inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Penta­lanthanum zinc diplumbide, La5Zn1−xPb2+x (x ≃ 0.6)

aDepartment of Inorganic Chemistry, Ivan Franko Lviv National University, Kyryla i Mefodia str. 6, 79005 Lviv, Ukraine, and bDepartment of Chemistry and Materials Science Centre, Philipps University of Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
*Correspondence e-mail: romaniuk@ua.fm

(Received 11 November 2013; accepted 11 December 2013; online 18 December 2013)

The title non-stoichiometric penta­lanthanum zinc diplumbide, La5Zn1−xPb2+x (x ≃ 0.6), was prepared from the elements in an evacuated silica ampoule. It adopts the Nb5Sn2Si-type structure (space group I4/mcm, Pearson symbol tI32), a ternary ordered superstructure of the W5Si3 type. Among the four independent crystallographic positions, three are fully occupied by La (Wyckoff 16k), La (4b), and Pb (8h) and one is occupied by a statistical mixture [occupancy ratio 0.394 (12):0.606 (12)] of Zn and Pb (4a). The structure is constructed by face-sharing 10-vertex polyhedra around the unmixed Pb sites. These fragments enclose channels of trans-face-sharing tetra­gonal anti­prisms occupied by the disordered Zn and Pb sites.

Related literature

For general background to electronic structure calculations, see: Andersen et al. (1986[Andersen, K., Povlovska, Z. & Jepsen, O. (1986). Phys. Rev. B, 34, 51-53.]); Becke & Edgecombe (1990[Becke, A. D. & Edgecombe, K. E. (1990). J. Chem. Phys. 92, 5397-5403.]); Dronskowski & Blöchl (1993[Dronskowski, R. & Blöchl, P. E. (1993). J. Phys. Chem. 97, 8617-8624.]); Lange (1999[Lange, N. A. (1999). Lange's Handbook of Chemistry, 15th ed., edited by J. A. Dean, p. 317. New-York: McGraw-Hill.]); Nowak et al. (1991[Nowak, H. J., Andersen, O. K., Fujiwara, T., Jepsen, O. & Vargas, P. (1991). Phys. Rev. B, 44, 3577.]). For related structures, see: Aronsson (1955[Aronsson, B. (1955). Acta Chem. Scand. 9, 1107.]); Oshchapovsky et al. (2011a[Oshchapovsky, I., Pavlyuk, V., Dmytriv, G., Chumak, I. & Ehrenberg, H. (2011a). Acta Cryst. E67, i65.],b[Oshchapovsky, I., Pavlyuk, V., Dmytriv, G. & White, F. (2011b). Acta Cryst. E67, i43.], 2012a[Oshchapovsky, I., Pavlyuk, V., Dmytriv, G. & Griffin, A. (2012a). Acta Cryst. C68, i37-i40.],b[Oshchapovsky, I., Zelinska, O., Rozdzynska-Kielbik, B. & Pavlyuk, V. (2012b). Acta Cryst. E68, i1.]); Stetskiv et al. (2012[Stetskiv, A., Tarasiuk, I., Rozdzynska-Kielbik, B., Oshchapovsky, I. & Pavlyuk, V. (2012). Acta Cryst. E68, i16.]). For isotypic structures, see: Horyn & Lukaszewich (1970[Horyn, R. & Lukaszewich, K. (1970). Bull. Akad. Pol. Sci. Ser. Sci. Chim. 18, 59-64.]).

Experimental

Crystal data
  • La5Zn0.394Pb2.606

  • Mr = 1259.40

  • Tetragonal, I 4/m c m

  • a = 12.7630 (18) Å

  • c = 6.3680 (13) Å

  • V = 1037.3 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 63.04 mm−1

  • T = 153 K

  • 0.04 × 0.02 × 0.01 mm

Data collection
  • Bruker P4 CCD diffractometer

  • Absorption correction: multi-scan (XSCANS; Bruker, 1999) Tmin = 0.332, Tmax = 0.525

  • 3933 measured reflections

  • 365 independent reflections

  • 352 reflections with I > 2σ(I)

  • Rint = 0.122

Refinement
  • R[F2 > 2σ(F2)] = 0.024

  • wR(F2) = 0.058

  • S = 1.25

  • 352 reflections

  • 18 parameters

  • Δρmax = 2.55 e Å−3

  • Δρmin = −1.27 e Å−3

Table 1
Bond lengths, negative iCOHPa values and distance contractions in the La5Zn1−xPb2+x compound

