Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102006856/br1370sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102006856/br1370Isup2.hkl |
Aqueous solutions of (Ta6Br12)Br2·8H2O (5 ml, 0.200 g, 0.085 mmol) and NdCl3·6H2O (2 ml, 0.0305 g, 0.085 mmol) were mixed and filtered over a G-4 frit, then left to evaporate at ambient conditions. Plate-like single crystals formed over a period of one week.
All Ta and bridging Br atoms of the clusters were located. The remainder of the atoms (except H atoms) were located from a difference Fourier synthesis. During isotropic refinements, it was observed that the displacement parameter of the Br13 atom was too large. Assuming that its position is also accupied by Cl anions in a disordered way, the remainder of the refinement cycles were performed constraining the Br13 and Cl1 anions to the same site and constraining the sum of their occupation factors to 1. The refinement converged to a value of 0.397 (5) for the site-occupation of the Br13 anion, from which the chemical formula of the compound was deduced.
Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO–SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO–SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2001) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: PLATON (Spek, 1990).
[Ta6Br12(H2O)6](Cl1.6Br0.4)·8H2O | Z = 2 |
Mr = 2385.53 | F(000) = 2078 |
Triclinic, P1 | DENZO-SCALEPACK software |
Hall symbol: -P 1 | Dx = 4.426 Mg m−3 |
a = 9.729 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.823 (2) Å | Cell parameters from 20232 reflections |
c = 19.392 (4) Å | θ = 2.1–30.5° |
α = 81.92 (3)° | µ = 32.29 mm−1 |
β = 80.28 (3)° | T = 200 K |
γ = 80.34 (3)° | Plate, dark-green |
V = 1788.7 (7) Å3 | 0.09 × 0.05 × 0.02 mm |
Nonius KappaCCD diffractometer | 10753 independent reflections |
Radiation source: fine-focus sealed tube | 8662 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
ω scans | θmax = 30.5°, θmin = 2.1° |
Absorption correction: multi-scan (DENZO-SCALEPACK; Otwinowski & Minor, 1997) | h = −13→13 |
Tmin = 0.055, Tmax = 0.524 | k = −13→13 |
20232 measured reflections | l = −27→27 |
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)] = 0.031 | w = 1/[σ2(Fo2) + (0.0157P)2 + 6.9837P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.063 | (Δ/σ)max = 0.001 |
S = 1.04 | Δρmax = 1.62 e Å−3 |
10753 reflections | Δρmin = −2.56 e Å−3 |
309 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.000817 (19) |
3 constraints |
[Ta6Br12(H2O)6](Cl1.6Br0.4)·8H2O | γ = 80.34 (3)° |
Mr = 2385.53 | V = 1788.7 (7) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.729 (2) Å | Mo Kα radiation |
b = 9.823 (2) Å | µ = 32.29 mm−1 |
c = 19.392 (4) Å | T = 200 K |
