Acta Cryst. (2009). E65, i70 [ doi:10.1107/S1600536809036058 ]
Caesium europium polyphosphate, CsEu(PO3)4, was synthesized by a high-temperature solution reaction. Its structure is charaterized by a three-dimensional framework made up of double PO4 spiral chains and EuO8 and CsO11 polyhedra.
The title compound was prepared by the high temperature solution reaction, using analytical reagents Cs2CO3, Eu2O3, and NH4H2PO4 in the molar ratio of Cs/Eu/P = 7:1:12. Starting mixtures were finely ground in an agate mortar to ensure the best 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 colorless and block-shaped crystals were obtained from the melt of the mixture.
A single-crystal of the compound was selected for X-ray Diffraction determination. The structure was solved using direct methods and refined on F2 by the full-matrix least-squares method with the SHELXL97 program package (Sheldrick, 2008). The position of the Eu atom was refined by the application of the direct method, and the remaining atoms were located in succeeding difference Fourier synthesis. In order to confirm the chemical composition of the the compound, the single-crystal investigated on the diffractometer was analyzed by Energy-dispersive X-ray spectrometry (EDX) using a JSM6700F scanning electron microscope. The obtained result is in good agreement with that obtained by the refinement of the crystal structure. No impurity elements have been detected.
Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS (Bruker, 1996); data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
| CsEu(PO3)4 | F(000) = 1096 |
| Mr = 600.75 | Dx = 4.002 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 2827 reflections |
| a = 10.3571 (9) Å | θ = 2.3–27.5° |
| b = 8.9615 (5) Å | µ = 10.60 mm−1 |
| c = 11.1957 (8) Å | T = 293 K |
| β = 106.354 (3)° | Prism, colorless |
| V = 997.09 (13) Å3 | 0.25 × 0.20 × 0.15 mm |
| Z = 4 |
| Bruker P4 diffractometer | 2284 independent reflections |
| Radiation source: fine-focus sealed tube | 2185 reflections with I > 2σ(I) |
| graphite | Rint = 0.025 |
| Detector resolution: 14.6306 pixels mm-1 | θmax = 27.5°, θmin = 2.4° |
| ω scans | h = −10→13 |
| Absorption correction: ψ scan (XSCANS; Bruker, 1996) | k = −10→11 |
| Tmin = 0.545, Tmax = 1.000 | l = −14→14 |
| 7446 measured reflections |
