Synthesis and Crystal Structure of a New Fluorogallophosphate Named Mu-12

Abstract

In the present paper, the synthesis and structure determination of a new three-dimensional microporous fluorogallophosphate, named Mu-12, is reported. This material (Ga20P16O72F4[C2N2H10]4) was obtained by hydrothermal synthesis in the presence of ethylenediamine as organic template, using the fluoride route. Its structure was determined by single-crystal X-ray diffraction. The symmetry is monoclinic, space group P21/n, with the following unit-cell parameters: a = 14.3753(9) Å, b = 11.9410(7) Å, c = 10.1760(6) Å, and β = 91.102(5)°. The three-dimensional framework of Mu-12 can completely be built from ladder chains obtained by connection of four-membered rings (4MR), which consist of 2 Ga and 2 P atoms. These chains are connected to each other in the a and b directions through GaO6 octahedra. The resulting three-dimensional framework displays a one-dimensional channel system parallel to the [100] direction delimited by 9-MR openings and hosting the protonated amine. This material was characterized by elemental and thermal analyses, XRD, SEM, and 13C, 19F, and 31P solid-state NMR spectroscopy.

Single-crystal XRD and solid-state NMR structural resolution of a layered fluorinated gallium phosphate: RbGa3(PO4)2(HPO4)F4·C5N2H16·2H2O (MIL-145)

“…Most of the NMR experiments were acquired on an Avance Bruker 500 spectrometer (Larmor frequencies of 500.1, 470.6, 202.5, 152.5, 125.7 and 50.7 MHz for 1 H, 19 F, 31 P, 71 Ga, 13 C and 15 N, respectively) using 2.5, 3.2 or 4 mm probes.…”

“…The 19 F Hahn-echo MAS NMR spectrum was acquired at a MAS frequency of 20 kHz, using a 3.5 μs π/2 pulse, inter-pulse delays synchronized with the rotor period and a 5 s recycle delay. 1 H SPINAL-64 decoupling was applied during acquisition for optimum resolution.…”

“…1 H SPINAL-64 decoupling was applied during acquisition for optimum resolution. The 2D double-quantum single-quantum (DQ-SQ) 19 F MAS (20 kHz) NMR correlation experiment was recorded with an offset compensated back-toback (BABA) pulse train sequence for excitation and reconversion of the DQ coherence. 48 The DQ excitation and reconversion blocks were set to 100 μs.…”

“…The recycle delay was set to 5 s, which ensured full return of the 31 P magnetization to equilibrium in this sample. 1 H SPINAL-64 decoupling was applied during acquisition for optimum resolution The 2D 19 F → 31 P CP heteronuclear correlation (CP-HETCOR) NMR spectrum was recorded in a 2.5 mm probe at a MAS frequency of 20 kHz using a 3 ms contact time. 1 H SPINAL-64 decoupling was applied during the whole experiment.…”

“…For the last two decades, there have been numerous illustrations of a variety of multi-dimensional networks reflected by different coordination environments of gallium (tetrahedral, trigonal bipyramidal or octahedral geometry) and the diversity of organic structure-directing agents (most often aliphatic poly-amines). 5,[14][15][16][17][18][19][20][21][22][23] In terms of diameter aperture of cavity/channels, extra-large pore compounds have been successfully reported with systems delimited by 12-, 24-28 14-, 29 16-, [30][31][32] 18-, [32][33][34] [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] or 24-membered 36 (Ga or P) rings. These compounds have been obtained exclusively with the use of organic template-like species, but very few studies investigated the association of alkali cations together with the amine.…”