Strontium oxide iodide

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inorganic papers

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Marten G. Barkeret al. Sr₄OI₆ DOI: 101107/S1600536801006626 Acta Cryst.(2001). E57, i44±i45 Acta Crystallographica Section E

Structure Reports Online

ISSN 1600-5368

Strontium oxide iodide

Marten G. Barker,² M. Grazia Francesconi, Thomas H. Shutt and Claire Wilson*

School of Chemistry, University of Nottingham, Nottingham NG7 2RD, England

² Deceased.

Correspondence e-mail: [email protected]

Key indicators Single-crystal X-ray study T= 150 K

Mean(Sr±O) = 0.01 AÊ Rfactor = 0.030 wRfactor = 0.055

Data-to-parameter ratio = 28.8

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

Strontium oxide iodide, Sr4OI6, has been prepared by a

solid-state reaction and shown to be isostructural with bothA4OCl6,

whereAis Ba or Sr, and Ba4OI6.

Comment

Alkaline earth oxide chlorides and oxide bromides, of general formulaA4OX6(A= alkaline earth;X= Clÿ, Brÿ) are known

for their luminescence properties, when the alkaline earth site is doped with small amounts of Eu2+_{or Pb}2+_(Schipper_{et al.}_,

1992). This family has now been extended to the strontium oxide iodide compounds Sr4OI6. Sr4OI6 was prepared by a

solid-state reaction and is isostructural with Sr4OCl6

(Hage-mannet al., 1996), Ba4OCl6(Bergerhoff & Goost, 1970) and

Ba4OI6(Barkeret al., 2001). The oxygen is four-coordinated

by Sr cations, the iodine is four- and ®ve-coordinated by Sr cations, and the Sr is eight-coordinated by one oxygen and seven iodine anions at one site and seven-coordinated by one oxygen and six iodine anions at the other (Fig. 1). shows the overall structure and ®gures for the isostructural Ba4OI6given

in Barkeret al.(2001) show the coordination at each of these sites.

Experimental

SrO and SrI2powders were mixed in stoichiometric proportions and

placed in a nickel crucible. The mixture was then heated at 1273 K for 24 h in a silica tube, under ¯owing nitrogen. The product was cooled to room temperature at a rate of 1 K hÿ1_.

Received 13 February 2001 Accepted 20 April 2001 Online 22 May 2001

Figure 1

[001] projection of the Sr4OI6structure showing the Iÿanions (blue) and

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Crystal data

Sr4OI6

Mr= 1127.88

Hexagonal,P63mc

a= 10.747 (1) AÊ

c= 7.8678 (9) AÊ

V= 787.0 (3) AÊ3

Z= 2

Dx= 4.760 Mg mÿ3

MoKradiation Cell parameters from 841

re¯ections

= 5.9±27.6

= 25.21 mmÿ1

T= 150 (2) K Block, colourless 0.050.040.04 mm

Data collection

Bruker SMART1000 CCD area-detector diffractometer

!scans

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

Tmin= 0.272,Tmax= 0.365

3527 measured re¯ections 776 independent re¯ections

586 re¯ections withI> 2(I)

Rint= 0.054

max= 27.6

h=ÿ13!6

k=ÿ10!4

l=ÿ9!10 Intensity decay: none

Re®nement

Re®nement onF2

R[F2_{> 2}₍_F2_{)] = 0.030}

wR(F2_{) = 0.055}

S= 0.94 721 re¯ections 25 parameters

w= 1/[2₍_F

o2) + (0.0206P)2]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 1.27 e AÊÿ3

min=ÿ0.99 e AÊÿ3

Absolute structure: Flack (1983) Flack parameter = 0.064 (18)

Table 1

Selected bond lengths (AÊ).

Sr1ÐO 2.37 (2)

Sr1ÐI1i _{3.366 (2)}

Sr1ÐI2ii _{3.830 (2)}

Sr2ÐO 2.393 (6)

Sr2ÐI2iii _{3.392 (2)}

Sr2ÐI1iv _{3.3947 (18)}

Sr2ÐI2v _{3.5567 (19)}

Sr2ÐI1vi _{3.5967 (17)}

OÐSr2iv _{2.393 (6)}

OÐSr2vii _{2.393 (6)}

Symmetry codes: (i) 1ÿy;1xÿy;1z; (ii)y;1ÿxy;1

2z; (iii)xÿy;x;12z; (iv)ÿxy;1ÿx;z; (v)ÿy;xÿy;z; (vi) 1ÿx;1ÿy;1

2z; (vii) 1ÿy;1xÿy;z.

