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inorganic papers

i12

Tursinaet al. CeRu2Al10 doi:10.1107/S1600536805000310 Acta Cryst.(2005). E61, i12±i14

Acta Crystallographica Section E

Structure Reports Online

ISSN 1600-5368

CeRu

2

Al

10

with the YbFe

2

Al

10

structure type

Anna I. Tursina,aSergei N.

Nesterenko,aElena V.

Murashova,aIlya V.

Chernyshev,aHenri NoeÈlband

Yuri D. Seropegina*

aDepartment of Chemistry, Moscow State

University, Leninskie Gory, 119 992 GSP-2 Moscow, Russia, andbLaboratoire de Chimie du Solide et Inorganigue MoleÂculaire, UMR±CNRS 6511, Universite de Rennes 1, Avenue du GeÂneÂral Leclerc, F-35042 Rennes, France

Correspondence e-mail: tursina@newmail.ru

Key indicators Single-crystal X-ray study

T= 293 K

Mean(l±Al) = 0.003 AÊ

Rfactor = 0.043

wRfactor = 0.123

Data-to-parameter ratio = 17.1

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

#2005 International Union of Crystallography Printed in Great Britain ± all rights reserved

The structure of cerium diruthenium decaaluminium, CeRu2Al10, is characterized by seven crystallographic sites in space groupCmcm,viz.Ce in 4c, Ru in 8a, two Al atoms in 8g, two Al atoms in 8fand one Al atom in 8e. The structure can be interpreted as a stacking of alternating columns running along [001], each formed by only one type of Ru cuboid with composition RuAl6or CeRuAl4.

Comment

There are only limited data available on the formation of ternary cerium ruthenium aluminides and their crystal struc-tures. In recent studies, the structures of two compounds were determined from single-crystal X-ray diffraction, namely Ce3Ru4Al12 (Bukhan'ko et al., 2004) with the Nd3Ru4Al12 structure type (Gladyshevskii et al., 1993) and Ce2Ru3Al15 with a new structure type (Tursinaet al., 2004). CeRu2Al10was ®rst synthesized by Thiedeet al.(1998) and, on the basis of the analysis of X-ray powder diffraction data, was assumed to be isotypic to the YbFe2Al10 structure (Niemann & Jeitschko, 1995).

In the title compound, the three-dimensional network of Ru atoms hypothetically divides the structure into equal cuboids of dimensiona/2b/2c/2, with Ru atoms in the vertices of the cuboids. Ce and Al atoms occupy these cuboids in two ways, giving the composition RuAl6for the ®rst type of cuboid (Fig. 1a) and CeRuAl4for the second type of cuboid (Fig. 1b). The structure can be described as the stacking of alternating columns running along [001], each formed by only one type of cuboid (Fig. 2).

The Ce atom is surrounded by four Ru and 16 Al atoms at distances of 3.188 (3)±3.6660 (13) AÊ, which results in a distorted hexagonal prism with eight additional atoms capping

Received 20 December 2004 Accepted 4 January 2005 Online 15 January 2005

Figure 1

Views of (a) an RuAl6cuboid and (b) a CeRuAl4cuboid, with Ce atoms

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all faces of the prism Ce[Ru4Al16]. The Ru atom in CeRu2Al10, as well as in Ce2Ru3Al15, has a distorted icosahedral coordi-nation, Ru[Ce2Al10], with RuÐAl interatomic distances ranging from 2.5786 (6) to 2.7640 (14) AÊ. The CeÐRu distances are 3.4884 (4) AÊ. Whereas the coordination poly-hedra of the Al atoms in Ce2Ru3Al15could be also regarded as distorted icosahedra, in CeRu2Al10the polyhedra around the Al atoms are irregular. Distorted pentagonal antiprisms around atoms Al1 (Al[CeRu2Al8]) and Al4 (Al[CeRu2Al8]) are capped on one basal face, while antiprisms around atoms Al2 (Al[CeRu2Al9]), Al3 (Al[Ce2Ru2Al8]) and Al5 (Al[Ce2Ru2Al8]) are capped on both basal faces. The analysis of the interatomic distances in the isotypic compound UFe2Al10(NoeÈl et al., 2004) leads to the same coordination numbers for the Al atoms. However, for the prototype compound YbFe2Al10, greater coordination numbers of the Al atoms were reported. Here it was considered that the inter-atomic contacts signi®cantly exceed the sum of the metallic radii.

