Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105028234/ta1512sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105028234/ta1512Isup2.hkl |
Single crystals of Ca2CuTe4O10Cl2 were synthesized by chemical transport reactions in sealed evacuated quartz glass tubes. CaO (ABCR, 99.95%), CuCl2 (Avocado Research Chemicals, +98%), CuO (Avocado Research Chemicals, +99%) and TeO2 (ABCR, +99%) were mixed in the non stoichiometric molar ratio 1:1:1:2 in a mortar and put into a quartz glass tube (length ~5 cm), which was then evacuated. The tube was heated for 72 h at 900 K in a muffle furnace. The product appeared as bright green plate-like single crystals and powder of undetermined composition. The synthesis product was non-hygroscopic.
Two different diffraction data sets were recorded with the same crystal in different χ orientations. Scale factors for the individual data sets were computed with SHELXL97 and finally the individual data sets were scaled and averaged with the program REFLEX (Eriksson, 2004). The structure was refined by full matrix least squares on F2. All heavy atoms were refined with anisotropic displacement parameters; the O atoms were refined with isotropic displacement parameters.
Data collection: program (reference)?; cell refinement: program (reference)?; data reduction: program (reference)?; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Bergerhoff, 1996); software used to prepare material for publication: program (reference)?.
Ca2CuTe4O10Cl2 | Z = 1 |
Mr = 885.00 | F(000) = 391 |
Triclinic, P1 | Dx = 4.656 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 5.421 (2) Å | Cell parameters from 1170 reflections |
b = 7.266 (3) Å | θ = 1.9–28.1° |
c = 8.717 (5) Å | µ = 12.07 mm−1 |
α = 71.60 (6)° | T = 291 K |
β = 79.26 (6)° | Plate, green |
γ = 77.63 (5)° | 0.16 × 0.14 × 0.12 mm |
V = 315.6 (3) Å3 |
STOE IPDS diffractometer | 1487 independent reflections |
Radiation source: fine-focus sealed tube | 1381 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.046 |
Detector resolution: 6.7 pixels mm-1 | θmax = 27.9°, θmin = 2.5° |
ϕ–scan | h = −7→7 |
Absorption correction: numerical [X-RED (Stoe & Cie, 1996) and X-SHAPE (Stoe & Cie, 1997)] | k = −9→9 |
Tmin = 0.136, Tmax = 0.234 | l = −11→11 |
4989 measured reflections |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F2 > 2σ(F2)] = 0.018 | Secondary atom site location: difference Fourier map |
wR(F2) = 0.044 | w = 1/[σ2(Fo2) + (0.0269P)2 + 0.0814P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
1487 reflections | Δρmax = 1.03 e Å−3 |
88 parameters | Δρmin = −0.83 e Å−3 |
Ca2CuTe4O10Cl2 | γ = 77.63 (5)° |
Mr = 885.00 | V = 315.6 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 5.421 (2) Å | Mo Kα radiation |
b = 7.266 (3) Å | µ = 12.07 mm−1 |
c = 8.717 (5) Å | T = 291 K |
α = 71.60 (6)° | 0.16 × 0.14 × 0.12 mm |
β = 79.26 (6)° |
STOE IPDS diffractometer | 1487 independent reflections |
Absorption correction: numerical [X-RED (Stoe & Cie, 1996) and X-SHAPE (Stoe & Cie, 1997)] | 1381 reflections with I > 2σ(I) |
Tmin = 0.136, Tmax = 0.234 | Rint = 0.046 |
4989 measured reflections |
R[F2 > 2σ(F2)] = 0.018 | 88 parameters |
wR(F2) = 0.044 | 0 restraints |
S = 1.06 | Δρmax = 1.03 e Å−3 |
1487 reflections | Δρmin = −0.83 e Å−3 |
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 | ||
