Influence of the Organic Species and Oxoanion in the Synthesis of two Uranyl Sulfate Hydrates, (H3O)2[(UO2)2(SO4)3(H2O)]·7H2O and (H3O)2[(UO2)2(SO4)3(H2O)]·4H2O,and a Uranyl Selenate‐Selenite [C5H6N][(UO2)(SeO4)(HSeO3)] |
| |
Authors: | Dr. Laurent J. Jouffret Ernest M. Wylie Peter C. Burns |
| |
Affiliation: | 1. Dept. of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA;2. Dept. of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA |
| |
Abstract: | Two uranyl sulfate hydrates, (H3O)2[(UO2)2(SO4)3(H2O)] · 7H2O (NDUS) and (H3O)2[(UO2)2(SO4)3(H2O)] · 4H2O (NDUS1), and one uranyl selenate‐selenite [C5H6N][(UO2)(SeO4)(HSeO3)] (NDUSe), were obtained and their crystal structures solved. NDUS and NDUSe result from reactions in highly acidic media in the presence of L ‐cystine at 373 K. NDUS crystallized in a closed vial at 278 K after 5 days and NDUSe in an open beaker at 278 K after 2 weeks. NDUS1 was synthesized from aqueous solution at room temperature over the course of a month. NDUS, NDUS1, and NDUSe crystallize in the monoclinic space group P21/n, a = 15.0249(4) Å,b = 9.9320(2) Å, c = 15.6518(4) Å, β = 112.778(1)°, V = 2153.52(9) Å3,Z = 4, the tetragonal space group P43212, a = 10.6111(2) Å,c = 31.644(1) Å, V = 3563.0(2) Å3, Z = 8, and in the monoclinic space group P21/n, a = 8.993(3) Å, b = 13.399(5) Å, c = 10.640(4) Å,β = 108.230(4)°, V = 1217.7(8) Å3, Z = 4, respectively.The structural units of NDUS and NDUS1 are two‐dimensional uranyl sulfate sheets with a U/S ratio of 2/3. The structural unit of NDUSe is a two‐dimensional uranyl selenate‐selenite sheets with a U/Se ratio of 1/2. In‐situ reaction of the L ‐cystine ligands gives two distinct products for the different acids used here. Where sulfuric acid is used, only H3O+ cations are located in the interlayer space, where they balance the charge of the sheets, whereas where selenic acid is used, interlayer C5H6N+ cations result from the cyclization of the carboxyl groups of L ‐cystine, balancing the charge of the sheets. |
| |
Keywords: | Uranyl sulfate Uranyl selenate‐selenite Infrared spectroscopy Raman spectroscopy Single crystal structure analysis X‐ray diffraction In‐situ ligand synthesis |
|
|