KSn4(PO4)3

inorganic papers

i116

Acta Crystallographica Section E

Structure Reports Online

ISSN 1600-5368

KSn4(PO4)3

Jin-Feng Deng,a_{You-Jun Kang,}a Jin-Xiao Mi,a_{Man-Rong Li,}b Jing-Tai Zhaob_and

Shao-Yu Maoa_*

a_{College of Chemistry and Chemical} Engineering, Xiamen University, Xiamen 361005, People's Republic of China, and b_{Chinese Academy of Sciences, Shanghai} Institute of Ceramics, State Key Laboratory of High Performance Ceramics and Superfine Microstructure, 1295 Dingxi Road, Shanghai 200050, People's Republic of China

Correspondence e-mail: [email protected]

Key indicators

Single-crystal X-ray study

T= 293 K

Mean(P±O) = 0.004 AÊ

Rfactor = 0.017

wRfactor = 0.041

Data-to-parameter ratio = 15.1

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2004 International Union of Crystallography Printed in Great Britain ± all rights reserved

The crystal structure of potassium tetratin(II) tris(ortho-phosphate), KSn4(PO4)3, obtained by hydrothermal synthesis,

has been determined from single-crystal X-ray diffraction

data. The structure consists of [Sn4(PO4)3] units sharing

common corners, which leads to a three-dimensional network

structure and generates cages along thecdirection. The cages

are occupied by K atoms on threefold axes.

Comment

Compounds with open framework structures, including phos-phates, have attracted great interest due to their potential

applications (Cheetham et al., 1999). While the SnIV

compound KSnOPO4, which is isotypic with KTiOPO4, has

been extensively studied for its non-linear optical properties (Thomaset al., 1990; Phillipset al., 1990), SnII_{phosphates have}

been less well investigated. To our knowledge, besides some organically templated compounds and recently reported ammonium and sodium tin(II) phosphate compounds (Ayyappanet al., 2000; Maoet al., 2004), no other phases with inorganic cations have been published. Here, we report the synthesis and characterization of the SnII_{title compound, (I),}

in the potassium phosphate system.

In the KSn4(PO4)3 structure there are eight

crystal-lographically independent atomic sites,viz. one K, two Sn, one P and four O atoms. The tetrahedron around the P atom is quite regular, with an average PÐO distance of 1.531 (4) AÊ

Received 26 July 2004 Accepted 9 August 2004 Online 21 August 2004

Figure 1

The crystal structure of KSn4(PO4)3. K atoms are represented by white

and an average bond angle of 109.5 (2) _{[ranging from}

107.3 (2) to 112.0 (2)_{]. These values are consistent with those}

typically observed in other orthophosphates.

In general, valences for Sn can be 4 or 2, with frequent coordination numbers of 6 and 3, respectively, as observed in KSnOPO4and Sn3(PO4)2(Thomaset al., 1990; Mathewet al.,

1977). In (I), the coordination number of Sn is 3. The average SnÐO distances are 2.110 and 2.101 AÊ for Sn1 and Sn2, respectively. On the basis of bond-valence calculations (Brese & O'Keeffe, 1991), the bond-valence sums for P and Sn are calculated to be 4.87, 2.13 and 2.18, respectively, which con®rms the formal assignment of the valences.

The structure of (I) can be described as constructed by

linkages of [Sn4(PO4)3] units sharing common corners with

Sn±O±P links. This construction leads to a three-dimensional

network structure and cagess are generated along the c

direction. The cages are occupied by K atoms with 12 coor-dinations of O atoms.

