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 st ructurally characterized. Linear-chain uranyl bis(phenylphosphinate), UO2(O 2PHC6H5)(2), was synthesized at 60 degrees C, and its structure was solved by single-crystal methods. UO2(O2PHC6H5)(2) crystallizes in the triclinic s pace 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 r ows pointing in opposite directions of each chain, and neighboring chains a rrange in a staircase fashion. Layered uranyl methylphosphonate, UO2(O3PCH3 ) (UPMe), was synthesized hydrothermally at 200 degrees C, and its structur e was solved by powder pattern X-ray methods and refined by the Rietveld me thod. UPMe crystallizes in space group P (1) over bar with unit cell parame ters 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)degre es, and Z = 2. The uranyl ions, connected by the phosphonate anions, form p arallel inorganic layers, and the methyl groups point perpendicularly betwe en the layers.