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Calcium platinum aluminium, CaPtAl

aThe University of Yaounde 1, Department of Inorganic Chemistry, Faculty of Sciences, PO Box 812 Yaounde, Cameroon, bThe University of Maroua, Department of Chemistry, Ecole Normale Supérieure de Maroua, Cameroon, and cThe University of Yaounde 1, Department of Chemistry, Ecole Normale Supérieure de Yaoundé, PO Box 47 Yaounde, Cameroon
*Correspondence e-mail: sponou@gmail.com

(Received 5 September 2011; accepted 9 September 2011; online 20 September 2011)

A preliminary X-ray study of CaPtAl has been reported previously by Hulliger [J. Alloys Compd (1993), 196, 225–228] based on X-ray powder diffraction data without structure refinement. With the present single-crystal X-ray study, we confirm the assignment of the TiNiSi type for CaPtAl, in a fully ordered inverse structure. All three atoms of the asymmetric unit have .m. site symmetry. The structure features a 3[AlPt] open framework with a fourfold coordination of Pt by Al atoms and vice versa. The Ca atoms are located in the large channels of the structure.

Related literature

For a previous X-ray powder diffraction study of CaPtAl, see: Hulliger (1993[Hulliger, F. (1993). J. Alloys Compd, 196, 225-228.]). For related compounds, see: Dascoulidou-Gritner & Schuster (1994[Dascoulidou-Gritner, K. & Schuster, H. U. (1994). Z. Anorg. Allg. Chem. 620, 1151-1156.]); Merlo et al. (1996[Merlo, F., Pani, M. & Fornasini, M. L. (1996). J. Alloys Compd, 232, 289-295.]). For structural systematics and properties of the TiNiSi structure type, see: Kussmann et al. (1998)[Kussmann, D., Hoffmann, R.-D. & Pöttgen, R. (1998). Z. Anorg. Allg. Chem. 624, 1727-1735.]; Hoffmann & Pöttgen (2001[Hoffmann, R.-D. & Pöttgen, R. (2001). Z. Kristallogr. 216, 127-145.]); Nuspl et al. (1996[Nuspl, G., Polborn, K., Evers, J., Landrum, G. A. & Hoffmann, R. (1996). Inorg. Chem. 35, 6922-6932.]); Evers et al. (1992[Evers, J., Oehlinger, G., Polborn, K. & Sendlinger, B. (1992). J. Alloys Compd, 182, L23-L29.]). For related compounds of the TiNiSi structure type, see: Ponou & Lidin (2008[Ponou, S. & Lidin, S. (2008). Z. Kristallogr. New Cryst. Struct. 223, 329-330.]); Ponou (2010[Ponou, S. (2010). Eur. J. Inorg. Chem., pp. 4139-4147.]); Banenzoué et al. (2009[Banenzoué, C., Ponou, S. & Lambi, J. N. (2009). Acta Cryst. E65, i90.]). For atomic radii, see: Pauling (1960[Pauling, L. (1960). The Nature of the Chemical Bond, 3rd ed. Ithaca: Cornell University Press.]).

Experimental

Crystal data
  • CaPtAl

  • Mr = 262.15

  • Orthorhombic, P n m a

  • a = 7.1581 (14) Å

  • b = 4.2853 (15) Å

  • c = 7.7536 (9) Å

  • V = 237.84 (10) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 61.08 mm−1

  • T = 293 K

  • 0.15 × 0.08 × 0.05 mm

Data collection
  • Oxford Diffraction Xcalibur diffractometer with Sapphire3 CCD

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England]) Tmin = 0.004, Tmax = 0.047

  • 4413 measured reflections

  • 511 independent reflections

  • 435 reflections with I > 2σ(I)

  • Rint = 0.091

Refinement
  • R[F2 > 2σ(F2)] = 0.028

  • wR(F2) = 0.064

  • S = 1.03

  • 511 reflections

  • 20 parameters

  • Δρmax = 2.61 e Å−3

  • Δρmin = −2.95 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England]); cell refinement: CrysAlis RED (Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England]); data reduction: CrysAlis CCD; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

