Acta Cryst. (2008). E64, i74 [ doi:10.1107/S1600536808032972 ]
Cerium(III) ultraphosphate, CeP5O14, was synthesized by a high-temperature solution reaction between CeO2 and NH4H2PO4 in a Ce-P molar ratio of 1:12. Colourless crystals of the orthorhombic polymorph were obtained by cooling the melt of the mixture. The structure contains (P5O14)3- anionic ribbons linked by distorted CeO8 polyhedra.
The title compound was prepared by a high-temperature solution reaction, using analytical reagent CeO2 and NH4H2PO4 in a molar ratio corresponding to Ce/P = 1:12. Starting mixtures were finely ground in an agate mortar to ensure optimal homogeneity and reactivity, then placed in a platinum crucible and heated at 373 K for 4 h. Afterwards, the mixtures were reground and heated to 973 K for 24 h. Finally, the temperature was cooled to 773 K at a rate of 2 K/h and air-quenched to room temperature. A few colourless, block-shaped crystals were obtained from the melt of the mixture.
The position of the Ce atom was obtained using direct methods, and the remaining atoms were located in succesive difference Fourier syntheses. The chemical composition of the single crystal was confirmed by energy-dispersive X-ray (EDX) analysis, and no impurity elements were detected.
Data collection: CrystalClear (Molecular Structure Corporation & Rigaku, 2001); cell refinement: CrystalClear (Molecular Structure Corporation & Rigaku, 2001); data reduction: CrystalClear (Molecular Structure Corporation & Rigaku, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
![[Figure 1]](./bi2303fig1thm.gif)
| Fig. 1. Asymmetric unit with displacement ellipsoids shown at 50% probability. |
![[Figure 2]](./bi2303fig2thm.gif)
| Fig. 2. Projection of the structure along the b axis. The tetrahedra represent PO4 groups and the gray circles represent Ce3+ cations. |
![[Figure 3]](./bi2303fig3thm.gif)
| Fig. 3. (P5O14)3- anionic ribbon running parallel to the b axis. |
| CeP5O14 | F(000) = 980 |
| Mr = 518.97 | Dx = 3.289 Mg m−3 |
| Orthorhombic, Pmna | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ac 2 | Cell parameters from 2047 reflections |
| a = 13.1252 (12) Å | θ = 2.3–27.5° |
| b = 8.7991 (9) Å | µ = 5.19 mm−1 |
| c = 9.0741 (9) Å | T = 293 K |
| V = 1047.97 (18) Å3 | Block, colourless |
| Z = 4 | 0.08 × 0.08 × 0.05 mm |
| Rigaku Mercury CCD diffractometer | 1262 independent reflections |
| Radiation source: fine-focus sealed tube | 1212 reflections with I > 2σ(I) |
| graphite | Rint = 0.072 |
| ω scans | θmax = 27.5°, θmin = 2.3° |
| Absorption correction: multi-scan (CrystalClear; Molecular Structure Corporation & Rigaku, 2001) | h = −17→16 |
| Tmin = 0.663, Tmax = 0.771 | k = −11→11 |
| 7608 measured reflections | l = −11→11 |
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.048 | w = 1/[σ2(Fo2) + 37.6801P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.094 | (Δ/σ)max = 0.001 |
| S = 1.00 | Δρmax = 1.70 e Å−3 |
| 1262 reflections | Δρmin = −1.08 e Å−3 |
| 99 parameters | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| 0 restraints | Extinction coefficient: 0.0114 (15) |
| CeP5O14 | V = 1047.97 (18) Å3 |
| Mr = 518.97 | Z = 4 |
| Orthorhombic, Pmna | Mo Kα radiation |
| a = 13.1252 (12) Å | µ = 5.19 mm−1 |
| b = 8.7991 (9) Å | T = 293 K |
