The lanthanum(III) molybdate(VI) La4Mo7O27

Wolf, B. van der; Held, P.; Becker, P.

doi:10.1107/S1600536809026415

inorganic compounds

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Volume 65| Part 8| August 2009| Page i59

doi:10.1107/S1600536809026415

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The lanthanum(III) molybdate(VI) La₄Mo₇O₂₇

Benjamin van der Wolf,^a ^* Peter Held ^a and Petra Becker ^a

^aInstitute of Crystallography, University of Cologne, 50674 Cologne, Germany
^*Correspondence e-mail: bvdwolf@uni-koeln.de

(Received 22 June 2009; accepted 7 July 2009; online 11 July 2009)

Crystals of the orthorhombic phase La₄Mo₇O₂₇ (lanthanum molybdenum oxide) were obtained from a non-stoichiometric melt in the pseudo-ternary system La₂O₃–MoO₃–B₂O₃. In the crystal structure, distorted square-antiprismatic [LaO₈] and monocapped square-antiprismatic [LaO₉] polyhedra are connected via common edges and faces into chains along [010]. These chains are arranged in layers that alternate with layers of [MoO₄] and [MoO₅] polyhedra parallel to (001). In the molybdate layers, a distorted [MoO₅] trigonal bipyramid is axially connected to two [MoO₄] tetrahedra, forming a [Mo₃O₁₁] unit.

Related literature

The isoformular compounds Eu₄Mo₇O₂₇ (Naruke & Yamase, 2001 ) and Gd₄Mo₇O₂₇ (Naruke & Yamase, 2002 ) have a similar structure, but have monoclinic symmetry. Parameters needed to calculate bond-valence sums from bond lengths were taken from Brown & Altermatt (1985 ).

Experimental

Crystal data

La₄Mo₇O₂₇
M_r = 1659.22
Orthorhombic, P c a 2₁
a = 14.1443 (14) Å
b = 7.2931 (4) Å
c = 22.9916 (13) Å
V = 2371.7 (3) Å³
Z = 4
Mo Kα radiation
μ = 10.71 mm⁻¹
T = 295 K
0.25 × 0.23 × 0.22 mm

Data collection

Nonius MACH3 diffractometer
Absorption correction: ψ scan (MolEN; Fair, 1990 ) T_min = 0.841, T_max = 0.999 (expected range = 0.080–0.095)
17773 measured reflections
7202 independent reflections
6225 reflections with I > 2σ(I)
R_int = 0.042
3 standard reflections every 100 reflections intensity decay: −4.1%

Refinement

R[F² > 2σ(F²)] = 0.028
wR(F²) = 0.076
S = 1.05
7202 reflections
345 parameters
1 restraint
Δρ_max = 2.27 e Å⁻³
Δρ_min = −1.35 e Å⁻³
Absolute structure: Flack (1983 ), 3515 Friedel pairs
Flack parameter: 0.039 (14)

Data collection: MACH3 (Enraf–Nonius, 1993 ); cell refinement: MACH3; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2005 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809026415/wm2242sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809026415/wm2242Isup2.hkl