Bond Length (δ in Å) -iCOHPa (eV) Contractionb (%) [{(r_1+r_2)-\delta \over r_1+r_2}] 100%
La1—La1 3.611 0.59 3.4
La1—La1 3.825 0.45 −2.3
La1—La1 3.997 0.40 −6.9
La1—La2 4.088 0.40 −9.3
La1—La1 4.193 0.32 −12.1
La2I—La2 3.184 1.26 14.9
       
La1—Zn4 3.365 0.26 −5.2
       
La2—Pb3 3.319 1.10 7.0
La1—Pb3 3.339 1.09 6.5
La1—Pb3 3.484 0.93 2.4
La1—Pb3 3.681 0.72 −3.1
       
Zn4—Zn4 3.184 −0.49 −19.7
Notes: (a) integrated Crystal Orbital Hamiltonian Population (see Dronskowski & Blöchl, 1993[Dronskowski, R. & Blöchl, P. E. (1993). J. Phys. Chem. 97, 8617-8624.]); calculated negative iCOHP values enable qualitative estimation of energies of two-center bonds; (b) based on metallic radii of elements R(La) = 1.86 Å R(Zn) = 1.33 Å and R(Pb) = 1.70 Å.

Data collection: XSCANS (Bruker, 1999[Bruker (1999). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: XSCANS; data reduction: XSCANS; 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, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]) and VESTA (Momma & Izumi, 2008[Momma, K. & Izumi, F. (2008). J. Appl. Cryst. 41, 653-658.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

The title compound, (I), adopts a Nb5Sn2Si (Horyn & Lukaszewich, 1970) type structure (space group I4/mcm, Pearson symbol tI32), a ternary ordered superstructure of the W5Si3 type (Aronsson, 1955). A relevant detail of the structure of (I) is presented in Fig. 1.

The coordination polyhedron of the La1 atoms is a 15-vertices polyhedron (CN=15). The nearest neighbours of La2 atoms form 14-vertices polyhedra with CN=14 (see Fig. 1a). The 10-vertices polyhedra around Pb3 can be seen as the major building block of the structure. The face-sharing 10-vertices polyhedra form a three-dimensional framework encasing channels of face-sharing tetragonal antiprisms which in turn accommodate Zn4 and Pb4 with C·N. 10 in a statistical way (see Fig. 1 b, 1c).

This work continues the investigation of {La,Tb}-Zn-{Sn,Pb} ternary systems. In previous articles the bonding interactions in the compounds LaZn4 (Oshchapovsky et al., 2012a), LaZn5 (Oshchapovsky et al., 2012b), LaZn12.37 (Oshchapovsky et al., 2011b) and TbLi1 - xZnxSn2 (Stetskiv et al., 2012) were estimated on the basis of electronic structure calculations using the TB-LMTO-ASA program package (Andersen et al., 1986; Nowak et al., 1991) with the additional implementation of two algorithms, the electron localization function (ELF) (Becke & Edgecombe, 1990) and – for quantifying nearest-neighbour bonding interactions – crystal orbital Hamilton population (COHP) (Dronskowski & Blöchl, 1993) analyses. Results arising from these analyses were put in relation to selected crystallographic data of La5Zn2Sn (Oshchapovsky et al., 2011a), namely a differential electronic density map obtained from diffraction data.

In all above mentioned compounds bonding interactions evolve similarly. Atoms of the rare-earth elements usually form metallic bonds with a certain ionic component as they donate part of their electrons to other atoms. The atoms of d- and p-metals, namely zinc and tin, accept these electrons used for covalent bonds among each other. This outcome can be easily explained by the higher electronegativity of zinc and tin compared with rare-earth and alkaline metals (Lange, 1999). Judged on the basis of integrated COHP, (iCOHP) values, R-{Zn,Sn} bonds are significantly weaker than {Zn,Sn}-{Zn,Sn} bonds. Latter mostly show significant bond length contraction compared to the next contacts in the elemental metals. The differential electronic density map of the structure of La5Zn2Sn, obtained from experimental diffraction data, indicate donation of electrons to zinc and tin atoms in the similar way as in other compounds, for which electronic structure calculations were performed.

The results of electronic structure calculations for (I) are given in Fig. 2 and 3. As an algorithm for calculating electronic structures for substances with mixed-occupied sites is not implemented in TB-LMTO-ASA package, a fictitious, crystallographically ordered phase was introduced by assuming the statistically occupied Zn/Pb site solely occupied by Zn without change of other crystallographic data.

Similar to R—Zn binary and R—Zn—Sn ternary compounds, large values of the electron localization function (ELF) around Pb3 and Zn4 (originally mixed-occupied) are found. In accordance with similar results for previously cited, structurally related compounds, these findings are interpreted as resulting from donation of electrons from lanthanum atoms to zinc and lead atoms (see Fig. 2a,b).