A recent re-investigation of the ternary CaAgGe phase from single-crystal X-ray data has revealed a superstructure with a tripling of the a-axis of the of the TiNiSi-type basic cell (i3, minimal isomorphic subgroup of index 3) and a complete ordering of the atomic sites (Ponou & Lidin, 2008; Ponou, 2010). This phase has previously been reported by Merlo et al. (1996) in the KHg2 structure type with Ag and Ge atoms randomly distributed on the Hg site. Hence, precice single crystals X-ray diffraction measurements is of importance in this family of compounds (Kussmann et al., 1998; Banenzoué et al., 2009) to access both the superstructure and a possible structure inversion with respect to the Ni and Si positions in the three-dimensional framework of fourfold interconnected atoms. Such a structure inversion is observed, for example, in CaGaPt, with Ga atoms at the orginal Ni position and Pt at the original Si position with respect to the prototype TiNiSi structure type (Dascoulidou-Gritner & Schuster, 1994). In 'normal' TiNiSi phases like CaPtGe, Ge occupies the Si position and Pt the Ni position (Evers et al., 1992; Nuspl et al., 1996). Here we report the structure refinement of CaPtAl from single-crystal X-ray diffraction data.

The structure of the title compound was first investigated by Hulliger (1993) from X-ray powder data and assigned to the orthorhombic TiNiSi structure type, however, without a detailed structural refinement. In the present study, the CaPtAl structure was successfully refined as an inverse TiNiSi type. Hence, Ca, Al and Pt atoms are found at Ti, Ni and Si atomic positions, respectively. The origin of the inversion in this structure type is generally ascribed to the relative electronegativity of the framework constituent elements, here Pt and Al. The more electronegative atom (here Pt) is found at the Si position in a strongly distorted tetrahedral (rather pyramidal) coordination whereas the coordination of the less electronegative atom at the Ni position is only slightly distorted from its idealized tetrahedral values (Hoffmann & Pöttgen, 2001). The Pt—Al interactomic distances range from 2.574 (3) Å to 2.675 (3) Å which is comparable with the sum of atomic radii of these elements, i.e. 2.62 Å (Al: 1.25 and Pt: 1.37 Å; Pauling, 1960), indicating a covalent character of the bonding. The first coordination sphere of the Ca atoms consists of two counter-tilted Pt3Al3 hexagons with Ca—Al and Ca—Pt distances ranging from 3.143 (3) Å to 3.489 (3) Å and from 2.978 (2) Å to 3.1179 (16) Å, respectively, also in agreement with the sum of atomic radii (Ca: 1.97 Å).

Related literature top

For a previous X-ray powder diffraction study of CaPtAl, see: Hulliger (1993). For related compounds, see: Dascoulidou-Gritner & Schuster (1994); Merlo et al. (1996). For structural systematics and properties of the TiNiSi structure type, see: Kussmann et al. (1998); Hoffmann & Pöttgen (2001); Nuspl et al. (1996); Evers et al. (1992). For related compounds of the TiNiSi structure type, see: Ponou & Lidin (2008); Ponou (2010); Banenzoué et al. (2009). For atomic radii, see: Pauling (1960).

Experimental top

Single crystals of the title compound, suitable for X-ray diffraction studies, were obtained from a mixture of the elements (Ca ingots (99.5%), Al chunk (99.9%) and Pt pieces (99%), all from ABCR) with a molar ratio Ca:Pt:Al = 2:2:1, by heating in a Nb ampoule at 1253 K for one hour and then slowly cooling at a rate of 6 K/h to room temperature. The product is air-stable, silver-grey with metallic lustre.

Refinement top

The refined unit cell parameters are quite close (slighly lower) to those obtained from a Guinier camera by Hulliger (1993) with a = 7.1722 (6), b = 4.2885 (4) and c = 7.7760 (7) Å. The refinement in the inverse TiNiSi structure model was straightforward. Full/mixed occupancies were checked for all atomic sites by freeing the site occupation factor for each given individual atom, while keeping that of the other atoms fixed. The residual map shows highest peak/deepest hole of 2.61/-2.95 e Å-2 at 0.75/0.60 Å from Pt1, respectively.