Experimental

The title compound was obtained by a mild hydrothermal method. Starting materials were of analytical grade and used without further puri®cation. A mixture of SnCl22H2O (0.226 g), H3BO3(0.432 g) and

KH2PO4 (1.087 g) was prepared and dissolved in distilled water

(10 ml) in a molar ratio of 1:7:8. The pH of the solution was about 1.5. The mixture was sealed in a glass tube about 20 cm in length, ®lled to about 30% of the tube volume. The glass tube was then placed in an oven and the temperature was increased slowly to about 413 K and maintained for two weeks before cooling to room temperature. The reaction proceeded under autogenous pressure. Colourless crystals of (I) with a trigonal prismatic shape were grown from this solution. X-ray powder diffraction showed that KSn(PO) is the only crystalline

Crystal data KSn4(PO4)3

Mr= 798.77

Trigonal,R3c a= 9.7342 (5) AÊ c= 24.4754 (14) AÊ V= 2008.4 (3) AÊ3

Z= 6

Dx= 3.962 Mg mÿ3

MoKradiation Cell parameters from 4440

re¯ections

= 2.9±28.2 = 8.10 mmÿ1

T= 293 (2) K

Trigonal prism, colourless 0.160.130.13 mm Data collection

Bruker SMART Apex 2000 diffractometer

'and!scans

Absorption correction: multi-scan (SADABS; Sheldrick, 1996) Tmin= 0.290,Tmax= 0.349

4440 measured re¯ections

936 independent re¯ections 927 re¯ections withI> 2(I) Rint= 0.025

max= 28.2

h=ÿ12!12 k=ÿ11!12 l=ÿ32!31 Re®nement

Re®nement onF2

R[F2_{> 2(F}2_{)] = 0.017}

wR(F2_{) = 0.041}

S= 1.25 936 re¯ections 62 parameters w= 1/[2_(F

o2) + (0.0167P)2]

whereP= (Fo2+ 2Fc2)/3

(/)max= 0.001

max= 0.94 e AÊÿ3

min=ÿ0.69 e AÊÿ3

Extinction correction:SHELXL97 Extinction coef®cient: 0.00092 (5) Absolute structure: Flack (1983),

with 446 Friedel pairs Flack parameter = 0.03 (3)

Table 1

Selected geometric parameters (AÊ,_).

Sn1ÐO2 2.110 (3)

Sn2ÐO4i _{2.095 (4)}

Sn2ÐO1 2.101 (3)

Sn2ÐO3 2.108 (4)

PÐO4 1.523 (4)

PÐO1ii _{1.524 (4)}

PÐO2 1.538 (3)

PÐO3iii _{1.541 (3)}

O2ÐSn1ÐO2iv _{86.44 (13)}

O4i_{ÐSn2ÐO1 88.16 (15)} O4

i_{ÐSn2ÐO3 84.92 (14)}

O1ÐSn2ÐO3 86.39 (14)

Symmetry codes: (i) 5

3ÿy;43ÿx;zÿ16; (ii) xÿ23;23‡xÿy;z‡76ÿ1; (iii)

1ÿx‡y;2ÿx;z; (iv) 2ÿy;1‡xÿy;z.

Data collection:SMART(Bruker, 2001); cell re®nement:SAINT

(Bruker, 2001); data reduction:SAINT; program(s) used to solve structure:SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:

DIAMOND (Brandenburg, 1996±2001); software used to prepare material for publication:SHELXL97.

References

Ayyappan, S., Chang, J. S., Stock, N., Hat®eld, R., Rao, C. N. R. & Cheetham, A. K. (2000).Int. J. Inorg. Mater.2, 21±27.

Brandenburg, K. (1996±2001). DIAMOND. Version 2.1a. Crystal Impact GbR, Bonn, Germany.

Brese, N. E. & O'Keeffe, M. (1991).Acta Cryst.B47, 192±197.

Bruker (2001).SAINT(Version 6.22) andSMART(Version 5.625). Bruker AXS Inc., Madison, Wisconsin, USA.

Cheetham, A. K., Ferey, G. C. & Loiseau, T. (1999).Angew. Chem. Int. Ed.38, 3268±3292.

Flack, H. D. (1983).Acta Cryst.A39, 876±881.

Mao, S., Deng, J., Mi, J., Li, M., Chen, H. & Zhao, J. (2004).Z. Kristallogr. Submitted.

Mathew, M., Schroeder, L. W. & Jordan, T. H. (1977).Acta Cryst.B33, 1812± 1816.

Phillips, M. L. F., Harrison, W. T. A. & Stucky, G. D. (1990).Inorg. Chem.29, 3245±3247.