checkCIF report

Comment top

The framework structure of La₄Mo₇O₂₇ (Fig. 1) can be described as a layered arrangement of alternating [LaO₈] and [LaO₉] polyhedra and of [MoO₄] and [MoO₅] polyhedra parallel to (001). Perpendicular to this layered arrangement the [LaO₈] and [LaO₉] polyhedra are connected via edge- and face-sharing to form chains along [010]. The chains are interconnected via [MoO₄] tetrahedra with an interchain distance of 1/2a = 7.072 Å. A similar layered arrangement of alternating [REO₇] and [REO₈] (RE = Eu, Gd) and of [MoO₄] and [MoO₅] polyhedra is present in the crystal strucures of Eu₄Mo₇O₂₇ (Naruke & Yamase, 2001) and Gd₄Mo₇O₂₇ (Naruke & Yamase, 2002). However, in the latter structures the rare earth oxygen polyhedra dimerize to [RE₂O₁₂] and [RE₂O₁₃] (RE = Eu, Gd) groups instead of forming chains. All four lanthanum atoms in La₄Mo₇O₂₇ are found with a square-antiprismatic [LaO₈] oxygen surrounding. In case of La1 and La3, this unit is monocapped to form a [LaO₉] polyhedron, in case of La2 a more irregular but also monocapped (with O33) [LaO₉] polyhedron may still be recognized, while La4 has a square-antiprismatic environment with two axial oxygen atoms O11 (La—O = 3.317 (6) Å) and O53 (La— O = 3.423 (7) Å) which we have not considered to be part of the La4 coordination polyhedron. Thereby, O53 is the only terminal oxygen atom connected to Mo5 only, but calculations of the bond valence sums (Brown & Altermatt, 1985) with 1.73 v.u. for the O53—Mo5 bond indicate no discrepancies and it can be assumed that the remaining bond charge is smeared out over farther atoms. The four molybdenum atoms Mo1, Mo4, Mo3, Mo6 are tetrahedrally surrounded by oxygen atoms resulting in [MoO₄] tetrahedra with Mo—O distances ranging from 1.723 (7) to 1.805 (6) Å. These polyhedra are connected to [LaO₈] or [LaO₉] polyhedra via corner- or edge-sharing. This is also the case for Mo5 and Mo7, which are tetrahedrally surrounded and connected to [LaO₈] or [LaO₉] via corner-sharing only, but connected to Mo2 as well, which is fivefold surrounded to form a distorted trigonal bipyramid. Overall, this results in a [Mo₃O₁₁] unit (Fig. 2) with a corner-shared connection of the three equatorial oxygen atoms in the trigonal bipyramid to [LaO₈] or [LaO₉] polyhedra. In the trigonal bipyramid, the axial oxygen atom O52 has the longest Mo—O distance of 2.100 (6) Å in the structure, but bond valence sum calculations do suggest a trigonal-bipyramidal Mo2 surrounding with a resulting bond valence sum for the bonds Mo2—O21, O22, O23, O24 of 5.44 v.u., and when including also O52 of 6.04 v.u. In both Eu₄Mo₇O₂₇ and Gd₄Mo₇O₂₇ structures a similar [Mo₃O₁₁] unit is present, but here the two tetrahedrally surrounded molybdenum atoms are connected via one axial and one equatorial oxygen atom of the trigonal bipyramidal coordination polyhedron of the central molybdenum atom.

Related literature top

The isoformular compounds Eu₄Mo₇O₂₇ (Naruke & Yamase, 2001) and Gd₄Mo₇O₂₇ (Naruke & Yamase, 2002) have a similar structure, but have monoclinic symmetry. Parameters needed to calculate bond-valence sums from bond lengths were taken from Brown & Altermatt (1985).

Experimental top

Single crystals of La₄Mo₇O₂₇ of ca 0.01 mm³ in volume were synthesized by heating a homogenized powder mixture of La₂O₃ (99.99%, Chempur), H₃BO₃ (99.8%, Merck) and MoO₃ (99.95%, Alfa Aesar) in a molar ratio of 0.16: 0.16: 0.68 in a covered platinum crucible in air atmosphere to 1023 K. After 95 h at this temperature the sample was quenched in air, washed with water, heated to 1100 K, cooled with 0.0013 K/min to 1093 K and quenched again in air. After a further similar heating-cooling cycle, colourless clear crystals of La₄Mo₇O₂₇ were obtained and separated mechanically from the solidified melt.

Computing details top

Data collection: MACH3 (Enraf–Nonius, 1993); cell refinement: MACH3 (Enraf–Nonius, 1993); data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. Fragment of the crystal structure of La₄Mo₇O₂₇. Atoms are indicated as ellipsoids with probability regions of 50%. [Symmetry codes: (i) -x+1,-y,z+1/2; (ii) -x+1, -y-1, z+1/2; (iii) -x+3/2, y, z+1/2; (iv) x, y+1, z; (v) x, y-1, z; (vi) x-1/2, -y-1, z; (vii) x-1/2, -y, z; (viii) -x+3/2, y-1, z+1/2; (ix) x+1/2, -y, z; (x) x+1/2, -y-1, z.]
	Fig. 2. The trigonal-bipyramidal oxygen surrounding of Mo2. The two apical oxygen atoms are linked via corner-sharing to the tetrahedrally surrounded Mo5 and Mo7 atoms, forming a [Mo₃O₁₁] unit. Ellipsoid probability regions of 50% are given.