Structure description top

A recent re-investigation of the ternary CaAgGe phase from single-crystal X-ray data has revealed a superstructure with a tripling of the a-axis of the of the TiNiSi-type basic cell (i3, minimal isomorphic subgroup of index 3) and a complete ordering of the atomic sites (Ponou & Lidin, 2008; Ponou, 2010). This phase has previously been reported by Merlo et al. (1996) in the KHg2 structure type with Ag and Ge atoms randomly distributed on the Hg site. Hence, precice single crystals X-ray diffraction measurements is of importance in this family of compounds (Kussmann et al., 1998; Banenzoué et al., 2009) to access both the superstructure and a possible structure inversion with respect to the Ni and Si positions in the three-dimensional framework of fourfold interconnected atoms. Such a structure inversion is observed, for example, in CaGaPt, with Ga atoms at the orginal Ni position and Pt at the original Si position with respect to the prototype TiNiSi structure type (Dascoulidou-Gritner & Schuster, 1994). In 'normal' TiNiSi phases like CaPtGe, Ge occupies the Si position and Pt the Ni position (Evers et al., 1992; Nuspl et al., 1996). Here we report the structure refinement of CaPtAl from single-crystal X-ray diffraction data.

The structure of the title compound was first investigated by Hulliger (1993) from X-ray powder data and assigned to the orthorhombic TiNiSi structure type, however, without a detailed structural refinement. In the present study, the CaPtAl structure was successfully refined as an inverse TiNiSi type. Hence, Ca, Al and Pt atoms are found at Ti, Ni and Si atomic positions, respectively. The origin of the inversion in this structure type is generally ascribed to the relative electronegativity of the framework constituent elements, here Pt and Al. The more electronegative atom (here Pt) is found at the Si position in a strongly distorted tetrahedral (rather pyramidal) coordination whereas the coordination of the less electronegative atom at the Ni position is only slightly distorted from its idealized tetrahedral values (Hoffmann & Pöttgen, 2001). The Pt—Al interactomic distances range from 2.574 (3) Å to 2.675 (3) Å which is comparable with the sum of atomic radii of these elements, i.e. 2.62 Å (Al: 1.25 and Pt: 1.37 Å; Pauling, 1960), indicating a covalent character of the bonding. The first coordination sphere of the Ca atoms consists of two counter-tilted Pt3Al3 hexagons with Ca—Al and Ca—Pt distances ranging from 3.143 (3) Å to 3.489 (3) Å and from 2.978 (2) Å to 3.1179 (16) Å, respectively, also in agreement with the sum of atomic radii (Ca: 1.97 Å).

For a previous X-ray powder diffraction study of CaPtAl, see: Hulliger (1993). For related compounds, see: Dascoulidou-Gritner & Schuster (1994); Merlo et al. (1996). For structural systematics and properties of the TiNiSi structure type, see: Kussmann et al. (1998); Hoffmann & Pöttgen (2001); Nuspl et al. (1996); Evers et al. (1992). For related compounds of the TiNiSi structure type, see: Ponou & Lidin (2008); Ponou (2010); Banenzoué et al. (2009). For atomic radii, see: Pauling (1960).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis CCD (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. A perspective view of the CaPtAl structure with displacement ellipsoids drawn at the 99% probability level. Ca, Al, and Pt atoms are drawn as white-crossed, grey and black spheres, respectively.
Calcium aluminium platinum top
Crystal data top
CaPtAlF(000) = 444
Mr = 262.15Dx = 7.321 Mg m3
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 2105 reflections
a = 7.1581 (14) Åθ = 2.6–33.7°
b = 4.2853 (15) ŵ = 61.08 mm1
c = 7.7536 (9) ÅT = 293 K
V = 237.84 (10) Å3Irregular block, metallic grey
Z = 40.15 × 0.08 × 0.05 mm
Data collection top
Oxford Diffraction Xcalibur
diffractometer with Sapphire3 CCD
511 independent reflections
Graphite monochromator435 reflections with I > 2σ(I)
Detector resolution: 16.1829 pixels mm-1Rint = 0.091
ω and φ scansθmax = 33.8°, θmin = 3.9°
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2007)
h = 1011
Tmin = 0.004, Tmax = 0.047k = 66
4413 measured reflectionsl = 1112
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028 w = 1/[σ2(Fo2) + (0.0326P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.064(Δ/σ)max < 0.001
S = 1.03Δρmax = 2.61 e Å3
511 reflectionsΔρmin = 2.95 e Å3
20 parametersExtinction correction: SHELXL97 (Sheldrick, 2008)
0 restraintsExtinction coefficient: 0.0027 (5)
Crystal data top
CaPtAlV = 237.84 (10) Å3
Mr = 262.15Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 7.1581 (14) ŵ = 61.08 mm1
b = 4.2853 (15) ÅT = 293 K
c = 7.7536 (9) Å0.15 × 0.08 × 0.05 mm
Data collection top
Oxford Diffraction Xcalibur
diffractometer with Sapphire3 CCD
511 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2007)
435 reflections with I > 2σ(I)
Tmin = 0.004, Tmax = 0.047Rint = 0.091
4413 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02820 parameters
wR(F2) = 0.0640 restraints
S = 1.03Δρmax = 2.61 e Å3
511 reflectionsΔρmin = 2.95 e Å3
Special details top