α = 81.92 (3)° | 0.09 × 0.05 × 0.02 mm |
β = 80.28 (3)° |
Nonius KappaCCD diffractometer | 10753 independent reflections |
Absorption correction: multi-scan (DENZO-SCALEPACK; Otwinowski & Minor, 1997) | 8662 reflections with I > 2σ(I) |
Tmin = 0.055, Tmax = 0.524 | Rint = 0.033 |
20232 measured reflections |
R[F2 > 2σ(F2)] = 0.031 | 309 parameters |
wR(F2) = 0.063 | 0 restraints |
S = 1.04 | Δρmax = 1.62 e Å−3 |
10753 reflections | Δρmin = −2.56 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 | Occ. (<1) | |
Ta1 | 0.11639 (3) | −0.15304 (3) | 0.057799 (14) | 0.00991 (6) | |
O1 | 0.2405 (5) | −0.3183 (5) | 0.1218 (3) | 0.0240 (12) | |
Ta2 | 0.12509 (3) | −0.05568 (3) | −0.090743 (13) | 0.00871 (6) | |
O2 | 0.2662 (5) | −0.1160 (4) | −0.1951 (2) | 0.0136 (9) | |
Ta3 | 0.13085 (3) | 0.13825 (3) | 0.008933 (13) | 0.00977 (6) | |
O3 | 0.2723 (5) | 0.2903 (5) | 0.0188 (3) | 0.0233 (11) | |
Br1 | 0.30274 (7) | −0.25923 (7) | −0.04072 (4) | 0.01870 (15) | |
Br2 | 0.31014 (7) | −0.01932 (7) | 0.08234 (4) | 0.01900 (15) | |
Br3 | 0.31787 (7) | 0.10204 (7) | −0.10231 (4) | 0.01591 (14) | |
Br4 | 0.01095 (7) | 0.12398 (7) | −0.18505 (3) | 0.01445 (14) | |
Br5 | −0.00622 (7) | −0.24156 (7) | −0.12498 (3) | 0.01635 (14) | |
Br6 | 0.01855 (8) | 0.36270 (6) | −0.06167 (4) | 0.01797 (15) | |
Ta4 | 0.11373 (3) | −0.19381 (2) | 0.488677 (13) | 0.00911 (6) | |
O4 | 0.2342 (5) | −0.4061 (4) | 0.4768 (2) | 0.0178 (10) | |
Ta5 | 0.15320 (3) | 0.08782 (3) | 0.430261 (13) | 0.00940 (6) | |
O5 | 0.3234 (5) | 0.1788 (5) | 0.3537 (3) | 0.0201 (11) | |
Ta6 | 0.10376 (3) | 0.01619 (2) | 0.581465 (13) | 0.00919 (6) | |
O6 | 0.2235 (5) | 0.0317 (4) | 0.6693 (2) | 0.0152 (10) | |
Br7 | 0.33338 (7) | −0.13126 (7) | 0.39980 (4) | 0.01567 (14) | |
Br8 | 0.27195 (7) | −0.22084 (7) | 0.58766 (4) | 0.01589 (14) | |
Br9 | 0.31877 (7) | 0.13085 (7) | 0.51474 (3) | 0.01530 (14) | |
Br10 | 0.05055 (7) | 0.35133 (6) | 0.42771 (3) | 0.01469 (14) | |
Br11 | 0.06044 (7) | 0.09173 (7) | 0.31113 (3) | 0.01574 (14) | |
Br12 | −0.01435 (7) | 0.26090 (6) | 0.61703 (3) | 0.01473 (14) | |
Br13 | 0.39445 (12) | 0.48365 (11) | 0.33228 (6) | 0.0215 (4) | 0.397 (5) |
Cl1 | 0.39445 (12) | 0.48365 (11) | 0.33228 (6) | 0.0215 (4) | 0.603 (5) |
Cl2 | 0.54777 (17) | 0.57439 (16) | 0.11061 (9) | 0.0179 (3) | |
O7 | 0.3563 (5) | 0.3170 (5) | 0.1425 (3) | 0.0230 (11) | |
O8 | 0.6813 (5) | 0.3799 (5) | 0.2274 (3) | 0.0272 (12) | |
O9 | 0.8831 (6) | 0.4881 (6) | 0.2808 (3) | 0.0388 (15) | |
O10 | 0.4567 (5) | 0.0756 (5) | 0.2303 (3) | 0.0220 (11) | |
O11 | 0.1642 (5) | 0.4911 (5) | 0.2272 (3) | 0.0286 (13) | |
O12 | 0.6956 (6) | 0.7364 (5) | 0.3102 (3) | 0.0283 (13) | |
O13 | 0.4637 (6) | 0.7806 (5) | 0.2359 (3) | 0.0290 (13) | |