The values of ELF around Pb3 atoms are significantly larger than around Zn4 atoms, which indicate that bonds between Pb3 and their neighbours should be significantly stronger than bonds between Zn4 atoms and their neighbours. The calculated iCOHP values enable qualitative estimation of energies of two-center bonds and confirm previous assumption. Negative values of iCOHP together with bond lengths and bond contractions are given in Table.

The DOS plot indicates metallic conductivity for the ordered model compound (see Fig. 3a) with small dip at -1 eV relative to Fermi level. Based on a rigid band approximation it can be suggested that these features don't change qualitatively for the title compound. A small dip in the DOS plot near Fermi level could be indirect proof of donation of electrons from lanthanum atoms towards zinc and lead atoms.

The graph negative iCOHP values versus. distance contraction shown in Fig. 3 b substantiates the assumption that the polyhedra around Pb3 are indeed the building blocks of the structure if seen as condensed into the given three-dimensional framework by sharing faces. Apparently, this interpretation is not only useful from a crystallographic point of view but also supported by the hierarchy of bonding interactions in the solid: La—Pb bonds are stronger and show larger distance contractions than most La—La bonds. An exception is the particularly strong La2IX—La2X bond enhancing the stability of the framework by connecting adjacent building blocks.

Related literature top

For general background, see: Andersen et al. (1986); Becke & Edgecombe (1990); Dronskowski & Blöchl (1993); Lange (1999); Nowak et al. (1991). For related structures, see: Aronsson (1955); Oshchapovsky et al. (2011a,b, 2012a,b); Stetskiv et al. (2012). For isostructural/isotypic structures, see: Horyn & Lukaszewich (1970).

Experimental top

A small irregular grey single-crystal of the title compound of suitable quality was isolated from an alloy with composition La7ZnPb2 prepared in the course of a systematic investigation of the ternary La—Zn—Pb system. The preparation process was according to that described for La5Zn2Sn (Oshchapovsky et al., 2011a).

The sample was prepared by melting pieces of pure metals (99.9% La, 99.999% Zn, 99.99% Pb) in an evacuated silica ampoule in a resistance furnace with subsequent annealing at 600°C for 30 days. Final phase analysis revealed the presence of the title compound in samples with composition La7ZnPb2 together with other lanthanum-rich ternary alloys. The latter samples, however, had not reached completely the liquid state, since the use of silica ampoules constraints the maximum temperature to 900°C. This limitation may hamper complete equilibration of the sample.

Refinement top

The fractional site occupancies of Pb4 and Zn4 were constrained to sum to unity.