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) top
xyzUiso*/Ueq
Pt10.78928 (5)0.250.38355 (4)0.01029 (15)
Al10.1446 (5)0.250.4346 (4)0.0103 (6)
Ca10.4796 (3)0.750.3234 (2)0.0106 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Pt10.00775 (19)0.0118 (2)0.0113 (2)00.00104 (12)0
Al10.0087 (13)0.0127 (15)0.0094 (11)00.0001 (11)0
Ca10.0088 (8)0.0129 (10)0.0102 (8)00.0011 (6)0
Geometric parameters (Å, º) top
Pt1—Al1i2.574 (3)Al1—Ca1xi3.160 (3)
Pt1—Al1ii2.6084 (17)Al1—Ca1ix3.160 (3)
Pt1—Al1iii2.6084 (17)Al1—Ca1ii3.280 (4)
Pt1—Al1iv2.675 (3)Al1—Ca13.329 (3)
Pt1—Ca1ii2.978 (2)Al1—Ca1vi3.329 (3)
Pt1—Ca1v3.0037 (14)Ca1—Pt1ii2.978 (2)
Pt1—Ca1iv3.0037 (14)Ca1—Pt1ix3.0037 (14)
Pt1—Ca1vi3.1179 (16)Ca1—Pt1xii3.0037 (14)
Pt1—Ca13.1179 (16)Ca1—Pt1xiii3.1179 (16)
Pt1—Ca1vii3.791 (2)Ca1—Al1xiv3.143 (3)
Al1—Pt1viii2.574 (3)Ca1—Al1iv3.160 (3)
Al1—Pt1ii2.6084 (17)Ca1—Al1xv3.160 (3)
Al1—Pt1iii2.6084 (17)Ca1—Al1ii3.280 (4)
Al1—Pt1ix2.675 (3)Ca1—Al1xiii3.329 (3)
Al1—Ca1x3.143 (3)Ca1—Ca1xvi3.489 (3)
Al1i—Pt1—Al1ii74.79 (9)Ca1xi—Al1—Ca1122.80 (9)
Al1i—Pt1—Al1iii74.79 (8)Ca1ix—Al1—Ca170.67 (4)
Al1ii—Pt1—Al1iii110.46 (10)Ca1ii—Al1—Ca163.73 (7)
Al1i—Pt1—Al1iv121.62 (9)Pt1viii—Al1—Ca1vi132.22 (7)
Al1ii—Pt1—Al1iv124.66 (5)Pt1ii—Al1—Ca1vi122.54 (12)
Al1iii—Pt1—Al1iv124.66 (5)Pt1iii—Al1—Ca1vi58.71 (5)
Al1i—Pt1—Ca1ii121.43 (7)Pt1ix—Al1—Ca1vi58.83 (6)
Al1ii—Pt1—Ca1ii72.83 (7)Ca1x—Al1—Ca1vi116.88 (8)
Al1iii—Pt1—Ca1ii72.83 (7)Ca1xi—Al1—Ca1vi70.67 (4)
Al1iv—Pt1—Ca1ii116.96 (8)Ca1ix—Al1—Ca1vi122.80 (9)
Al1i—Pt1—Ca1v68.52 (5)Ca1ii—Al1—Ca1vi63.73 (7)
Al1ii—Pt1—Ca1v142.42 (8)Ca1—Al1—Ca1vi80.12 (9)
Al1iii—Pt1—Ca1v67.70 (7)Pt1ii—Ca1—Pt1ix96.57 (5)
Al1iv—Pt1—Ca1v71.52 (6)Pt1ii—Ca1—Pt1xii96.57 (5)
Ca1ii—Pt1—Ca1v134.49 (3)Pt1ix—Ca1—Pt1xii91.01 (6)