The origin was ®xed by application of a ¯oating origin restraint which effectively ®xes the centre of gravity of the structure in the polar-axis direction. This leads to smaller correlations than ®xing a single atom in structures with no dominant heavy atom (Flack & Schwarzenbach 1988).

Data collection:SMART(Bruker, 1998); cell re®nement:SAINT

(Bruker, 2000); data reduction:SAINTandSHELXL97 (Sheldrick, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to re®ne structure:SHELXL97 andWINGX

(Farrugia, 1999); molecular graphics: ATOMS (Dowty, 1998) and

ORTEP-3 (Farrugia, 1997); software used to prepare material for publication:SHELXL97 andPLATON(Spek, 2001).

References

Altomare, A., Burla, M. C., Camalli, M., Cascarano, G, Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999).J. Appl. Cryst.32, 115±119.

Barker, M. G., Francesconi, M. G., & Wilson, C. (2001).Acta Cryst.E57, i41± 43.

Bergerhoff, G. & Goost, L. (1970).Acta Cryst.B26, 19±23.

Bruker (1996).SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Bruker (1998). SMART Area-Detector Software Package. Version 5.054.

Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2000). SAINT Frame Integration Software. Version 6.02a. Bruker AXS Inc., Madison, Wisconsin, USA.

Dowty, E. (1998).ATOMS. Version 4.1. Shape Software, 521 Hidden Valley Road, Kingsport, TN 37663, USA.

Farrugia, L. J. (1997).J. Appl. Cryst.30, 565. Farrugia, L. J. (1999).J. Appl. Cryst.32, 837±838. Flack, H. D. (1983).Acta Cryst.A39, 876±881.

Flack, H. D & Schwarzenbach, D. (1988).Acta Cryst.A44, 499±506. Hagemann, H., Kubel, F. & Bill, H. (1996).Eur. J. Solid State Inorg. Chem.33,

1101±1109.

Schipper, W. J., Vroon, Z. A. E. P., Blasse, G. & Schleid, T. (1992).Chem. Mater.4, 688±692.

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supporting information

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Acta Cryst. (2001). E57, i44–i45

supporting information

Acta Cryst. (2001). E57, i44–i45 [https://doi.org/10.1107/S1600536801006626]

Strontium oxide iodide

Marten G. Barker, M. Grazia Francesconi, Thomas H. Shutt and Claire Wilson

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Crystal data

Sr4OI6 Mr = 1127.88 Hexagonal, P63mc a = 10.747 (1) Å

c = 7.8678 (9) Å

V = 787.0 (3) Å3 Z = 2

F(000) = 956

Dx = 4.760 Mg m−3

Mo Kα radiation, λ = 0.71069 Å Cell parameters from 841 reflections

θ = 5.9–27.6°

µ = 25.21 mm−1 T = 150 K Block, colourless 0.05 × 0.04 × 0.04 mm

Data collection

Bruker SMART1000 CCD area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

ω scans

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

Tmin = 0.272, Tmax = 0.365

3527 measured reflections 776 independent reflections 586 reflections with I > 2σ(I)

Rint = 0.054

θmax = 27.6°, θmin = 5.9° h = −13→6

k = −10→4

l = −9→10

Refinement

Refinement on F2

Least-squares matrix: full

R[F2_{> 2}_σ₍_F2_{)] = 0.030} wR(F2_{) = 0.055} S = 0.94 721 reflections 25 parameters 1 restraint

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

w = 1/[σ2₍_F

o2) + (0.0206P)2]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001

Δρmax = 1.27 e Å−3

Δρmin = −0.99 e Å−3

Absolute structure: Flack (1983) Absolute structure parameter: 0.064 (18)

Special details

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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₎

x y z Uiso*/Ueq

Sr1 0.3333 0.6667 0.8847 (3) 0.0290 (6)

Sr2 0.21157 (7) 0.42313 (14) 0.48599 (16) 0.0172 (3) I1 0.46542 (5) 0.53458 (5) 0.17690 (10) 0.0174 (2) I2 0.25533 (9) 0.12766 (5) 0.36865 (10) 0.0175 (2)

O 0.3333 0.6667 0.584 (3) 0.031 (5)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Sr1 0.0391 (10) 0.0391 (10) 0.0088 (12) 0.0196 (5) 0.000 0.000 Sr2 0.0181 (5) 0.0200 (7) 0.0142 (7) 0.0100 (4) −0.0004 (3) −0.0008 (6) I1 0.0187 (3) 0.0187 (3) 0.0129 (4) 0.0078 (4) 0.0015 (2) −0.0015 (2) I2 0.0195 (5) 0.0166 (3) 0.0174 (5) 0.0098 (2) 0.0008 (5) 0.0004 (2) O 0.027 (7) 0.027 (7) 0.038 (12) 0.014 (4) 0.000 0.000