Computing details top

Data collection: XSCANS (Bruker, 1999); cell refinement: XSCANS (Bruker, 1999); data reduction: XSCANS (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006) and VESTA (Momma & Izumi, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Details of the crystal structure of La5Zn1 - xPb2 + x: Projection of the unit cell and coordination polyhedra (a); building blocks (b); channels in the structure (c).
[Figure 2] Fig. 2. Results of ELF calculations for the La5Zn1 - xPb2 + xcompound: Isosurfaces drawn at 0.45 level (a); section [001] drawn at z=1/2 (b).
[Figure 3] Fig. 3. Density of states plot (a); Comparison of bond contractions and -iCOHP values in the title compound (b).
Pentalanthanum zinc diplumbide top
Crystal data top
La5Pb2.606Zn0.394Dx = 8.068 Mg m3
Mr = 1259.40Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I4/mcmCell parameters from 3933 reflections
Hall symbol: -I 4 2cθ = 4.5–27.9°
a = 12.7630 (18) ŵ = 63.04 mm1
c = 6.3680 (13) ÅT = 153 K
V = 1037.3 (3) Å3Irregularly shaped, metallic grey
Z = 40.04 × 0.02 × 0.01 mm
F(000) = 2041.6
Data collection top
Bruker P4 CCD
diffractometer
365 independent reflections
Radiation source: fine-focus sealed tube352 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.122
ω scansθmax = 27.9°, θmin = 4.5°
Absorption correction: multi-scan
(XSCANS; Bruker, 1999)
h = 1616
Tmin = 0.332, Tmax = 0.525k = 1516
3933 measured reflectionsl = 88
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)] = 0.024 w = 1/[σ2(Fo2) + 23.7905P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.058(Δ/σ)max = 0.012
S = 1.25Δρmax = 2.55 e Å3
352 reflectionsΔρmin = 1.27 e Å3
18 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 3948 (389)
Crystal data top
La5Pb2.606Zn0.394Z = 4
Mr = 1259.40Mo Kα radiation
Tetragonal, I4/mcmµ = 63.04 mm1
a = 12.7630 (18) ÅT = 153 K
c = 6.3680 (13) Å0.04 × 0.02 × 0.01 mm
V = 1037.3 (3) Å3
Data collection top
Bruker P4 CCD
diffractometer
365 independent reflections
Absorption correction: multi-scan
(XSCANS; Bruker, 1999)
352 reflections with I > 2σ(I)
Tmin = 0.332, Tmax = 0.525Rint = 0.122
3933 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0240 restraints
wR(F2) = 0.058 w = 1/[σ2(Fo2) + 23.7905P]
where P = (Fo2 + 2Fc2)/3
S = 1.25Δρmax = 2.55 e Å3
352 reflectionsΔρmin = 1.27 e Å3
18 parameters
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*/UeqOcc. (<1)
La10.08312 (9)0.21698 (9)0.00000.0229 (4)
La20.00000.50000.25000.0188 (6)
Pb30.16124 (5)0.66124 (5)0.00000.0187 (4)
Pb40.00000.00000.25000.0231 (9)0.606 (12)
Zn40.00000.00000.25000.0231 (9)0.394 (12)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
