inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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Heptasodium tetra­aluminium tetra­kis­(diphosphate) orthophosphate, Na7Al4(P2O7)4(PO4)

aDepartment of Physics and Chemistry, Henan Polytechnic University, Jiaozuo, Henan 454000, People's Republic of China
*Correspondence e-mail: iamzd@hpu.edu.cn

(Received 3 September 2011; accepted 10 October 2011; online 22 October 2011)

The asymmetric unit of title compound contains three Na+, one Al3+, three P5+ and eight O2− atoms, with one Na+ atom lying on a twofold rotation axis and one Na+ and one P5+ atom on fourfold rotoinversion axes. The fundamental building units of the title structure are isolated PO4 tetra­hedra, AlO6 octa­hedra and P2O7 groups, which are further inter­locked by corner-sharing O atoms, forming a three-dimensional framework structure. The Na+ atoms are located within the cavities of the framework, showing coordination numbers of 4, 6 and 7.

Related literature

For isotypic structures, see: Rochère et al. (1985[Rochère, M., Kahn, A., d'Yvoire, F. & Bretey, E. (1985). Mater. Res. Bull. 20, 27-34.]); Stus et al. (2001[Stus, N. V., Lisnyak, V. V. & Nagornyi, P. G. (2001). J. Alloys Compd, 314, 62-66.]).

Experimental

Crystal data
  • Na7Al4(P2O7)4(PO4)

  • Mr = 1059.58

  • Tetragonal, [P \overline 42_1 c ]

  • a = 14.054 (3) Å

  • c = 6.1718 (16) Å

  • V = 1219.1 (4) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 1.06 mm−1

  • T = 296 K

  • 0.15 × 0.05 × 0.05 mm

Data collection
  • Rigaku Saturn70 CCD diffractometer

  • Absorption correction: multi-scan (ABSCOR; Higashi, 1995[Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.857, Tmax = 0.949

  • 5562 measured reflections

  • 1347 independent reflections

  • 1287 reflections with I > 2σ(I)

  • Rint = 0.024

Refinement
  • R[F2 > 2σ(F2)] = 0.017

  • wR(F2) = 0.047

  • S = 1.08

  • 1347 reflections

  • 118 parameters

  • Δρmax = 0.22 e Å−3

  • Δρmin = −0.29 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 540 Friedel pairs

  • Flack parameter: −0.04 (9)

Data collection: CrystalClear (Rigaku, 2004[Rigaku (2004). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 2004[Brandenburg, K. (2004). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Supporting information


Comment top

Metal phosphates possessing open-framework structures with defined tunnels have been extensively investigated for their structural diversity, properties, and potential applications in shape-selective catalysis, adsorbents, ion exchangers, and molecular sieves. Among them, a series of isotypic ortho-diphosphates Na7(MP2O7)4PO4 (M = Al, Cr, Fe) (Rochère et al., 1985) and Na7(InP2O7)4PO4 (Stus et al., 2001) were synthesized, and their ion exchange and conductivity properties studied. However, for compound Na7(AlP2O7)4PO4, a detailed crystal structure analysis has not been reported so far. In this work, the synthesis and results of the crystal structure refinement of this compound is reported. In comparison with the unit cell parameters reported by Rochère from X-ray powder data (a = 14.046 (3), c = 6.169 (2) Å; Rochère et al., 1985), the determined unit cell parameters from the single crystal X-ray study are slighty larger.

