Two new types of oxyfluoro­tellur­ates(IV): ScTeO₃F and InTeO₃F

In the course of a general study of oxyfluoro­tellurates(IV), materials likely to exhibit interesting nonlinear optical properties, the crystal structures of the new phases scandium tellurium trioxide fluoride, ScTeO₃F, and indium tellurium trioxide fluoride, InTeO₃F, belonging to two different structural types and also differing from that of the recently published MTeO₃F (M = Fe, Ga and Cr) series, have been determined. The ScTeO₃F structure can be described as an inter­growth of two different layers of scandium octa­hedra connected via isolated TeO₃ groups. The scandium ions occupy two different sites with ..2 and 2.. site symmetry. The Te, F and O atoms are on general positions of the Pnna space group. The InTeO₃F structure consists of zigzag sheets of InO₅F octa­hedra. The In, Te, O and F atoms are all located on general positions of the P2₁/a space group. TeO₃F polyhedra are inserted between the zigzag sheets of InO₅F octa­hedra and with them form double (InTeO₃F)_n layers. Therefore, InTeO₃F is a true layer structure, unlike the previous types. In all these phases, the electronic lone pair of the Te^IV atom is stereochemically active and a full O/F anionic ordering is observed.

S1. Comment

In recent years, many tellurates(IV) of transition metals or heavy metals have generated interest for their excellent nonlinear optical properties. Therefore, a general study of the structural and physical properties of some homologous oxyfluorotellurates(IV) and oxyfluoroiodates(V) has been undertaken. Indeed, few fluorides and oxyfluorides of tellurium(IV) and iodine(V) were known because of the highly hygroscopic character of most of these phases. In the present series of studies, the compounds are generally more thermally stable and moisture resistant. Following on our characterization of the new series MTeO₃F (M = Fe, Ga and Cr; Laval et al., 2008) and NaIO₂F₂ (Laval & Jennene Boukharrata, 2008), the present paper describes the synthesis and crystal structure of two phases, ScTeO₃F and InTeO₃F, belonging to two new structure types that differ from that of the first MTeO₃F (M = Fe, Ga and Cr) series.

In ScTeO₃F, the Te^IV atom is bonded to three O atoms, O1, O2 and O3, and occupies the center of a tetrahedron whose fourth corner corresponds to the direction of the stereochemically active lone pair E (Fig. 1 and Table 1). If weak bonds are considered, Te1 is connected to two additional O atoms at more remote distances.

Atoms Sc1 and Sc2 occupy two different sixfold-coordinated sites. Atom Sc1 occupies the center of an ScO₆ irregular octahedron with two shorter and four slightly longer Sc1—O bonds (Fig. 2a and Table 1). Atom Sc2 is located at the center of an almost regular ScF₄O₂ octahedron in which the F atoms occupy the square base and the O atoms the two apices (Fig. 2b). The Sc^III cations are generally six-coordinated by O atoms in oxides and can be sevenfold coordinated in mixed oxyfluorides, for example in ScOF belonging to the ZrO₂ baddeleyite type (Vlasse et al., 1979). The ScO₆ octahedra are often irregular with a low point symmetry and Sc—O distances generally ranging from 2.0 to 2.25 Å or more. The octahedra evidenced in ScTeO₃F are in agreement with those described in most Sc oxide phases.

The ScTeO₃F structure results from the stacking of two types of scandium layers interconnected via layers of isolated TeO₃ polyhedra.

The first type of layer consists of Sc1O₆ octahedra sharing O1···O1) edges in the [100] direction, so forming `zigzag' chains (Fig. 3a). These chains are similar to those observed in the MoOCl₃ structure (Hyde & Andersson, 1989) and to the zigzag chains of MO₄F₂ octahedra, alternately sharing O···O and F···F edges, in the MTeO₃F (M = Fe, Ga and Cr) series (Laval et al., 2008). Along the [001] direction, successive parallel chains are interconnected via O1 and O2 corners of TeO₃ polyhedra, so forming layers perpendicular to the [010] direction. In the MTeO₃F (M = Fe, Ga and Cr) type, zigzag chains of octahedra are also interconnected via TeO₃ polyhedra, giving a structure related to the α-PbO₂ classical type of hcp framework (Hyde & Andersson, 1989). However, this last interconnection occurs on one side via one O3 corner and on the other side via O1 and O2 corners belonging to three different chains of the same type. In ScTeO₃F, the O3 atoms of the TeO₃ polyhedra are shared with Sc2 atoms belonging to a second completely different type of layer.