| 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)] = 0.019 | w = 1/[σ2(Fo2) + (0.0273P)2 + 2.176P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.048 | (Δ/σ)max = 0.001 |
| S = 1.00 | Δρmax = 1.16 e Å−3 |
| 2284 reflections | Δρmin = −1.17 e Å−3 |
| 164 parameters | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| 0 restraints | Extinction coefficient: 0.0154 (3) |
| CsEu(PO3)4 | V = 997.09 (13) Å3 |
| Mr = 600.75 | Z = 4 |
| Monoclinic, P21/n | Mo Kα radiation |
| a = 10.3571 (9) Å | µ = 10.60 mm−1 |
| b = 8.9615 (5) Å | T = 293 K |
| c = 11.1957 (8) Å | 0.25 × 0.20 × 0.15 mm |
| β = 106.354 (3)° |
| Bruker P4 diffractometer | 2284 independent reflections |
| Absorption correction: ψ scan (XSCANS; Bruker, 1996) | 2185 reflections with I > 2σ(I) |
| Tmin = 0.545, Tmax = 1.000 | Rint = 0.025 |
| 7446 measured reflections | θmax = 27.5° |
| R[F2 > 2σ(F2)] = 0.019 | Δρmax = 1.16 e Å−3 |
| wR(F2) = 0.048 | Δρmin = −1.17 e Å−3 |
| S = 1.00 | Absolute structure: ? |
| 2284 reflections | Flack parameter: ? |
| 164 parameters | Rogers parameter: ? |
| 0 restraints |
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 | ||
| Eu | 0.498050 (16) | 0.226449 (17) | 0.180852 (15) | 0.00580 (8) | |
| Cs | 0.67980 (2) | −0.06549 (3) | 0.45979 (2) | 0.01775 (9) | |
| P1 | 0.45959 (9) | −0.17482 (9) | 0.13333 (8) | 0.00609 (17) | |
| P2 | 0.75501 (8) | 0.02838 (9) | 0.78552 (8) | 0.00606 (17) | |
| P3 | 0.67259 (9) | 0.39350 (9) | 0.47427 (8) | 0.00652 (17) | |
| P4 | 0.64481 (9) | −0.40738 (9) | 0.25829 (8) | 0.00669 (17) | |
| O1 | 0.8311 (3) | 0.0968 (3) | 0.7052 (2) | 0.0103 (5) | |
| O2 | 0.8623 (2) | −0.0428 (3) | 0.9043 (2) | 0.0084 (5) | |
| O3 | 0.6485 (3) | −0.0823 (3) | 0.7252 (2) | 0.0097 (5) | |
| O4 | 0.5366 (2) | −0.0336 (3) | 0.1654 (2) | 0.0112 (5) | |
| O5 | 0.3125 (3) | 0.1627 (3) | 0.0137 (2) | 0.0122 (5) | |
| O6 | 0.5645 (3) | 0.2902 (3) | 0.4047 (2) | 0.0110 (5) | |
| O7 | 0.5603 (3) | 0.2458 (3) | −0.0102 (2) | 0.0110 (5) | |
| O8 | 0.5213 (2) | −0.2937 (3) | 0.2424 (2) | 0.0097 (5) | |
| O9 | 0.6665 (3) | −0.4514 (3) | 0.4006 (2) | 0.0116 (5) | |
| O10 | 0.7367 (2) | 0.1781 (3) | 0.2529 (2) | 0.0120 (5) | |
| O11 | 0.6003 (3) | 0.4610 (3) | 0.1767 (2) | 0.0115 (5) | |
| O12 | 0.6881 (2) | 0.1588 (3) | 0.8470 (2) | 0.0085 (5) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Eu | 0.00621 (11) | 0.00206 (10) | 0.00886 (11) | −0.00049 (5) | 0.00168 (7) | −0.00068 (5) |
| Cs | 0.02071 (15) | 0.01835 (13) | 0.01329 (14) | 0.00425 (9) | 0.00334 (10) | −0.00079 (8) |