Sheldrick, G. M. (1996).SADABS.University of GoÈttingen, Germany. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of

GoÈttingen, Germany.

Figure 2

The coordination environment of the metal atoms in KSn4(PO4)3, with

displacement ellipsoids drawn at the 50% probability level. [Symmetry codes : (ii)ÿx,xÿy,z; (iii)ÿx+y,ÿx,z; (xi)1

3+x, 2/3 +xÿy,16+z;

(xvi)2

3ÿy,13ÿx,65+z; (xvii)23+x,13+xÿy,56+z; (xviii)32ÿx+y,13+y, 5

supporting information

sup-1 Acta Cryst. (2004). E60, i116–i117

supporting information

Acta Cryst. (2004). E60, i116–i117 [https://doi.org/10.1107/S160053680401966X]

KSn

(PO

)

Jin-Feng Deng, You-Jun Kang, Jin-Xiao Mi, Man-Rong Li, Jing-Tai Zhao and Shao-Yu Mao

Potassium tetratin(II) tris(orthophosphate)

Crystal data

KSn4(PO4)3 Mr = 798.77 Trigonal, R3c

Hall symbol: R 3 -2"c

a = 9.7342 (5) Å

c = 24.4754 (14) Å

V = 2008.4 (3) Å3 Z = 6

F(000) = 2160

Dx = 3.962 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 4440 reflections

θ = 2.9–28.2°

µ = 8.10 mm−1 T = 293 K

Trigonal prism, colourless 0.16 × 0.13 × 0.13 mm

Data collection

Bruker SMART Apex 2000 diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

φ and ω scans

Absorption correction: multi-scan (SADABS; Sheldrick, 1996)

Tmin = 0.290, Tmax = 0.349

4440 measured reflections 936 independent reflections 927 reflections with I > 2σ(I)

Rint = 0.025

θmax = 28.2°, θmin = 2.9° h = −12→12

k = −11→12

l = −32→31

Refinement

Refinement on F2

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.017} wR(F2_{) = 0.041} S = 1.25 936 reflections 62 parameters 1 restraint

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

w = 1/[σ2_(Fo2_{) + (0.0167P)}2_]

where P = (Fo2 _{+ 2Fc}2_)/3

(Δ/σ)max = 0.001

Δρmax = 0.94 e Å−3

Δρmin = −0.69 e Å−3

Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*_{=kFc[1+0.001xFc}2_λ3_/sin(2θ)]-1/4

Extinction coefficient: 0.00092 (5)

Absolute structure: Flack (1983), with 446 Friedel pairs

Absolute structure parameter: 0.03 (3)

Special details

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_,

conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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₎

x y z Uiso*/Ueq

Sn1 1.0000 1.0000 0.82700 (2) 0.01923 (15)

Sn2 1.14901 (4) 0.73914 (4) 0.630155 (11) 0.01765 (11)

P 0.67206 (14) 0.87550 (14) 0.75941 (5) 0.0119 (2)

O1 1.2176 (4) 0.9535 (4) 0.58913 (16) 0.0249 (8)

O2 0.8366 (3) 1.0149 (4) 0.77424 (14) 0.0186 (7)

O3 1.1921 (4) 0.8698 (4) 0.70307 (13) 0.0187 (7)

O4 0.6269 (5) 0.7469 (4) 0.80247 (15) 0.0231 (8)

K 1.0000 1.0000 0.67666 (9) 0.0208 (4)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Sn1 0.0222 (2) 0.0222 (2) 0.0133 (3) 0.01110 (11) 0.000 0.000

Sn2 0.01883 (18) 0.01411 (18) 0.02176 (17) 0.00954 (15) 0.00202 (12) −0.00066 (13)

P 0.0103 (5) 0.0113 (5) 0.0135 (5) 0.0049 (5) 0.0034 (4) 0.0018 (4)

O1 0.0206 (17) 0.0146 (18) 0.024 (2) −0.0030 (14) −0.0038 (14) 0.0044 (14)

O2 0.0094 (16) 0.0117 (15) 0.0319 (19) 0.0032 (13) 0.0005 (14) 0.0019 (14)