This second type of layer (Fig. 3b), perpendicular to the [010] axis, consists of F1 corner-connected Sc2O₂F₄ tilted octahedra forming a square 4⁴ plane net similar to the plane net of SnF₆ octahedra described in the SnF₄ type (Wells, 1975). Two TeO₃ isolated units are connected to each Sc2 atom above and below the empty square holes of the 4⁴ plane net through O3 corners. However, the Te1 atoms are not located above and below the center of these square holes, which would give overly long Te1—O3 bonds, like, for example, the Ca—O bonds in CaTiO₃ perovskite (Hyde & Anderson, 1989), but rather are shifted along the [100] direction towards the Sc2 atoms, sitting above and below an F1···F1 edge of each Sc2O₂F₄ octahedron. This shift allows a stronger connection between the Sc2 and Te1 polyhedra via O3 corners and releases the volume necessary for the active lone pair of Te^IV to be directed towards the center of the empty square holes.

Therefore, the Te atoms, located between the scandium layers, provide the connection between the [(Sc1)_nO_4n+2] chains through O1—Te1—O2 bridges, so forming mixed [(Sc1)_n(Te1)_nO_4n+2] layers, and also provide the linking of both types of layers through Te1—O3 bonds (Fig. 4). This constitutes the main difference from the MTeO₃F (M = Fe, Ga and Cr) type: the chains of MO₄F₂ octahedra, interconnected by TeO₃ polyhedra, are replaced by alternate chains of ScO₆ and layers of ScO₂F₄ octahedra, these chains and layers being also interconnected by TeO₃ polyhedra.

In the InTeO₃F structure, the Te atom is surrounded by four O and two F atoms (Fig. 5). Three O atoms are strongly bonded at distances less than 2 Å, while the first Te—F bond is somewhat longer, and the fourth O (O2^iv) and the second F (F1^v) atoms are weakly bonded at much longer distances (Table 2). The corresponding complete polyhedron can be described as a distorted TeO₄F₂ octahedron. The stereochemically active lone pair E is located between the two longest bonds. Taking into account only the four shortest bonds, TeO₃F is a square pyramid whose vertex is occupied by the lone pair E, but in a first approximation, it can also be described as a TeO₃ trigonal bipyramid, like those in the other MTeO₃F structures. The In atom is sixfold coordinated. It is slightly shifted from the center of a distorted InO₅F octahedron (Fig. 6).

The InTeO₃F structure consists of zigzag sheets of InO₅F octahedra separated by spaces into which the stereochemically active lone pair E of the Te atom is directed (Fig. 7a). Each sheet is formed by isolated chains of tilted InO₅F octahedra sharing O corners and connected by TeO₃F polyhedra (Fig.7b). Contrary to the two other MTeO₃F types in which TeO₃ polyhedra connect single sheets of M octahedra, in InTeO₃F, the TeO₃F polyhedra form with the zigzag sheets of InO₅F octahedra independent double (InTeO₃F)_n sheets, with the lone pairs pointing to the space between successive sheets. Therefore, InTeO₃F is a true layer structure, different from the two other MTeO₃F types, with only weak Te—O and Te—F bonds connecting the double sheets (Fig. 8).

Bond valence calculations (Brown, 1981) show O valences varying from 2.04 to 2.14 and from 2.00 to 2.23, and F valences as 0.96 and 0.82 in ScTeO₃F (Table 3) and InTeO₃F (Table 4), respectively. It must be noted that, in most oxyfluorides, the calculated anionic valences are sometimes imprecise. The discrepancies can be attributed to imperfect electrostatic equilibrium in some cases, to the empirical character of the constants used in Brown's equation and to a poor knowledge of the ionic radii of rare elements (e.g. scandium), based on a limited number of solved structures. In spite of these limitations, the calculated valences of atoms Sc1, Sc2, In1 and Te1 are very close to their ideal values, which are consistent with a full O/F ordering in both ScTeO₃F and InTeO₃F.

In conclusion, these three structure types differ in the manner of connection of the M(O,F)₆ octahedra and in the respective O/F distribution in these octahedra, but they have an interesting common feature: in the MTeO₃F (M = Fe, Cr and Ga) type, in ScTeO₃F and to a first approximation in InTeO₃F, the fluoride anions are not directly bonded to the tellurium cations, which are threefold coordinated by O cations only. This feature draws these compounds closer to Te oxides than to the Te fluorides or oxyfluorides previously described, the latter phases being characterized by four- or fivefold coordination (Guillet et al., 1999, 2001; Ider et al., 1996, 1999). This may also explain the unusually high thermal and chemical stability of these phases compared with the main oxyfluorotellurates(IV) already known.