| P1 | 0.0062 (4) | 0.0021 (4) | 0.0096 (4) | 0.0002 (3) | 0.0017 (3) | −0.0003 (3) |
| P2 | 0.0059 (4) | 0.0031 (4) | 0.0094 (4) | −0.0003 (3) | 0.0026 (3) | 0.0003 (3) |
| P3 | 0.0070 (4) | 0.0036 (4) | 0.0082 (4) | 0.0000 (3) | 0.0009 (3) | 0.0006 (3) |
| P4 | 0.0074 (4) | 0.0025 (4) | 0.0094 (4) | 0.0003 (3) | 0.0011 (3) | 0.0006 (3) |
| O1 | 0.0109 (12) | 0.0084 (11) | 0.0128 (12) | −0.0017 (9) | 0.0056 (10) | 0.0008 (9) |
| O2 | 0.0074 (11) | 0.0076 (11) | 0.0101 (12) | 0.0008 (9) | 0.0025 (10) | 0.0017 (9) |
| O3 | 0.0114 (12) | 0.0069 (11) | 0.0104 (12) | −0.0026 (9) | 0.0020 (10) | −0.0032 (9) |
| O4 | 0.0085 (12) | 0.0052 (11) | 0.0203 (14) | −0.0010 (9) | 0.0048 (10) | −0.0013 (10) |
| O5 | 0.0105 (13) | 0.0127 (12) | 0.0133 (13) | −0.0055 (10) | 0.0032 (10) | −0.0025 (10) |
| O6 | 0.0111 (13) | 0.0081 (12) | 0.0127 (13) | −0.0027 (9) | 0.0016 (10) | −0.0037 (9) |
| O7 | 0.0109 (13) | 0.0108 (11) | 0.0116 (13) | −0.0016 (9) | 0.0035 (10) | −0.0014 (9) |
| O8 | 0.0092 (12) | 0.0066 (11) | 0.0130 (13) | 0.0032 (9) | 0.0028 (10) | 0.0032 (9) |
| O9 | 0.0189 (13) | 0.0047 (11) | 0.0104 (12) | −0.0017 (10) | 0.0027 (10) | −0.0002 (9) |
| O10 | 0.0085 (12) | 0.0084 (12) | 0.0177 (13) | 0.0018 (9) | 0.0015 (10) | −0.0041 (10) |
| O11 | 0.0165 (13) | 0.0037 (11) | 0.0152 (13) | −0.0027 (9) | 0.0063 (10) | −0.0019 (9) |
| O12 | 0.0053 (11) | 0.0028 (10) | 0.0171 (13) | −0.0006 (8) | 0.0024 (10) | −0.0022 (9) |
| Eu—O5 | 2.344 (3) | P2—O1 | 1.485 (2) |
| Eu—O11 | 2.360 (2) | P2—O3 | 1.495 (3) |
| Eu—O4 | 2.379 (2) | P2—O2 | 1.605 (3) |
| Eu—O7 | 2.408 (3) | P2—O12 | 1.609 (2) |
| Eu—O10 | 2.413 (2) | P2—Euii | 3.5752 (9) |
| Eu—O1i | 2.416 (2) | P3—O5viii | 1.479 (3) |
| Eu—O3ii | 2.445 (2) | P3—O6 | 1.492 (3) |
| Eu—O6 | 2.471 (3) | P3—O2ix | 1.607 (2) |
| Eu—P2ii | 3.5752 (9) | P3—O9x | 1.609 (3) |
| Eu—P3 | 3.5994 (9) | P4—O10iv | 1.481 (3) |
| Eu—Cs | 4.1024 (3) | P4—O11xi | 1.484 (3) |
| Eu—Csiii | 4.4773 (4) | P4—O9 | 1.594 (3) |
| Cs—O3 | 3.083 (2) | P4—O8 | 1.605 (3) |
| Cs—O11iv | 3.089 (2) | P4—Csiv | 3.7102 (9) |
| Cs—O7iv | 3.093 (3) | O1—Euviii | 2.416 (2) |
| Cs—O1 | 3.114 (3) | O2—P3v | 1.607 (2) |
| Cs—O4 | 3.224 (3) | O3—Euii | 2.445 (2) |
| Cs—O8 | 3.249 (3) | O3—Csii | 3.693 (3) |
| Cs—O12v | 3.315 (2) | O5—P3i | 1.479 (3) |
| Cs—O10 | 3.354 (3) | O7—P1vi | 1.479 (3) |
| Cs—O6 | 3.399 (3) | O7—Csiii | 3.093 (3) |