Te1 | 0.38491 (4) | 0.58760 (3) | 0.14712 (2) | 0.00890 (7) | |
Te2 | −0.39092 (3) | 0.81909 (3) | 0.38968 (2) | 0.00850 (7) | |
Cu1 | 0.0000 | 1.0000 | 0.5000 | 0.01125 (12) | |
Ca1 | 0.17134 (13) | 1.10242 (9) | 0.10488 (7) | 0.01070 (12) | |
Cl1 | −0.11270 (17) | 0.39350 (13) | 0.34489 (12) | 0.02541 (19) | |
O1 | 0.3293 (4) | 0.4007 (3) | 0.0257 (3) | 0.0121 (4) | |
O2 | −0.1067 (4) | 0.9451 (3) | 0.3201 (2) | 0.0134 (4) | |
O3 | 0.5523 (4) | 0.8242 (3) | 0.1759 (2) | 0.0119 (4) | |
O4 | −0.6544 (4) | 1.0432 (3) | 0.3753 (2) | 0.0115 (4) | |
O5 | 0.1675 (4) | 0.7991 (3) | 0.0367 (3) | 0.0136 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Te1 | 0.00890 (11) | 0.00888 (11) | 0.00852 (10) | −0.00125 (7) | −0.00136 (7) | −0.00197 (7) |
Te2 | 0.00704 (11) | 0.00997 (11) | 0.00889 (10) | −0.00177 (8) | −0.00164 (7) | −0.00269 (7) |
Cu1 | 0.0073 (2) | 0.0201 (3) | 0.0096 (2) | −0.0037 (2) | −0.00124 (18) | −0.00787 (19) |
Ca1 | 0.0103 (3) | 0.0109 (3) | 0.0111 (3) | −0.0033 (2) | −0.0030 (2) | −0.0014 (2) |
Cl1 | 0.0185 (4) | 0.0192 (4) | 0.0333 (4) | 0.0003 (3) | −0.0058 (3) | −0.0011 (3) |
O1 | 0.0107 (10) | 0.0136 (10) | 0.0136 (9) | −0.0043 (9) | 0.0022 (8) | −0.0067 (8) |
O2 | 0.0114 (11) | 0.0225 (11) | 0.0097 (9) | −0.0089 (9) | 0.0000 (8) | −0.0061 (8) |
O3 | 0.0133 (11) | 0.0151 (10) | 0.0106 (9) | −0.0017 (9) | −0.0049 (8) | −0.0068 (8) |
O4 | 0.0075 (10) | 0.0136 (10) | 0.0133 (10) | 0.0006 (8) | −0.0020 (8) | −0.0048 (8) |
O5 | 0.0130 (11) | 0.0115 (10) | 0.0166 (10) | 0.0020 (9) | −0.0079 (8) | −0.0035 (8) |
Te1—O5 | 1.841 (3) | Cu1—Cl1vii | 2.738 (2) |
Te1—O1i | 1.945 (3) | Cu1—Cl1viii | 2.738 (2) |
Te1—O1 | 2.064 (2) | Cu1—Te2vi | 3.1456 (14) |
Te1—O3 | 2.206 (2) | Cu1—Ca1 | 3.281 (2) |
Te1—Te1i | 3.153 (2) | Cu1—Ca1vi | 3.281 (2) |
Te1—Te2ii | 3.5854 (18) | Cu1—Te2ii | 3.363 (2) |
Te1—Ca1 | 3.5920 (19) | Cu1—Te2v | 3.363 (2) |
Te1—Ca1iii | 3.593 (3) | Ca1—O5ix | 2.266 (3) |
Te2—O2 | 1.867 (2) | Ca1—O2 | 2.330 (3) |
Te2—O4 | 1.910 (2) | Ca1—O1vii | 2.353 (3) |
Te2—O3iv | 1.932 (2) | Ca1—O5 | 2.462 (3) |
Te2—O4v | 2.616 (3) | Ca1—O3 | 2.575 (3) |
Cu1—O2 | 1.945 (2) | Ca1—O4ii | 2.579 (3) |
Cu1—O2vi | 1.945 (2) | Ca1—O3iii | 2.583 (3) |
Cu1—O4ii | 2.017 (3) | Ca1—Cl1vii | 3.379 (2) |
Cu1—O4v | 2.017 (3) | Ca1—Te2ii | 3.593 (3) |
O5—Te1—O1i | 97.39 (11) | O5ix—Ca1—O1vii | 99.20 (10) |
O5—Te1—O1 | 94.28 (11) | O2—Ca1—O1vii | 136.04 (9) |
O1i—Te1—O1 | 76.28 (11) | O5ix—Ca1—O5 | 79.76 (10) |
O5—Te1—O3 | 81.82 (10) | O2—Ca1—O5 | 77.71 (9) |
O1i—Te1—O3 | 79.69 (10) | O1vii—Ca1—O5 | 146.24 (8) |
O1—Te1—O3 | 154.95 (8) | O5ix—Ca1—O3 | 142.86 (9) |
O2—Te2—O4 | 99.67 (11) | O2—Ca1—O3 | 93.49 (10) |
O2—Te2—O3iv | 96.44 (11) | O1vii—Ca1—O3 | 106.83 (9) |
O4—Te2—O3iv | 87.52 (11) | O5—Ca1—O3 | 63.84 (8) |
O2—Te2—O4v | 73.44 (9) | O5ix—Ca1—O4ii | 148.15 (9) |
O4—Te2—O4v | 75.35 (10) | O2—Ca1—O4ii | 70.95 (9) |
O3iv—Te2—O4v | 157.99 (8) | O1vii—Ca1—O4ii | 84.62 (10) |
O2—Cu1—O2vi | 180.000 (1) | O5—Ca1—O4ii | 114.06 (9) |
O2—Cu1—O4ii | 92.22 (10) | O3—Ca1—O4ii | 62.08 (9) |
O2vi—Cu1—O4ii | 87.78 (10) | O5ix—Ca1—O3iii | 86.05 (9) |
O2—Cu1—O4v | 87.78 (10) | O2—Ca1—O3iii | 158.22 (8) |
O2vi—Cu1—O4v | 92.22 (10) | O1vii—Ca1—O3iii | 65.22 (9) |
O4ii—Cu1—O4v | 180.000 (1) | O5—Ca1—O3iii | 81.09 (9) |
O2—Cu1—Cl1vii | 88.81 (9) | O3—Ca1—O3iii | 81.48 (10) |
