β-K3Fe(MoO4)2Mo2O7.

The title compound, tripotassium iron(III) bis-(ortho-molyb-date) dimolybdate, was obtained by a solid-state reaction. The main structural building units are one FeO6 octa-hedron, two MoO4 tetra-hedra and one Mo2O7 dimolybdate group, all with point group symmetries m. These units are linked via corner-sharing to form ribbons parallel to [010]. The three K(+) cations are located between the ribbons on mirror planes and have coordination numbers of 10 and 12. Two O atoms of one of the MoO4 tetra-hedra of the dimolybdate group are disordered over two positions in a 0.524 (11):0.476 (11) ratio. The structure of the title compound is compared briefly with that of Rb3FeMo4O15.

Related literature

For properties of related molybdates, see: Zhang et al. (2000 ▶); Muessig et al. (2003 ▶); Bramnik et al. (2003 ▶); Soares & Portela (2005 ▶); Bowker et al. (2008 ▶); Otko et al. (1978 ▶); Klimin et al. (2003 ▶); Jorge et al. (2004 ▶); Maczka et al. (2005 ▶). The closely related crystal structures of α-K3Fe(MoO4)2(Mo2O7) and Rb3Fe(MoO4)2Mo2O7 were determined by Maczka et al. (2009 ▶) and Khal’baeva et al. (2010 ▶), respectively. For bond-valence sums, see: Brown & Altermatt (1985 ▶).

Experimental

Crystal data

K3Fe(MoO4)2Mo2O7

M = 796.91

Monoclinic,

a = 32.873 (2) Å

b = 5.7137 (7) Å

c = 7.9177 (9) Å

β = 91.143 (8)°

V = 1486.9 (3) Å3

Z = 4

Mo Kα radiation

μ = 5.15 mm−1

T = 298 K

0.36 × 0.22 × 0.18 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

Absorption correction: ψ scan (North et al., 1968 ▶) T min = 0.286, T max = 0.488

3443 measured reflections

1789 independent reflections

1636 reflections with I > 2σ(I)

R int = 0.028

2 standard reflections every 120 min intensity decay: 1.3%

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.076

S = 1.06

1789 reflections

138 parameters

Δρmax = 1.22 e Å−3

Δρmin = −1.57 e Å−3

Data collection: CAD-4 EXPRESS (Duisenberg, 1992 ▶; Macíček & Yordanov, 1992 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 1999 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536814013087/wm5025sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814013087/wm5025Isup2.hkl

CCDC reference: 1006924

Additional supporting information: crystallographic information; 3D view; checkCIF report

K3Fe(MoO4)2Mo2O7	F(000) = 1484
Mr = 796.91	Dx = 3.560 Mg m−3
Monoclinic, C2/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2y	Cell parameters from 25 reflections
a = 32.873 (2) Å	θ = 11–15°
b = 5.7137 (7) Å	µ = 5.15 mm−1
c = 7.9177 (9) Å	T = 298 K
β = 91.143 (8)°	Prism, green
V = 1486.9 (3) Å3	0.36 × 0.22 × 0.18 mm
Z = 4

Enraf–Nonius CAD-4 diffractometer	1636 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
Graphite monochromator	θmax = 27.0°, θmin = 2.5°
ω/2θ scans	h = −41→41
Absorption correction: ψ scan (North et al., 1968)	k = −1→7
Tmin = 0.286, Tmax = 0.488	l = −10→5
3443 measured reflections	2 standard reflections every 120 min
1789 independent reflections	intensity decay: 1.3%

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029	w = 1/[σ2(Fo2) + (0.0306P)2 + 20.6944P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.076	(Δ/σ)max = 0.001
S = 1.06	Δρmax = 1.22 e Å−3
1789 reflections	Δρmin = −1.57 e Å−3
138 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.00379 (16)