Related literature

For related literature, see: Brown (1981); Bruker (2001); Guillet et al. (1999, 2001); Hyde & Andersson (1989); Ider et al. (1996, 1999); Laval & Jennene Boukharrata (2008); Laval, Jennene Boukharrata & Thomas (2008); Sheldrick (2008); Vlasse et al. (1979); Wells (1975).

S2. Experimental

ScTeO₃F was prepared by a solid-state reaction. A mixture of Sc₂O₃ (Aldrich 99%), ScF₃ (Aldrich 99%) and TeO₂ (1:1:3) was heated in a platinum sealed tube. The temperature was progressively increased to 1123 K, held for 48 h and water-quenched to room temperature. TeO₂ was prepared in the laboratory by decomposition at 823 K under flowing oxygen of commercial H₆TeO₆ (Aldrich, 99.9%). For the preparation of InTeO₃F, a mixture of InF₃ (Aldrich 99.9%) and TeO₂ (1.8:1) was heated in a sealed platinum tube with the following thermal treatment: the temperature was increased from 298 to 943 K (5 K min^-1), held for 106 h, and then decreased slowly to 673 K (0.1 K min^-1) and held for 164 h. The tube was then water-quenched. Transparent tablet-shaped single crystals, air-stable and suitable for X-ray diffraction study, were obtained in both cases.

S3. Refinement

The residues of electronic density are minimal for ScTeO₃F, but for InTeO₃F, a residual density peak of 4.37 e Å^-3 persists 0.6 Å from Te1. It clearly cannot correspond to an extra atom but more likely to an imperfect absorption correction, resulting from the much more irregular shape and poorer quality of the single crystal of InTeO₃F. However, the structural results do not seem adversely affected, as attested by the reasonable R factors, interatomic distances and bond valences.

Computing details

For both compounds, data collection: KappaCCD Server Software (Nonius, 1998); cell refinement: DIRAX/LSQ (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg et al., 2003); 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: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. : The tellurium coordination in ScTeO3F. The arrow indicates the direction towards which the lone pair E points. [Symmetry code: (i) x + 1/2, y, - z.]
	Fig. 2. : (a) The coordination polyhedron of Sc1 in ScTeO3F. [Symmetry codes: (ii) -x + 1/2, -y + 1, z + 1; (iii) -x, -y + 1, -z + 1; (v) -x + 1/2, -y + 1, z; (vi) x + 1/2, y, -z + 1; (vii) x, y, z + 1.] (b) The coordination polyhedron of Sc2 in ScTeO3F. [Symmetry codes: (iv) x - 1/2, y, -z + 1; (viii) x, -y + 1/2, -z + 1/2; (ix) x - 1/2, -y + 1/2, z - 1/2; (x) x, -y + 1/2, -z + 1/2.]
	Fig. 3. : (a) A projection onto (101), showing the [(Sc1)nO4n+2] chains linked through O—Te—O bridges. (b) A projection onto (101), showing the layer of Sc2O2F4 octahedra (SnF4-type network).
	Fig. 4. : A projection onto (110), showing the connection between the two scandium layers.
	Fig. 5. : The tellurium coordination in InTeO3F. The arrow indicates the direction towards which the lone pair E points. [Symmetry codes: (iv) x + 1/2, -y + 1/2, z; (v) -x + 3/2, y + 1/2, -z + 1.]
	Fig. 6. : The coordination polyhedron of In1 in InTeO3F. [Symmetry codes: (i) x - 1/2, -y + 3/2, z; (ii) -x + 3/2, y + 1/2, -z + 2; (iii) x, y + 1, z.]
	Fig. 7. : (a) A projection onto (101), showing the zigzag sheets of InO5F and the interlayer spaces. (b) A projection onto (110), showing a single sheet of InO5F octahedra connected through TeO3F units.
	Fig. 8. : The three-dimensional framework of InTeO3F, taking into account the weak Te—O and Te—F bonds.

