New Layered Uranium(VI) Molybdates: Syntheses and Structures of (NH₃(CH₂)₃NH₃)(H₃O)₂(UO₂)₃(MoO₄)₅, C(NH₂)₃(UO₂)(OH)(MoO₄), (C₄H₁₂N₂)(UO₂)(MoO₄)₂, and (C₅H₁₄N₂)(UO₂)(MoO₄)₂·H₂O

Abstract

Single crystals of (NH3(CH2)3NH3)(H3O)2(UO2)3(MoO4)5 (1), C(NH2)3(UO2)(OH)(MoO4) (2), (C4H12N2)(UO2)(MoO4)2 (3) and (C5H14N2)(UO2)(MoO4)2·H2O (4) have been synthesized hydrothermally by using UO2(CH3COO)2·2H2O, (NH4)2Mo2O7, HF(aq), H2O, and the respective organic template. The materials have layered structures with anionic uranium molybdate sheets separated by cationic organic templates. Compound 1 has an unprecedented uranium molybdate topology, whereas 2 is structurally related to johannite, Cu[(UO2)2(SO4)2(OH)2](H2O)8, and 3 and 4 have layer topologies similar to zippiete, K2[UO2(MoO4)2]. Thermogravimetric measurements indicate all that four materials, after template loss, form a crystalline mixture of UO2MoO4 and MoO3. Crystal data: (NH3(CH2)3NH3)(H3O)2(UO2)3(MoO4)5, orthorhombic, space group Pbnm (No. 62), with a = 10.465(1) Å, b = 16.395(1) Å, c = 20.241(1) Å, and Z = 4; C(NH2)3(UO2)(OH)(MoO4), monoclinic, space group P21/c (No. 14), with a = 15.411(1) Å, b = 7.086(1) Å, c = 18.108(1) Å, β = 113.125(2)°, and Z = 4; (C4H12N2)(UO2)(MoO4)2, triclinic, space group P1̄ (No. 2), with a = 7.096(1) Å, b = 8.388(1) Å, c = 11.634(1) Å, α = 97.008(3)°, β = 96.454(2)°, γ = 110.456(3)°, and Z = 2; (C5H14N2)(UO2)(MoO4)2·H2O, orthorhombic, space group Pbca (No. 61), with a = 12.697(1) Å, b = 13.247(1) Å, c = 17.793(1) Å, and Z = 8.