O14 | 0.6094 (6) | 0.5591 (5) | 0.4361 (3) | 0.0319 (14) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ta1 | 0.00955 (13) | 0.01136 (12) | 0.00744 (13) | 0.00100 (10) | −0.00045 (10) | −0.00045 (9) |
O1 | 0.020 (3) | 0.025 (3) | 0.021 (3) | 0.003 (2) | −0.003 (2) | 0.010 (2) |
Ta2 | 0.00911 (12) | 0.01024 (12) | 0.00618 (12) | −0.00072 (9) | 0.00073 (9) | −0.00194 (9) |
O2 | 0.015 (2) | 0.014 (2) | 0.010 (2) | −0.0021 (18) | 0.0016 (18) | −0.0005 (18) |
Ta3 | 0.01056 (13) | 0.01211 (12) | 0.00711 (13) | −0.00366 (10) | 0.00030 (10) | −0.00225 (10) |
O3 | 0.028 (3) | 0.030 (3) | 0.018 (3) | −0.018 (2) | −0.003 (2) | −0.004 (2) |
Br1 | 0.0174 (3) | 0.0189 (3) | 0.0140 (3) | 0.0087 (3) | 0.0026 (3) | −0.0017 (3) |
Br2 | 0.0126 (3) | 0.0282 (4) | 0.0175 (4) | −0.0043 (3) | −0.0065 (3) | −0.0004 (3) |
Br3 | 0.0130 (3) | 0.0226 (3) | 0.0131 (3) | −0.0077 (3) | 0.0033 (3) | −0.0051 (3) |
Br4 | 0.0170 (3) | 0.0178 (3) | 0.0067 (3) | 0.0004 (3) | −0.0005 (2) | −0.0004 (2) |
Br5 | 0.0217 (4) | 0.0171 (3) | 0.0115 (3) | −0.0078 (3) | 0.0026 (3) | −0.0065 (3) |
Br6 | 0.0264 (4) | 0.0107 (3) | 0.0163 (4) | −0.0040 (3) | −0.0014 (3) | −0.0001 (3) |
Ta4 | 0.01195 (13) | 0.00828 (12) | 0.00704 (13) | −0.00136 (10) | −0.00067 (10) | −0.00172 (9) |
O4 | 0.019 (3) | 0.014 (2) | 0.019 (3) | 0.001 (2) | −0.005 (2) | −0.002 (2) |
Ta5 | 0.01235 (13) | 0.00939 (12) | 0.00648 (12) | −0.00304 (10) | 0.00052 (10) | −0.00156 (9) |
O5 | 0.022 (3) | 0.020 (2) | 0.018 (3) | −0.011 (2) | 0.007 (2) | −0.002 (2) |
Ta6 | 0.01246 (13) | 0.00923 (12) | 0.00633 (12) | −0.00202 (10) | −0.00154 (10) | −0.00175 (9) |
O6 | 0.021 (3) | 0.018 (2) | 0.010 (2) | −0.0028 (19) | −0.0053 (19) | −0.0069 (18) |
Br7 | 0.0146 (3) | 0.0146 (3) | 0.0158 (3) | −0.0006 (3) | 0.0040 (3) | −0.0043 (3) |
Br8 | 0.0191 (3) | 0.0144 (3) | 0.0149 (3) | 0.0015 (3) | −0.0075 (3) | −0.0029 (3) |
Br9 | 0.0145 (3) | 0.0198 (3) | 0.0135 (3) | −0.0073 (3) | −0.0016 (3) | −0.0034 (3) |
Br10 | 0.0193 (3) | 0.0097 (3) | 0.0145 (3) | −0.0043 (3) | 0.0001 (3) | −0.0001 (2) |
Br11 | 0.0228 (4) | 0.0191 (3) | 0.0062 (3) | −0.0073 (3) | −0.0009 (3) | −0.0008 (2) |
Br12 | 0.0208 (3) | 0.0124 (3) | 0.0122 (3) | −0.0004 (3) | −0.0042 (3) | −0.0057 (2) |
Br13 | 0.0265 (7) | 0.0194 (6) | 0.0194 (7) | −0.0081 (5) | 0.0016 (5) | −0.0050 (4) |
Cl1 | 0.0265 (7) | 0.0194 (6) | 0.0194 (7) | −0.0081 (5) | 0.0016 (5) | −0.0050 (4) |
Cl2 | 0.0137 (8) | 0.0180 (8) | 0.0192 (9) | −0.0007 (6) | 0.0020 (6) | 0.0000 (7) |
O7 | 0.026 (3) | 0.025 (3) | 0.019 (3) | −0.006 (2) | −0.004 (2) | −0.004 (2) |
O8 | 0.027 (3) | 0.024 (3) | 0.031 (3) | −0.001 (2) | −0.004 (2) | −0.008 (2) |
O9 | 0.034 (3) | 0.040 (3) | 0.041 (4) | −0.006 (3) | −0.006 (3) | −0.004 (3) |