(I) scandium tellurium trioxide fluoride

Crystal data

ScTeO3F	F(000) = 848
Mr = 239.56	Dx = 4.542 Mg m^−3
Orthorhombic, Pnna	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2a2bc	Cell parameters from 13064 reflections
a = 5.7740 (5) Å	θ = 5.1–30.0°
b = 22.062 (5) Å	µ = 10.13 mm^−1
c = 5.5000 (12) Å	T = 293 K
V = 700.6 (2) Å^3	Tablet shape, colourless
Z = 8	0.1 × 0.08 × 0.04 mm

Data collection

Nonius KappaCCD diffractometer	1019 independent reflections
Radiation source: fine-focus sealed tube	895 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.046
Detector resolution: 9 pixels mm^-1	θmax = 30.0°, θmin = 5.1°
CCD scans	h = −7→8
Absorption correction: multi-scan (SADABS; Bruker 2001)	k = −30→30
Tmin = 0.363, Tmax = 0.667	l = −7→7
17528 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.018	w = 1/[σ^2(Fo^2) + (0.0112P)^2 + 1.5494P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.035	(Δ/σ)max = 0.001
S = 1.18	Δρmax = 0.98 e Å^−3
1019 reflections	Δρmin = −1.00 e Å^−3
57 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0091 (2)

Special details

Experimental. The integrated intensities were corrected for absorption effects by using a multi-scan method (SADABS, Bruker 2001). Structure solution by direct methods in the Pnna space group for ScTeO₃F and in the P2₁/a space group for InTeO₃F followed by refinement of atomic coordinates and anisotropic thermal parameters were performed using successively the SHELXS97 and the SHELXL97 programs (Sheldrick, 2008).

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 (Ų)

	x	y	z	Uiso*/Ueq
Te1	0.20456 (3)	0.392628 (7)	0.19594 (3)	0.00529 (7)
Sc1	0.2500	0.5000	0.67882 (14)	0.00527 (16)
Sc2	−0.06902 (14)	0.2500	0.2500	0.00481 (16)
F1	0.1863 (3)	0.26783 (8)	0.4982 (4)	0.0165 (4)
O1	0.0563 (4)	0.44955 (8)	0.4069 (4)	0.0086 (4)
O2	0.1338 (4)	0.43931 (9)	−0.0742 (4)	0.0093 (4)
O3	−0.0468 (4)	0.33984 (9)	0.1528 (4)	0.0094 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Te1	0.00610 (12)	0.00480 (9)	0.00497 (11)	0.00010 (6)	−0.00010 (8)	0.00012 (6)
Sc1	0.0066 (4)	0.0051 (3)	0.0041 (4)	−0.0006 (3)	0.000	0.000
Sc2	0.0057 (4)	0.0044 (3)	0.0044 (4)	0.000	0.000	0.0007 (2)
F1	0.0160 (10)	0.0167 (8)	0.0170 (9)	−0.0007 (8)	−0.0111 (8)	0.0012 (8)
O1	0.0091 (10)	0.0084 (9)	0.0082 (10)	0.0021 (7)	−0.0003 (9)	−0.0045 (8)
O2	0.0086 (11)	0.0099 (9)	0.0094 (11)	−0.0016 (8)	0.0003 (9)	0.0035 (8)
O3	0.0103 (11)	0.0061 (8)	0.0119 (11)	−0.0027 (7)	−0.0021 (8)	0.0012 (8)

Geometric parameters (Å, º)

