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An anhydrous orthophosphate, K3Eu5(PO4)6 (tripotassium penta­europium hexa­phosphate), has been prepared by a high-temperature solid-state reaction combined with hydro­thermal synthesis, and its crystal structure was determined by single-crystal X-ray diffraction analysis (SC-XRD). The results show that the compound crystallizes in the monoclinic space group C2/c and the structure features a three-dimensional framework of [Eu5(PO4)6], with the tunnel filled by K+ ions. The IR spectrum, UV–Vis spectrum and luminescence properties of polycrystalline samples of K3Eu5(PO4)6, annealed at temperatures of 650, 700, 750, 800 and 850 °C, were investigated. Although with a full Eu3+ concentration (9.96 × 1021 ions cm−3), the self-activated phosphor K3Eu5(PO4)6 shows s strong luminescence emission intensity with a quantum yield of 37%. Under near-UV light excitation (393 nm), the series of samples shows the characteristic emissions of Eu3+ ions in the visible region from 575 to 715 nm. The sample sintered at 800 °C gives the strongest emission and its lifetime sintered at 800 °C (1.88 ms) is also the longest of all.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S2053229619007794/yp3185sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S2053229619007794/yp3185Isup2.hkl
Contains datablock I

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S2053229619007794/yp3185sup3.pdf
Table S1 and Figs. S1 and S2

CCDC reference: 1919592

Computing details top

Data collection: APEX2 (Bruker, 2017); cell refinement: APEX2 (Bruker, 2017); data reduction: APEX2 (Bruker, 2017); program(s) used to solve structure: SHELXT2017 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2017 (Sheldrick, 2015b); molecular graphics: ?; software used to prepare material for publication: SHELXL2017 (Sheldrick, 2015b).

Tripotassium pentaeuropium hexaphosphate top
Crystal data top
K3Eu5(PO4)6F(000) = 2616
Mr = 1446.92Dx = 4.786 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 17.4950 (11) ÅCell parameters from 1295 reflections
b = 6.9483 (4) Åθ = 2.0–24.9°
c = 18.1452 (12) ŵ = 16.61 mm1
β = 114.447 (1)°T = 296 K
V = 2008.0 (2) Å3Block, colorless
Z = 40.20 × 0.15 × 0.15 mm
Data collection top
Bruker APEXII CCD
diffractometer
2117 reflections with I > 2σ(I)
Detector resolution: 83.33 pixels mm-1Rint = 0.031
ω scansθmax = 28.3°, θmin = 2.5°
Absorption correction: multi-scan
SADABS (Bruker, 2017)
h = 1923
Tmin = 0.085, Tmax = 0.413k = 97
6490 measured reflectionsl = 2323
2460 independent reflections
Refinement top
Refinement on F20 restraints
Least-squares matrix: full w = 1/[σ2(Fo2) + (0.027P)2]
where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.026(Δ/σ)max = 0.001
wR(F2) = 0.062Δρmax = 1.13 e Å3
S = 1.01Δρmin = 1.47 e Å3
2460 reflectionsExtinction correction: SHELXL2017 (Sheldrick, 2015b), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
174 parametersExtinction coefficient: 0.00040 (2)
Special details top

