Hydrothermal synthesis, structure, and catalytic properties of UO2Sb2O4

Abstract A new uranyl antimonite, UO 2 Sb 2 O 4 ( 1 ), has been prepared from the hydrothermal reaction of UO 3 with Sb 2 O 3 and KCl. The structure of 1 consists of neutral two-dimensional ∞ 2 [UO 2 Sb 2 O 4 ] layers. The U(VI) centers are ligated by two trans oxo ligands and four square pyramidal antimonite anions. In addition, the U(VI) also forms long contacts with two additional oxygen atoms that are distorted by 12.7(2)° out of the equatorial plane perpendicular to the uranyl unit. These long interactions are significant owing to evidence supplied by bond valence sum calculations. The two-dimensional layers found in 1 are built from one-dimensional chains formed from edge-sharing UO 6 octahedra that run along the b -axis, and are linked together by [Sb 2 O 4 ] 2− chains. A flow microreactor system has been used to study the catalytic activity of 1 , and these results show that it can be used as a catalyst in the conversion of propene and O 2 to acrolein. Crystallographic data: 1 , monoclinic, space group C 2 /m , a =13.490(2) A, b =4.0034(6) A, c =5.1419(8) A, β =104.165(3)°, Z =2, Mo K α, λ =0.71073, R ( F )=1.74% for 30 parameters with 365 reflections with I >2 σ ( I ).