Lanthanum molybdate oxide top

Crystal data top

La₄Mo₇O₂₇	F(000) = 2952
M_r = 1659.22	D_x = 4.647 Mg m⁻³
Orthorhombic, Pca2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 25 reflections
a = 14.1443 (14) Å	θ = 20.8–27.4°
b = 7.2931 (4) Å	µ = 10.71 mm⁻¹
c = 22.9916 (13) Å	T = 295 K
V = 2371.7 (3) Å³	Prism, colourless
Z = 4	0.25 × 0.23 × 0.22 mm

Data collection top

Nonius MACH3 diffractometer	6225 reflections with I > 2σ(I)
Radiation source: fine-focus sealed X-ray tube	R_int = 0.042
Graphite monochromator	θ_max = 30.4°, θ_min = 2.8°
ω/2θ scans	h = −20→20
Absorption correction: ψ scan (MolEN; Fair, 1990)	k = −10→10
T_min = 0.841, T_max = 0.999	l = −32→32
17773 measured reflections	3 standard reflections every 100 reflections
7202 independent reflections	intensity decay: −4.1%

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[σ²(F_o²) + (0.04P)² + 3.1563P] where P = (F_o² + 2F_c²)/3
R[F² > 2σ(F²)] = 0.028	(Δ/σ)_max = 0.001
wR(F²) = 0.076	Δρ_max = 2.27 e Å⁻³
S = 1.05	Δρ_min = −1.35 e Å⁻³
7202 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
345 parameters	Extinction coefficient: 0.00021 (2)
1 restraint	Absolute structure: Flack (1983), 3515 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.039 (14)

Crystal data top

La₄Mo₇O₂₇	V = 2371.7 (3) Å³
M_r = 1659.22	Z = 4
Orthorhombic, Pca2₁	Mo Kα radiation
a = 14.1443 (14) Å	µ = 10.71 mm⁻¹
b = 7.2931 (4) Å	T = 295 K
c = 22.9916 (13) Å	0.25 × 0.23 × 0.22 mm

Data collection top

Nonius MACH3 diffractometer	6225 reflections with I > 2σ(I)
Absorption correction: ψ scan (MolEN; Fair, 1990)	R_int = 0.042
T_min = 0.841, T_max = 0.999	3 standard reflections every 100 reflections
17773 measured reflections	intensity decay: −4.1%
7202 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.028	1 restraint
wR(F²) = 0.076	Δρ_max = 2.27 e Å⁻³
S = 1.05	Δρ_min = −1.35 e Å⁻³
7202 reflections	Absolute structure: Flack (1983), 3515 Friedel pairs
345 parameters	Absolute structure parameter: 0.039 (14)