As shown in Figs 1 and 2, the structure of the title compound consists of a three-dimensional framework of isolated PO4 tetrahedra, AlO6 octahedra and P2O7 groups, the conformation of the latter more eclipsed than staggered. The sodium cations are located in sites within cavities in the framework, exhibiting coordination numbers of 7 (Na1), 6 (Na2) and 4 (Na3). There are three crystallography distinct P atoms in the structure of the title compound. P1 and P2 atoms are located in general positions and their corresponding P1O4 and P2O4 tetrahedra are connected by the bridging O5 atom to form a P2O7 group, which is further linked to four AlO6 octahedra. P3 atoms are located on 4 axes, forming isolated P3O4 tetrahedra which are further connected to four AlO6 octahedra. The P3O4 tetrahedra are regular with a P—O bond length of 1.5351 (18) Å, while the P–O distances in the P2O7 group are irregular, showing the characteristic variance of smaller P–Oterminal bonds (1.4862 (14) to 1.5199 (14) Å) and larger P–Obridging bonds (1.6097 (14) and 1.6284 (15) Å) as typically observed for diphosphate unit. The title structure differs in their P–O–P bridging angle of the diphosphate group and the average metal–O distances from those of the isotypic congeners. For the Al compound, the interatomic distances in the MO6 octahedron are decreasing (Fe–O6 1.968–2.021 Å, InO6 2.091–2.146 Å, AlO6 1.8391 (15)–1.9278 (16) Å), as expected from the smaller ionic radius of Al3+ comparerd to Fe3+ and In3+. With a decrease of the unit-cell parameters a trend in a likewise decreasing P–O–P bridging angle of the diphosphate groups is observed: (Na7(FeP2O7)4PO4: 136.6 (3)°; Na7(InP2O7)4PO4: 136.7 (3)°, Na7(AlP2O7)4PO4: 127.92 (9)°.

Related literature top

For isotypic structures, see: Rochère et al. (1985); Stus et al. (2001).

Experimental top

The finely ground reagents Na2CO3, Al2O3 and NH4H2PO4 were mixed in the molar ratio Na: Al: P = 2: 1: 8, were placed in a Pt crucible, and heated at 673 K for 4 h. The mixture was then re-ground and heated at 1173 K for 20 h, then cooled to 673 K at a rate of 3 K h-1, and finally quenched to room temperature. A few colorless crystals of the title compound with prismatic shape were obtained.

Refinement top

The highest peak in the difference electron density map equals to 0.22 e/Å3 at the distance of 0.63 Å from O4 site while the deepest hole equals to -0.29 e/Å3 at the distance of 0.68 Å from the P3 site.

