Uranyl oxalate complexes. Part II. Preparation and crystal and molecular structure of ammonium uranyl dioxalate

Abstract

The crystal structure of the title compound has been determined from diffractometer data by the heavy-atom method. Crystals are triclinic, space group P, a= 12·91(2), b= 7·20(1), c= 6·31(1)Å, α= 110·56(5), β= 107·85(5), γ= 84·25(5)°, Z= 2. 1351 Reflections were refined by least squares to a final R of 0·130. The crystal contains NH₄⁺ and [(UO₂)(C₂O₄)₂]_n^2n– ions. In the latter one oxalate group is bidentate, and one bidentate to one uranium atom and unidentate to another, giving chains parallel to c. Mean distances are U–O(uranyl) 1·77, and U–O(oxalate) 2·37 Å.