Crystal structure of K4Pu(SO4)(4)center dot 2H(2)O

The crystal structure of potassium plutonium(IV) tetrasulphate, K4Pu(SO4)(4 ). 2H(2)O has been investigated and resolved by Rietveld refinement of X-ra y powder diffraction data. The Compound crystallises in a monoclinic unit c ell with lattice parameters a=1.24175(7) nm, b=1.11583(7) nm, c=1.35530(9) nm, beta =111.81(1)degrees, space group P2(1)/c and Z=4. The structure cons ists of dimeric [(SO4)(3)Pu(SO4)(2)Pu(SO4)(3)](8-) anions in which each plu tonium has nine oxygen atoms from five sulphate groups coordinated to it at an average Pu-O distance of 0.739(4) nm, forming distorted monocapped squa re antiprism geometry. Bridging sulphate groups are tridentate while others are bidentate chelating type. The two water molecules are not coordinated to the plutonium atom in the structure. (C) 2000 Elsevier Science B.V. All rights reserved.