| Cs—O9 | 3.517 (2) | O9—P3xi | 1.609 (3) |
| Cs—O10iv | 3.586 (3) | O10—P4iii | 1.481 (3) |
| Cs—P2 | 3.6075 (9) | O10—Csiii | 3.586 (3) |
| P1—O7vi | 1.479 (3) | O11—P4x | 1.484 (3) |
| P1—O4 | 1.485 (2) | O11—Csiii | 3.089 (2) |
| P1—O8 | 1.611 (3) | O12—P1ii | 1.612 (2) |
| P1—O12ii | 1.612 (2) | O12—Csix | 3.315 (2) |
| P1—Csvii | 3.7970 (9) | ||
| O5—Eu—O11 | 118.20 (9) | O4—Cs—O10iv | 60.36 (6) |
| O5—Eu—O4 | 79.62 (9) | O8—Cs—O10iv | 42.64 (6) |
| O11—Eu—O4 | 141.79 (8) | O12v—Cs—O10iv | 79.81 (6) |
| O5—Eu—O7 | 70.90 (9) | O10—Cs—O10iv | 80.580 (8) |
| O11—Eu—O7 | 71.60 (8) | O6—Cs—O10iv | 128.21 (6) |
| O4—Eu—O7 | 85.04 (9) | O9—Cs—O10iv | 41.28 (6) |
| O5—Eu—O10 | 139.03 (9) | O3—Cs—P2 | 24.24 (5) |
| O11—Eu—O10 | 75.15 (9) | O11iv—Cs—P2 | 120.18 (5) |
| O4—Eu—O10 | 70.81 (8) | O7iv—Cs—P2 | 90.79 (5) |
| O7—Eu—O10 | 78.72 (9) | O1—Cs—P2 | 24.12 (4) |
| O5—Eu—O1i | 78.33 (9) | O4—Cs—P2 | 156.80 (5) |
| O11—Eu—O1i | 75.98 (8) | O8—Cs—P2 | 145.49 (5) |
| O4—Eu—O1i | 142.22 (8) | O12v—Cs—P2 | 65.31 (5) |
| O7—Eu—O1i | 115.59 (9) | O10—Cs—P2 | 121.11 (5) |
| O10—Eu—O1i | 141.10 (9) | O6—Cs—P2 | 85.97 (5) |
| O5—Eu—O3ii | 75.28 (8) | O9—Cs—P2 | 113.94 (4) |
| O11—Eu—O3ii | 144.64 (8) | O10iv—Cs—P2 | 142.83 (4) |
| O4—Eu—O3ii | 69.56 (8) | O7vi—P1—O4 | 121.10 (15) |
| O7—Eu—O3ii | 140.72 (8) | O7vi—P1—O8 | 110.06 (14) |
| O10—Eu—O3ii | 117.57 (9) | O4—P1—O8 | 108.01 (15) |
| O1i—Eu—O3ii | 75.37 (8) | O7vi—P1—O12ii | 106.09 (14) |
| O5—Eu—O6 | 142.87 (8) | O4—P1—O12ii | 110.89 (13) |
| O11—Eu—O6 | 79.39 (9) | O8—P1—O12ii | 98.32 (13) |
| O4—Eu—O6 | 107.21 (9) | O7vi—P1—Csvii | 51.19 (10) |
| O7—Eu—O6 | 144.72 (9) | O4—P1—Csvii | 157.90 (11) |
| O10—Eu—O6 | 74.71 (9) | O8—P1—Csvii | 93.73 (10) |
| O1i—Eu—O6 | 74.81 (9) | O12ii—P1—Csvii | 60.52 (9) |
| O3ii—Eu—O6 | 73.47 (8) | O7vi—P1—Cs | 152.14 (11) |
| O5—Eu—P2ii | 57.86 (6) | O4—P1—Cs | 54.51 (10) |
| O11—Eu—P2ii | 156.53 (6) | O8—P1—Cs | 56.39 (10) |
| O4—Eu—P2ii | 61.64 (6) | O12ii—P1—Cs | 100.29 (10) |
| O7—Eu—P2ii | 121.82 (6) | Csvii—P1—Cs | 143.55 (2) |
| O10—Eu—P2ii | 124.21 (6) | O1—P2—O3 | 116.76 (15) |
| O1i—Eu—P2ii | 80.66 (6) | O1—P2—O2 | 107.71 (14) |
| O3ii—Eu—P2ii | 19.06 (6) | O3—P2—O2 | 111.15 (14) |
| O6—Eu—P2ii | 92.51 (6) | O1—P2—O12 | 108.98 (14) |
| O5—Eu—P3 | 156.63 (6) | O3—P2—O12 | 108.82 (14) |
| O11—Eu—P3 | 62.28 (6) | O2—P2—O12 | 102.45 (13) |
| O4—Eu—P3 | 114.99 (6) | O1—P2—Euii | 149.02 (11) |