Geometric parameters (Å, º)

Sr1—O 2.37 (2) Sr2—I2 3.5567 (19)

Sr1—I1i _{3.366 (2)} _Sr2—I1vi _{3.5967 (17)}

Sr1—I1ii _{3.366 (2)} _Sr2—I1v _{3.5967 (17)}

Sr1—I1iii _{3.366 (2)} _Sr2—Sr2viii _{3.926 (3)}

Sr1—I2iv _{3.830 (2)} _Sr2—Sr2vii _{3.926 (3)}

Sr1—I2v _{3.830 (2)} _I1—Sr1x _{3.366 (2)}

Sr1—I2vi _{3.830 (2)} _I1—Sr2viii _{3.3947 (18)}

Sr1—Sr2vii _{3.870 (3)} _I1—Sr2xi _{3.5967 (17)}

Sr1—Sr2 3.870 (3) I1—Sr2xii _{3.5967 (17)}

Sr1—Sr2viii _{3.870 (3)} _I2—Sr2xi _{3.392 (2)}

Sr2—O 2.393 (6) I2—Sr2xiii _{3.5567 (19)}

Sr2—I2v _{3.392 (2)} _I2—Sr1xii _{3.830 (2)}

Sr2—I1vii _{3.3947 (18)} _O—Sr2vii _{2.393 (6)}

Sr2—I1 3.3947 (18) O—Sr2viii _{2.393 (6)}

Sr2—I2ix _{3.5567 (19)}

O—Sr1—I1i _{133.08 (4)} _I2v_—Sr2—I1vi _{71.32 (3)}

O—Sr1—I1ii _{133.08 (4)} _I1vii_—Sr2—I1vi _{146.26 (4)}

I1i_—Sr1—I1ii _{78.48 (6)} _{I1—Sr2—I1}vi _{72.54 (4)}

O—Sr1—I1iii _{133.08 (4)} _I2ix_—Sr2—I1vi _{135.64 (4)}

I1i_—Sr1—I1iii _{78.48 (6)} _{I2—Sr2—I1}vi _{70.80 (3)}

I1ii_—Sr1—I1iii _{78.48 (6)} _O—Sr2—I1v _{76.25 (17)}

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Acta Cryst. (2001). E57, i44–i45

