Synthesis and Crystal Structure of New Uranium(IV) Sulfate K(Al(H2O)6)3[U2(SO4)9]

Crystals of new compound K(Al(H2O)6)3[U2(SO4)9] (1) are obtained and studied within the research of systems containing sulfates of U(IV) and lower charged cations. The synthesis is performed in the reducing medium (Al powder in the H2SO4 and iPrOH solution under UV radiation). Crystals of 1 are analyzed by single crystal X-ray diffraction and Raman spectroscopy. New ternary sulfate crystallizes in the trigonal crystal system with unit cell parameters: space group $P\bar{3}1c$ ; a = 9.7988(3) Å, c = 24.4342(9) Å, V = 2031.8(1) Å3; Z = 2. The crystal structure of the new compound contains isolated charged [U2(SO4)9]10– anionic complexes linked by hydrogen bonds through octahedral aqua complexes [Al(H2O)6]3+ into a 3D framework with voids filled by potassium cations.