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

	x	y	z	U_iso*/U_eq
La1	0.66087 (3)	0.01728 (6)	−0.111991 (17)	0.00665 (9)
La2	0.53737 (3)	−0.51499 (6)	−0.346670 (18)	0.00663 (8)
La3	0.40385 (3)	−0.00377 (6)	−0.348693 (18)	0.00607 (8)
La4	0.79779 (3)	−0.49072 (6)	−0.105332 (18)	0.00796 (9)
Mo1	0.56718 (5)	−0.50458 (8)	−0.17097 (3)	0.00648 (12)
Mo2	0.52350 (5)	−0.21023 (9)	−0.48626 (3)	0.00797 (12)
Mo3	0.63252 (5)	−0.01478 (9)	−0.28977 (3)	0.00647 (12)
Mo4	0.88677 (5)	−0.00727 (8)	−0.16706 (3)	0.00596 (12)
Mo5	0.42705 (5)	−0.67540 (9)	−0.50044 (3)	0.00924 (12)
Mo6	0.80799 (5)	−0.48959 (8)	−0.29088 (3)	0.00678 (12)
Mo7	0.69027 (5)	0.18663 (9)	−0.46606 (3)	0.00880 (12)
O11	0.6097 (5)	−0.2827 (9)	−0.1607 (3)	0.0194 (13)
O12	0.5618 (5)	−0.5645 (9)	−0.2443 (2)	0.0153 (12)
O13	0.9529 (4)	−0.4730 (10)	−0.1422 (3)	0.0217 (15)
O14	0.6456 (4)	0.3508 (8)	−0.1297 (2)	0.0112 (11)
O21	0.6007 (4)	−0.3416 (9)	−0.5274 (3)	0.0157 (12)
O22	0.4384 (4)	−0.0813 (9)	−0.5225 (3)	0.0158 (12)
O23	0.5073 (4)	−0.2372 (8)	−0.4093 (2)	0.0120 (11)
O24	0.6147 (5)	−0.0175 (8)	−0.4721 (3)	0.0155 (12)
O31	0.6554 (5)	0.0575 (9)	−0.2186 (2)	0.0148 (12)
O32	0.5662 (4)	−0.8518 (8)	−0.3325 (2)	0.0118 (11)
O33	0.5583 (4)	−0.2059 (8)	−0.2937 (3)	0.0131 (12)
O34	0.2400 (4)	0.0632 (9)	−0.3232 (3)	0.0169 (13)
O41	0.4954 (5)	0.0377 (10)	−0.1345 (3)	0.0185 (13)
O42	0.4018 (5)	0.0247 (10)	−0.2425 (3)	0.0198 (14)
O43	0.8293 (5)	0.1988 (9)	−0.1478 (3)	0.0193 (14)
O44	0.8030 (4)	−0.1691 (8)	−0.1377 (3)	0.0120 (11)
O51	0.4290 (5)	−0.7789 (10)	−0.4302 (3)	0.0236 (15)
O52	0.4298 (4)	−0.4333 (8)	−0.4899 (3)	0.0189 (13)
O53	0.5258 (5)	−0.7338 (9)	−0.5387 (3)	0.0191 (13)
O54	0.3242 (5)	−0.7323 (8)	−0.5428 (3)	0.0137 (12)
O61	0.7039 (5)	−0.4836 (9)	−0.3311 (3)	0.0166 (13)
O62	0.7826 (5)	−0.4752 (9)	−0.2169 (3)	0.0153 (13)
O63	0.3730 (5)	−0.3124 (9)	−0.3092 (3)	0.0215 (14)
O64	0.3901 (5)	−0.6789 (9)	−0.3162 (3)	0.0173 (13)
O71	0.6315 (5)	0.3739 (8)	−0.4350 (3)	0.0164 (13)
O72	0.7380 (4)	0.2446 (8)	−0.5355 (3)	0.0141 (12)
O73	0.7859 (5)	0.1294 (9)	−0.4229 (3)	0.0189 (13)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
La1	0.00731 (18)	0.00518 (17)	0.00747 (19)	0.00098 (14)	0.00029 (15)	0.00006 (17)
La2	0.00777 (18)	0.00519 (18)	0.00694 (18)	0.00041 (14)	−0.00001 (15)	0.00120 (17)
La3	0.00763 (18)	0.00497 (18)	0.00560 (17)	−0.00037 (14)	0.00081 (15)	−0.00027 (15)
La4	0.0102 (2)	0.00603 (19)	0.00765 (19)	−0.00306 (15)	0.00111 (15)	−0.00116 (16)
Mo1	0.0075 (3)	0.0049 (3)	0.0070 (3)	0.0002 (2)	−0.0010 (2)	−0.0005 (2)
Mo2	0.0105 (3)	0.0084 (3)	0.0050 (3)	0.0013 (2)	0.0007 (2)	0.0003 (2)
Mo3	0.0072 (3)	0.0059 (3)	0.0063 (3)	0.0004 (2)	−0.0009 (2)	0.0008 (2)
Mo4	0.0063 (3)	0.0051 (3)	0.0065 (3)	−0.0005 (2)	0.0011 (2)	0.0000 (2)
Mo5	0.0138 (3)	0.0077 (3)	0.0062 (3)	−0.0019 (2)	−0.0017 (2)	−0.0001 (2)
Mo6	0.0069 (3)	0.0061 (3)	0.0073 (3)	−0.0007 (2)	0.0006 (2)	−0.0009 (2)
Mo7	0.0104 (3)	0.0103 (3)	0.0058 (2)	−0.0017 (2)	−0.0001 (2)	0.0017 (2)
O11	0.031 (4)	0.013 (3)	0.014 (3)	−0.004 (3)	0.003 (3)	−0.002 (2)
O12	0.030 (4)	0.012 (3)	0.004 (2)	−0.004 (3)	−0.003 (2)	−0.002 (2)
O13	0.006 (3)	0.031 (4)	0.028 (4)	−0.001 (3)	0.005 (3)	0.000 (3)
O14	0.009 (3)	0.011 (3)	0.014 (3)	0.000 (2)	−0.002 (2)	−0.002 (2)
O21	0.012 (3)	0.015 (3)	0.020 (3)	−0.001 (2)	0.008 (2)	−0.007 (2)
O22	0.012 (3)	0.021 (3)	0.015 (3)	−0.002 (2)	−0.006 (2)	0.004 (2)
O23	0.018 (3)	0.010 (3)	0.008 (3)	0.004 (2)	0.002 (2)	0.001 (2)
O24	0.014 (3)	0.015 (3)	0.018 (3)	−0.007 (2)	0.000 (3)	0.001 (2)
O31	0.024 (3)	0.015 (3)	0.006 (2)	−0.001 (3)	−0.006 (2)	0.000 (2)
O32	0.012 (3)	0.009 (3)	0.015 (3)	0.004 (2)	−0.005 (2)	0.002 (2)
O33	0.014 (3)	0.011 (3)	0.014 (3)	−0.006 (2)	−0.001 (2)	0.000 (2)
O34	0.008 (3)	0.023 (3)	0.020 (3)	0.000 (2)	0.003 (2)	−0.002 (3)
O41	0.012 (3)	0.025 (3)	0.018 (3)	0.005 (3)	−0.004 (2)	0.000 (3)
O42	0.028 (4)	0.023 (3)	0.009 (3)	0.001 (3)	0.001 (2)	0.001 (2)
O43	0.026 (4)	0.013 (3)	0.019 (3)	0.002 (3)	−0.004 (3)	−0.010 (2)
O44	0.011 (3)	0.008 (2)	0.017 (3)	0.001 (2)	0.005 (2)	−0.004 (2)
O51	0.029 (4)	0.031 (4)	0.011 (3)	0.000 (3)	0.001 (3)	0.010 (3)
O52	0.015 (3)	0.008 (3)	0.034 (4)	−0.003 (2)	0.005 (3)	−0.006 (3)
O53	0.025 (4)	0.016 (3)	0.015 (3)	0.004 (3)	0.003 (3)	−0.006 (2)
O54	0.015 (3)	0.014 (3)	0.011 (3)	−0.002 (2)	−0.006 (2)	0.000 (2)
O61	0.010 (3)	0.027 (4)	0.012 (3)	0.000 (3)	−0.005 (2)	−0.001 (2)
O62	0.022 (3)	0.018 (3)	0.006 (2)	0.004 (3)	0.002 (2)	0.000 (2)
O63	0.028 (4)	0.015 (3)	0.021 (3)	−0.004 (3)	0.003 (3)	0.007 (3)
O64	0.013 (3)	0.009 (3)	0.029 (3)	0.000 (2)	0.001 (3)	−0.004 (3)
O71	0.021 (3)	0.015 (3)	0.014 (3)	0.003 (2)	−0.002 (2)	−0.005 (2)
O72	0.012 (3)	0.021 (3)	0.010 (3)	0.003 (2)	0.001 (2)	0.003 (2)
O73	0.015 (3)	0.024 (3)	0.018 (3)	−0.003 (3)	−0.004 (2)	0.008 (3)