O10 | 0.018 (3) | 0.032 (3) | 0.016 (3) | −0.004 (2) | 0.001 (2) | −0.009 (2) |
O11 | 0.026 (3) | 0.032 (3) | 0.023 (3) | −0.002 (2) | 0.001 (2) | 0.003 (2) |
O12 | 0.033 (3) | 0.023 (3) | 0.034 (3) | −0.014 (2) | −0.007 (3) | −0.009 (2) |
O13 | 0.039 (3) | 0.027 (3) | 0.021 (3) | −0.014 (3) | 0.001 (2) | −0.001 (2) |
O14 | 0.036 (3) | 0.025 (3) | 0.038 (4) | −0.002 (2) | −0.021 (3) | 0.003 (2) |
Ta1—O1 | 2.217 (4) | Ta4—O4 | 2.236 (4) |
Ta1—Br4i | 2.5985 (10) | Ta4—Br7 | 2.6104 (11) |
Ta1—Br1 | 2.6041 (12) | Ta4—Br10ii | 2.6130 (11) |
Ta1—Br6i | 2.6079 (10) | Ta4—Br12ii | 2.6143 (9) |
Ta1—Br2 | 2.6104 (10) | Ta4—Br8 | 2.6157 (10) |
Ta1—Ta3i | 2.8918 (8) | Ta4—Ta5 | 2.9004 (9) |
Ta1—Ta2i | 2.8941 (11) | Ta4—Ta6 | 2.9017 (9) |
Ta1—Ta2 | 2.8965 (8) | Ta4—Ta6ii | 2.9047 (11) |
Ta1—Ta3 | 2.9039 (8) | Ta4—Ta5ii | 2.9110 (11) |
Ta2—O2 | 2.336 (5) | Ta5—O5 | 2.244 (5) |
Ta2—Br3 | 2.5891 (10) | Ta5—Br9 | 2.6022 (10) |
Ta2—Br1 | 2.6053 (11) | Ta5—Br7 | 2.6066 (11) |
Ta2—Br4 | 2.6101 (11) | Ta5—Br10 | 2.6103 (10) |
Ta2—Br5 | 2.6109 (9) | Ta5—Br11 | 2.6116 (9) |
Ta2—Ta3i | 2.8908 (10) | Ta5—Ta6 | 2.8950 (8) |
Ta2—Ta1i | 2.8941 (11) | Ta5—Ta6ii | 2.9086 (8) |
Ta2—Ta3 | 2.9113 (9) | Ta5—Ta4ii | 2.9110 (11) |
Ta3—O3 | 2.241 (5) | Ta6—O6 | 2.254 (4) |
Ta3—Br3 | 2.6007 (11) | Ta6—Br9 | 2.6049 (11) |
Ta3—Br6 | 2.6034 (11) | Ta6—Br8 | 2.6120 (11) |
Ta3—Br2 | 2.6033 (11) | Ta6—Br11ii | 2.6149 (12) |
Ta3—Br5i | 2.6214 (11) | Ta6—Br12 | 2.6164 (10) |
Ta3—Ta2i | 2.8909 (10) | Ta6—Ta4ii | 2.9047 (11) |
Ta3—Ta1i | 2.8918 (8) | Ta6—Ta5ii | 2.9086 (8) |
Br4—Ta1i | 2.5985 (10) | Br10—Ta4ii | 2.6130 (11) |
Br5—Ta3i | 2.6214 (11) | Br11—Ta6ii | 2.6149 (12) |
Br6—Ta1i | 2.6079 (10) | Br12—Ta4ii | 2.6143 (9) |
O1—Ta1—Br4i | 77.68 (14) | O4—Ta4—Br7 | 79.58 (13) |
O1—Ta1—Br1 | 79.52 (14) | O4—Ta4—Br10ii | 78.23 (13) |
Br4i—Ta1—Br1 | 157.20 (3) | Br7—Ta4—Br10ii | 157.81 (3) |
O1—Ta1—Br6i | 78.47 (13) | O4—Ta4—Br12ii | 78.37 (12) |
Br4i—Ta1—Br6i | 87.34 (4) | Br7—Ta4—Br12ii | 87.90 (3) |
Br1—Ta1—Br6i | 88.17 (4) | Br10ii—Ta4—Br12ii | 87.88 (3) |
O1—Ta1—Br2 | 79.05 (13) | O4—Ta4—Br8 | 79.28 (12) |
Br4i—Ta1—Br2 | 88.38 (3) | Br7—Ta4—Br8 | 87.01 (3) |
Br1—Ta1—Br2 | 87.28 (3) | Br10ii—Ta4—Br8 | 88.66 (3) |
Br6i—Ta1—Br2 | 157.52 (3) | Br12ii—Ta4—Br8 | 157.62 (2) |
O1—Ta1—Ta3i | 134.69 (13) | O4—Ta4—Ta5 | 135.74 (12) |
Br4i—Ta1—Ta3i | 98.03 (3) | Br7—Ta4—Ta5 | 56.16 (3) |
Br1—Ta1—Ta3i | 97.97 (3) | Br10ii—Ta4—Ta5 | 146.03 (3) |
Br6i—Ta1—Ta3i | 56.22 (3) | Br12ii—Ta4—Ta5 | 97.61 (3) |
Br2—Ta1—Ta3i | 146.26 (2) | Br8—Ta4—Ta5 | 97.59 (3) |
O1—Ta1—Ta2i | 134.12 (14) | O4—Ta4—Ta6 | 135.49 (12) |
Br4i—Ta1—Ta2i | 56.44 (3) | Br7—Ta4—Ta6 | 97.42 (3) |
Br1—Ta1—Ta2i | 146.36 (2) | Br10ii—Ta4—Ta6 | 98.19 (3) |
