amounts. [1] [2]
It has been reported that trace quantities of polonium trioxide form during the anodic deposition of polonium from acidic solutions. Although there is no experimental evidence for this, the fact that the deposit dissolves in hydrogen peroxide suggests that it contains polonium in a high oxidation state. It has been predicted that polonium trioxide may be formed by heating polonium dioxide and chromium trioxide together in air. [2]
It is very difficult to
oxidize polonium beyond Po(IV); for example, the only hexa
halide of polonium is the
hexafluoride,
PoF6, and fluorine is already the most
electronegative element
[2] (though polonium hexaiodide was once reportedly formed in the vapour phase, it immediately decomposed).
[3] However, the difficulty in obtaining polonium trioxide and polonates (containing the PoO2−
4
anion, analogous to
sulfate,
selenate, and
tellurate) by direct oxidation of Po(IV) compounds may be due to the fact that
polonium-210, while the most easily available
isotope of polonium, is strongly radioactive. Similar work with
curium shows that it is easier to achieve higher oxidation states with longer-lived isotopes; thus, it may be easier to obtain Po(VI) (especially polonium trioxide) using the longer-lived
polonium-208 or
polonium-209.
[2] It has been suggested that Po(VI) might be more stabilized in anions such as PoF2−
8 or PoO6−
6, like other high oxidation states.
[3]