Geometric parameters (Å, º) top

La1—O41	2.402 (7)	La4—O14^v	2.506 (6)
La1—O31	2.470 (6)	La4—O21ⁱⁱⁱ	2.540 (6)
La1—O14	2.476 (6)	La4—O72^viii	2.561 (6)
La1—O44	2.498 (6)	La4—O62	2.578 (6)
La1—O22ⁱ	2.535 (6)	La4—O54ⁱⁱ	2.773 (6)
La1—O11	2.562 (6)	La4—Mo1	3.5955 (9)
La1—O54ⁱⁱ	2.625 (6)	La4—La1^v	4.0804 (6)
La1—O72ⁱⁱⁱ	2.809 (6)	Mo1—O11	1.742 (6)
La1—O43	2.847 (7)	Mo1—O12	1.742 (6)
La1—Mo4	3.4416 (9)	Mo1—O13^vi	1.754 (6)
La1—La4^iv	4.0804 (6)	Mo1—O14^v	1.801 (6)
La1—La4	4.1834 (7)	Mo2—O21	1.734 (6)
La2—O61	2.394 (6)	Mo2—O22	1.740 (6)
La2—O12	2.407 (6)	Mo2—O23	1.796 (6)
La2—O64	2.502 (7)	Mo2—O24	1.936 (6)
La2—O32	2.511 (6)	Mo2—O52	2.100 (6)
La2—O23	2.521 (6)	Mo3—O34^ix	1.740 (6)
La2—O71^v	2.559 (6)	Mo3—O33	1.747 (6)
La2—O33	2.579 (6)	Mo3—O31	1.749 (6)
La2—O63	2.886 (7)	Mo3—O32^iv	1.805 (6)
La2—O51	3.121 (7)	Mo4—O41^ix	1.723 (7)
La2—Mo6^vi	3.4889 (9)	Mo4—O42^ix	1.753 (6)
La2—La3^v	4.0344 (6)	Mo4—O43	1.765 (6)
La2—La3	4.1797 (6)	Mo4—O44	1.804 (6)
La3—O34	2.439 (6)	Mo5—O53	1.704 (7)
La3—O42	2.450 (6)	Mo5—O52	1.782 (6)
La3—O63	2.466 (6)	Mo5—O51	1.784 (6)
La3—O64^iv	2.492 (6)	Mo5—O54	1.799 (6)
La3—O51^iv	2.515 (6)	Mo6—O61	1.739 (6)
La3—O73^vii	2.557 (6)	Mo6—O62	1.741 (6)
La3—O32^iv	2.577 (6)	Mo6—O63^x	1.763 (7)
La3—O23	2.642 (6)	Mo6—O64^x	1.788 (6)
La3—O33	2.923 (6)	Mo6—La2^x	3.4889 (9)
La3—Mo3	3.5076 (9)	Mo7—O73	1.728 (6)
La3—La2^iv	4.0344 (6)	Mo7—O71	1.752 (6)
La4—O13	2.356 (6)	Mo7—O72	1.784 (6)
La4—O44	2.462 (6)	Mo7—O24	1.838 (6)
La4—O43^v	2.505 (6)