Br6i—Ta1—Ta2i | 98.11 (3) | Br12ii—Ta4—Ta6 | 146.14 (2) |
Br2—Ta1—Ta2i | 97.84 (3) | Br8—Ta4—Ta6 | 56.22 (3) |
Ta3i—Ta1—Ta2i | 60.42 (2) | Ta5—Ta4—Ta6 | 59.863 (19) |
O1—Ta1—Ta2 | 135.75 (14) | O4—Ta4—Ta6ii | 134.65 (12) |
Br4i—Ta1—Ta2 | 146.56 (2) | Br7—Ta4—Ta6ii | 98.44 (3) |
Br1—Ta1—Ta2 | 56.24 (3) | Br10ii—Ta4—Ta6ii | 97.27 (3) |
Br6i—Ta1—Ta2 | 98.02 (3) | Br12ii—Ta4—Ta6ii | 56.30 (3) |
Br2—Ta1—Ta2 | 97.69 (3) | Br8—Ta4—Ta6ii | 146.07 (2) |
Ta3i—Ta1—Ta2 | 59.92 (3) | Ta5—Ta4—Ta6ii | 60.14 (2) |
Ta2i—Ta1—Ta2 | 90.13 (3) | Ta6—Ta4—Ta6ii | 89.85 (3) |
O1—Ta1—Ta3 | 135.07 (13) | O4—Ta4—Ta5ii | 134.31 (12) |
Br4i—Ta1—Ta3 | 98.17 (3) | Br7—Ta4—Ta5ii | 146.10 (2) |
Br1—Ta1—Ta3 | 97.89 (3) | Br10ii—Ta4—Ta5ii | 56.09 (3) |
Br6i—Ta1—Ta3 | 146.45 (2) | Br12ii—Ta4—Ta5ii | 98.18 (3) |
Br2—Ta1—Ta3 | 56.04 (3) | Br8—Ta4—Ta5ii | 98.18 (3) |
Ta3i—Ta1—Ta3 | 90.23 (3) | Ta5—Ta4—Ta5ii | 89.95 (3) |
Ta2i—Ta1—Ta3 | 59.81 (3) | Ta6—Ta4—Ta5ii | 60.05 (2) |
Ta2—Ta1—Ta3 | 60.25 (3) | Ta6ii—Ta4—Ta5ii | 59.71 (2) |
O2—Ta2—Br3 | 78.88 (11) | O5—Ta5—Br9 | 78.70 (13) |
O2—Ta2—Br1 | 79.75 (11) | O5—Ta5—Br7 | 77.24 (12) |
Br3—Ta2—Br1 | 87.77 (3) | Br9—Ta5—Br7 | 87.61 (3) |
O2—Ta2—Br4 | 78.13 (11) | O5—Ta5—Br10 | 80.25 (12) |
Br3—Ta2—Br4 | 87.14 (3) | Br9—Ta5—Br10 | 87.16 (3) |
Br1—Ta2—Br4 | 157.86 (3) | Br7—Ta5—Br10 | 157.47 (3) |
O2—Ta2—Br5 | 78.32 (11) | O5—Ta5—Br11 | 78.92 (13) |
Br3—Ta2—Br5 | 157.20 (3) | Br9—Ta5—Br11 | 157.58 (3) |
Br1—Ta2—Br5 | 88.04 (3) | Br7—Ta5—Br11 | 88.83 (4) |
Br4—Ta2—Br5 | 88.35 (3) | Br10—Ta5—Br11 | 87.70 (4) |
O2—Ta2—Ta3i | 134.95 (11) | O5—Ta5—Ta6 | 134.94 (13) |
Br3—Ta2—Ta3i | 146.17 (2) | Br9—Ta5—Ta6 | 56.27 (3) |
Br1—Ta2—Ta3i | 97.97 (3) | Br7—Ta5—Ta6 | 97.67 (4) |
Br4—Ta2—Ta3i | 98.23 (3) | Br10—Ta5—Ta6 | 97.57 (4) |
Br5—Ta2—Ta3i | 56.63 (3) | Br11—Ta5—Ta6 | 146.14 (2) |
O2—Ta2—Ta1i | 134.18 (11) | O5—Ta5—Ta4 | 133.53 (12) |
Br3—Ta2—Ta1i | 97.46 (2) | Br9—Ta5—Ta4 | 98.19 (3) |
Br1—Ta2—Ta1i | 146.07 (2) | Br7—Ta5—Ta4 | 56.29 (3) |
Br4—Ta2—Ta1i | 56.05 (3) | Br10—Ta5—Ta4 | 146.23 (2) |
Br5—Ta2—Ta1i | 98.49 (3) | Br11—Ta5—Ta4 | 98.19 (3) |
Ta3i—Ta2—Ta1i | 60.26 (2) | Ta6—Ta5—Ta4 | 60.09 (3) |
O2—Ta2—Ta1 | 135.94 (10) | O5—Ta5—Ta6ii | 135.13 (13) |
Br3—Ta2—Ta1 | 97.95 (3) | Br9—Ta5—Ta6ii | 146.16 (2) |
Br1—Ta2—Ta1 | 56.20 (3) | Br7—Ta5—Ta6ii | 98.43 (3) |
Br4—Ta2—Ta1 | 145.92 (3) | Br10—Ta5—Ta6ii | 98.08 (3) |
Br5—Ta2—Ta1 | 98.28 (3) | Br11—Ta5—Ta6ii | 56.24 (3) |
Ta3i—Ta2—Ta1 | 59.96 (3) | Ta6—Ta5—Ta6ii | 89.90 (3) |
Ta1i—Ta2—Ta1 | 89.87 (3) | Ta4—Ta5—Ta6ii | 60.00 (3) |
O2—Ta2—Ta3 | 134.94 (11) | O5—Ta5—Ta4ii | 136.42 (12) |
Br3—Ta2—Ta3 | 56.07 (3) | Br9—Ta5—Ta4ii | 97.80 (3) |
Br1—Ta2—Ta3 | 97.68 (3) | Br7—Ta5—Ta4ii | 146.34 (2) |
Br4—Ta2—Ta3 | 97.28 (3) | Br10—Ta5—Ta4ii | 56.17 (3) |