Computing details top

Data collection: CrystalClear (Rigaku, 2004); cell refinement: CrystalClear (Rigaku, 2004); data reduction: CrystalClear (Rigaku, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2004); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The expanded asymmetric unit of Na7(AlP2O7)4PO4 showing the coordination environments of the P and Al atoms. The displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (iii) -y + 1, x, -z + 1; (vii) -x + 1, -y + 1, z; (viii) -y + 1, x, -z + 2; (ix) x - 1/2, -y + 3/2, -z + 3/2; (x) y, -x + 1, -z + 1.]
[Figure 2] Fig. 2. View of the crystal structure of Na7(AlP2O7)4PO4. PO4 and AlO6 units are given in the polyhedral representation.
Heptasodium tetraaluminium tetrakis(diphosphate) orthophosphate top
Crystal data top
Na7Al4(P2O7)4(PO4)Dx = 2.887 Mg m3
Mr = 1059.58Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P421cCell parameters from 3720 reflections
Hall symbol: P -4 2nθ = 2.9–27.5°
a = 14.054 (3) ŵ = 1.06 mm1
c = 6.1718 (16) ÅT = 296 K
V = 1219.1 (4) Å3Prism, colourless
Z = 20.15 × 0.05 × 0.05 mm
F(000) = 1040
Data collection top
Rigaku Saturn70 CCD
diffractometer
1347 independent reflections
Radiation source: fine-focus sealed tube1287 reflections with I > 2σ(I)
Graphite Monochromator monochromatorRint = 0.024
Detector resolution: 14.6306 pixels mm-1θmax = 27.5°, θmin = 3.2°
ω scansh = 1817
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
k = 1816
Tmin = 0.857, Tmax = 0.949l = 77
5562 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.017 w = 1/[σ2(Fo2) + (0.0297P)2 + 0.278P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.047(Δ/σ)max = 0.001
S = 1.08Δρmax = 0.22 e Å3
1347 reflectionsΔρmin = 0.29 e Å3
118 parametersAbsolute structure: Flack (1983), 540 Friedel pairs
0 restraintsAbsolute structure parameter: 0.04 (9)
Crystal data top
Na7Al4(P2O7)4(PO4)Z = 2
Mr = 1059.58Mo Kα radiation
Tetragonal, P421cµ = 1.06 mm1
a = 14.054 (3) ÅT = 296 K
c = 6.1718 (16) Å0.15 × 0.05 × 0.05 mm
V = 1219.1 (4) Å3
Data collection top
Rigaku Saturn70 CCD
diffractometer
1347 independent reflections
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
1287 reflections with I > 2σ(I)
Tmin = 0.857, Tmax = 0.949Rint = 0.024
5562 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0170 restraints
wR(F2) = 0.047Δρmax = 0.22 e Å3
S = 1.08Δρmin = 0.29 e Å3
1347 reflectionsAbsolute structure: Flack (1983), 540 Friedel pairs
118 parametersAbsolute structure parameter: 0.04 (9)
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Na10.42251 (6)0.75865 (7)0.09314 (15)0.0200 (2)
Na20.50001.00000.3156 (2)0.0268 (3)
Na30.50000.50001.00000.0411 (6)
Al10.32097 (4)0.62225 (4)0.63747 (9)0.00558 (13)
P10.62752 (3)0.74207 (3)0.84990 (8)0.00573 (11)
P20.46166 (3)0.79988 (3)0.60041 (8)0.00656 (11)
P30.50000.50000.50000.00535 (19)
O10.42717 (10)0.89936 (10)0.5600 (2)0.0117 (3)
O20.54197 (10)0.81323 (10)0.7882 (2)0.0109 (3)
O30.38751 (10)0.73621 (10)0.7038 (2)0.0128 (3)
O40.51085 (9)0.75581 (10)0.4067 (2)0.0104 (3)
O50.71136 (9)0.80522 (10)0.8791 (2)0.0129 (3)
O60.59683 (10)0.69263 (10)1.0575 (2)0.0113 (3)
O70.63718 (10)0.66852 (9)0.6721 (2)0.0087 (3)
O80.43148 (9)0.55247 (10)0.6522 (2)0.0100 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Na10.0224 (4)0.0242 (5)0.0133 (4)0.0060 (3)0.0034 (4)0.0031 (4)
Na20.0280 (7)0.0405 (9)0.0118 (6)0.0216 (6)0.0000.000
Na30.0561 (9)0.0561 (9)0.0111 (9)0.0000.0000.000
Al10.0049 (2)0.0063 (3)0.0055 (3)0.0010 (2)0.0002 (2)0.0000 (2)
P10.0056 (2)0.0069 (2)0.0047 (2)0.00024 (16)0.00004 (17)0.00036 (18)
P20.0064 (2)0.0068 (2)0.0064 (2)0.00048 (16)0.00085 (19)0.00024 (18)
P30.0053 (3)0.0053 (3)0.0054 (4)0.0000.0000.000
O10.0133 (7)0.0101 (6)0.0117 (8)0.0030 (6)0.0018 (6)0.0007 (6)
O20.0106 (7)0.0123 (7)0.0097 (7)0.0043 (5)0.0043 (6)0.0034 (6)