O41—La1—O31	75.5 (2)	O51^iv—La3—O32^iv	72.6 (2)
O41—La1—O14	79.6 (2)	O73^vii—La3—O32^iv	146.4 (2)
O31—La1—O14	73.56 (19)	O34—La3—O23	141.4 (2)
O41—La1—O44	140.1 (2)	O42—La3—O23	125.9 (2)
O31—La1—O44	81.7 (2)	O63—La3—O23	72.8 (2)
O14—La1—O44	124.46 (19)	O64^iv—La3—O23	144.5 (2)
O41—La1—O22ⁱ	67.9 (2)	O51^iv—La3—O23	87.1 (2)
O31—La1—O22ⁱ	140.0 (2)	O73^vii—La3—O23	77.2 (2)
O14—La1—O22ⁱ	84.5 (2)	O32^iv—La3—O23	81.95 (19)
O44—La1—O22ⁱ	137.6 (2)	O34—La3—O33	135.00 (19)
O41—La1—O11	71.6 (2)	O42—La3—O33	67.7 (2)
O31—La1—O11	70.1 (2)	O63—La3—O33	60.8 (2)
O14—La1—O11	137.9 (2)	O64^iv—La3—O33	114.10 (19)
O44—La1—O11	70.1 (2)	O51^iv—La3—O33	123.0 (2)
O22ⁱ—La1—O11	110.8 (2)	O73^vii—La3—O33	126.56 (19)
O41—La1—O54ⁱⁱ	104.9 (2)	O32^iv—La3—O33	59.22 (17)
O31—La1—O54ⁱⁱ	134.2 (2)	O23—La3—O33	59.25 (17)
O14—La1—O54ⁱⁱ	152.20 (19)	O13—La4—O44	79.1 (2)
O44—La1—O54ⁱⁱ	69.36 (19)	O13—La4—O43^v	75.1 (2)
O22ⁱ—La1—O54ⁱⁱ	72.5 (2)	O44—La4—O43^v	137.6 (2)
O11—La1—O54ⁱⁱ	67.1 (2)	O13—La4—O14^v	138.1 (2)
O41—La1—O72ⁱⁱⁱ	126.5 (2)	O44—La4—O14^v	113.4 (2)
O31—La1—O72ⁱⁱⁱ	124.6 (2)	O43^v—La4—O14^v	69.5 (2)
O14—La1—O72ⁱⁱⁱ	64.38 (18)	O13—La4—O21ⁱⁱⁱ	72.8 (2)
O44—La1—O72ⁱⁱⁱ	93.38 (19)	O44—La4—O21ⁱⁱⁱ	77.8 (2)
O22ⁱ—La1—O72ⁱⁱⁱ	70.44 (19)	O43^v—La4—O21ⁱⁱⁱ	124.1 (2)
O11—La1—O72ⁱⁱⁱ	157.2 (2)	O14^v—La4—O21ⁱⁱⁱ	147.2 (2)
O54ⁱⁱ—La1—O72ⁱⁱⁱ	92.70 (18)	O13—La4—O72^viii	116.8 (2)
O41—La1—O43	136.4 (2)	O44—La4—O72^viii	155.97 (19)
O31—La1—O43	71.6 (2)	O43^v—La4—O72^viii	66.3 (2)
O14—La1—O43	64.43 (19)	O14^v—La4—O72^viii	67.87 (19)
O44—La1—O43	60.74 (19)	O21ⁱⁱⁱ—La4—O72^viii	89.5 (2)
O22ⁱ—La1—O43	127.78 (19)	O13—La4—O62	73.5 (2)
O11—La1—O43	120.5 (2)	O44—La4—O62	70.1 (2)
O54ⁱⁱ—La1—O43	118.4 (2)	O43^v—La4—O62	70.5 (2)
O72ⁱⁱⁱ—La1—O43	58.68 (17)	O14^v—La4—O62	74.1 (2)
O61—La2—O12	74.2 (2)	O21ⁱⁱⁱ—La4—O62	136.9 (2)
O61—La2—O64	145.4 (2)	O72^viii—La4—O62	129.9 (2)
O12—La2—O64	76.9 (2)	O13—La4—O54ⁱⁱ	137.2 (2)
O61—La2—O32	85.1 (2)	O44—La4—O54ⁱⁱ	67.43 (18)
O12—La2—O32	72.7 (2)	O43^v—La4—O54ⁱⁱ	147.4 (2)
O64—La2—O32	68.4 (2)	O14^v—La4—O54ⁱⁱ	81.49 (19)
O61—La2—O23	100.1 (2)	O21ⁱⁱⁱ—La4—O54ⁱⁱ	74.64 (19)
O12—La2—O23	134.7 (2)	O72^viii—La4—O54ⁱⁱ	89.67 (18)
O64—La2—O23	113.8 (2)	O62—La4—O54ⁱⁱ	115.98 (19)