La10.0150 (6)0.0150 (6)0.0386 (9)0.0005 (4)0.0000.000
La20.0171 (6)0.0171 (6)0.0222 (12)0.0000.0000.000
Pb30.0137 (4)0.0137 (4)0.0287 (7)0.0013 (3)0.0000.000
Pb40.0142 (8)0.0142 (8)0.0410 (16)0.0000.0000.000
Zn40.0142 (8)0.0142 (8)0.0410 (16)0.0000.0000.000
Geometric parameters (Å, º) top
La1—Pb3i3.3394 (14)La2—La1iii4.0875 (12)
La1—Zn4ii3.3658 (11)Pb3—La2iii3.3173 (9)
La1—Pb4ii3.3658 (11)Pb3—La1xiv3.3394 (14)
La1—Pb43.3658 (11)Pb3—La1xv3.3394 (14)
La1—Pb3iii3.4846 (12)Pb3—La1iii3.4846 (12)
La1—La1iv3.608 (2)Pb3—La1iv3.4846 (12)
La1—Pb3v3.6807 (8)Pb3—La1xii3.6807 (8)
La1—Pb3vi3.6807 (8)Pb3—La1xvi3.6807 (8)
La1—La1vii3.8261 (13)Pb3—La1xi3.6807 (8)
La1—La1viii3.8261 (13)Pb3—La1xvii3.6807 (8)
La1—La1ix3.9969 (14)Pb4—Zn4xviii3.1840 (7)
La2—La2x3.1840 (7)Pb4—Zn4ii3.1840 (6)
La2—La2iii3.1840 (6)Pb4—Pb4xviii3.1840 (7)
La2—Pb3iii3.3173 (9)Pb4—Pb4ii3.1840 (6)
La2—Pb33.3173 (9)Pb4—La1xix3.3658 (11)
La2—Pb3v3.3173 (9)Pb4—La1ii3.3658 (11)
La2—Pb3xi3.3173 (9)Pb4—La1viii3.3658 (11)
La2—La1xii4.0875 (12)Pb4—La1xx3.3658 (11)
La2—La1xi4.0875 (12)Pb4—La1xxi3.3658 (11)
La2—La1xiii4.0875 (12)Pb4—La1xxii3.3658 (11)
La2—La1v4.0875 (12)Pb4—La1xxiii3.3658 (11)
Pb3i—La1—Zn4ii97.62 (3)La1xii—La2—La1149.92 (3)
Pb3i—La1—Pb4ii97.62 (3)La1xi—La2—La198.725 (6)
Zn4ii—La1—Pb4ii0.0La1xiii—La2—La1107.88 (3)
Pb3i—La1—Pb497.62 (3)La1v—La2—La198.725 (6)
Zn4ii—La1—Pb456.46 (2)La1iii—La2—La1134.156 (16)
Pb4ii—La1—Pb456.46 (2)La2iii—Pb3—La257.36 (2)
Pb3i—La1—Pb3iii165.81 (4)La2iii—Pb3—La1xiv137.584 (15)
Zn4ii—La1—Pb3iii94.87 (3)La2—Pb3—La1xiv137.584 (15)
Pb4ii—La1—Pb3iii94.87 (3)La2iii—Pb3—La1xv137.584 (15)
Pb4—La1—Pb3iii94.87 (3)La2—Pb3—La1xv137.584 (15)
Pb3i—La1—La1iv57.30 (2)La1xiv—Pb3—La1xv65.40 (4)
Zn4ii—La1—La1iv143.576 (15)La2iii—Pb3—La1iii73.83 (2)
Pb4ii—La1—La1iv143.576 (15)La2—Pb3—La1iii73.83 (2)
Pb4—La1—La1iv143.576 (15)La1xiv—Pb3—La1iii75.81 (4)
Pb3iii—La1—La1iv108.51 (2)La1xv—Pb3—La1iii141.21 (2)
Pb3i—La1—Pb3v79.94 (3)La2iii—Pb3—La1iv73.83 (2)
Zn4ii—La1—Pb3v147.35 (3)La2—Pb3—La1iv73.83 (2)
Pb4ii—La1—Pb3v147.35 (3)La1xiv—Pb3—La1iv141.21 (2)
Pb4—La1—Pb3v91.356 (15)La1xv—Pb3—La1iv75.81 (4)
Pb3iii—La1—Pb3v93.10 (3)La1iii—Pb3—La1iv142.98 (5)
La1iv—La1—Pb3v60.650 (17)La2iii—Pb3—La1xii120.60 (3)
Pb3i—La1—Pb3vi79.94 (3)La2—Pb3—La1xii71.26 (2)
Zn4ii—La1—Pb3vi91.356 (15)La1xiv—Pb3—La1xii69.21 (3)
Pb4ii—La1—Pb3vi91.356 (15)La1xv—Pb3—La1xii100.06 (3)
Pb4—La1—Pb3vi147.35 (3)La1iii—Pb3—La1xii64.48 (2)
Pb3iii—La1—Pb3vi93.10 (3)La1iv—Pb3—La1xii119.919 (19)
La1iv—La1—Pb3vi60.650 (17)La2iii—Pb3—La1xvi71.26 (2)
Pb3v—La1—Pb3vi119.78 (3)La2—Pb3—La1xvi120.60 (3)