Fig. 3 shows the asymmetric unit of the title compound.

Experimental

The title compound was prepared by arc-melting of the constituent elements (all with nominal purities equal to or greater than 99.8%) with the composition Ce8.9Ru13.3Al77.8. The weight loss was less than 1%. The melted button was subsequently sealed in an evacuated silica tube and annealed at 1170 K for one week. A single crystal was isolated from the annealed sample by mechanical fragmentation.

Crystal data

CeRu2Al10

Mr= 612.06

Orthorhombic,Cmcm a= 9.1272 (16) AÊ b= 10.282 (2) AÊ c= 9.1902 (14) AÊ V= 862.5 (3) AÊ3

Z= 4

Dx= 4.714 Mg mÿ3

MoKradiation

Cell parameters from 25 re¯ections

= 18.1±27.8

= 9.59 mmÿ1

T= 293 (2) K

Prism, metallic light grey 0.150.100.03 mm

Data collection

Enraf±Nonius CAD-4 diffractometer

!scans

Absorption correction: scan (Northet al., 1968) Tmin= 0.321,Tmax= 0.746

769 measured re¯ections 703 independent re¯ections 661 re¯ections withI> 2(I)

Rint= 0.044

max= 29.9

h=ÿ12!0 k=ÿ14!1 l= 0!12 1 standard re¯ection

frequency: 120 min intensity decay: 0.6%

Refinement

Re®nement onF2

R[F2> 2(F2)] = 0.043

wR(F2) = 0.123

S= 1.10 703 re¯ections 41 parameters

w= 1/[2(F

o2) + (0.0963P)2

+ 3.3337P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.0001

max= 3.91 e AÊÿ3

min=ÿ4.50 e AÊÿ3

Extinction correction:SHELXL97 Extinction coef®cient: 0.0127 (10)

Table 1

Selected geometric parameters (AÊ).

Al1ÐRu 2.5902 (12)

Al1ÐAl2 2.665 (4)

Al1ÐAl5i 2.7237 (15)

Al1ÐAl4 2.755 (3)

Al1ÐAl2 2.823 (3)

Al1ÐAl3ii 2.872 (3)

Al1ÐCe 3.212 (3)

Al2ÐAl2iii 2.722 (5)

Al2ÐRui 2.7640 (14)

Al2ÐAl3ii 2.888 (3)

Al2ÐAl5 2.888 (2)

Al2ÐCe 3.203 (3)

Al3ÐAl4 2.627 (3)

Al3ÐRuiv 2.6290 (13)

Al3ÐAl3 2.737 (5)

Al3ÐAl5v 2.812 (3)

Al3ÐCevi 3.230 (2)

Al3ÐCe 3.249 (3)

Al4ÐRuvii 2.6715 (12)

Al4ÐAl4viii 2.686 (5)

Al4ÐAl5 2.826 (3)

Al4ÐCe 3.188 (3)

Al5ÐRu 2.5786 (6)

Al5ÐCeix 3.349 (2)

RuÐCe 3.4884 (4)

Symmetry codes: (i)ÿx‡1

2;ÿy‡12;z‡12; (ii)ÿx‡12;ÿy‡12;ÿz‡1; (iii)ÿx‡1;y;z;

(iv)ÿx;y;ÿz‡1

2; (v)ÿx;ÿy;z‡12; (vi)ÿx;ÿy;ÿz‡1; (vii)xÿ12;ÿy‡12;ÿz; (viii)

ÿx;ÿy‡1;ÿz; (ix)ÿx;ÿy;ÿz.

inorganic papers

Acta Cryst.(2005). E61, i12±i14 Tursinaet al. CeRu2Al10

i13

Figure 2

Projection of the structure along the c axis. Ru cuboids RuAl6 and

CeRuAl4, as well as the unit cell, are outlined.

Figure 3

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The atomic parameters were standardized with the program

STRUCTURE TIDY(Gelato & PartheÂ, 1987). The highest peak and the deepest hole in the ®nal difference map are located 0.90 and 0.81 AÊ, respectively, from the Ce atom.

Data collection: CAD-4 EXPRESS (Enraf±Nonius, 1994); cell re®nement: CAD-4 EXPRESS; data reduction:XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97

(Sheldrick, 1997); program(s) used to re®ne structure:SHELXL97

(Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1998) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication:WinGX(Farrugia, 1999).

