User:Benjah-bmm27/Polonium dichloride

Polonium compounds, e.g. polonium dichloride, PoCl2.

Holleman & Wiberg p. 594: ruby-red, m.p. 355 °C, subl. pt. 130 °C: http://books.google.com/books?id=Mtth5g59dEIC&lpg=RA1-PA1394&dq=isbn%3A0123526515&pg=RA1-PA594.

'[http://dx.doi.org/10.1039/JR9550002320 J. Chem. Soc. (1955) 2320-2326]:'

Preparation
Prepared by thermal decomp. of PoCl4 at 300 °C, by reduction of cold, slightly moist PoCl4 by SO2, and by heating PoCl4 in a stream of CO or H2S at 150 °C.

Reactions
Dissolves in dil. HCl to give a pink soln. which autoxidises to Po(IV), and is immediately oxidised by H2O2 or Cl2 water. Addition of KOH to the pink soln. gives dark brown ppt. - hydrated PoO or Po(OH)2? Rapidly oxidised to Po(IV). With 0.1 N HNO3, get dark red soln. then white flocculent ppt. of unknown comp.

Structure
Crystal structure: orthorhombic (space group P222 or Pmmm? paper and CIF disagree). Lattice parameters in Å: a = (3.66 ± 0.01), b = (4.34 ± 0.01), c = (4.49 ± 0.01). Calculated density 6.50 g/cm3. Distorted cubic (box 3.122 Å × 3.122 Å × 3.660 Å) coordination of Po as {PoCl8}. Distorted square planar coordination of Cl as {ClPo4} (Cl1 rectangle 4.430 Å × 3.660 Å, Cl2 rectangle 4.490 Å × 3.660 Å).