| O7—Eu—P3 | 126.11 (6) | O3—P2—Euii | 32.27 (10) |
| O10—Eu—P3 | 64.27 (6) | O2—P2—Euii | 90.91 (9) |
| O1i—Eu—P3 | 79.40 (6) | O12—P2—Euii | 90.11 (9) |
| O3ii—Eu—P3 | 92.32 (6) | O1—P2—Cs | 58.96 (10) |
| O6—Eu—P3 | 18.85 (6) | O3—P2—Cs | 57.81 (10) |
| P2ii—Eu—P3 | 111.36 (2) | O2—P2—Cs | 130.28 (9) |
| O5—Eu—Cs | 123.34 (6) | O12—P2—Cs | 127.26 (10) |
| O11—Eu—Cs | 118.09 (6) | Euii—P2—Cs | 90.08 (2) |
| O4—Eu—Cs | 51.71 (6) | O5viii—P3—O6 | 118.20 (15) |
| O7—Eu—Cs | 122.82 (6) | O5viii—P3—O2ix | 107.64 (14) |
| O10—Eu—Cs | 54.82 (6) | O6—P3—O2ix | 110.36 (14) |
| O1i—Eu—Cs | 121.45 (6) | O5viii—P3—O9x | 109.94 (14) |
| O3ii—Eu—Cs | 62.80 (6) | O6—P3—O9x | 110.66 (15) |
| O6—Eu—Cs | 55.84 (6) | O2ix—P3—O9x | 98.14 (13) |
| P2ii—Eu—Cs | 72.864 (15) | O5viii—P3—Eu | 109.19 (11) |
| P3—Eu—Cs | 64.255 (15) | O6—P3—Eu | 32.35 (10) |
| O5—Eu—Csiii | 110.19 (6) | O2ix—P3—Eu | 138.19 (9) |
| O11—Eu—Csiii | 40.47 (6) | O9x—P3—Eu | 87.37 (10) |
| O4—Eu—Csiii | 103.03 (6) | O5viii—P3—Cs | 69.17 (11) |
| O7—Eu—Csiii | 40.98 (6) | O6—P3—Cs | 51.61 (10) |
| O10—Eu—Csiii | 52.97 (6) | O2ix—P3—Cs | 113.51 (9) |
| O1i—Eu—Csiii | 113.24 (6) | O9x—P3—Cs | 147.29 (10) |
| O3ii—Eu—Csiii | 170.28 (6) | Eu—P3—Cs | 63.810 (14) |
| O6—Eu—Csiii | 103.77 (6) | O10iv—P4—O11xi | 118.71 (15) |
| P2ii—Eu—Csiii | 160.739 (15) | O10iv—P4—O9 | 108.98 (15) |
| P3—Eu—Csiii | 85.139 (15) | O11xi—P4—O9 | 110.52 (14) |
| Cs—Eu—Csiii | 107.796 (7) | O10iv—P4—O8 | 108.41 (14) |
| O3—Cs—O11iv | 140.63 (7) | O11xi—P4—O8 | 109.63 (15) |
| O3—Cs—O7iv | 96.87 (7) | O9—P4—O8 | 98.71 (14) |
| O11iv—Cs—O7iv | 53.65 (6) | O10iv—P4—Csiv | 64.61 (11) |
| O3—Cs—O1 | 48.36 (6) | O11xi—P4—Csiv | 54.28 (10) |
| O11iv—Cs—O1 | 98.19 (7) | O9—P4—Csiv | 127.28 (10) |
| O7iv—Cs—O1 | 84.17 (7) | O8—P4—Csiv | 133.76 (10) |
| O3—Cs—O4 | 147.89 (6) | O10iv—P4—Cs | 71.77 (11) |
| O11iv—Cs—O4 | 71.25 (6) | O11xi—P4—Cs | 167.85 (11) |
| O7iv—Cs—O4 | 111.18 (6) | O9—P4—Cs | 68.87 (9) |
| O1—Cs—O4 | 146.42 (6) | O8—P4—Cs | 59.27 (10) |
| O3—Cs—O8 | 121.57 (6) | Csiv—P4—Cs | 136.34 (2) |
| O11iv—Cs—O8 | 88.01 (6) | P2—O1—Euviii | 149.05 (16) |
| O7iv—Cs—O8 | 91.30 (6) | P2—O1—Cs | 96.92 (12) |
| O1—Cs—O8 | 167.93 (6) | Euviii—O1—Cs | 113.90 (9) |
| O4—Cs—O8 | 45.55 (6) | P2—O2—P3v | 125.03 (15) |
| O3—Cs—O12v | 58.05 (6) | P2—O3—Euii | 128.67 (14) |
| O11iv—Cs—O12v | 98.84 (6) | P2—O3—Cs | 97.95 (11) |
