Syntheses and crystal structures of a linear-chain uranyl phenylphosphinate UO2(O2PHC6H5)2 and layered uranyl methylphosphonate UO2(O3PCH3)

Two extended uranyl organophosphorus compounds have been synthesized and structurally characterized. Linear-chain uranyl bis(phenylphosphinate), UO2(O2PHC6H5)(2), was synthesized at 60 degrees C, and its structure was solved by single-crystal methods. UO2(O2PHC6H5)(2) crystallizes in the triclinic space group P (1) over bar with unit cell parameters a = 5.648(1) Angstrom, b = 8.115(2) Angstrom, c = 9.171(2) Angstrom, alpha = 64.97(3)degrees, beta = 80.59(3)degrees, gamma = 83.34(3)degrees and Z = 1. The geometry of the uranium atom is tetragonal bipyramidal, and the neighboring uranyl ions are bridged by pairs of phenylphosphinate anions. The phenyl groups form two rows pointing in opposite directions of each chain, and neighboring chains arrange in a staircase fashion. Layered uranyl methylphosphonate, UO2(O3PCH3) (UPMe), was synthesized hydrothermally at 200 degrees C, and its structure was solved by powder pattern X-ray methods and refined by the Rietveld method. UPMe crystallizes in space group P (1) over bar with unit cell parameters a = 6.4027(3) Angstrom, b = 6.6912(3) Angstrom, c = 7.0983(3) Angstrom, alpha = 90.473(2)degrees, beta = 99.684(2)degrees, gamma = 97.333(2)degrees, and Z = 2. The uranyl ions, connected by the phosphonate anions, form parallel inorganic layers, and the methyl groups point perpendicularly between the layers.