Polonium dichloride

Polonium dichloride

Identifiers
3D model (JSmol)	Interactive image
PubChem CID	144504549
InChI InChI=1S/2ClH.Po/h2*1H;/q;;+2/p-2 Key: DUSGZPHDYXXYGD-UHFFFAOYSA-L
SMILES Cl[Po]Cl
Properties
Chemical formula	PoCl2
Molar mass	279.91 g/mol
Appearance	ruby-red solid[1]
Density	6.50 g cm−3[2]
Melting point	355 °C (671 °F; 628 K) (sublimes at 130 °C)[1]
Structure
Crystal structure	orthorhombic, oP3[2]
Space group	Pmmm (No 47)
Lattice constant	a = 0.367 nm, b = 0.435 nm, c = 0.450 nm
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Polonium dichloride is a chemical compound of the radioactive metalloid, polonium and chlorine. Its chemical formula is PoCl₂. It is an ionic salt.

Structure

Polonium dichloride appears to crystallise with an orthorhombic unit cell in either the P222, Pmm2 or Pmmm space group, although this is likely a pseudo-cell. Alternatively, the true space group may be monoclinic or triclinic, with one or more cell angles close to 90°.^[2] Assuming the space group is P222, the structure exhibits distorted cubic coordination of Po as {PoCl₈} and distorted square planar coordination of Cl as {ClPo₄}.

Preparation

PoCl₂ can be obtained either by halogenation of polonium metal or by dehalogenation of polonium tetrachloride, PoCl₄.^[1] Methods for dehalogenating PoCl₄ include thermal decomposition at 300 °C, reduction of cold, slightly moist PoCl₄ by sulfur dioxide; and heating PoCl₄ in a stream of carbon monoxide or hydrogen sulfide at 150 °C.^[2]

Reactions

PoCl₂ dissolves in dilute hydrochloric acid to give a pink solution, which autoxidises to Po(IV). PoCl₂ is rapidly oxidised by hydrogen peroxide or chlorine water. Addition of potassium hydroxide to the pink solution results in a dark brown precipitate – possibly hydrated PoO or Po(OH)₂ – which is rapidly oxidised to Po(IV). With dilute nitric acid, PoCl₂ forms a dark red solution followed by a flaky white precipitate of unknown composition.^[2]

See also

• Polonium tetrachloride

References