Br5—Ta2—Ta3 | 146.74 (2) | Br11—Ta5—Ta4ii | 97.39 (3) |
Ta3i—Ta2—Ta3 | 90.10 (3) | Ta6—Ta5—Ta4ii | 60.04 (3) |
Ta1i—Ta2—Ta3 | 59.75 (2) | Ta4—Ta5—Ta4ii | 90.05 (3) |
Ta1—Ta2—Ta3 | 60.00 (2) | Ta6ii—Ta5—Ta4ii | 59.82 (2) |
O3—Ta3—Br3 | 79.82 (14) | O6—Ta6—Br9 | 77.54 (12) |
O3—Ta3—Br6 | 78.32 (13) | O6—Ta6—Br8 | 77.41 (12) |
Br3—Ta3—Br6 | 87.49 (4) | Br9—Ta6—Br8 | 87.77 (3) |
O3—Ta3—Br2 | 79.28 (13) | O6—Ta6—Br11ii | 80.06 (12) |
Br3—Ta3—Br2 | 87.66 (3) | Br9—Ta6—Br11ii | 157.60 (3) |
Br6—Ta3—Br2 | 157.58 (3) | Br8—Ta6—Br11ii | 87.64 (4) |
O3—Ta3—Br5i | 78.30 (14) | O6—Ta6—Br12 | 79.87 (12) |
Br3—Ta3—Br5i | 158.12 (2) | Br9—Ta6—Br12 | 88.28 (3) |
Br6—Ta3—Br5i | 88.20 (3) | Br8—Ta6—Br12 | 157.27 (2) |
Br2—Ta3—Br5i | 88.20 (3) | Br11ii—Ta6—Br12 | 87.53 (4) |
O3—Ta3—Ta2i | 134.59 (13) | O6—Ta6—Ta5 | 133.69 (12) |
Br3—Ta3—Ta2i | 145.59 (2) | Br9—Ta6—Ta5 | 56.18 (3) |
Br6—Ta3—Ta2i | 98.26 (3) | Br8—Ta6—Ta5 | 97.81 (4) |
Br2—Ta3—Ta2i | 98.09 (3) | Br11ii—Ta6—Ta5 | 146.22 (2) |
Br5i—Ta3—Ta2i | 56.29 (3) | Br12—Ta6—Ta5 | 98.53 (3) |
O3—Ta3—Ta1i | 134.68 (13) | O6—Ta6—Ta4 | 133.75 (11) |
Br3—Ta3—Ta1i | 97.25 (3) | Br9—Ta6—Ta4 | 98.09 (3) |
Br6—Ta3—Ta1i | 56.37 (3) | Br8—Ta6—Ta4 | 56.35 (3) |
Br2—Ta3—Ta1i | 146.04 (2) | Br11ii—Ta6—Ta4 | 97.55 (3) |
Br5i—Ta3—Ta1i | 98.15 (3) | Br12—Ta6—Ta4 | 146.38 (2) |
Ta2i—Ta3—Ta1i | 60.119 (19) | Ta5—Ta6—Ta4 | 60.05 (2) |
O3—Ta3—Ta1 | 135.54 (13) | O6—Ta6—Ta4ii | 136.08 (11) |
Br3—Ta3—Ta1 | 97.50 (4) | Br9—Ta6—Ta4ii | 97.90 (3) |
Br6—Ta3—Ta1 | 146.14 (2) | Br8—Ta6—Ta4ii | 146.50 (2) |
Br2—Ta3—Ta1 | 56.27 (3) | Br11ii—Ta6—Ta4ii | 98.00 (3) |
Br5i—Ta3—Ta1 | 98.00 (3) | Br12—Ta6—Ta4ii | 56.23 (3) |
Ta2i—Ta3—Ta1 | 59.92 (3) | Ta5—Ta6—Ta4ii | 60.25 (3) |
Ta1i—Ta3—Ta1 | 89.77 (3) | Ta4—Ta6—Ta4ii | 90.15 (3) |
O3—Ta3—Ta2 | 135.51 (13) | O6—Ta6—Ta5ii | 136.19 (12) |
Br3—Ta3—Ta2 | 55.69 (3) | Br9—Ta6—Ta5ii | 146.27 (2) |
Br6—Ta3—Ta2 | 97.79 (3) | Br8—Ta6—Ta5ii | 98.32 (3) |
Br2—Ta3—Ta2 | 97.48 (3) | Br11ii—Ta6—Ta5ii | 56.13 (3) |
Br5i—Ta3—Ta2 | 146.19 (2) | Br12—Ta6—Ta5ii | 97.36 (3) |
Ta2i—Ta3—Ta2 | 89.90 (3) | Ta5—Ta6—Ta5ii | 90.10 (3) |
Ta1i—Ta3—Ta2 | 59.83 (3) | Ta4—Ta6—Ta5ii | 60.13 (3) |
Ta1—Ta3—Ta2 | 59.75 (2) | Ta4ii—Ta6—Ta5ii | 59.86 (2) |
Ta1—Br1—Ta2 | 67.56 (3) | Ta5—Br7—Ta4 | 67.55 (3) |
Ta3—Br2—Ta1 | 67.69 (3) | Ta6—Br8—Ta4 | 67.43 (3) |
Ta2—Br3—Ta3 | 68.24 (3) | Ta5—Br9—Ta6 | 67.56 (3) |
Ta1i—Br4—Ta2 | 67.51 (3) | Ta5—Br10—Ta4ii | 67.74 (3) |
Ta2—Br5—Ta3i | 67.08 (3) | Ta5—Br11—Ta6ii | 67.63 (3) |
Ta3—Br6—Ta1i | 67.41 (3) | Ta4ii—Br12—Ta6 | 67.47 (3) |
Symmetry codes: (i) −x, −y, −z; (ii) −x, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Ta6Br12(H2O)6](Cl1.6Br0.4)·8H2O |
Mr | 2385.53 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 200 |
