Hydrothermal synthesis, crystal structure, and characterization of a new pseudo-two-dimensional uranyl oxyfluoride, [N(C2H5)4]2[(UO2)4(OH2)3F10]

A new uranyl oxyfluoride, [N(C2H5)4]2[(UO2)4(OH2)3F10] has been synthesized by a hydrothermal reaction technique using (C2H5)4NBr, UO2(OCOCH3)2.2H2O, and HF as reagents. The structure of [N(C2H5)4]2[(UO2)4(OH2)3F10] has been determined by a single-crystal X-ray diffraction technique. [N(C2H5)4]2[(UO2)4(OH2)3F10] crystallizes in the monoclinic space group P21/n (No. 14), with a=13.852(3)A, b=15.532(3)A, c=16.481(3)A, β=98.88(3)o, V=3503.4(12)A3, and Z=4. [N(C2H5)4]2[(UO2)4(OH2)3F10] reveals a novel pseudo-two-dimensional crystal structure that is composed of UO2F5, UO3F4, and UO4F3 pentagonal bipyramids. Each uranyl pentagonal bipyramid shares edges and corners through F atoms to form a six-membered ring. The rings are further interconnected to generate infinite strips running along the b-axis. [N(C2H5)4]2[(UO2)4(OH2)3F10] has been further characterized by elemental analysis, bond valence calculations, Infrared and Raman spectroscopy, and thermogravimetric analysis