| c = 9.0741 (9) Å | 0.08 × 0.08 × 0.05 mm |
| Rigaku Mercury CCD diffractometer | 1262 independent reflections |
| Absorption correction: multi-scan (CrystalClear; Molecular Structure Corporation & Rigaku, 2001) | 1212 reflections with I > 2σ(I) |
| Tmin = 0.663, Tmax = 0.771 | Rint = 0.072 |
| 7608 measured reflections | θmax = 27.5° |
| R[F2 > 2σ(F2)] = 0.048 | w = 1/[σ2(Fo2) + 37.6801P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.094 | Δρmax = 1.70 e Å−3 |
| S = 1.00 | Δρmin = −1.08 e Å−3 |
| 1262 reflections | Absolute structure: ? |
| 99 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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. |
| x | y | z | Uiso*/Ueq | ||
| Ce | 0.5000 | 0.72337 (7) | 0.68985 (6) | 0.00797 (19) | |
| P1 | 0.2936 (2) | 0.5000 | 0.5000 | 0.0113 (6) | |
| P2 | 0.0000 | 0.3121 (3) | 0.7524 (3) | 0.0091 (5) | |
| P3 | 0.3233 (2) | 0.0000 | 0.5000 | 0.0102 (5) | |
| P4 | 0.16332 (14) | 0.2351 (2) | 0.54996 (19) | 0.0098 (4) | |
| O1 | 0.1129 (4) | 0.2256 (7) | 0.4081 (6) | 0.0189 (12) | |
| O2 | 0.3474 (4) | 0.5859 (7) | 0.6151 (6) | 0.0182 (12) | |
| O3 | 0.2451 (5) | 0.1123 (8) | 0.5815 (6) | 0.0295 (16) | |
| O4 | 0.0000 | 0.4655 (9) | 0.6859 (9) | 0.0155 (16) | |
| O5 | 0.2151 (5) | 0.3901 (7) | 0.5849 (7) | 0.0307 (17) | |
| O6 | 0.3778 (4) | −0.0799 (6) | 0.6175 (6) | 0.0165 (12) | |
| O7 | 0.0000 | 0.2893 (10) | 0.9131 (8) | 0.0176 (17) | |
| O8 | 0.0934 (4) | 0.2133 (6) | 0.6876 (6) | 0.0161 (11) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Ce | 0.0074 (3) | 0.0090 (3) | 0.0075 (3) | 0.000 | 0.000 | 0.0003 (2) |
| P1 | 0.0062 (11) | 0.0135 (13) | 0.0143 (13) | 0.000 | 0.000 | −0.0033 (11) |
| P2 | 0.0089 (12) | 0.0120 (13) | 0.0063 (11) | 0.000 | 0.000 | −0.0008 (10) |
| P3 | 0.0080 (11) | 0.0124 (13) | 0.0102 (12) | 0.000 | 0.000 | −0.0013 (10) |
| P4 | 0.0059 (8) | 0.0152 (10) | 0.0083 (8) | 0.0002 (7) | 0.0001 (6) | −0.0019 (7) |
| O1 | 0.021 (3) | 0.023 (3) | 0.013 (2) | 0.006 (3) | −0.008 (2) | −0.001 (2) |
| O2 | 0.014 (3) | 0.023 (3) | 0.018 (3) | −0.006 (2) | −0.003 (2) | 0.000 (2) |
| O3 | 0.029 (3) | 0.050 (4) | 0.010 (3) | 0.028 (3) | 0.001 (2) | −0.004 (3) |
| O4 | 0.019 (4) | 0.012 (4) | 0.016 (4) | 0.000 | 0.000 | −0.005 (3) |
| O5 | 0.034 (4) | 0.031 (4) | 0.027 (3) | −0.027 (3) | 0.019 (3) | −0.015 (3) |
| O6 | 0.016 (3) | 0.017 (3) | 0.016 (3) | 0.006 (2) | −0.002 (2) | 0.001 (2) |
| O7 | 0.021 (4) | 0.024 (4) | 0.008 (3) | 0.000 | 0.000 | −0.002 (3) |
| O8 | 0.017 (3) | 0.017 (3) | 0.014 (2) | 0.007 (2) | 0.005 (2) | 0.004 (2) |
| Ce—O2 | 2.436 (5) | P2—O8ix | 1.614 (5) |
| Ce—O2i | 2.436 (5) | P2—O8 | 1.614 (5) |
| Ce—O6ii | 2.449 (5) | P3—O6x | 1.464 (5) |
| Ce—O6iii | 2.449 (5) | P3—O6 | 1.464 (5) |
| Ce—O7iv | 2.513 (7) | P3—O3x | 1.606 (6) |
| Ce—O1v | 2.514 (5) | P3—O3 | 1.606 (6) |
| Ce—O1vi | 2.514 (5) | P4—O1 | 1.450 (5) |
| Ce—O4vii | 2.534 (8) | P4—O3 | 1.549 (6) |
| P1—O2 | 1.470 (6) | P4—O5 | 1.557 (6) |
| P1—O2viii | 1.470 (6) | P4—O8 | 1.562 (5) |
| P1—O5viii | 1.609 (6) | O1—Ceiv | 2.514 (5) |
| P1—O5 | 1.609 (6) | O4—Cexi | 2.534 (7) |
| P2—O7 | 1.472 (8) | O6—Cexii | 2.449 (5) |
| P2—O4 | 1.479 (8) | O7—Cevi | 2.513 (7) |
| O2—Ce—O2i | 110.6 (3) | O2viii—P1—O5viii | 106.0 (3) |
| O2—Ce—O6ii | 144.55 (18) | O2—P1—O5 | 106.0 (3) |