| O7iv—Cs—O12v | 45.19 (6) | Euii—O3—Cs | 133.38 (9) |
| O1—Cs—O12v | 76.10 (6) | P2—O3—Csii | 117.46 (12) |
| O4—Cs—O12v | 136.03 (6) | Euii—O3—Csii | 81.12 (7) |
| O8—Cs—O12v | 92.77 (6) | Cs—O3—Csii | 76.82 (6) |
| O3—Cs—O10 | 141.66 (6) | P1—O4—Eu | 139.70 (15) |
| O11iv—Cs—O10 | 46.43 (6) | P1—O4—Cs | 103.46 (12) |
| O7iv—Cs—O10 | 99.72 (6) | Eu—O4—Cs | 92.90 (8) |
| O1—Cs—O10 | 99.37 (6) | P3i—O5—Eu | 146.62 (16) |
| O4—Cs—O10 | 49.90 (6) | P3—O6—Eu | 128.80 (15) |
| O8—Cs—O10 | 92.42 (6) | P3—O6—Cs | 108.25 (13) |
| O12v—Cs—O10 | 144.62 (6) | Eu—O6—Cs | 87.17 (7) |
| O3—Cs—O6 | 95.38 (6) | P1vi—O7—Eu | 142.64 (15) |
| O11iv—Cs—O6 | 96.23 (6) | P1vi—O7—Csiii | 106.94 (12) |
| O7iv—Cs—O6 | 142.10 (6) | Eu—O7—Csiii | 108.31 (9) |
| O1—Cs—O6 | 77.64 (6) | P4—O8—P1 | 129.62 (16) |
| O4—Cs—O6 | 72.20 (6) | P4—O8—Cs | 95.59 (11) |
| O8—Cs—O6 | 112.13 (6) | P1—O8—Cs | 99.22 (11) |
| O12v—Cs—O6 | 151.27 (6) | P4—O9—P3xi | 134.46 (17) |
| O10—Cs—O6 | 52.07 (6) | P4—O9—Cs | 86.11 (10) |
| O3—Cs—O9 | 97.16 (6) | P3xi—O9—Cs | 139.40 (13) |
| O11iv—Cs—O9 | 88.72 (6) | P4iii—O10—Eu | 149.26 (16) |
| O7iv—Cs—O9 | 58.85 (6) | P4iii—O10—Cs | 91.87 (12) |
| O1—Cs—O9 | 127.52 (6) | Eu—O10—Cs | 89.14 (7) |
| O4—Cs—O9 | 84.95 (6) | P4iii—O10—Csiii | 85.12 (11) |
| O8—Cs—O9 | 41.82 (6) | Eu—O10—Csiii | 94.52 (8) |
| O12v—Cs—O9 | 51.48 (6) | Cs—O10—Csiii | 176.32 (8) |
| O10—Cs—O9 | 121.00 (6) | P4x—O11—Eu | 139.40 (15) |
| O6—Cs—O9 | 153.49 (6) | P4x—O11—Csiii | 102.77 (12) |
| O3—Cs—O10iv | 136.01 (6) | Eu—O11—Csiii | 109.80 (8) |
| O11iv—Cs—O10iv | 51.06 (6) | P2—O12—P1ii | 131.54 (16) |
| O7iv—Cs—O10iv | 53.89 (6) | P2—O12—Csix | 132.22 (12) |
| O1—Cs—O10iv | 136.86 (6) | P1ii—O12—Csix | 94.44 (10) |
| Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) −x+1, −y, −z+1; (iii) −x+3/2, y+1/2, −z+1/2; (iv) −x+3/2, y−1/2, −z+1/2; (v) −x+3/2, y−1/2, −z+3/2; (vi) −x+1, −y, −z; (vii) x−1/2, −y−1/2, z−1/2; (viii) x+1/2, −y+1/2, z+1/2; (ix) −x+3/2, y+1/2, −z+3/2; (x) x, y+1, z; (xi) x, y−1, z. |
This investigation was based on work supported by the Foundation of Yunnan University (project No. 2007Q013B), the National Natural Science Foundation of China (project No. 20901066) and the Education Science Foundation of Yunnan Province. We thank Dr Qingyan Liu for fruitful discussions concerning the crystal structure.
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![[Figure 1]](./bt5050fig1thm.gif)
