Crystal structure of UO2Cl2 and Cs(UO2)Cl5

UO2Cl2 and Cs(UO2)2Cl5 structures are determined using the method of roentgenography of monocrystals grown from the melt. It is shown that interatomic distances and valence angles in the UO2Cl2 structure are in a good agreement with the data of structure interpretation using the method of neutron diffraction of the UO2Cl2 powder. It is shown that the Cs(UO2)2Cl5 structure is constructed of dipyramidal-pentagonal (UO2Cl5) complex, bound into the polymer skeleton by the mutual vertex and mutual ribs so that the [(UO2)2Cl5]- complex anion and Cs+ cation are the main structural units. UO22+ groups are almost linear, symmetric (U-O=0.166; ).165 nm) and oriented approximately over the normal to the equator bipyromid plane, somewhat corru.g.ated, in which 5 Cl atoms are situated (U-Cl=0.254; 0.277; 0.275; 0.276, 0.284 nm). Equator planes connected by a joint vertex from the angle of approximately 150 deg. Cs and Cl atoms form a polymer Cs-Cl-Cs-Cl chain which unites the structure into a trimetric skeleton. The Cs-Cl distances in the chain are 0.320; 0.338 nm