| O2i—Ce—O6ii | 74.82 (19) | O2viii—P1—O5 | 109.8 (3) |
| O2—Ce—O6iii | 74.82 (19) | O5viii—P1—O5 | 100.4 (6) |
| O2i—Ce—O6iii | 144.55 (18) | O7—P2—O4 | 121.9 (5) |
| O6ii—Ce—O6iii | 81.8 (3) | O7—P2—O8ix | 106.7 (3) |
| O2—Ce—O7iv | 72.54 (17) | O4—P2—O8ix | 110.1 (3) |
| O2i—Ce—O7iv | 72.54 (17) | O7—P2—O8 | 106.7 (3) |
| O6ii—Ce—O7iv | 76.3 (2) | O4—P2—O8 | 110.1 (3) |
| O6iii—Ce—O7iv | 76.3 (2) | O8ix—P2—O8 | 98.9 (4) |
| O2—Ce—O1v | 142.43 (19) | O6x—P3—O6 | 121.5 (5) |
| O2i—Ce—O1v | 79.83 (19) | O6x—P3—O3x | 105.8 (3) |
| O6ii—Ce—O1v | 72.48 (18) | O6—P3—O3x | 110.6 (3) |
| O6iii—Ce—O1v | 118.08 (19) | O6x—P3—O3 | 110.6 (3) |
| O7iv—Ce—O1v | 142.65 (14) | O6—P3—O3 | 105.8 (3) |
| O2—Ce—O1vi | 79.83 (19) | O3x—P3—O3 | 100.5 (5) |
| O2i—Ce—O1vi | 142.43 (19) | O1—P4—O3 | 116.1 (3) |
| O6ii—Ce—O1vi | 118.08 (19) | O1—P4—O5 | 115.5 (4) |
| O6iii—Ce—O1vi | 72.48 (18) | O3—P4—O5 | 105.7 (4) |
| O7iv—Ce—O1vi | 142.65 (14) | O1—P4—O8 | 115.8 (3) |
| O1v—Ce—O1vi | 72.2 (3) | O3—P4—O8 | 100.0 (3) |
| O2—Ce—O4vii | 71.29 (16) | O5—P4—O8 | 101.6 (3) |
| O2i—Ce—O4vii | 71.29 (16) | P4—O1—Ceiv | 163.4 (4) |
| O6ii—Ce—O4vii | 138.78 (13) | P1—O2—Ce | 148.0 (4) |
| O6iii—Ce—O4vii | 138.78 (14) | P4—O3—P3 | 141.9 (4) |
| O7iv—Ce—O4vii | 113.9 (3) | P2—O4—Cexi | 129.5 (5) |
| O1v—Ce—O4vii | 79.0 (2) | P4—O5—P1 | 135.1 (4) |
| O1vi—Ce—O4vii | 79.0 (2) | P3—O6—Cexii | 148.7 (3) |
| O2—P1—O2viii | 122.6 (5) | P2—O7—Cevi | 174.7 (6) |
| O2—P1—O5viii | 109.8 (3) | P4—O8—P2 | 132.2 (4) |
| Symmetry codes: (i) −x+1, y, z; (ii) −x+1, y+1, z; (iii) x, y+1, z; (iv) −x+1/2, −y+1, z−1/2; (v) x+1/2, −y+1, z+1/2; (vi) −x+1/2, −y+1, z+1/2; (vii) x+1/2, y, −z+3/2; (viii) x, −y+1, −z+1; (ix) −x, y, z; (x) x, −y, −z+1; (xi) x−1/2, y, −z+3/2; (xii) x, y−1, z. |
This investigation was based on work supported by the Foundation of Yunnan University (Project No. 2007Q013B).
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Rare-earth ultraphosphates, LnP5O14 (Ln = rare-earth element), have attracted wide interest because of their potential applications in the laser domain (Schulz et al., 1974; Kobayashi et al., 1976; Katrusiak & Kaczmarek, 1995; Cole et al., 2000). These compounds can be generally classified into four structure types: monoclinic (P21/a), monoclinic (C2/c), orthorhombic (Pnma), and triclinic (P1) (Averbuch-Pouchot & Durif, 1992). In this chemical system, many of the compounds are isotypic, and some are polymorphic. However, many polymorphs of ultraphosphates LnP5O14 have not been realised to date. Herein, we present the synthesis and crystal structure of an orthorhombic polymorph of CeP5O14.
In the structure (Figs. 1 and 2), the Ce3+ cation plays an important bridging role, connecting neighbouring (P5O14)3- anionic ribbons. The CeO8 polyhedron is corner-sharing with eight PO4 tetrahedra, with the Ce—O bond distances ranging from 2.436 (5) to 2.534 (8) Å. The shortest Ce—Ce distance is 5.2271 (9) Å. The (P5O14)3- anionic ribbon may be described as two PO4 infinite chains linked by P(2)O4 tetrahedra, as shown in Fig. 3. P(1)O4, P(3)O4, and P(4)O4 tetrahedra are corner-shared to form screwed infinite chains along the b axis. P(2)O4 tetrahedra are corner-shared with two surrounding PO4 infinite chains along the a axis. Thus, a (P5O14)3- anionic ribbon is observed parallel to b.