Condensed alkaline metal-rare earth polyphosphates with the general formula MLn(PO3)4 (M = alkali metal, Ln = rare earth metal) possess various structures (Ettis et al., 2003; Rekik et al., 2004) and desirable optical properties (Chinn et al., 1975; Otsuka et al., 1977; Tsujimoto et al., 1977; Hong et al., 1975; Koizumi et al., 1976). Furthermore, their chemical and thermal stability ensures the feasibility of the industrial applications. For this reason some polyphosphates (Naïli et al., 2005; Palkina et al., 1978; Maksimova et al., 1982) were synthesized and investigated in the Cs–Ln–P–O system as an important potential. However, polyphosphates containing europium have not to date been fully explored in the system. Our exploration on the system afforded caesium europium polyphosphate CsEu(PO3)4. We report herein the synthesis and crystal structure of CsEu(PO3)4.
Crystallographic data and structural refinement of CsEu(PO3)4 are summarized in Table 1. The atomic coordinates and thermal parameters are listed in Table 2. Selected bond lengths and angles are given in Table 3.
The structure of crystal CsEu(PO3)4 is shown in Fig. 1. It belongs to the monoclinic space group P21/n, which is isostructural with CsGd(PO3)4 (Naïli et al., 2005). The crystallographically distinct atoms of the asymmetric unit in the structure are one caesium, one europium, four phosphorus, and twelve oxygen atoms. It is described as a three-dimensional framework made up from double PO4 spiral chains and Cs- and Eu-polyhedra. As illustrated in Fig. 2, the double PO4 spiral chains have the same repeating unit (eight PO4 tetrahedra) as single one of CsNd(PO3)4 (Koizumi et al., 1978). These spiral chains are linked by EuO8 and CsO11 polyhedra. In addition, comparing with CsNd(PO3)4, the different characteristics are noted in the coordination environments of the cations. The Eu cation is eight-coordinated with the Eu—O band distances ranging from 2.344 (3) to 2.471 (3) Å. Each EuO8 polyhedron is corner- and face-connected with two and two CsO11 polyhedra, respectively (Fig. 3). The isolation of EuO8 polyhedra gives rise to the large Eu—Eu distances, the shortest of which is 5.7415 (3) Å. The Cs cation is coordinated by eleven oxygen atoms, and the large range of the Cs—O bond distances implies that CsO11 polyhedra are distorted. Neighboring two CsO11 polyhedra are linked by corner-sharing (Fig. 4).