Highly kinked uranyl chromate nitrate layers in the crystal structures of A[(UO 2)(CrO 4)(NO 3)] (A = K, Rb)

Abstract

Two first uranyl chromate nitrates, K[(UO 2)(CrO 4)(NO 3)] (1) and Rb[(UO 2)(CrO 4)(NO 3)] (2), were prepared by solid-state reactions and characterized by electron microprobe analysis and single-crystal X-ray diffraction. The compounds are isotypic [1: monoclinic, P2 1/c, a = 9.881(5), b = 7.215(4), c = 14.226(6) Å, β = 124.85(3)°, V = 832.3(7) Å 3; 2: monoclinic, P2 1/c, a = 9.804(1), b = 7.359(1), c = 14.269(1) Å, β = 122.048(4), V = 872.6(1) Å 3]. The structures of 1 and 2 are based upon the complex [(UO 2)(CrO 4)(NO 3)] - layers with unprecedented structural topology, which consist of the UrO 3NO 3 units linked through CrO 4 tetrahedra. The resulted kinked layer can be divided into chains arranged in the ladder fashion. The layers are parallel to (100) and are linked by A + (A = K, Rb) cations located between the layers. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.