The proton/lithium exchange property of the lithium lanthanum titanate Li(0.30)La(0.57)TiO(3) (named LLTO) is shown to occur at room temperature under ambient air.
View Article and Find Full Text PDFThe room temperature structure of Pb5Ga3F19 is investigated by combining neutron diffraction and multinuclear 19F, 71Ga, and 207Pb one-dimensional and two-dimensional solid-state nuclear magnetic resonance (NMR) experiments. Two models built in space group I4cm are reported for the description of the crystalline structure of Pb5Ga3F19. The structure is built from a network of both opposite corner-sharing Ga2F6(3-) octahedra forming infinite chains along the c-axis and isolated Ga1F6(3-) octahedra.
View Article and Find Full Text PDFAdvantages and limitations of (19)F-(27)Al and (19)F-(19)F dipolar-based 2D NMR experiments for (19)F MAS spectra assignments of fluoroaluminates are presented. In beta-BaAlF(5), combination of 2D MAS (19)F-(27)Al CP-HETCOR and (19)F-(19)F DQ-SQ NMR correlation experiments allows complete unambiguous assignment of the ten poorly resolved resonances of same relative intensities of the (19)F MAS NMR spectrum. The gain in resolution of the (19)F MAS 2D spectrum compared to a 1D spectrum is evidenced, allowing distinction of the two shared-fluorine resonances of Ba(3)Al(2)F(12).
View Article and Find Full Text PDFThe results from one-dimensional multinuclear (19F, 207Pb and 67Zn) magic-angle spinning nuclear magnetic resonance experiments combined with the use of the ISODISPLACE program allow for the space group determination of beta-Pb2ZnF6 (no. 138 P4(2)/ncm). The structure was refined from X-ray powder diffraction data (a = 5.
View Article and Find Full Text PDFNew oxyfluorides Li(2x)Ca(1.5-x) square (0.5-x)M2O6F (M = Nb, Ta), belonging to the cubic pyrochlore structural type (Z = 8, a approximately 10.
View Article and Find Full Text PDFThe alpha1-(Br-(CH(2))(2)-NH(3))(2)PbI(4) hybrid perovskite undergoes a solid-state transformation, that is, the reaction between the organic cations and the perovskite layers to give the new hybrid perovskite (Br-(CH(2))(2)-NH(3))(2-x)(I-(CH(2))(2)-NH(3))(x)PbBr(x)I(4-x), based on mixed halide inorganic layers. This transformation has been followed by a conventional powder X-ray diffraction system equipped with a super speed detector, and both solid-state (13)C NMR and ESI/MS measurements have been adopted in the estimation of the rate of halide substitution. The first reaction step leads to the special composition of x approximately 1 (A phase), while the complete substitution is not achieved even at elevated temperature (x(max) approximately 1.
View Article and Find Full Text PDFA new solid-state MAS NMR experiment is proposed to accurately measure heteronuclear (19)F-(207)Pb J-coupling constants, even though these couplings are not visible on high speed (19)F 1D MAS spectra; in particular, we demonstrate that the J-resolved experiment combined with scalar multiple-quantum filtering considerably improves the resolution of J-multiplet patterns for dilute spin systems.
View Article and Find Full Text PDFPb(n)I(4n+2)((2n+2)-) (n = 3, 5) ribbons, which can be regarded as dimensional reductions of 2D perovskite layers, are stabilized by diprotonated cystamine cations in (NH(3)(CH(2))(2)SS(CH(2))(2)NH(3))(4)Pb(3)I(14),I(2) (1) and (NH(3)(CH(2))(2)SS(CH(2))(2)NH(3))(6)Pb(5)I(22).4H(2)O (2). Both 1 and 2 have interesting structural characteristics; it is unprecedented that the ribbons are linked via I(2) molecules incorporated in the lattice of 1, while tetrameric water clusters are trapped in the structure of 2.
View Article and Find Full Text PDF(19)F NMR isotropic chemical shift (delta(iso)) calculations are performed in crystallized compounds using the GIAO method with the B3LYP hybrid functional at DFT level. Clusters centered on the studied fluorine atoms mimic the crystalline structures. The 6-311+G(d) basis set is chosen for the central fluorine atom, and the LanL2DZ basis set for the others.
View Article and Find Full Text PDFThe structure of the very strong solid Lewis acid aluminum chlorofluoride (ACF, AlCl(x)F(3-x), x = 0.05-0.3) was studied by IR, ESR, Cl K XANES, (19)F MAS NMR, and (27)Al SATRAS NMR spectroscopic methods and compared with amorphous aluminum fluoride conventionally prepared by dehydration of alpha-AlF(3) x 3H(2)O.
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