Al1i—Pt1—Ca1iv68.52 (5)Pt1ii—Ca1—Pt1xiii110.21 (5)
Al1ii—Pt1—Ca1iv67.70 (7)Pt1ix—Ca1—Pt1xiii153.20 (7)
Al1iii—Pt1—Ca1iv142.42 (8)Pt1xii—Ca1—Pt1xiii84.96 (3)
Al1iv—Pt1—Ca1iv71.52 (6)Pt1ii—Ca1—Pt1110.21 (5)
Ca1ii—Pt1—Ca1iv134.49 (3)Pt1ix—Ca1—Pt184.96 (3)
Ca1v—Pt1—Ca1iv91.01 (6)Pt1xii—Ca1—Pt1153.20 (7)
Al1i—Pt1—Ca1vi136.51 (3)Pt1xiii—Ca1—Pt186.82 (5)
Al1ii—Pt1—Ca1vi140.75 (8)Pt1ii—Ca1—Al1xiv123.30 (9)
Al1iii—Pt1—Ca1vi69.23 (7)Pt1ix—Ca1—Al1xiv50.15 (4)
Al1iv—Pt1—Ca1vi65.60 (6)Pt1xii—Ca1—Al1xiv50.15 (4)
Ca1ii—Pt1—Ca1vi69.79 (5)Pt1xiii—Ca1—Al1xiv110.15 (6)
Ca1v—Pt1—Ca1vi75.66 (3)Pt1—Ca1—Al1xiv110.15 (6)
Ca1iv—Pt1—Ca1vi137.12 (3)Pt1ii—Ca1—Al1iv136.43 (5)
Al1i—Pt1—Ca1136.51 (3)Pt1ix—Ca1—Al1iv49.29 (6)
Al1ii—Pt1—Ca169.23 (7)Pt1xii—Ca1—Al1iv108.36 (7)
Al1iii—Pt1—Ca1140.74 (8)Pt1xiii—Ca1—Al1iv107.15 (8)
Al1iv—Pt1—Ca165.60 (6)Pt1—Ca1—Al1iv50.44 (6)
Ca1ii—Pt1—Ca169.79 (5)Al1xiv—Ca1—Al1iv59.91 (8)
Ca1v—Pt1—Ca1137.12 (3)Pt1ii—Ca1—Al1xv136.43 (5)
Ca1iv—Pt1—Ca175.66 (3)Pt1ix—Ca1—Al1xv108.36 (7)
Ca1vi—Pt1—Ca186.82 (5)Pt1xii—Ca1—Al1xv49.29 (6)
Al1i—Pt1—Ca1vii55.28 (7)Pt1xiii—Ca1—Al1xv50.44 (6)
Al1ii—Pt1—Ca1vii55.55 (5)Pt1—Ca1—Al1xv107.15 (8)
Al1iii—Pt1—Ca1vii55.55 (5)Al1xiv—Ca1—Al1xv59.91 (8)
Al1iv—Pt1—Ca1vii176.90 (8)Al1iv—Ca1—Al1xv85.38 (9)
Ca1ii—Pt1—Ca1vii66.144 (17)Pt1ii—Ca1—Al1ii95.37 (7)
Ca1v—Pt1—Ca1vii106.42 (4)Pt1ix—Ca1—Al1ii132.66 (3)
Ca1iv—Pt1—Ca1vii106.42 (4)Pt1xii—Ca1—Al1ii132.66 (3)
Ca1vi—Pt1—Ca1vii116.41 (5)Pt1xiii—Ca1—Al1ii48.04 (3)
Ca1—Pt1—Ca1vii116.41 (5)Pt1—Ca1—Al1ii48.04 (3)
Pt1viii—Al1—Pt1ii105.21 (8)Al1xiv—Ca1—Al1ii141.34 (12)
Pt1viii—Al1—Pt1iii105.21 (8)Al1iv—Ca1—Al1ii93.19 (5)
Pt1ii—Al1—Pt1iii110.46 (10)Al1xv—Ca1—Al1ii93.19 (5)
Pt1viii—Al1—Pt1ix103.93 (10)Pt1ii—Ca1—Al148.46 (5)
Pt1ii—Al1—Pt1ix115.36 (8)Pt1ix—Ca1—Al149.65 (5)