Pb3i—La1—La1vii122.81 (3)La1xiv—Pb3—La1xvi69.21 (3)
Zn4ii—La1—La1vii55.363 (14)La1xv—Pb3—La1xvi100.06 (3)
Pb4ii—La1—La1vii55.363 (14)La1iii—Pb3—La1xvi64.48 (2)
Pb4—La1—La1vii102.64 (3)La1iv—Pb3—La1xvi119.919 (19)
Pb3iii—La1—La1vii60.24 (3)La1xii—Pb3—La1xvi119.78 (3)
La1iv—La1—La1vii113.086 (18)La2iii—Pb3—La1xi120.60 (3)
Pb3v—La1—La1vii150.47 (3)La2—Pb3—La1xi71.26 (2)
Pb3vi—La1—La1vii55.274 (16)La1xiv—Pb3—La1xi100.06 (3)
Pb3i—La1—La1viii122.81 (3)La1xv—Pb3—La1xi69.21 (3)
Zn4ii—La1—La1viii102.64 (3)La1iii—Pb3—La1xi119.919 (19)
Pb4ii—La1—La1viii102.64 (3)La1iv—Pb3—La1xi64.48 (2)
Pb4—La1—La1viii55.363 (14)La1xii—Pb3—La1xi58.70 (3)
Pb3iii—La1—La1viii60.24 (3)La1xvi—Pb3—La1xi167.71 (4)
La1iv—La1—La1viii113.086 (18)La2iii—Pb3—La1xvii71.26 (2)
Pb3v—La1—La1viii55.274 (16)La2—Pb3—La1xvii120.60 (3)
Pb3vi—La1—La1viii150.47 (3)La1xiv—Pb3—La1xvii100.06 (3)
La1vii—La1—La1viii112.64 (6)La1xv—Pb3—La1xvii69.21 (3)
Pb3i—La1—La1ix59.42 (3)La1iii—Pb3—La1xvii119.919 (19)
Zn4ii—La1—La1ix53.576 (15)La1iv—Pb3—La1xvii64.48 (2)
Pb4ii—La1—La1ix53.576 (15)La1xii—Pb3—La1xvii167.71 (4)
Pb4—La1—La1ix99.20 (3)La1xvi—Pb3—La1xvii58.70 (3)
Pb3iii—La1—La1ix124.98 (2)La1xi—Pb3—La1xvii119.78 (3)
La1iv—La1—La1ix90.0Zn4xviii—Pb4—Zn4ii180.0
Pb3v—La1—La1ix138.92 (3)Zn4xviii—Pb4—Pb4xviii0.0
Pb3vi—La1—La1ix51.362 (18)Zn4ii—Pb4—Pb4xviii180.0
La1vii—La1—La1ix64.79 (2)Zn4xviii—Pb4—Pb4ii180.0
La1viii—La1—La1ix154.150 (9)Zn4ii—Pb4—Pb4ii0.0
La2x—La2—La2iii180.0Pb4xviii—Pb4—Pb4ii180.0
La2x—La2—Pb3iii118.679 (10)Zn4xviii—Pb4—La1xix61.771 (11)
La2iii—La2—Pb3iii61.321 (10)Zn4ii—Pb4—La1xix118.229 (11)
La2x—La2—Pb3118.679 (10)Pb4xviii—Pb4—La1xix61.771 (11)
La2iii—La2—Pb361.321 (10)Pb4ii—Pb4—La1xix118.229 (11)
Pb3iii—La2—Pb3122.64 (2)Zn4xviii—Pb4—La1ii118.229 (11)
La2x—La2—Pb3v61.321 (10)Zn4ii—Pb4—La1ii61.771 (11)
La2iii—La2—Pb3v118.679 (10)Pb4xviii—Pb4—La1ii118.229 (11)
Pb3iii—La2—Pb3v103.315 (9)Pb4ii—Pb4—La1ii61.771 (11)
Pb3—La2—Pb3v103.315 (9)La1xix—Pb4—La1ii137.93 (4)
La2x—La2—Pb3xi61.321 (10)Zn4xviii—Pb4—La1viii61.771 (11)
La2iii—La2—Pb3xi118.679 (10)Zn4ii—Pb4—La1viii118.229 (11)
Pb3iii—La2—Pb3xi103.315 (9)Pb4xviii—Pb4—La1viii61.771 (11)
Pb3—La2—Pb3xi103.315 (9)Pb4ii—Pb4—La1viii118.229 (11)
Pb3v—La2—Pb3xi122.64 (2)La1xix—Pb4—La1viii77.072 (9)
La2x—La2—La1xii67.078 (8)La1ii—Pb4—La1viii143.26 (4)
La2iii—La2—La1xii112.922 (8)Zn4xviii—Pb4—La1118.229 (11)
Pb3iii—La2—La1xii153.655 (15)Zn4ii—Pb4—La161.771 (11)
Pb3—La2—La1xii58.513 (15)Pb4xviii—Pb4—La1118.229 (11)
Pb3v—La2—La1xii101.555 (15)Pb4ii—Pb4—La161.771 (11)
Pb3xi—La2—La1xii54.961 (15)La1xix—Pb4—La172.85 (3)
La2x—La2—La1xi67.078 (8)La1ii—Pb4—La1123.54 (2)