O30.0139 (7)0.0127 (7)0.0118 (7)0.0066 (6)0.0023 (6)0.0033 (6)
O40.0086 (6)0.0138 (7)0.0088 (6)0.0027 (5)0.0000 (5)0.0019 (6)
O50.0101 (7)0.0166 (7)0.0121 (8)0.0056 (5)0.0004 (6)0.0012 (6)
O60.0149 (7)0.0134 (7)0.0055 (7)0.0024 (5)0.0008 (6)0.0021 (5)
O70.0119 (7)0.0076 (7)0.0065 (7)0.0015 (5)0.0005 (5)0.0007 (5)
O80.0081 (6)0.0135 (7)0.0084 (6)0.0039 (5)0.0000 (6)0.0014 (5)
Geometric parameters (Å, º) top
Na1—O42.2998 (17)P1—O71.5136 (14)
Na1—O1i2.3993 (17)P1—O61.5199 (14)
Na1—O3ii2.4730 (18)P1—O21.6097 (14)
Na1—O7iii2.5789 (17)P2—O11.5006 (14)
Na1—O6ii2.6291 (18)P2—O41.5134 (14)
Na1—O2ii2.6363 (18)P2—O31.5145 (15)
Na1—O6iii2.9419 (18)P2—O21.6284 (15)
Na2—O1iv2.3072 (16)P3—O8iii1.5341 (14)
Na2—O12.3072 (17)P3—O8x1.5341 (14)
Na2—O1i2.3532 (17)P3—O81.5341 (14)
Na2—O1v2.3532 (17)P3—O8vii1.5341 (14)
Na2—O2i2.6957 (15)O1—Na2xi2.3532 (17)
Na2—O2v2.6957 (15)O1—Na1xii2.3993 (17)
Na3—O8vi2.4655 (16)O2—Na1xiii2.6363 (18)
Na3—O82.4655 (16)O2—Na2xi2.6957 (15)
Na3—O8vii2.4655 (16)O3—Na1xiii2.4730 (18)
Na3—O8viii2.4655 (16)O4—Al1x1.9210 (15)
Al1—O81.8391 (15)O5—Al1xiv1.8500 (15)
Al1—O5ix1.8500 (15)O6—Al1vi1.9258 (16)
Al1—O31.8993 (16)O6—Na1xiii2.6291 (18)
Al1—O4iii1.9210 (15)O6—Na1x2.9419 (18)
Al1—O6viii1.9258 (16)O7—Al1x1.9278 (16)
Al1—O7iii1.9278 (16)O7—Na1x2.5789 (17)
P1—O51.4862 (14)
O4—Na1—O1i99.33 (6)O3—Al1—O6viii89.69 (7)
O4—Na1—O3ii157.36 (7)O4iii—Al1—O6viii86.10 (7)
O1i—Na1—O3ii90.92 (6)O8—Al1—O7iii92.43 (7)
O4—Na1—O7iii77.49 (5)O5ix—Al1—O7iii87.07 (6)
O1i—Na1—O7iii129.35 (6)O3—Al1—O7iii94.82 (7)
O3ii—Na1—O7iii111.27 (6)O4iii—Al1—O7iii89.49 (6)
O4—Na1—O6ii63.97 (5)O6viii—Al1—O7iii175.36 (7)
O1i—Na1—O6ii117.88 (6)O5—P1—O7115.13 (8)
O3ii—Na1—O6ii93.38 (6)O5—P1—O6113.31 (8)
O7iii—Na1—O6ii106.00 (5)O7—P1—O6108.92 (9)
O4—Na1—O2ii105.20 (6)O5—P1—O2104.47 (8)
O1i—Na1—O2ii74.83 (5)O7—P1—O2108.65 (8)
O3ii—Na1—O2ii58.00 (5)O6—P1—O2105.76 (8)
O7iii—Na1—O2ii155.46 (6)O1—P2—O4113.43 (9)
O6ii—Na1—O2ii56.60 (5)O1—P2—O3113.46 (8)
O4—Na1—O6iii123.33 (6)O4—P2—O3113.91 (8)
O1i—Na1—O6iii131.42 (6)O1—P2—O2103.58 (8)
O3ii—Na1—O6iii59.00 (5)O4—P2—O2107.01 (8)
O7iii—Na1—O6iii52.62 (5)O3—P2—O2104.19 (8)
O6ii—Na1—O6iii102.31 (6)O8iii—P3—O8x104.48 (11)
O2ii—Na1—O6iii110.46 (5)O8iii—P3—O8112.02 (6)
O1iv—Na2—O198.36 (9)O8x—P3—O8112.02 (6)
O1iv—Na2—O1i166.32 (7)O8iii—P3—O8vii112.02 (6)
O1—Na2—O1i84.54 (5)O8x—P3—O8vii112.02 (6)
O1iv—Na2—O1v84.54 (5)O8—P3—O8vii104.48 (11)
O1—Na2—O1v166.32 (7)P1—O2—P2127.92 (9)
O1i—Na2—O1v95.80 (8)P1—O2—Na1xiii97.23 (7)
O1iv—Na2—O2i109.82 (5)P2—O2—Na1xiii91.90 (7)
O1—Na2—O2i75.12 (5)P1—O2—Na2xi138.90 (8)
O1i—Na2—O2i57.84 (5)P2—O2—Na2xi90.30 (6)
O1v—Na2—O2i116.61 (6)Na1xiii—O2—Na2xi95.69 (5)
O1iv—Na2—O2v75.12 (5)P2—O3—Al1138.27 (10)
O1—Na2—O2v109.82 (5)P2—O3—Na1xiii101.37 (7)
O1i—Na2—O2v116.61 (6)Al1—O3—Na1xiii114.51 (7)
O1v—Na2—O2v57.84 (5)P2—O4—Al1x135.59 (9)
O2i—Na2—O2v172.79 (8)P2—O4—Na1114.27 (8)
O8vi—Na3—O8139.29 (4)Al1x—O4—Na1109.28 (7)
O8vi—Na3—O8vii139.29 (4)P1—O5—Al1xiv169.27 (10)
O8—Na3—O8vii58.94 (7)P1—O6—Al1vi144.77 (10)
O8vi—Na3—O8viii58.94 (7)P1—O6—Na1xiii100.00 (7)
O8—Na3—O8viii139.29 (4)Al1vi—O6—Na1xiii97.24 (6)
O8vii—Na3—O8viii139.29 (4)P1—O6—Na1x76.46 (6)
O8—Al1—O5ix178.73 (7)Al1vi—O6—Na1x96.37 (6)
O8—Al1—O391.33 (7)Na1xiii—O6—Na1x160.22 (7)
O5ix—Al1—O387.55 (7)P1—O7—Al1x131.02 (9)
O8—Al1—O4iii92.68 (6)P1—O7—Na1x89.48 (7)
O5ix—Al1—O4iii88.48 (6)Al1x—O7—Na1x131.83 (7)
O3—Al1—O4iii173.98 (7)P3—O8—Al1139.13 (10)
O8—Al1—O6viii86.36 (7)P3—O8—Na398.29 (7)
O5ix—Al1—O6viii94.23 (6)Al1—O8—Na3122.17 (7)
Symmetry codes: (i) y1/2, x+1/2, z1/2; (ii) x, y, z1; (iii) y+1, x, z+1; (iv) x+1, y+2, z; (v) y+3/2, x+3/2, z1/2; (vi) y, x+1, z+2; (vii) x+1, y+1, z; (viii) y+1, x, z+2; (ix) x1/2, y+3/2, z+3/2; (x) y, x+1, z+1; (xi) y+3/2, x+3/2, z+1/2; (xii) y1/2, x+1/2, z+1/2; (xiii) x, y, z+1; (xiv) x+1/2, y+3/2, z+3/2.