Pt1iii—Al1—Pt1ix115.36 (8)Pt1xii—Ca1—Al1105.70 (8)
Pt1viii—Al1—Ca1x82.41 (9)Pt1xiii—Ca1—Al1156.29 (8)
Pt1ii—Al1—Ca1x62.14 (6)Pt1—Ca1—Al191.78 (5)
Pt1iii—Al1—Ca1x62.14 (6)Al1xiv—Ca1—Al192.55 (6)
Pt1ix—Al1—Ca1x173.66 (14)Al1iv—Ca1—Al189.81 (6)
Pt1viii—Al1—Ca1xi62.19 (7)Al1xv—Ca1—Al1150.39 (11)
Pt1ii—Al1—Ca1xi165.23 (11)Al1ii—Ca1—Al1116.27 (7)
Pt1iii—Al1—Ca1xi81.55 (4)Pt1ii—Ca1—Al1xiii48.46 (5)
Pt1ix—Al1—Ca1xi63.96 (6)Pt1ix—Ca1—Al1xiii105.70 (8)
Ca1x—Al1—Ca1xi120.09 (8)Pt1xii—Ca1—Al1xiii49.65 (5)
Pt1viii—Al1—Ca1ix62.19 (7)Pt1xiii—Ca1—Al1xiii91.78 (5)
Pt1ii—Al1—Ca1ix81.55 (4)Pt1—Ca1—Al1xiii156.29 (8)
Pt1iii—Al1—Ca1ix165.23 (11)Al1xiv—Ca1—Al1xiii92.55 (6)
Pt1ix—Al1—Ca1ix63.96 (6)Al1iv—Ca1—Al1xiii150.39 (10)
Ca1x—Al1—Ca1ix120.09 (8)Al1xv—Ca1—Al1xiii89.81 (6)
Ca1xi—Al1—Ca1ix85.38 (9)Al1ii—Ca1—Al1xiii116.27 (7)
Pt1viii—Al1—Ca1ii153.94 (11)Al1—Ca1—Al1xiii80.12 (9)
Pt1ii—Al1—Ca1ii62.73 (6)Pt1ii—Ca1—Ca1xvi56.99 (5)
Pt1iii—Al1—Ca1ii62.73 (6)Pt1ix—Ca1—Ca1xvi153.54 (10)
Pt1ix—Al1—Ca1ii102.13 (11)Pt1xii—Ca1—Ca1xvi91.10 (3)
Ca1x—Al1—Ca1ii71.53 (6)Pt1xiii—Ca1—Ca1xvi53.22 (4)
Ca1xi—Al1—Ca1ii131.96 (7)Pt1—Ca1—Ca1xvi104.19 (8)
Ca1ix—Al1—Ca1ii131.96 (7)Al1xiv—Ca1—Ca1xvi140.93 (5)
Pt1viii—Al1—Ca1132.22 (7)Al1iv—Ca1—Ca1xvi151.87 (11)
Pt1ii—Al1—Ca158.71 (5)Al1xv—Ca1—Ca1xvi92.82 (5)
Pt1iii—Al1—Ca1122.54 (12)Al1ii—Ca1—Ca1xvi58.83 (7)
Pt1ix—Al1—Ca158.83 (6)Al1—Ca1—Ca1xvi104.61 (9)
Ca1x—Al1—Ca1116.88 (8)Al1xiii—Ca1—Ca1xvi57.44 (6)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y+1, z+1; (iii) x+1, y, z+1; (iv) x+1/2, y, z+1/2; (v) x+1/2, y1, z+1/2; (vi) x, y1, z; (vii) x+3/2, y+1, z+1/2; (viii) x1, y, z; (ix) x1/2, y, z+1/2; (x) x+1/2, y+1, z+1/2; (xi) x1/2, y1, z+1/2; (xii) x1/2, y+1, z+1/2; (xiii) x, y+1, z; (xiv) x+1/2, y+1, z1/2; (xv) x+1/2, y+1, z+1/2; (xvi) x+1, y+2, z+1.

