New three-dimensional inorganic frameworks based on the uranophane-type sheet in monoamine templated uranyl-vanadates

Seven new uranyl vanadates with mono-protonated amine or tetramethylammonium used as structure directing cations, (C₂NH₈)₂{(UO₂)(H₂O)](UO₂)(VO₄)]₄}·H₂O (DMetU5V4) (C₂NH₈){(UO₂)(H₂O)₂](UO₂)(VO₄)]₃}·H₂O (DMetU4V3), (C₅NH₆)₂{(UO₂)(H₂O)](UO₂)(VO₄)]₄}·H₂O (PyrU5V4), (C₃NH₁₀){(UO₂)(H₂O)₂](UO₂)(VO₄)]₃}·H₂O (isoPrU4V3), (N(CH₃)₄){(UO₂)(H₂O)₂](UO₂)(VO₄)]₃}·H₂O (TMetU4V3), (C₆NH₁₄){(UO₂)(H₂O)₂](UO₂)(VO₄)]₃}·H₂O (CHexU4V3), and (C₄NH₁₂){(UO₂)(H₂O)](UO₂)(VO₄)]₃} (TButU4V3) were prepared from mild-hydrothermal reactions using dimethylamine, pyridine, isopropylamine, tetramethylammonium hydroxide, cyclohexylamine and tertiobutylamine, respectively, with uranyl nitrate and vanadium oxide in acidic medium. The structures were solved using single-crystal X-ray diffraction data. The compounds exhibit three-dimensional uranyl-vanadate inorganic frameworks built from uranophane-type uranyl-vanadate layers pillared by uranyl polyhedra with cavities in between occupied by protonated organic moieties. In the uranyl-vanadate layers the orientations of the vanadate tetrahedra give new geometrical isomers leading to unprecedented pillared systems and new inorganic frameworks with U/V=4/3. Crystallographic data: (DMetU5V4) orthorhombic, Cmc2₁ space group, a=15.6276(4), b=14.1341(4), c=13.6040(4) Å; (DMetU4V3) monoclinic, P2₁/n space group, a=10.2312(4), b=13.5661(7), c=17.5291(7) Å, β=96.966(2); (PyrU5V4), triclinic, P1 space group, a=9.6981(3), b=9.9966(2), c=10.5523(2) Å, α=117.194(1), β=113.551(1), γ=92.216(1)°; (isoPrU4V3) monoclinic, P2₁/n space group, a=10.3507(1), b=13.6500(2), c=17.3035(2) Å, β=97.551(1)°; (TMetU4V3) orthorhombic, Pbca space group, a=17.1819(2), b=13.6931(1), c=21.4826(2) Å; (CHexU4V3), triclinic P−1 space group, a=9.8273(6), b=11.0294(7), c=12.7506(8) Å, α=98.461(3), β=96.437(3), γ=105.955(3)°; (TButU4V3), monoclinic, P2₁/m space group, a=9.8048(4), b=17.4567(8), c=15.4820(6) Å, β=106.103(2).