O32—La2—O23	152.58 (19)	O11—Mo1—O12	112.3 (3)
O61—La2—O71^v	68.7 (2)	O11—Mo1—O13^vi	110.7 (3)
O12—La2—O71^v	130.8 (2)	O12—Mo1—O13^vi	107.5 (3)
O64—La2—O71^v	120.3 (2)	O11—Mo1—O14^v	105.1 (3)
O32—La2—O71^v	73.1 (2)	O12—Mo1—O14^v	112.9 (3)
O23—La2—O71^v	83.65 (19)	O13^vi—Mo1—O14^v	108.4 (3)
O61—La2—O33	74.5 (2)	O21—Mo2—O22	118.2 (3)
O12—La2—O33	69.7 (2)	O21—Mo2—O23	123.9 (3)
O64—La2—O33	112.4 (2)	O22—Mo2—O23	116.3 (3)
O32—La2—O33	140.80 (18)	O21—Mo2—O24	94.2 (3)
O23—La2—O33	65.57 (19)	O22—Mo2—O24	98.6 (3)
O71^v—La2—O33	126.2 (2)	O23—Mo2—O24	90.0 (3)
O61—La2—O63	134.4 (2)	O21—Mo2—O52	87.0 (3)
O12—La2—O63	84.3 (2)	O22—Mo2—O52	87.9 (3)
O64—La2—O63	59.4 (2)	O23—Mo2—O52	82.8 (3)
O32—La2—O63	126.34 (19)	O24—Mo2—O52	171.9 (3)
O23—La2—O63	67.86 (18)	O34^ix—Mo3—O33	109.9 (3)
O71^v—La2—O63	144.88 (19)	O34^ix—Mo3—O31	108.2 (3)
O33—La2—O63	60.28 (19)	O33—Mo3—O31	113.6 (3)
O61—La2—O51	129.4 (2)	O34^ix—Mo3—O32^iv	110.3 (3)
O12—La2—O51	125.4 (2)	O33—Mo3—O32^iv	100.7 (3)
O64—La2—O51	57.9 (2)	O31—Mo3—O32^iv	114.0 (3)
O32—La2—O51	63.67 (18)	O41^ix—Mo4—O42^ix	108.2 (3)
O23—La2—O51	93.53 (18)	O41^ix—Mo4—O43	114.2 (3)
O71^v—La2—O51	64.7 (2)	O42^ix—Mo4—O43	111.5 (3)
O33—La2—O51	152.36 (19)	O41^ix—Mo4—O44	109.7 (3)
O63—La2—O51	96.0 (2)	O42^ix—Mo4—O44	113.8 (3)
O34—La3—O42	74.5 (2)	O43—Mo4—O44	99.3 (3)
O34—La3—O63	85.8 (2)	O53—Mo5—O52	107.4 (3)
O42—La3—O63	73.0 (2)	O53—Mo5—O51	110.4 (3)
O34—La3—O64^iv	70.3 (2)	O52—Mo5—O51	107.2 (3)
O42—La3—O64^iv	67.6 (2)	O53—Mo5—O54	109.0 (3)
O63—La3—O64^iv	138.0 (2)	O52—Mo5—O54	108.6 (3)
O34—La3—O51^iv	100.5 (2)	O51—Mo5—O54	113.9 (3)
O42—La3—O51^iv	133.5 (2)	O61—Mo6—O62	110.1 (3)
O63—La3—O51^iv	153.4 (2)	O61—Mo6—O63^x	109.6 (3)
O64^iv—La3—O51^iv	67.3 (2)	O62—Mo6—O63^x	113.0 (3)
O34—La3—O73^vii	67.2 (2)	O61—Mo6—O64^x	111.1 (3)
O42—La3—O73^vii	133.4 (2)	O62—Mo6—O64^x	114.2 (3)
O63—La3—O73^vii	78.7 (2)	O63^x—Mo6—O64^x	98.4 (3)
O64^iv—La3—O73^vii	119.3 (2)	O73—Mo7—O71	109.0 (3)
O51^iv—La3—O73^vii	80.2 (2)	O73—Mo7—O72	106.0 (3)
O34—La3—O32^iv	136.5 (2)	O71—Mo7—O72	111.1 (3)
O42—La3—O32^iv	80.2 (2)	O73—Mo7—O24	107.6 (3)
O63—La3—O32^iv	119.8 (2)	O71—Mo7—O24	112.8 (3)
O64^iv—La3—O32^iv	67.5 (2)	O72—Mo7—O24	110.1 (3)