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Mo1	0.568576 (15)	0.5000	−0.03610 (7)	0.01354 (16)
Mo2	0.649834 (16)	0.0000	0.73776 (7)	0.01577 (16)
Mo3	0.718491 (15)	0.0000	0.18432 (7)	0.01355 (16)
Mo4	0.55700 (2)	0.5000	0.49609 (8)	0.0375 (2)
Fe1	0.68040 (3)	0.5000	−0.01846 (11)	0.0118 (2)
K1	0.51309 (5)	0.0000	0.7616 (2)	0.0253 (3)
K2	0.60638 (5)	0.0000	0.2307 (2)	0.0340 (4)
K3	0.68689 (5)	0.5000	0.4756 (2)	0.0361 (5)
O1	0.62085 (14)	0.5000	0.0211 (7)	0.0257 (11)
O2	0.73729 (17)	0.0000	0.3855 (7)	0.0373 (15)
O3	0.54601 (11)	0.7403 (7)	0.0504 (5)	0.0277 (8)
O4	0.68711 (12)	0.7469 (9)	0.1610 (6)	0.0459 (13)
O5	0.60430 (19)	0.5000	0.4216 (9)	0.053 (2)
O6	0.75919 (14)	0.0000	0.0434 (6)	0.0223 (11)
O7	0.67523 (14)	0.2575 (11)	0.8080 (7)	0.0669 (19)
O8	0.55792 (18)	0.5000	0.7337 (6)	0.0329 (13)
O9	0.64948 (18)	0.0000	0.5221 (7)	0.0346 (14)
O10	0.60110 (17)	0.0000	0.8120 (8)	0.0396 (15)
O11	0.5491 (2)	0.1696 (14)	0.4498 (9)	0.031 (2)	0.524 (11)
O12	0.5224 (3)	0.3608 (15)	0.3916 (10)	0.034 (3)	0.476 (11)

	U11	U22	U33	U12	U13	U23
Mo1	0.0084 (3)	0.0180 (3)	0.0142 (3)	0.000	−0.00063 (19)	0.000
Mo2	0.0111 (3)	0.0210 (3)	0.0151 (3)	0.000	−0.00068 (19)	0.000
Mo3	0.0080 (2)	0.0163 (3)	0.0164 (3)	0.000	−0.00035 (19)	0.000
Mo4	0.0169 (3)	0.0820 (6)	0.0137 (3)	0.000	0.0003 (2)	0.000
Fe1	0.0092 (4)	0.0101 (4)	0.0160 (4)	0.000	−0.0006 (3)	0.000
K1	0.0184 (7)	0.0324 (9)	0.0250 (8)	0.000	−0.0022 (6)	0.000
K2	0.0195 (7)	0.0563 (12)	0.0260 (8)	0.000	−0.0046 (6)	0.000
K3	0.0226 (8)	0.0665 (14)	0.0191 (8)	0.000	−0.0004 (6)	0.000
O1	0.010 (2)	0.042 (3)	0.025 (3)	0.000	−0.0025 (19)	0.000
O2	0.023 (3)	0.065 (4)	0.023 (3)	0.000	−0.008 (2)	0.000
O3	0.0224 (17)	0.0242 (18)	0.037 (2)	0.0016 (16)	0.0069 (15)	−0.0049 (17)
O4	0.031 (2)	0.051 (3)	0.058 (3)	−0.029 (2)	0.0281 (19)	−0.040 (2)
O5	0.027 (3)	0.085 (6)	0.048 (4)	0.000	0.011 (3)	0.000
O6	0.009 (2)	0.032 (3)	0.026 (3)	0.000	0.0045 (18)	0.000
O7	0.038 (2)	0.087 (4)	0.077 (4)	−0.036 (3)	0.026 (2)	−0.068 (3)
O8	0.035 (3)	0.048 (4)	0.015 (2)	0.000	−0.006 (2)	0.000
O9	0.033 (3)	0.056 (4)	0.015 (2)	0.000	−0.004 (2)	0.000
O10	0.018 (3)	0.056 (4)	0.045 (4)	0.000	0.005 (2)	0.000
O11	0.031 (4)	0.036 (4)	0.025 (4)	0.005 (3)	0.002 (3)	−0.002 (3)
O12	0.036 (5)	0.033 (5)	0.031 (4)	−0.017 (4)	−0.003 (3)	−0.015 (4)