Experimental details

Crystal data
Chemical formulaNa7Al4(P2O7)4(PO4)
Mr1059.58
Crystal system, space groupTetragonal, P421c
Temperature (K)296
a, c (Å)14.054 (3), 6.1718 (16)
V3)1219.1 (4)
Z2
Radiation typeMo Kα
µ (mm1)1.06
Crystal size (mm)0.15 × 0.05 × 0.05
Data collection
DiffractometerRigaku Saturn70 CCD
diffractometer
Absorption correctionMulti-scan
(ABSCOR; Higashi, 1995)
Tmin, Tmax0.857, 0.949
No. of measured, independent and
observed [I > 2σ(I)] reflections
5562, 1347, 1287
Rint0.024
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.017, 0.047, 1.08
No. of reflections1347
No. of parameters118
Δρmax, Δρmin (e Å3)0.22, 0.29
Absolute structureFlack (1983), 540 Friedel pairs
Absolute structure parameter0.04 (9)

Computer programs: CrystalClear (Rigaku, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2004), SHELXTL (Sheldrick, 2008).

 

Acknowledgements

The author acknowledges the Doctoral Foundation of Henan Polytechnic University (B2010–92, 648483).

References

First citationBrandenburg, K. (2004). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationHigashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationRigaku (2004). CrystalClear. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationRochère, M., Kahn, A., d'Yvoire, F. & Bretey, E. (1985). Mater. Res. Bull. 20, 27–34.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStus, N. V., Lisnyak, V. V. & Nagornyi, P. G. (2001). J. Alloys Compd, 314, 62–66.  Web of Science CrossRef CAS Google Scholar

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