This work was supported by the RFBR project N 03-03-20001BNTS_a.

References

Brandenburg, K. (1998).DIAMOND. Version 2.1b. Crystal Impact GbR, Bonn, Germany.

Bukhan'ko, N. G., Tursina, A. I., Malyshev, S. V., Gribanov, A. V., Seropegin, Yu. D. & Bodak, O. I. (2004).J. Alloys Compd.367, 149±151.

Enraf±Nonius (1994).CAD-4 EXPRESS. Enraf±Nonius, Delft, The Nether-lands.

Farrugia, L. J. (1997).J. Appl. Cryst.30, 565. Farrugia, L. J. (1999).J. Appl. Cryst.32, 837±838.

Gelato, L. M. & PartheÂ, E. (1987).J. Appl. Cryst.20, 139±143.

Gladyshevskii, R. E., Strusievicz, O. R., Cenzual, K. & PartheÂ, E. (1993).Acta Cryst.B49, 474±478.

Harms, K. & Wocadlo, S. (1995).XCAD4. University of Marburg, Germany. Niemann, S. & Jeitschko, W. (1995).Z. Kristallogr.210, 338±341.

NoeÈl, H., GoncËalves, A. P. & Waerenborgh, J. C. (2004).Intermetallics,12, 189± 194.

North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968).Acta. Cryst.A24, 351. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of

GoÈttingen, Germany.

Thiede, V. M. T., Ebel, T. & Jeitschko, W. (1998).J. Mater. Chem.8, 125±130. Tursina, A. I., Nesterenko, S. N., Murashova, E. V., Chernyshev, I. V., NoeÈl, H.

& Seropegin, Y. D. (2004).Acta Cryst.E60, i145±i146.

inorganic papers

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supporting information

sup-1 Acta Cryst. (2005). E61, i12–i14

supporting information

Acta Cryst. (2005). E61, i12–i14 [https://doi.org/10.1107/S1600536805000310]

CeRu

2

Al

10

with the YbFe

2

Al

10

structure type

Anna I. Tursina, Sergei N. Nesterenko, Elena V. Murashova, Ilya V. Chernyshev, Henri No

ë

l and

Yuri D. Seropegin

Cerium diruthenium decaaluminium

Crystal data CeRu2Al10

Mr = 612.06

Orthorhombic, Cmcm Hall symbol: -C 2c 2 a = 9.1272 (16) Å b = 10.282 (2) Å c = 9.1902 (14) Å V = 862.5 (3) Å3

Z = 4

F(000) = 1104 Dx = 4.714 Mg m−3

Mo radiation, λ = 0.71073 Å Cell parameters from 25 reflections θ = 18.1–27.8°

µ = 9.59 mm−1

T = 293 K

Prism, metallic light grey 0.15 × 0.10 × 0.03 mm

Data collection Enraf–Nonius CAD-4

diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

ω scans

Absorption correction: ψ scan (North et al., 1968)

Tmin = 0.321, Tmax = 0.746 769 measured reflections

703 independent reflections 661 reflections with I > 2σ(I) Rint = 0.044

θmax = 29.9°, θmin = 3.0°

h = −12→0 k = −14→1 l = 0→12

1 standard reflections every 120 min intensity decay: 0.6%

Refinement Refinement on F2 Least-squares matrix: full R[F2 > 2σ(F2)] = 0.043

wR(F2) = 0.123

S = 1.10 703 reflections 41 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

w = 1/[σ2(F

o2) + (0.0963P)2 + 3.3337P] where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001 Δρmax = 3.91 e Å−3 Δρmin = −4.50 e Å−3

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supporting information

sup-2 Acta Cryst. (2005). E61, i12–i14

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

x y z Uiso*/Ueq

Al1 0.2248 (3) 0.3641 (2) 0.2500 0.0071 (5)

Al2 0.3509 (3) 0.1304 (2) 0.2500 0.0072 (5)

Al3 0.0000 0.1607 (2) 0.6011 (3) 0.0066 (5)

Al4 0.0000 0.3774 (2) 0.0504 (3) 0.0076 (5)

Al5 0.2276 (3) 0.0000 0.0000 0.0067 (6)

Ru 0.2500 0.2500 0.0000 0.0038 (3)