Mo1—O3	1.710 (4)	K1—O3x	2.882 (4)
Mo1—O3i	1.710 (4)	K1—O10	2.913 (6)
Mo1—O1	1.768 (5)	K1—O3xi	2.916 (4)
Mo1—O8ii	1.849 (5)	K1—O3xii	2.916 (4)
Mo2—O9	1.708 (5)	K1—O11iii	2.924 (7)
Mo2—O10	1.717 (6)	K1—O11	2.924 (7)
Mo2—O7	1.776 (5)	K1—O8iv	3.224 (3)
Mo2—O7iii	1.776 (5)	K2—O9	2.683 (6)
Mo3—O2	1.697 (5)	K2—O11	2.762 (7)
Mo3—O6	1.759 (5)	K2—O11iii	2.762 (7)
Mo3—O4iv	1.784 (4)	K2—O3iv	2.841 (4)
Mo3—O4i	1.784 (4)	K2—O3i	2.841 (4)
Mo4—O12	1.605 (7)	K2—O4i	3.082 (5)
Mo4—O12i	1.605 (7)	K2—O4iv	3.082 (5)
Mo4—O5	1.674 (6)	K2—O5	3.233 (3)
Mo4—O8	1.881 (5)	K2—O5iv	3.233 (3)
Mo4—O11	1.940 (8)	K2—O10ii	3.317 (7)
Mo4—O11i	1.940 (8)	K2—O1iv	3.343 (3)
Fe1—O7ii	1.956 (4)	K2—O1	3.343 (3)
Fe1—O7v	1.956 (4)	K3—O2xiii	2.704 (6)
Fe1—O1	1.989 (5)	K3—O5	2.740 (7)
Fe1—O6vi	2.000 (5)	K3—O4i	2.863 (5)
Fe1—O4	2.011 (4)	K3—O4	2.863 (5)
Fe1—O4i	2.011 (4)	K3—O7i	3.005 (7)
K1—O12vii	2.650 (8)	K3—O7	3.005 (7)
K1—O12viii	2.650 (8)	K3—O9	3.135 (3)
K1—O11vii	2.789 (8)	K3—O9xiv	3.135 (3)
K1—O11viii	2.789 (8)	K3—O2xiv	3.386 (3)
K1—O3ix	2.882 (4)	K3—O2	3.386 (3)
O3—Mo1—O3i	106.8 (3)	O12—Mo4—O11	47.9 (4)
O3—Mo1—O1	108.94 (15)	O12i—Mo4—O11	107.1 (4)
O3i—Mo1—O1	108.94 (15)	O5—Mo4—O11	93.2 (2)
O3—Mo1—O8ii	108.63 (16)	O8—Mo4—O11	100.9 (2)
O3i—Mo1—O8ii	108.63 (16)	O12—Mo4—O11i	107.1 (4)
O1—Mo1—O8ii	114.6 (2)	O12i—Mo4—O11i	47.9 (4)
O9—Mo2—O10	110.8 (3)	O5—Mo4—O11i	93.2 (2)
O9—Mo2—O7	107.9 (2)	O8—Mo4—O11i	100.9 (2)
O10—Mo2—O7	109.20 (18)	O11—Mo4—O11i	153.4 (4)
O9—Mo2—O7iii	107.9 (2)	O7ii—Fe1—O7v	90.2 (4)
O10—Mo2—O7iii	109.20 (18)	O7ii—Fe1—O1	92.22 (17)
O7—Mo2—O7iii	111.9 (4)	O7v—Fe1—O1	92.22 (17)
O2—Mo3—O6	109.2 (3)	O7ii—Fe1—O6vi	90.18 (17)
O2—Mo3—O4iv	107.2 (2)	O7v—Fe1—O6vi	90.18 (17)
O6—Mo3—O4iv	112.33 (14)	O1—Fe1—O6vi	176.6 (2)
O2—Mo3—O4i	107.2 (2)	O7ii—Fe1—O4	178.6 (2)
O6—Mo3—O4i	112.33 (14)	O7v—Fe1—O4	90.4 (3)
O4iv—Mo3—O4i	108.3 (3)	O1—Fe1—O4	89.03 (15)
O12—Mo4—O12i	59.4 (7)	O6vi—Fe1—O4	88.54 (16)
O12—Mo4—O5	118.2 (4)	O7ii—Fe1—O4i	90.4 (3)
O12i—Mo4—O5	118.2 (4)	O7v—Fe1—O4i	178.6 (2)
O12—Mo4—O8	120.8 (3)	O1—Fe1—O4i	89.03 (15)
O12i—Mo4—O8	120.8 (3)	O6vi—Fe1—O4i	88.54 (16)
O5—Mo4—O8	110.9 (3)	O4—Fe1—O4i	89.1 (3)