O3 0.0204 (18) 0.0150 (18) 0.0163 (17) 0.0055 (14) −0.0028 (14) 0.0021 (14)

O4 0.034 (2) 0.0142 (18) 0.0155 (18) 0.0082 (16) 0.0065 (15) 0.0032 (13)

K 0.0189 (6) 0.0189 (6) 0.0247 (10) 0.0094 (3) 0.000 0.000

Geometric parameters (Å, º)

Sn1—O2 2.110 (3) O2—K 2.913 (4)

Sn1—O2i _{2.110 (3) O3—P}i _{1.541 (3)}

Sn1—O2ii _{2.110 (3) O3—K 2.809 (4)}

Sn1—K 3.680 (2) O4—Sn2vii _{2.095 (4)}

Sn2—O4iii _{2.095 (4) O4—K}v _{2.747 (4)}

Sn2—O1 2.101 (3) K—O4iii _{2.747 (4)}

Sn2—O3 2.108 (4) K—O4vi _{2.747 (4)}

Sn2—K 3.6784 (9) K—O4viii _{2.747 (4)}

P—O4 1.523 (4) K—O3i _{2.809 (4)}

P—O1iv _{1.524 (4) K—O3}ii _{2.809 (4)}

P—O2 1.538 (3) K—O2ii _{2.913 (4)}

P—O3ii _{1.541 (3) K—O2}i _{2.913 (4)}

P—K 3.4485 (17) K—O2 2.913 (4)

P—Kv _{3.5383 (17) K—O1}ii _{3.200 (4)}

O1—Pvi _{1.524 (4) K—O1}i _{3.200 (4)}

supporting information

sup-3 Acta Cryst. (2004). E60, i116–i117

O2—Sn1—O2i _{86.44 (13) O4}viii_—K—O3i _{75.47 (10)}

O2—Sn1—O2ii _{86.44 (13) O4}iii_—K—O3ii _{75.47 (10)}

O2i_—Sn1—O2ii _{86.44 (13) O4}vi_—K—O3ii _{168.69 (13)}

O2—Sn1—K 52.26 (9) O4viii_—K—O3ii _{61.41 (11)}

O2i_{—Sn1—K 52.26 (9) O3}i_—K—O3ii _{114.87 (6)}

O2ii_{—Sn1—K 52.26 (9) O4}iii_{—K—O3 61.41 (11)}

O4iii_{—Sn2—O1 88.16 (15) O4}vi_{—K—O3 75.47 (10)}

O4iii_{—Sn2—O3 84.92 (14) O4}viii_{—K—O3 168.69 (13)}

O1—Sn2—O3 86.39 (14) O3i_{—K—O3 114.87 (6)}

O4iii_{—Sn2—K 47.69 (10) O3}ii_{—K—O3 114.87 (6)}

O1—Sn2—K 60.10 (11) O4iii_—K—O2ii _{130.42 (12)}

O3—Sn2—K 49.46 (10) O4vi_—K—O2ii _{76.99 (12)}

O4—P—O1iv _{112.0 (2) O4}viii_—K—O2ii _{118.17 (11)}

O4—P—O2 107.9 (2) O3i_—K—O2ii _{52.31 (9)}

O1iv_{—P—O2 110.5 (2) O3}ii_—K—O2ii _{109.71 (12)}

O4—P—O3ii _{109.0 (2) O3—K—O2}ii _{73.04 (10)}

O1iv_—P—O3ii _{107.3 (2) O4}iii_—K—O2i _{76.99 (12)}

O2—P—O3ii _{110.17 (18) O4}vi_—K—O2i _{118.17 (11)}

O2—Sn1—O2i _{86.44 (13) O4}viii_—K—O2i _{130.42 (12)}

O2—Sn1—O2ii _{86.44 (13) O3}i_—K—O2i _{109.71 (12)}

O2i_—Sn1—O2ii _{86.44 (13) O3}ii_—K—O2i _{73.04 (10)}

O2—Sn1—K 52.26 (9) O3—K—O2i _{52.31 (9)}

O2i_{—Sn1—K 52.26 (9) O2}ii_—K—O2i _{59.47 (11)}

O2ii_{—Sn1—K 52.26 (9) O4}iii_{—K—O2 118.17 (11)}

O4iii_{—Sn2—O1 88.16 (15) O4}vi_{—K—O2 130.42 (12)}

O4iii_{—Sn2—O3 84.92 (14) O4}viii_{—K—O2 76.99 (12)}

O1—Sn2—O3 86.39 (14) O3i_{—K—O2 73.04 (10)}

O4iii_{—Sn2—K 47.69 (10) O3}ii_{—K—O2 52.31 (9)}

O1—Sn2—K 60.10 (11) O3—K—O2 109.71 (12)