a, b, c (Å) | 9.729 (2), 9.823 (2), 19.392 (4) |
α, β, γ (°) | 81.92 (3), 80.28 (3), 80.34 (3) |
V (Å3) | 1788.7 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 32.29 |
Crystal size (mm) | 0.09 × 0.05 × 0.02 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (DENZO-SCALEPACK; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.055, 0.524 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 20232, 10753, 8662 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.713 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.063, 1.04 |
No. of reflections | 10753 |
No. of parameters | 309 |
Δρmax, Δρmin (e Å−3) | 1.62, −2.56 |
Computer programs: COLLECT (Nonius, 1998), DENZO–SCALEPACK (Otwinowski & Minor, 1997), DENZO–SCALEPACK, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ATOMS (Dowty, 2001) and ORTEP-3 (Farrugia, 1997), PLATON (Spek, 1990).
Angle | (I)' | (II)a | (III)a |
Cluster A | |||
(Ta1, Ta2, Ta3) – ab | 75.82 (1) | 78.72 | 78.85 |
(Ta1, Ta2, Ta3) – b | 2.46 (1) | 3.25 | 3.34 |
(Ta1, Ta2, Ta3) – c | 0.82 (1) | 2.14 | 1.98 |
(Ta1, Ta2i, Ta3) – a | 30.06 (1) | 31.11 | 31.03 |
(Ta1, Ta2i, Ta3) – b | 16.49 (1) | 21.08 | 21.34 |
(Ta1, Ta2i, Ta3) – c | 68.66 (1) | 64.78 | 68.82 |
Cluster B | |||
(Ta4, Ta5, Ta6) – a | 75.92 (1) | 75.51 | 76.01 |
(Ta4, Ta5, Ta6) – b | 4.42 (1) | 5.18 | 4.64 |
(Ta4, Ta5, Ta6) – c | 8.08 (1) | 7.15 | 7.18 |
(Ta4, Ta5ii, Ta6) – a | 10.40 (1) | 9.22 | 9.60 |
(Ta4, Ta5ii, Ta6) – b | 36.59 (1) | 37.22 | 37.21 |
(Ta4, Ta5ii, Ta6) – c | 43.88 (1) | 42.42 | 42.21 |
Notes: (a) faces corresponding to (Ta1, Ta2, Ta3), (Ta1, Ta2i, Ta3), (Ta4, Ta5, Ta6) and (Ta4, Ta5ii, Ta6) are (Ta6, Ta5iii, Ta4), (Ta6, Ta5, Ta4), (Ta2iv, Ta1, Ta3iv) and (Ta2iv, Ta1iv, Ta3iv) in (II) and (III) (Vojnović et al., 2002), respectively. (b) The angle between the plane defined by atoms Ta1, Ta2 and Ta3 and the crystallographic a axis. Complete symmetry codes: (i) -x, -y, -z; (ii) -x, -y, 1-y; (iii) 1-x, -y, 1-z; (iv) 1-x, -y, -y. |
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The (M6X12)X2·8H2O (M = Nb, Ta; X = Cl, Br) and (M6X12)X2·6ROH (R = CH3, C2H5) cluster compounds are usually used as starting materials for reactions in aqueous or non-aqueous media. The only structure within these two series which has thus far been solved is that of [(Ta6Cl12)Cl2(H2O)4]·4H2O (Burbank, 1966). The six Ta atoms form a nearly regular octahedron and the 12 Cl atoms are bridging (µ). The terminal octahedral coordination sites are occupied by four H2O molecules and two Cl atoms in trans positions. The crystal structure determination of the title compound revealed that two additional halogen atoms are not coordinated to the cluster [Ta6Br12]2+ entity.