Symmetry codes: (i) −x+1, −y, z+1/2; (ii) −x+1, −y−1, z+1/2; (iii) −x+3/2, y, z+1/2; (iv) x, y+1, z; (v) x, y−1, z; (vi) x−1/2, −y−1, z; (vii) x−1/2, −y, z; (viii) −x+3/2, y−1, z+1/2; (ix) x+1/2, −y, z; (x) x+1/2, −y−1, z.

Experimental details

Crystal data
Chemical formula	La₄Mo₇O₂₇
M_r	1659.22
Crystal system, space group	Orthorhombic, Pca2₁
Temperature (K)	295
a, b, c (Å)	14.1443 (14), 7.2931 (4), 22.9916 (13)
V (Å³)	2371.7 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	10.71
Crystal size (mm)	0.25 × 0.23 × 0.22

Data collection
Diffractometer	Nonius MACH3 diffractometer
Absorption correction	ψ scan (MolEN; Fair, 1990)
T_min, T_max	0.841, 0.999
No. of measured, independent and observed [I > 2σ(I)] reflections	17773, 7202, 6225
R_int	0.042
(sin θ/λ)_max (Å⁻¹)	0.713

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.028, 0.076, 1.05
No. of reflections	7202
No. of parameters	345
No. of restraints	1
Δρ_max, Δρ_min (e Å⁻³)	2.27, −1.35
Absolute structure	Flack (1983), 3515 Friedel pairs
Absolute structure parameter	0.039 (14)

Computer programs: MACH3 (Enraf–Nonius, 1993), MolEN (Fair, 1990), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2005).

Acknowledgements

This work was supported by the Deutsche Forschungsgemeinschaft (DFG) under project BE 2147/6–1&2.

References

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