O3—Sn2—K 49.46 (10) O2ii_{—K—O2 59.47 (11)}

O4—P—O1iv _{112.0 (2) O2}i_{—K—O2 59.47 (11)}

O4—P—O2 107.9 (2) O4iii_—K—O1ii _{49.55 (11)}

O1iv_{—P—O2 110.5 (2) O4}vi_—K—O1ii _{116.40 (15)}

O4—P—O3ii _{109.0 (2) O4}viii_—K—O1ii _{58.20 (11)}

O1iv_—P—O3ii _{107.3 (2) O3}i_—K—O1ii _{131.13 (10)}

O2—P—O3ii _{110.17 (18) O3}ii_—K—O1ii _{56.84 (10)}

O4—P—K 122.08 (15) O3—K—O1ii _{110.56 (10)}

O1iv_{—P—K 125.84 (16) O2}ii_—K—O1ii _{166.53 (11)}

O2—P—K 57.04 (13) O2i_—K—O1ii _{111.73 (10)}

O3ii_{—P—K 53.15 (14) O2—K—O1}ii _{107.68 (9)}

O4—P—Kv _{47.40 (16) O4}iii_{—K—O1 58.20 (11)}

O1iv_—P—Kv _{64.74 (15) O4}vi_{—K—O1 49.55 (10)}

O2—P—Kv _{129.06 (14) O4}viii_{—K—O1 116.40 (15)}

O3ii_—P—Kv _{119.72 (15) O3}i_{—K—O1 110.56 (10)}

K—P—Kv _{167.36 (4) O3}ii_{—K—O1 131.13 (10)}

Pvi_{—O1—Sn2 140.7 (2) O3—K—O1 56.84 (10)}

Pvi_{—O1—K 89.74 (16) O2}ii_{—K—O1 111.73 (10)}

P—O2—Sn1 124.9 (2) O2—K—O1 166.53 (10)

P—O2—K 96.67 (15) O1ii_{—K—O1 80.08 (11)}

Sn1—O2—K 92.80 (11) O4iii_—K—O1i _{116.40 (15)}

Pi_{—O3—Sn2 124.6 (2) O4}vi_—K—O1i _{58.20 (11)}

Pi_{—O3—K 100.82 (17) O4}viii_—K—O1i _{49.55 (11)}

Sn2—O3—K 95.78 (13) O3i_—K—O1i _{56.84 (10)}

P—O4—Sn2vii _{131.1 (2) O3}ii_—K—O1i _{110.56 (10)}

P—O4—Kv _{108.5 (2) O3—K—O1}i _{131.13 (10)}

Sn2vii_—O4—Kv _{97.98 (13) O2}ii_—K—O1i _{107.68 (9)}

O4iii_—K—O4vi _{107.53 (11) O2}i_—K—O1i _{166.53 (10)}

O4iii_—K—O4viii _{107.53 (11) O2—K—O1}i _{111.73 (10)}

O4vi_—K—O4viii _{107.53 (11) O1}ii_—K—O1i _{80.08 (11)}

O4iii_—K—O3i _{168.69 (13) O1—K—O1}i _{80.08 (11)}

O4vi_—K—O3i _{61.41 (11)}

Symmetry codes: (i) −y+2, x−y+1, z; (ii) −x+y+1, −x+2, z; (iii) −y+5/3, −x+4/3, z−1/6; (iv) x−2/3, x−y+2/3, z+1/6; (v) −x+y+1/3, y−1/3, z+1/6; (vi) x+2/3,