O2vi—Cu1—Cl1vii | 91.19 (9) | O4ii—Ca1—O3iii | 123.31 (8) |
O4ii—Cu1—Cl1vii | 80.98 (9) | O5ix—Ca1—Cl1vii | 90.17 (8) |
O4v—Cu1—Cl1vii | 99.02 (9) | O2—Ca1—Cl1vii | 68.43 (8) |
O2—Cu1—Cl1viii | 91.19 (9) | O1vii—Ca1—Cl1vii | 67.86 (7) |
O2vi—Cu1—Cl1viii | 88.81 (9) | O5—Ca1—Cl1vii | 145.35 (7) |
O4ii—Cu1—Cl1viii | 99.02 (9) | O3—Ca1—Cl1vii | 123.88 (7) |
O4v—Cu1—Cl1viii | 80.98 (9) | O4ii—Ca1—Cl1vii | 61.80 (7) |
Cl1vii—Cu1—Cl1viii | 180.000 (1) | O3iii—Ca1—Cl1vii | 131.59 (7) |
O5ix—Ca1—O2 | 85.36 (10) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x+1, y, z; (iii) −x+1, −y+2, −z; (iv) x−1, y, z; (v) −x−1, −y+2, −z+1; (vi) −x, −y+2, −z+1; (vii) x, y+1, z; (viii) −x, −y+1, −z+1; (ix) −x, −y+2, −z. |
Experimental details
Crystal data | |
Chemical formula | Ca2CuTe4O10Cl2 |
Mr | 885.00 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 291 |
a, b, c (Å) | 5.421 (2), 7.266 (3), 8.717 (5) |
α, β, γ (°) | 71.60 (6), 79.26 (6), 77.63 (5) |
V (Å3) | 315.6 (3) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 12.07 |
Crystal size (mm) | 0.16 × 0.14 × 0.12 |
Data collection | |
Diffractometer | STOE IPDS diffractometer |
Absorption correction | Numerical [X-RED (Stoe & Cie, 1996) and X-SHAPE (Stoe & Cie, 1997)] |
Tmin, Tmax | 0.136, 0.234 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4989, 1487, 1381 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.659 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.018, 0.044, 1.06 |
No. of reflections | 1487 |
No. of parameters | 88 |
Δρmax, Δρmin (e Å−3) | 1.03, −0.83 |
Computer programs: program (reference)?, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Bergerhoff, 1996).
Te1—O5 | 1.841 (3) | Cu1—Cl1v | 2.738 (2) |
Te1—O1i | 1.945 (3) | Ca1—O5vi | 2.266 (3) |
Te1—O1 | 2.064 (2) | Ca1—O2 | 2.330 (3) |
Te1—O3 | 2.206 (2) | Ca1—O1v | 2.353 (3) |
Te2—O2 | 1.867 (2) | Ca1—O5 | 2.462 (3) |
Te2—O4 | 1.910 (2) | Ca1—O3 | 2.575 (3) |
Te2—O3ii | 1.932 (2) | Ca1—O4iv | 2.579 (3) |
Te2—O4iii | 2.616 (3) | Ca1—O3vii | 2.583 (3) |
Cu1—O2 | 1.945 (2) | Ca1—Cl1v | 3.379 (2) |
Cu1—O4iv | 2.017 (3) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x−1, y, z; (iii) −x−1, −y+2, −z+1; (iv) x+1, y, z; (v) x, y+1, z; (vi) −x, −y+2, −z; (vii) −x+1, −y+2, −z. |
Oxohalogenides comprising transition metals and elements having an asymmetric coordination due to presence of stereochemically active lone pairs, such as TeIV, SeIV, AsIII or SbIII, have proved to be a very interesting family of compounds, in which there is a high probability of finding novel host–guest compounds, quantum spin systems and low-dimensional compounds (Johnsson et al., 2000, 2003, 2004). The lone-pair elements and the halogens constitute `structural scissors', hindering the development of three-dimensional networks. In these kinds of oxohalogenide compounds, the lone-pair elements are coordinated only by oxygen and the metal ions are coordinated by both oxygen and halogens. The synthesis strategy involves the use of the halogens Cl, Br and I but not F, as the latter is so electronegative that it will also bond to the lone-pair elements; in this case the F atom may then constitute a bridge directly to a transition metal ion and thus will not act as `scissors', forcing the transition metal ions to take low-dimensional arrangements in the crystal structures.