Te1—O2	1.854 (2)	Sc1—Sc1^iv	3.4934 (14)
Te1—O3	1.876 (2)	Sc1—Sc1^vii	3.4934 (14)
Te1—O1	1.912 (2)	Sc2—F1^viii	2.017 (2)
Te1—O3^i	2.664 (2)	Sc2—F1^ix	2.017 (2)
Te1—O2^i	2.766 (2)	Sc2—F1	2.047 (2)
Sc1—O2^ii	2.022 (2)	Sc2—F1^x	2.047 (2)
Sc1—O2^iii	2.022 (2)	Sc2—O3^x	2.057 (2)
Sc1—O1^iv	2.142 (2)	Sc2—O3	2.057 (2)
Sc1—O1^v	2.142 (2)	F1—Sc2^v	2.017 (2)
Sc1—O1	2.174 (2)	O1—Sc1^iv	2.142 (2)
Sc1—O1^vi	2.174 (2)	O2—Sc1^xi	2.022 (2)
O2—Te1—O3	94.20 (9)	O1^vi—Sc1—Sc1^iv	92.17 (8)
O2—Te1—O1	91.31 (10)	O2^ii—Sc1—Sc1^vii	95.97 (7)
O3—Te1—O1	97.93 (9)	O2^iii—Sc1—Sc1^vii	130.73 (6)
O2—Te1—O3^i	77.55 (9)	O1^iv—Sc1—Sc1^vii	123.95 (7)
O3—Te1—O3^i	93.12 (7)	O1^v—Sc1—Sc1^vii	36.28 (5)
O1—Te1—O3^i	164.87 (7)	O1—Sc1—Sc1^vii	92.17 (7)
O2—Te1—O2^i	78.26 (6)	O1^vi—Sc1—Sc1^vii	35.66 (5)
O3—Te1—O2^i	153.36 (8)	Sc1^iv—Sc1—Sc1^vii	111.47 (6)
O1—Te1—O2^i	107.67 (7)	F1^viii—Sc2—F1^ix	91.07 (13)
O3^i—Te1—O2^i	60.38 (6)	F1^viii—Sc2—F1	178.40 (12)
O2^ii—Sc1—O2^iii	95.59 (13)	F1^ix—Sc2—F1	90.52 (5)
O2^ii—Sc1—O1^iv	94.45 (8)	F1^viii—Sc2—F1^x	90.52 (5)
O2^iii—Sc1—O1^iv	102.59 (8)	F1^ix—Sc2—F1^x	178.40 (12)
O2^ii—Sc1—O1^v	102.59 (8)	F1—Sc2—F1^x	87.89 (13)
O2^iii—Sc1—O1^v	94.45 (8)	F1^viii—Sc2—O3^x	91.95 (8)
O1^iv—Sc1—O1^v	154.58 (12)	F1^ix—Sc2—O3^x	93.05 (8)
O2^ii—Sc1—O1	166.38 (8)	F1—Sc2—O3^x	88.11 (8)
O2^iii—Sc1—O1	87.27 (9)	F1^x—Sc2—O3^x	86.75 (8)
O1^iv—Sc1—O1	71.93 (8)	F1^viii—Sc2—O3	93.05 (8)
O1^v—Sc1—O1	90.42 (7)	F1^ix—Sc2—O3	91.95 (8)
O2^ii—Sc1—O1^vi	87.27 (9)	F1—Sc2—O3	86.75 (8)
O2^iii—Sc1—O1^vi	166.38 (8)	F1^x—Sc2—O3	88.11 (8)
O1^iv—Sc1—O1^vi	90.42 (7)	O3^x—Sc2—O3	172.86 (13)
O1^v—Sc1—O1^vi	71.93 (8)	Sc2^v—F1—Sc2	157.62 (10)
O1—Sc1—O1^vi	93.07 (12)	Te1—O1—Sc1^iv	125.27 (11)
O2^ii—Sc1—Sc1^iv	130.73 (6)	Te1—O1—Sc1	121.55 (11)
O2^iii—Sc1—Sc1^iv	95.97 (7)	Sc1^iv—O1—Sc1	108.07 (8)
O1^iv—Sc1—Sc1^iv	36.28 (5)	Te1—O2—Sc1^xi	146.46 (12)
O1^v—Sc1—Sc1^iv	123.95 (7)	Te1—O3—Sc2	127.85 (11)
O1—Sc1—Sc1^iv	35.66 (5)

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

(II) indium tellurium trioxide fluoride

Crystal data

InTeO3F	F(000) = 536
Mr = 309.42	Dx = 5.968 Mg m^−3
Monoclinic, P21/a	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2yab	Cell parameters from 6421 reflections
a = 7.9395 (11) Å	θ = 5.1–32.0°
b = 5.3867 (8) Å	µ = 15.03 mm^−1
c = 8.0529 (12) Å	T = 293 K
β = 91.058 (13)°	Tablet shape, colourless
V = 344.35 (9) Å^3	0.06 × 0.04 × 0.02 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer	1187 independent reflections
Radiation source: fine-focus sealed tube	1044 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
Detector resolution: 9 pixels mm^-1	θmax = 32.0°, θmin = 5.1°
CCD scans	h = −11→11
Absorption correction: multi-scan (SADABS; Bruker 2001)	k = −8→7
Tmin = 0.406, Tmax = 0.740	l = −12→12
7758 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.029	w = 1/[σ^2(Fo^2) + (0.0509P)^2 + 2.4678P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.086	(Δ/σ)max = 0.001
S = 1.06	Δρmax = 4.37 e Å^−3
1187 reflections	Δρmin = −2.73 e Å^−3
56 parameters	Extinction correction: SHELXL97, Fc^*^=kFc[1+0.001xFc^2^λ^3^/sin(2θ)]^-1/4^
0 restraints	Extinction coefficient: 0.0027 (6)

Special details

Experimental. The integrated intensities were corrected for absorption effects by using a multi-scan method (SADABS, Bruker 2001). Structure solution by direct methods in the Pnna space group for ScTeO₃F and in the P2₁/a space group for InTeO₃F followed by refinement of atomic coordinates and anisotropic thermal parameters were performed using successively the SHELXS97 and the SHELXL97 programs (Sheldrick, 2008).