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

Refinement. A single crystal with dimensions of 0.20 × 0.15 × 0.15 mm was mounted on a glass fiber for SC-XRD experiments. A set of intensity data was collected using a Bruker SMART APEX2 CCD equipped with a graphite-monochromated Mo Kα radiation source (λ = 0.71073 Å) with a tube power of 50 kV and 20 mA. The frames were collected at ambient temperature with a scan width of 0.5 in ω and integrated with the Bruker SAINT software package using a narrow-frame integration algorithm (Bruker, 2017). The unit cells were determined and refined by least-squares upon the refinement of XYZ-centeroids of reflections above 2σ(I). The data were then scaled for absorption using the SADABS programme of APEX2 package. Intensities of all measured reflections were corrected for Lp and multi-scan crystal absorption effects. The crystal structures of title complexes were solved using SHELX2017 crystallographic computing system (Sheldrick, 2015).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
K10.07658 (9)0.09710 (19)0.07467 (8)0.0177 (3)
K20.0000000.1711 (3)0.2500000.0477 (8)
Eu10.0000000.36450 (5)0.2500000.00466 (10)
Eu20.14403 (2)0.58607 (4)0.48109 (2)0.00453 (9)
Eu30.22012 (2)0.12515 (4)0.29233 (2)0.00454 (9)
P10.20791 (9)0.61898 (19)0.34185 (8)0.0042 (3)
P20.13583 (9)0.08484 (19)0.41326 (8)0.0041 (3)
P30.07312 (8)0.4036 (2)0.11707 (7)0.0039 (3)
O10.1227 (2)0.2509 (6)0.4603 (2)0.0095 (8)
O20.0975 (2)0.1012 (5)0.4269 (2)0.0099 (8)
O30.0928 (2)0.1276 (5)0.3200 (2)0.0064 (8)
O40.2286 (2)0.0676 (5)0.4260 (2)0.0068 (8)
O50.2554 (2)0.4596 (5)0.3180 (2)0.0080 (8)
O60.1207 (2)0.5480 (5)0.3297 (2)0.0068 (8)
O70.2538 (2)0.6711 (5)0.4307 (2)0.0066 (8)
O80.1999 (2)0.7859 (5)0.2837 (2)0.0082 (8)
O90.0997 (2)0.2527 (6)0.1859 (2)0.0087 (8)
O100.0048 (2)0.5229 (5)0.1291 (2)0.0072 (8)
O110.1462 (2)0.5361 (5)0.1234 (2)0.0091 (8)
O120.0475 (2)0.3043 (5)0.0357 (2)0.0070 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
K10.0158 (7)0.0120 (7)0.0187 (7)0.0032 (5)0.0007 (5)0.0042 (5)
K20.0331 (14)0.0055 (11)0.0623 (17)0.0000.0225 (12)0.000
Eu10.00403 (19)0.00320 (19)0.00728 (19)0.0000.00288 (15)0.000
Eu20.00473 (15)0.00307 (15)0.00693 (15)0.00021 (10)0.00355 (11)0.00003 (9)
Eu30.00474 (15)0.00313 (15)0.00682 (15)0.00011 (10)0.00344 (11)0.00051 (9)
P10.0052 (7)0.0028 (7)0.0067 (7)0.0015 (5)0.0047 (6)0.0005 (5)
P20.0045 (7)0.0026 (7)0.0068 (6)0.0009 (5)0.0040 (5)0.0015 (5)
P30.0023 (7)0.0053 (7)0.0048 (7)0.0005 (5)0.0021 (6)0.0001 (5)
O10.011 (2)0.005 (2)0.012 (2)0.0020 (16)0.0049 (16)0.0043 (15)
O20.008 (2)0.003 (2)0.019 (2)0.0006 (15)0.0063 (17)0.0021 (15)
O30.0067 (19)0.0059 (19)0.0057 (18)0.0013 (15)0.0018 (15)0.0003 (14)
O40.0074 (19)0.0041 (19)0.011 (2)0.0011 (15)0.0054 (16)0.0011 (15)
O50.011 (2)0.005 (2)0.010 (2)0.0002 (16)0.0077 (16)0.0011 (15)
O60.0066 (19)0.0042 (19)0.012 (2)0.0003 (15)0.0060 (16)0.0009 (15)
O70.0064 (19)0.0065 (19)0.0079 (18)0.0010 (15)0.0038 (15)0.0021 (15)
O80.010 (2)0.004 (2)0.012 (2)0.0007 (16)0.0070 (16)0.0014 (15)
O90.009 (2)0.008 (2)0.011 (2)0.0036 (16)0.0063 (16)0.0031 (15)
O100.0051 (19)0.010 (2)0.010 (2)0.0011 (15)0.0064 (15)0.0008 (15)
O110.0058 (19)0.010 (2)0.012 (2)0.0043 (16)0.0039 (16)0.0008 (16)
O120.008 (2)0.0048 (19)0.0100 (19)0.0014 (15)0.0055 (15)0.0006 (15)
Geometric parameters (Å, º) top
K1—O122.683 (4)Eu2—O2viii2.385 (4)
K1—O1i2.736 (4)Eu2—O12ix2.409 (3)
K1—O5ii2.801 (4)Eu2—O4x2.416 (4)
K1—O11iii2.806 (4)Eu2—O7xi2.497 (4)
K1—O12iv2.871 (4)Eu2—O72.515 (3)
K1—O2v3.034 (4)Eu2—O10i2.581 (4)
K1—O9iv3.077 (4)Eu2—O62.618 (3)
K1—O2i3.168 (4)Eu2—O11ix2.703 (4)
K1—O10iii3.248 (4)Eu3—O11xii2.287 (4)
K2—O32.617 (4)Eu3—O92.363 (4)
K2—O3i2.617 (4)Eu3—O8vii2.379 (4)
K2—O6vi2.798 (4)Eu3—O52.400 (4)
K2—O6vii2.798 (4)Eu3—O42.402 (3)
K2—O2i2.986 (4)Eu3—O32.478 (4)
K2—O22.986 (4)Eu3—O5xii2.495 (3)
K2—O10vii3.080 (4)Eu3—O8xii2.590 (3)
K2—O10vi3.080 (4)P1—O71.518 (4)
K2—O8vi3.305 (4)P1—O61.531 (4)
K2—O8vii3.305 (4)P1—O81.535 (4)
Eu1—O32.291 (4)P1—O51.550 (4)
Eu1—O3i2.291 (4)P2—O11.508 (4)
Eu1—O62.376 (4)P2—O21.523 (4)
Eu1—O6i2.376 (4)P2—O41.547 (4)
Eu1—O10i2.486 (4)P2—O31.570 (4)
Eu1—O102.486 (4)P3—O121.519 (4)
Eu1—O9i2.585 (3)P3—O111.541 (4)
Eu1—O92.585 (3)P3—O101.543 (4)
Eu2—O12.364 (4)P3—O91.548 (4)
O7—P1—O6106.7 (2)O1—P2—O3110.3 (2)
O7—P1—O8114.1 (2)O2—P2—O3106.8 (2)
O6—P1—O8110.0 (2)O4—P2—O3100.5 (2)
O7—P1—O5111.0 (2)O12—P3—O11104.2 (2)
O6—P1—O5110.4 (2)O12—P3—O10116.6 (2)
O8—P1—O5104.8 (2)O11—P3—O10109.6 (2)
O1—P2—O2112.2 (2)O12—P3—O9110.2 (2)
O1—P2—O4111.8 (2)O11—P3—O9112.4 (2)
O2—P2—O4114.5 (2)O10—P3—O9104.0 (2)
Symmetry codes: (i) x, y, z+1/2; (ii) x1/2, y+1/2, z1/2; (iii) x, y+1, z; (iv) x, y, z; (v) x, y, z1/2; (vi) x, y1, z+1/2; (vii) x, y1, z; (viii) x, y+1, z; (ix) x, y+1, z+1/2; (x) x+1/2, y+1/2, z+1; (xi) x+1/2, y+3/2, z+1; (xii) x+1/2, y1/2, z+1/2.
 

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