Experimental details

Crystal data
Chemical formulaCaPtAl
Mr262.15
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)293
a, b, c (Å)7.1581 (14), 4.2853 (15), 7.7536 (9)
V3)237.84 (10)
Z4
Radiation typeMo Kα
µ (mm1)61.08
Crystal size (mm)0.15 × 0.08 × 0.05
Data collection
DiffractometerOxford Diffraction Xcalibur
diffractometer with Sapphire3 CCD
Absorption correctionMulti-scan
(CrysAlis RED; Oxford Diffraction, 2007)
Tmin, Tmax0.004, 0.047
No. of measured, independent and
observed [I > 2σ(I)] reflections
4413, 511, 435
Rint0.091
(sin θ/λ)max1)0.783
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.064, 1.03
No. of reflections511
No. of parameters20
Δρmax, Δρmin (e Å3)2.61, 2.95

Computer programs: CrysAlis CCD (Oxford Diffraction, 2007), CrysAlis RED (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999), WinGX (Farrugia, 1999).

 

Acknowledgements

This work was supported financially by the University of Lund (Sweden). SP thanks Professor Sven Lidin (Division of Material Chemistry, Lund University) for continuing support.

References

First citationBanenzoué, C., Ponou, S. & Lambi, J. N. (2009). Acta Cryst. E65, i90.  Web of Science CrossRef IUCr Journals Google Scholar
First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationDascoulidou-Gritner, K. & Schuster, H. U. (1994). Z. Anorg. Allg. Chem. 620, 1151–1156.  CAS Google Scholar
First citationEvers, J., Oehlinger, G., Polborn, K. & Sendlinger, B. (1992). J. Alloys Compd, 182, L23–L29.  CrossRef CAS Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationHoffmann, R.-D. & Pöttgen, R. (2001). Z. Kristallogr. 216, 127–145.  Web of Science CrossRef CAS Google Scholar
First citationHulliger, F. (1993). J. Alloys Compd, 196, 225–228.  CrossRef CAS Google Scholar
First citationKussmann, D., Hoffmann, R.-D. & Pöttgen, R. (1998). Z. Anorg. Allg. Chem. 624, 1727–1735.  CAS Google Scholar
First citationMerlo, F., Pani, M. & Fornasini, M. L. (1996). J. Alloys Compd, 232, 289–295.  CrossRef CAS Web of Science Google Scholar
First citationNuspl, G., Polborn, K., Evers, J., Landrum, G. A. & Hoffmann, R. (1996). Inorg. Chem. 35, 6922–6932.  CrossRef PubMed CAS Web of Science Google Scholar
First citationOxford Diffraction (2007). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England  Google Scholar
First citationPauling, L. (1960). The Nature of the Chemical Bond, 3rd ed. Ithaca: Cornell University Press.  Google Scholar
First citationPonou, S. (2010). Eur. J. Inorg. Chem., pp. 4139–4147.  Google Scholar
First citationPonou, S. & Lidin, S. (2008). Z. Kristallogr. New Cryst. Struct. 223, 329–330.  CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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