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 F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ 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 (Ų)

	x	y	z	Uiso*/Ueq
In1	0.67668 (4)	0.78326 (7)	0.85804 (4)	0.00767 (13)
Te1	0.84905 (4)	0.30493 (6)	0.70479 (4)	0.00916 (13)
O1	0.8228 (4)	0.1146 (7)	0.9037 (4)	0.0097 (7)
F1	0.7013 (4)	−0.0355 (7)	0.6209 (4)	0.0165 (7)
O2	0.6371 (5)	0.4518 (7)	0.7228 (5)	0.0126 (7)
O3	0.9277 (5)	0.5886 (7)	0.8392 (5)	0.0127 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
In1	0.00724 (19)	0.0062 (2)	0.0095 (2)	0.00016 (11)	−0.00046 (13)	0.00065 (11)
Te1	0.00793 (18)	0.0098 (2)	0.00979 (19)	0.00137 (10)	0.00186 (12)	0.00217 (11)
O1	0.0126 (16)	0.0072 (17)	0.0093 (16)	−0.0031 (13)	0.0010 (13)	0.0011 (13)
F1	0.0209 (16)	0.0140 (16)	0.0147 (15)	−0.0056 (13)	0.0024 (13)	−0.0016 (13)
O2	0.0057 (15)	0.0111 (17)	0.0208 (19)	0.0005 (13)	−0.0018 (13)	−0.0040 (16)
O3	0.0079 (15)	0.0097 (18)	0.0205 (19)	−0.0019 (13)	−0.0003 (14)	−0.0011 (15)

Geometric parameters (Å, º)

In1—O3^i	2.097 (4)	Te1—O3	1.968 (4)
In1—O2	2.112 (4)	Te1—F1	2.273 (4)
In1—O1^ii	2.122 (4)	Te1—O2^iv	2.674 (4)
In1—O1^iii	2.157 (4)	Te1—F1^v	2.782 (3)
In1—F1^iii	2.157 (4)	O1—In1^vi	2.122 (4)
In1—O3	2.260 (4)	O1—In1^vii	2.157 (4)
In1—Te1	3.1776 (6)	F1—In1^vii	2.157 (4)
Te1—O2	1.868 (4)	O3—In1^viii	2.097 (4)
Te1—O1	1.917 (4)
O3^i—In1—O2	96.31 (15)	F1^iii—In1—Te1	88.66 (10)
O3^i—In1—O1^ii	101.10 (15)	O2—Te1—O1	92.83 (17)
O2—In1—O1^ii	95.86 (16)	O2—Te1—O3	84.58 (17)
O3^i—In1—O1^iii	104.07 (15)	O1—Te1—O3	89.64 (17)
O2—In1—O1^iii	149.57 (15)	O2—Te1—F1	84.49 (15)
O1^ii—In1—O1^iii	102.00 (9)	O1—Te1—F1	75.72 (14)
O3^i—In1—F1^iii	83.55 (15)	O3—Te1—F1	161.23 (15)
O2—In1—F1^iii	86.63 (15)	O1—Te1—In1	93.14 (12)
O1^ii—In1—F1^iii	174.42 (14)	F1—Te1—In1	123.09 (9)
O1^iii—In1—F1^iii	73.69 (13)	Te1—O1—In1^vi	121.9 (2)
O3^i—In1—O3	168.39 (16)	Te1—O1—In1^vii	111.51 (17)
O2—In1—O3	72.32 (14)	In1^vi—O1—In1^vii	120.04 (16)
O1^ii—In1—O3	82.81 (14)	In1^vii—F1—Te1	99.02 (14)
O1^iii—In1—O3	85.60 (14)	Te1—O2—In1	105.81 (17)
F1^iii—In1—O3	93.24 (15)	Te1—O3—In1^viii	125.8 (2)
O3^i—In1—Te1	130.63 (11)	Te1—O3—In1	97.23 (15)
O1^ii—In1—Te1	90.59 (10)	In1^viii—O3—In1	132.37 (19)
O1^iii—In1—Te1	120.22 (10)

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