La2iii—La2—La1xi112.922 (8)La1viii—Pb4—La169.27 (3)
Pb3iii—La2—La1xi153.655 (15)Zn4xviii—Pb4—La1xx118.229 (11)
Pb3—La2—La1xi58.513 (15)Zn4ii—Pb4—La1xx61.771 (11)
Pb3v—La2—La1xi54.961 (15)Pb4xviii—Pb4—La1xx118.229 (11)
Pb3xi—La2—La1xi101.555 (15)Pb4ii—Pb4—La1xx61.771 (11)
La1xii—La2—La1xi52.38 (3)La1xix—Pb4—La1xx69.27 (3)
La2x—La2—La1xiii112.922 (8)La1ii—Pb4—La1xx77.072 (9)
La2iii—La2—La1xiii67.078 (8)La1viii—Pb4—La1xx137.93 (4)
Pb3iii—La2—La1xiii54.961 (15)La1—Pb4—La1xx77.072 (9)
Pb3—La2—La1xiii101.555 (15)Zn4xviii—Pb4—La1xxi118.229 (11)
Pb3v—La2—La1xiii153.655 (15)Zn4ii—Pb4—La1xxi61.771 (11)
Pb3xi—La2—La1xiii58.513 (15)Pb4xviii—Pb4—La1xxi118.229 (11)
La1xii—La2—La1xiii98.725 (6)Pb4ii—Pb4—La1xxi61.771 (11)
La1xi—La2—La1xiii149.92 (3)La1xix—Pb4—La1xxi143.26 (4)
La2x—La2—La1v67.078 (8)La1ii—Pb4—La1xxi77.072 (9)
La2iii—La2—La1v112.922 (8)La1viii—Pb4—La1xxi72.85 (3)
Pb3iii—La2—La1v58.513 (15)La1—Pb4—La1xxi77.072 (10)
Pb3—La2—La1v153.655 (15)La1xx—Pb4—La1xxi123.54 (2)
Pb3v—La2—La1v101.555 (15)Zn4xviii—Pb4—La1xxii61.771 (11)
Pb3xi—La2—La1v54.961 (15)Zn4ii—Pb4—La1xxii118.229 (11)
La1xii—La2—La1v107.88 (3)Pb4xviii—Pb4—La1xxii61.771 (11)
La1xi—La2—La1v134.156 (16)Pb4ii—Pb4—La1xxii118.229 (11)
La1xiii—La2—La1v55.81 (2)La1xix—Pb4—La1xxii123.54 (2)
La2x—La2—La1iii112.922 (8)La1ii—Pb4—La1xxii72.85 (3)
La2iii—La2—La1iii67.078 (8)La1viii—Pb4—La1xxii77.072 (9)
Pb3iii—La2—La1iii101.555 (15)La1—Pb4—La1xxii137.93 (4)
Pb3—La2—La1iii54.961 (15)La1xx—Pb4—La1xxii143.26 (4)
Pb3v—La2—La1iii153.655 (15)La1xxi—Pb4—La1xxii69.27 (3)
Pb3xi—La2—La1iii58.513 (15)Zn4xviii—Pb4—La1xxiii61.771 (11)
La1xii—La2—La1iii55.81 (2)Zn4ii—Pb4—La1xxiii118.229 (11)
La1xi—La2—La1iii98.725 (6)Pb4xviii—Pb4—La1xxiii61.771 (11)
La1xiii—La2—La1iii52.38 (3)Pb4ii—Pb4—La1xxiii118.229 (11)
La1v—La2—La1iii98.725 (6)La1xix—Pb4—La1xxiii77.072 (9)
La2x—La2—La1112.922 (8)La1ii—Pb4—La1xxiii69.27 (3)
La2iii—La2—La167.078 (8)La1viii—Pb4—La1xxiii123.54 (2)
Pb3iii—La2—La154.961 (15)La1—Pb4—La1xxiii143.26 (4)
Pb3—La2—La1101.555 (15)La1xx—Pb4—La1xxiii72.85 (3)
Pb3v—La2—La158.513 (15)La1xxi—Pb4—La1xxiii137.93 (4)
Pb3xi—La2—La1153.655 (15)La1xxii—Pb4—La1xxiii77.072 (9)
Symmetry codes: (i) y+1, x, z; (ii) x, y, z; (iii) x, y+1, z; (iv) y+1/2, x+1/2, z; (v) y1/2, x+1/2, z+1/2; (vi) y1/2, x+1/2, z1/2; (vii) x, y, z1/2; (viii) x, y, z+1/2; (ix) y, x, z1/2; (x) x, y+1, z+1; (xi) y+1/2, x+1/2, z+1/2; (xii) x, y+1, z+1/2; (xiii) y1/2, x+1/2, z; (xiv) y, x+1, z; (xv) x+1/2, y+1/2, z; (xvi) x, y+1, z1/2; (xvii) y+1/2, x+1/2, z1/2; (xviii) x, y, z+1; (xix) y, x, z+1/2; (xx) y, x, z; (xxi) y, x, z; (xxii) y, x, z+1/2; (xxiii) x, y, z+1/2.