The structure of the title compound consists of two cluster cations of the same chemical composition, i.e. [Ta6Br12(H2O)6]2+ (denoted A and B; Fig. 1), together with Cl- or Br- as counter-ions and free H2O molecules (Fig. 2). One cluster cation (A) is located at the origin, while the other (B) is located at the centre of inversion with fractional coordinates (0,0,1/2). Thus, both clusters are centrosymmetric and very close to having octahedral Oh symmetry. The Ta—Ta bond lengths of clusters A and B are in the ranges 2.8908 (10)–2.9113 (9) Å (average 2.8981 Å) and 2.8950 (8)–2.9110 (11) Å (average 2.9036 Å), respectively, and are comparable to the average values of 2.898 and 2.9000 (8) Å found for CsEr[(Ta6Br12)Br6] (Cordier et al., 1995) and [Ta6Br12(H2O)6](HgBr4).12H2O (Vojnović et al., 1997), respectively. These values and local charge-neutrality requirements dictate the presence of [Ta6Br12(H2O)6]2+ explicitly. The Ta—Br interatomic distances, with average values of 2.6054 and 2.6110 Å in clusters A and B, respectively, are as expected for [Ta6Br12]2+ (Cordier et al., 1995; Vojnović et al., 1997). The Ta—O bond lengths, in the ranges 2.217 (4)–2.336 (5) and 2.236 (4)–2.254 (4) Å for clusters A and B, respectively, are as expected for Ta—O(H2O) interatomic distances.
Cluster cations A and B form two distinct layers parallel to the ab plane of the unit cell (Fig 2). Each face of the Ta6 octahedron defines a plane which forms three angles with crystallographic axes. The planes of two faces of an octahedron uniquely define the orientation of that cluster in the unit cell. Faces (Ta1, Ta2, Ta3) and (Ta1, Ta2i, Ta3) [symmetry code: (i) -x, -y, -z] define the orientation of clusters A, while faces (Ta4, Ta5, Ta6) and (Ta4, Ta5ii, Ta6) [symmetry code: (ii) -x, -y, 1 - z] define the orientation of clusters B (Table 1 and Fig 2). It is evident that faces (Ta1, Ta2, Ta3) and (Ta4, Ta5, Ta6) have similar orientations [the angle between them is 7.88 (2)°]. In contrast, the angle between the (Ta1, Ta2i, Ta3) and (Ta4, Ta5ii, Ta6) faces is 53.60 (1)°. This means that clusters B are rotated with respect to clusters A by an angle of ~60° around the normal to the (Ta1, Ta2, Ta3) face. By this rotation, and by translation along the c axis by a half of the period, Ta1 coincides with Ta4, Ta2 with Ta5 and Ta3 with Ta6. This is a non-crystallographic symmetry operation and results in the crystallographic independence of the A and B cluster cations. A similar type of crystal packing has been observed recently in the crystal structures of double salts [Ta6Br12(H2O)6]X2.trans-[Ta6Br12(OH)4(H2O)2].18H2O (X = Cl, compound (II), and X = Br, compound (III)], which contain [Ta6Br12]n+, with n = 2 and 4, simultaneously in the same compound (Vojnović et al., 2002). These clusters crystallize in space group P1 with a similar unit cell; the dimensions are a = 9.3264 (2) Å, b = 9.8272 (2) Å, c = 19.0158 (4) Å, α = 80.931 (1)°, β = 81.772 (2)° and γ = 80.691 (1)° for (II), and a = 9.3399 (2) Å, b = 9.8796 (2) Å, c = 19.0494 (4) Å, α = 81.037 (1)°, β = 81.808 (1)° and γ = 80.736 (1)° for (III). The orientations of clusters A and B in the unit cell of compound (I) are compared with the orientations of the corresponding cluster entities in the unit cells of (II) and (III), where trans-[Ta6Br12(OH)4(H2O)2] is denoted as A and [Ta6Br12(H2O)6]2+ as B (Table 1). Considering the clusters of type B, the particular angles are essentially the same for all three compounds. The orientations of the clusters A in (I) differ slightly (to a maximum of 5°) from those in (II) and (III), most probably due to the difference in the chemical composition of [Ta6Br12(H2O)6]2+ in relation to trans-[Ta6Br12(OH)4(H2O)2]. The locations of the counter-ions and free H2O molecules are similar in all three structures with respect to the cluster positions. The positions of the Cl2 counter-anion in (I) (Fig. 2) is occupied by a free H2O molecule (O15) in both (II) and (III).
In conclusion, this analysis indicates that the three structures are isoconfigurational (Lima-de-Faria et al., 1990), in spite of the difference in chemical compositions, the charges of the cluster entities and the number of counter-anions or free H2O molecules. These structures can be used as a starting model in Rietveld refinements for other compounds in this series which crystallize in space group P1 and which have similar values of the unit-cell parameters.