Ce 0.0000 0.12381 (5) 0.2500 0.0053 (3)

Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23

Al1 0.0122 (11) 0.0058 (11) 0.0034 (11) 0.0010 (8) 0.000 0.000

Al2 0.0075 (10) 0.0056 (10) 0.0086 (11) −0.0013 (8) 0.000 0.000

Al3 0.0074 (9) 0.0062 (10) 0.0063 (10) 0.000 0.000 0.0002 (8)

Al4 0.0054 (10) 0.0041 (11) 0.0131 (12) 0.000 0.000 0.0011 (8)

Al5 0.0107 (11) 0.0023 (11) 0.0073 (13) 0.000 0.000 0.0007 (8)

Ru 0.0053 (4) 0.0020 (4) 0.0041 (4) 0.00007 (16) −0.00051 (19) −0.00020 (17)

Ce 0.0078 (4) 0.0018 (4) 0.0063 (4) 0.000 0.000 0.000

Geometric parameters (Å, º)

Al1—Ru 2.5902 (12) Al4—Al1xvi 2.755 (3)

Al1—Rui 2.5902 (11) Al4—Al5ii 2.826 (3)

Al1—Al2 2.665 (4) Al4—Al5xvii 2.826 (3)

Al1—Al5i 2.7237 (15) Al4—Ce 3.188 (3)

Al1—Al5ii 2.7237 (15) Al5—Ru 2.5786 (6)

Al1—Al4 2.755 (3) Al5—Ruxviii 2.5786 (6)

Al1—Al4iii 2.755 (3) Al5—Al1viii 2.7237 (15)

Al1—Al2iv 2.823 (3) Al5—Al1ii 2.7237 (15)

Al1—Al3v 2.872 (3) Al5—Al3xix 2.812 (3)

Al1—Al3vi 2.872 (3) Al5—Al3iii 2.812 (3)

Al1—Ce 3.212 (3) Al5—Al4ii 2.826 (3)

Al2—Al2vii 2.722 (5) Al5—Al4xx 2.826 (3)

Al2—Rui 2.7640 (14) Al5—Al2xviii 2.888 (2)

Al2—Ru 2.7640 (14) Al5—Cexxi 3.349 (2)

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supporting information

sup-3 Acta Cryst. (2005). E61, i12–i14

Al2—Al3v 2.888 (3) Ru—Al5ii 2.5786 (6)

Al2—Al3vi 2.888 (3) Ru—Al1ii 2.5902 (12)

Al2—Al5 2.888 (2) Ru—Al3iii 2.6290 (13)

Al2—Al5iii 2.888 (2) Ru—Al3vi 2.6290 (13)

Al2—Ce 3.203 (3) Ru—Al4ii 2.6715 (12)

Al3—Al4iii 2.627 (3) Ru—Al2ii 2.7640 (14)

Al3—Ruix 2.6290 (13) Ru—Ceii 3.4884 (4)

Al3—Rui 2.6290 (13) Ru—Ce 3.4884 (4)

Al3—Al3x 2.737 (5) Ce—Al4iii 3.188 (3)

Al3—Al5xi 2.812 (3) Ce—Al2xvi 3.203 (3)

Al3—Al5iii 2.812 (3) Ce—Al1xvi 3.212 (3)

Al3—Al1v 2.872 (3) Ce—Al3xix 3.230 (2)

Al3—Al1xii 2.872 (3) Ce—Al3xiii 3.230 (2)

Al3—Al2v 2.888 (3) Ce—Al3iii 3.249 (3)

Al3—Al2xii 2.888 (3) Ce—Al5xxi 3.349 (2)

Al3—Cexiii 3.230 (2) Ce—Al5iii 3.349 (2)

Al3—Ce 3.249 (3) Ce—Al5xi 3.349 (2)

Al4—Al3iii 2.627 (3) Ce—Rui 3.4884 (4)

Al4—Ruxiv 2.6715 (12) Ce—Ruxiv 3.4884 (4)

Al4—Ru 2.6715 (12) Ce—Ruix 3.4884 (4)

Al4—Al4xv 2.686 (5)

Ru—Al1—Rui 125.00 (9) Rui—Al1—Al2 63.45 (5)

Ru—Al1—Al2 63.45 (5) Ru—Al1—Al5i 165.12 (13)

References

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