Structure of tin hafnium sulfide and lead hafnium sulfide

SnHfS 3, M r = 393.36, orthorhombic, Pnma, a=9.139(1), b=3.694(1), c--13.875(4) A, V= 468.4 (2) ,/k 3, Z = 4, D x = 5.578 g cm 3, 2(Mo Kii) = 0.71073 ,~, g= 284.1 cm -~, F(000) 680, T= 298 K, R r=0.036 for 1301 observed reflections with I >_ 2.5tr(I). PbHfS 3, Mr = 481.88, orthorhombic, Pnma, a = 8.988 (2), b = 3-739 (I), c = 13.924 (2) ,~,, V=467.9(2)A 3, Z=4, Dx=6.840gcm ~, 2(MoK/i) =0.71073 A, g= 593-0cm ~, F(000)= 808, T= 298 K, R F = 0-036 for 1343 observed reflections with I>_2.5a(I). The compounds are isostructural with PbZrS 3 with modified NH4CdC13 structure. There are columns running along the b axis of double edgesharing octahedra (HfxS6)~; these columns are linked by Sn or Pb with coordinations typical for Sn 2+ and Pb 2+ with lone-pair s 2 electrons.