title: A new chiral uranyl phosphonate framework consisting of achiral building units generated from ionothermal reaction: structure and spectroscopy characterizations.
abstract: The ionothermal reactions of uranyl nitrate and 1,3-pbpH4 (1,3-pbpH4 = 1,3-phenylenebis(phosphonic acid) ligand in ionic liquids of [C4mim][Dbp], [C4mpyr][Br], and [Etpy][Br], respectively, afforded three new uranyl phosphonates, namely [C4mim][(UO2)2(1,3-pbpH)(1,3-pbpH)·Hmim] (1), [UO2(1,3-pbpH2)H2O·mpr] (2), and [Etpy][UO2(1,3-pbpH2)F] (3). Compound 1 exhibits a rare example of a chiral uranyl phosphonate 3D framework structure built from achiral building units of tetragonal bipyramidal uranium polyhedra and 1,3-pbp ligands. The structure adopts a network with channels extending along the b axis, which are filled with C4mim(+) and protonated 1-methylimidazole. In sharp contrast, compounds 2 & 3 both show pillared topology composed of uranyl pentagonal bipyramid polyhedra and phosphonate ligands. The layers are neutral in compound 2 with N-methylpyrrole molecules in the interlayer space, while compound 3 adopts anionic layer, and the charge is compensated with N-ethyl-pyridinium cations between the layers. Although compounds 1, 2, and 3 were synthesized under identical conditions with sole variation of the ionic liquid species, the resulting structures show a rich diversity in the local coordination environment of uranyl ions, the protonation of the phosphonate ligand, the conformation of ionic liquid ions, and the overall arrangement of the structure. All compounds were characterized by absorption, temperature dependent fluorescence, as well as infrared and Raman spectroscopies.
authors.affiliation: School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, Jiangsu 215123, China. diwujuan@suda.edu.cn shuaowang@suda.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Zheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.forename: Lanhua
authors.initials: L
authors.lastname: Chen
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Liu
authors.forename: Juan
authors.initials: J
authors.lastname: Diwu
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Chai
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Albrecht-Schmitt
authors.forename: Shuao
authors.initials: S
authors.lastname: Wang
mesh_terms: D018360:Crystallography, X-Ray; D052578:Ionic Liquids / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D063065:Organophosphonates / Q000737:chemistry*; D013696:Temperature; D014501:Uranium / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D008024:Ligands; D009942:Organometallic Compounds; D063065:Organophosphonates; D014501:Uranium