I1i_—Sr1—I2iv _{69.97 (2)} _I1vii_—Sr2—I1v _{72.54 (4)}

I1ii_—Sr1—I2iv _{69.97 (2)} _{I1—Sr2—I1}v _{146.26 (4)}

I1iii_—Sr1—I2iv _{138.80 (8)} _I2ix_—Sr2—I1v _{70.80 (3)}

O—Sr1—I2v _{88.11 (4)} _{I2—Sr2—I1}v _{135.64 (4)}

I1i_—Sr1—I2v _{138.80 (8)} _I1vi_—Sr2—I1v _{128.84 (6)}

I1ii_—Sr1—I2v _{69.97 (2)} _{O—Sr2—Sr1} _{35.4 (5)}

I1iii_—Sr1—I2v _{69.97 (2)} _I2v_—Sr2—Sr1 _{63.27 (5)}

I2iv_—Sr1—I2v _{119.893 (5)} _I1vii_—Sr2—Sr1 _{113.68 (5)}

O—Sr1—I2vi _{88.11 (4)} _{I1—Sr2—Sr1} _{113.68 (5)}

I1i_—Sr1—I2vi _{69.97 (2)} _I2ix_—Sr2—Sr1 _{131.55 (3)}

I1ii_—Sr1—I2vi _{138.80 (8)} _{I2—Sr2—Sr1} _{131.55 (3)}

I1iii_—Sr1—I2vi _{69.97 (2)} _I1vi_—Sr2—Sr1 _{66.26 (3)}

I2iv_—Sr1—I2vi _{119.893 (5)} _I1v_—Sr2—Sr1 _{66.26 (3)}

I2v_—Sr1—I2vi _{119.893 (5)} _{O—Sr2—Sr2}viii _{34.9 (2)}

O—Sr1—Sr2vii _{35.85 (4)} _I2v_—Sr2—Sr2viii _{113.50 (3)}

I1i_—Sr1—Sr2vii _{109.86 (4)} _I1vii_—Sr2—Sr2viii _{92.81 (2)}

I1ii_—Sr1—Sr2vii _{109.86 (4)} _{I1—Sr2—Sr2}viii _{54.67 (3)}

I1iii_—Sr1—Sr2vii _{168.93 (6)} _I2ix_—Sr2—Sr2viii _{163.52 (2)}

I2iv_—Sr1—Sr2vii _{52.26 (3)} _{I2—Sr2—Sr2}viii _{112.351 (18)}

I2v_—Sr1—Sr2vii _{105.43 (5)} _I1vi_—Sr2—Sr2viii _{56.92 (2)}

I2vi_—Sr1—Sr2vii _{105.43 (5)} _I1v_—Sr2—Sr2viii _{110.87 (2)}

O—Sr1—Sr2 35.85 (4) Sr1—Sr2—Sr2viii _{59.52 (3)}

I1i_—Sr1—Sr2 _{168.93 (6)} _{O—Sr2—Sr2}vii _{34.9 (2)}

I1ii_—Sr1—Sr2 _{109.86 (4)} _I2v_—Sr2—Sr2vii _{113.50 (3)}

I1iii_—Sr1—Sr2 _{109.86 (4)} _I1vii_—Sr2—Sr2vii _{54.67 (3)}

I2iv_—Sr1—Sr2 _{105.43 (5)} _{I1—Sr2—Sr2}vii _{92.81 (2)}

I2v_—Sr1—Sr2 _{52.26 (3)} _I2ix_—Sr2—Sr2vii _{112.351 (18)}

I2vi_—Sr1—Sr2 _{105.43 (5)} _{I2—Sr2—Sr2}vii _{163.52 (2)}

Sr2vii_—Sr1—Sr2 _{60.96 (6)} _I1vi_—Sr2—Sr2vii _{110.87 (2)}

O—Sr1—Sr2viii _{35.85 (4)} _I1v_—Sr2—Sr2vii _{56.92 (2)}

I1i_—Sr1—Sr2viii _{109.86 (4)} _{Sr1—Sr2—Sr2}vii _{59.52 (3)}

I1ii_—Sr1—Sr2viii _{168.93 (6)} _Sr2viii_—Sr2—Sr2vii _60.0

I1iii_—Sr1—Sr2viii _{109.86 (4)} _Sr1x_—I1—Sr2viii _{101.78 (5)}

I2iv_—Sr1—Sr2viii _{105.43 (5)} _Sr1x_—I1—Sr2 _{101.78 (5)}

I2v_—Sr1—Sr2viii _{105.43 (5)} _Sr2viii_—I1—Sr2 _{70.65 (6)}

I2vi_—Sr1—Sr2viii _{52.26 (3)} _Sr1x_—I1—Sr2xi _{104.20 (5)}

Sr2vii_—Sr1—Sr2viii _{60.96 (6)} _Sr2viii_—I1—Sr2xi _{153.95 (4)}

Sr2—Sr1—Sr2viii _{60.96 (6)} _{Sr2—I1—Sr2}xi _{105.50 (4)}

O—Sr2—I2v _{98.7 (5)} _Sr1x_—I1—Sr2xii _{104.20 (5)}

O—Sr2—I1vii _{86.6 (4)} _Sr2viii_—I1—Sr2xii _{105.50 (4)}

I2v_—Sr2—I1vii _{140.95 (3)} _{Sr2—I1—Sr2}xii _{153.95 (4)}

O—Sr2—I1 86.6 (4) Sr2xi_—I1—Sr2xii _{66.15 (4)}

I2v_—Sr2—I1 _{140.95 (3)} _Sr2xi_—I2—Sr2 _{106.45 (2)}

I1vii_—Sr2—I1 _{77.69 (5)} _Sr2xi_—I2—Sr2xiii _{106.45 (2)}

O—Sr2—I2ix _{144.645 (17)} _{Sr2—I2—Sr2}xiii _{147.04 (5)}

I2v_—Sr2—I2ix _{82.78 (4)} _Sr2xi_—I2—Sr1xii _{64.47 (5)}

I1vii_—Sr2—I2ix _{71.78 (3)} _{Sr2—I2—Sr1}xii _{96.08 (2)}

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O—Sr2—I2 144.645 (18) Sr1—O—Sr2vii _{108.7 (5)}

I2v_—Sr2—I2 _{82.78 (4)} _{Sr1—O—Sr2} _{108.7 (5)}

I1vii_—Sr2—I2 _{114.41 (5)} _Sr2vii_—O—Sr2 _{110.2 (4)}

I1—Sr2—I2 71.78 (3) Sr1—O—Sr2viii _{108.7 (5)}

I2ix_—Sr2—I2 _{70.71 (3)} _Sr2vii_—O—Sr2viii _{110.2 (4)}

O—Sr2—I1vi _{76.25 (17)} _{Sr2—O—Sr2}viii _{110.2 (4)}