The present work is an outcome of an ongoing investigation of transition metal oxohalogenides containing alkaline earth elements and asymmetrically coordinated lone-pair elements. The crystal structures of a few compounds in this family have been described before [Ba3Te2O6Cl2 (Hottentot & Loopstra, 1983), Ba2Co(SeO3)2Cl2 (Johnston & Harrison, 2002), Ba2Cu4Te4O11Cl4 and BaCu2Te2O6Cl2 (Feger & Kolis, 1998)]. To our best knowledge, the novel compound Ca2CuTe4O10Cl2 is the first oxohalogenide described with CaII in combination with CuII and TeIV.
There are two crystallographically distinct Te atoms. Atom Te1 has a see-saw [TeO4] coordination to oxygen. When the stereochemically active 5s2 lone pair (designated E) is also taken into account, the coordination becomes a distorted trigonal bipyramid [TeO4E], where E is located in the equatorial plane. The bonding distances are in the range 1.841 (3)–2.206 (2) Å. Atom Te2 has a threefold one-sided [TeO3] coordination, having Te—O bond distances in the range 1.867 (2)–1.932 (2) Å. A fourth longer Te2—O4 bond [2.616 (3) Å] completes the see-saw coordination. Bond valence sum calculations (Brown & Altermatt, 1985) suggest that this long Te—O distance contributes to the bond valence and that it therefore should be regarded as coordinated. Taking the stereochemically active lone pair into account the coordination polyhedron becomes a [TeO3 + 1E] trigonal bipyramid for Te2, with the lone pair in the equatorial plane. Geometrically placing the lone pairs assuming a Te—E distance (radius) of 1.25 Å (Galy et al., 1975) gives the fractional coordinates E1 (x = 0.3175, y = 0.4855, z = 0.2878) and E2 (x = −0.3943, y = 0.6409, z = 0.4123) for Te1 and Te2, respectively.
The Cu atom, located at a centre of symmetry, is coordinated by four O atoms in a square planar configuration, with Cu—O distances of 1.945 (2)–2.017 (3) Å, and two Cl atoms complete a [CuO4Cl2] octahedron, with Cu—Cl distances of 2.738 (2) Å. The Ca atom is coordinated by seven O atoms to form an irregular [CaO7] polyhedron. The Ca—O distances are 2.330 (3)–2.583 (3) Å, except for the short Ca—O5 distance which is only 2.266 (3) Å. A long Ca—Cl distance of 3.379 (2) Å does not contribute significantly to the bond valence sum and the Cl atom is therefore not regarded as bonded.
An overview of the structure is shown in Fig. 1. The [Te1O4E] and [Te2O3 + 1E] polyhedra build infinite [TeO2.5]n chains along [011] by corner sharing and edge sharing. The [TeO2.5]n chains are linked by [CuO4Cl2] octahedra via the [Te2O3 + 1E] polyhedra to form layers in the (0–11) plane (see Fig. 2). Each [CuO4Cl2] octahedra share edges with two [CaO7] polyhedra and with two [Te2O3 + 1E] bipyramids and corners with two more such bipyramids (see Fig. 3). Each [CaO7] polyhedron shares edges with two [Te1O4E] and two [Te2O3 + 1E] bipyramids and corners with two more of each kind of Te polyhedron. The [CaO7] polyhedra also share edges with two more [CaO7] polyhedra to build up [CaO5]n chains along [100]. The [CaO5]n chains link the Te–O–Cu–Cl layers to build up the three-dimensional structure and channels develop along [100] where the chlorine atoms and the lone pairs (E) are located (see Fig. 1).