Experimental details

Crystal data
Chemical formulaLa5Pb2.606Zn0.394
Mr1259.40
Crystal system, space groupTetragonal, I4/mcm
Temperature (K)153
a, c (Å)12.7630 (18), 6.3680 (13)
V3)1037.3 (3)
Z4
Radiation typeMo Kα
µ (mm1)63.04
Crystal size (mm)0.04 × 0.02 × 0.01
Data collection
DiffractometerBruker P4 CCD
diffractometer
Absorption correctionMulti-scan
(XSCANS; Bruker, 1999)
Tmin, Tmax0.332, 0.525
No. of measured, independent and
observed [I > 2σ(I)] reflections
3933, 365, 352
Rint0.122
(sin θ/λ)max1)0.658
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.058, 1.25
No. of reflections352
No. of parameters18
w = 1/[σ2(Fo2) + 23.7905P]
where P = (Fo2 + 2Fc2)/3
Δρmax, Δρmin (e Å3)2.55, 1.27

Computer programs: XSCANS (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006) and VESTA (Momma & Izumi, 2008), publCIF (Westrip, 2010).

Bond lengths, negative iCOHPa values and distance contractions in the La5Zn1-xPb2+x compound top
BondLength (Å)-iCOHPa (eV)Contractionb (%) (r1+r2) - δ - 100%r1+r2
La1I—La1VII3.6110.593.4
La1I—La1V3.8250.45-2.3
La1I—La1VIII3.9970.40-6.9
La1I—La2IX4.0880.40-9.3
La1I—La2IX4.0880.40-9.3
La1I—La1III4.1930.32-12.1
La1I—La1IV4.1930.32-12.1
La2IX—La2X3.1841.2614.9
La2IX—La1II4.0880.40-9.3
La2IX—La1III4.0880.40-9.3
La2IX—La1IV4.0880.40-9.3
La2IX—La1V4.0880.40-9.3
La2IX—La1VI4.0880.40-9.3
La2IX—La1VII4.0880.40-9.3
La2IX—La1VIII4.0880.40-9.3
La1I—Zn4XV3.3650.26-5.2
La1I—Zn4XVI3.3650.26-5.2
La1II—Zn4XV3.3650.26-5.2
La1III—Zn4XV3.3650.26-5.2
La1IV—Zn4XV3.3650.26-5.2
La1V—Zn4XV3.3650.26-5.2
La1VI—Zn4XV3.3650.26-5.2
La1VII—Zn4XV3.3650.26-5.2
La1VIII—Zn4XV3.3650.26-5.2
La2IX—Pb3XI3.3191.107.0
La2IX—Pb3XII3.3191.107.0
La2IX—Pb3XIII3.3191.107.0
La2IX—Pb3XIV3.3191.107.0
La2X—Pb3XI3.3191.107.0
La1III—Pb3XI3.3391.096.5
La1VI—Pb3XI3.3391.096.5
La1VIII—Pb3XI3.4840.932.4
La1IV—Pb3XI3.6810.72-3.1
La1V—Pb3XI3.6810.72-3.1
Zn4XV—Zn4XVI3.184-0.49-19.7
(a) integrated Crystal Orbital Hamiltonian Population. See (Dronskowski & Blöchl, 1993).
Calculated negative iCOHP values enable qualitative estimation of energies of two-center bonds.
(b) is based on metallic radii of elements R(La)=1.86 Å R(Zn)=1.33 Å R(Pb)=1.70 Å.
 

Footnotes

Also at Institute of Chemistry and Environmental Protection, Jan Dlugosz University, Armii Krajowej 13/15 Ave., 42-200 Czestochowa, Poland

Acknowledgements

This work was performed with support of the DAAD stipendium programme for PhD students, postdoctoral students and young scientists.

References

First citationAndersen, K., Povlovska, Z. & Jepsen, O. (1986). Phys. Rev. B, 34, 51–53.  CrossRef Web of Science
First citationAronsson, B. (1955). Acta Chem. Scand. 9, 1107.  CrossRef Web of Science
First citationBecke, A. D. & Edgecombe, K. E. (1990). J. Chem. Phys. 92, 5397–5403.  CrossRef CAS Web of Science
First citationBrandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.
First citationBruker (1999). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationDronskowski, R. & Blöchl, P. E. (1993). J. Phys. Chem. 97, 8617–8624.  CrossRef CAS Web of Science
First citationHoryn, R. & Lukaszewich, K. (1970). Bull. Akad. Pol. Sci. Ser. Sci. Chim. 18, 59–64.  CAS
First citationLange, N. A. (1999). Lange's Handbook of Chemistry, 15th ed., edited by J. A. Dean, p. 317. New-York: McGraw–Hill.
First citationMomma, K. & Izumi, F. (2008). J. Appl. Cryst. 41, 653–658.  Web of Science CrossRef CAS IUCr Journals
First citationNowak, H. J., Andersen, O. K., Fujiwara, T., Jepsen, O. & Vargas, P. (1991). Phys. Rev. B, 44, 3577.  CrossRef Web of Science
First citationOshchapovsky, I., Pavlyuk, V., Dmytriv, G., Chumak, I. & Ehrenberg, H. (2011a). Acta Cryst. E67, i65.  Web of Science CrossRef IUCr Journals
First citationOshchapovsky, I., Pavlyuk, V., Dmytriv, G. & Griffin, A. (2012a). Acta Cryst. C68, i37–i40.  Web of Science CrossRef CAS IUCr Journals
First citationOshchapovsky, I., Pavlyuk, V., Dmytriv, G. & White, F. (2011b). Acta Cryst. E67, i43.  Web of Science CrossRef IUCr Journals
First citationOshchapovsky, I., Zelinska, O., Rozdzynska-Kielbik, B. & Pavlyuk, V. (2012b). Acta Cryst. E68, i1.  Web of Science CrossRef IUCr Journals
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationStetskiv, A., Tarasiuk, I., Rozdzynska-Kielbik, B., Oshchapovsky, I. & Pavlyuk, V. (2012). Acta Cryst. E68, i16.  Web of Science CrossRef IUCr Journals
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds