Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802014794/mg6012sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802014794/mg6012Isup2.hkl |
The title compound was prepared fortuitously during attempts to recrystallize CeCl3(Ph3PO)3 from hot acetone by slow cooling and allowing the room-temperature solution to evaporate.
For the refinement in P1, a solution readily emerged and a later electron-density map showed plausible positions for all H atoms [d(O—H) = 0.78–1.05 Å and reasonable H—O—H angles]. H-atom positions were refined ith restraints on d(O—H) [target value of 0.84 (2) Å], two anti-bumping restraints to control short H.·H contacts (on H6B···H6B' and H4A···H3A" of 2.0 Å), and a common refined anisotropic displacement parameter. Inclusion of an extinction correction led to a modest improvement, giving an R1 (all data) value of 0.032.
For the refinement in P1, the reflection intensities were transformed to the cell reported by Peterson et al. (1979). Refinement proceeded using their published coordinates with anisotropic non-H atoms and fixed H atoms. Problems were experienced with non-positive definite anisotropic anisotropic displacement parameter values for several O atoms and large correlation coefficients (ca 0.90). Convergence was slow, yielding an R1 (all data) value of 0.036 but retaining the unsatisfactory anisotropic displacement parameter values.
Data collection: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); cell refinement: COLLECT and DENZO; data reduction: COLLECT and DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976).
[Ce2Cl2(H2O)14]Cl4 | Z = 1 |
Mr = 745.16 | F(000) = 358 |
Triclinic, P1 | Dx = 2.304 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.9018 (5) Å | Cell parameters from 5200 reflections |
b = 8.2096 (10) Å | θ = 2.9–27.5° |
c = 9.1877 (10) Å | µ = 4.98 mm−1 |
α = 70.521 (7)° | T = 120 K |
β = 73.142 (6)° | Block, colourless |
γ = 81.660 (5)° | 0.26 × 0.20 × 0.20 mm |
V = 536.98 (10) Å3 |
Nonius KappaCCD area-detector diffractometer | 1879 independent reflections |
Radiation source: Nonius rotating anode | 1849 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.053 |
ϕ and ω scans | θmax = 25.0°, θmin = 3.0° |
Absorption correction: multi-scan (SORTAV; Blessing, 1997) | h = −9→9 |
Tmin = 0.287, Tmax = 0.369 | k = −9→9 |
7877 measured reflections | l = −10→10 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.030 | H-atom parameters constrained |
wR(F2) = 0.080 | w = 1/[σ2(Fo2) + (0.049P)2 + 0.908P] where P = (Fo2 + 2Fc2)/3 |
S = 1.17 | (Δ/σ)max = 0.004 |
1879 reflections | Δρmax = 2.28 e Å−3 |
144 parameters | Δρmin = −2.39 e Å−3 |
15 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.029 (2) |
[Ce2Cl2(H2O)14]Cl4 | γ = 81.660 (5)° |
Mr = 745.16 | V = 536.98 (10) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.9018 (5) Å | Mo Kα radiation |
b = 8.2096 (10) Å | µ = 4.98 mm−1 |
c = 9.1877 (10) Å | T = 120 K |
α = 70.521 (7)° | 0.26 × 0.20 × 0.20 mm |
β = 73.142 (6)° |
Nonius KappaCCD area-detector diffractometer | 1879 independent reflections |
Absorption correction: multi-scan (SORTAV; Blessing, 1997) | 1849 reflections with I > 2σ(I) |
Tmin = 0.287, Tmax = 0.369 | Rint = 0.053 |
7877 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | 15 restraints |
wR(F2) = 0.080 | H-atom parameters constrained |
S = 1.17 | Δρmax = 2.28 e Å−3 |
1879 reflections | Δρmin = −2.39 e Å−3 |
144 parameters |
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. d(O—H) was restrained to 0.84 Å and two anti-bumping restraints included to short H···H distances. All H atoms were given a common refined adp. The max. and min. features in the difference electron-density map are ca 1 Å from the Ce atom. |
x | y | z | Uiso*/Ueq | ||
Ce1 | 0.21775 (2) | 0.18631 (3) | 0.82399 (2) | 0.00634 (17) | |
Cl1 | 0.14623 (12) | −0.17924 (12) | 0.98564 (12) | 0.0097 (3) | |
Cl2 | 0.78962 (13) | 0.22189 (13) | 0.46539 (13) | 0.0125 (3) | |
Cl3 | 0.34275 (13) | 0.38684 (13) | 0.21261 (13) | 0.0128 (3) | |
O1 | 0.0731 (4) | 0.0816 (4) | 0.6630 (4) | 0.0127 (6) | |
O2 | 0.0307 (4) | 0.4217 (4) | 0.6751 (4) | 0.0131 (7) | |
O3 | 0.2303 (4) | 0.0936 (4) | 1.1152 (4) | 0.0122 (6) | |
O4 | 0.5201 (4) | 0.2292 (4) | 0.8417 (4) | 0.0146 (7) | |
O5 | 0.4510 (4) | −0.0093 (4) | 0.6985 (4) | 0.0132 (7) | |
O6 | 0.3850 (4) | 0.3509 (4) | 0.5503 (4) | 0.0131 (7) | |
O7 | 0.2202 (4) | 0.4603 (4) | 0.8867 (4) | 0.0167 (7) | |
H1A | 0.011 (7) | 0.149 (7) | 0.606 (7) | 0.033 (5)* | |
H1B | 0.126 (8) | −0.004 (6) | 0.637 (8) | 0.033 (5)* | |
H2A | −0.059 (5) | 0.462 (8) | 0.728 (7) | 0.033 (5)* | |
H2B | 0.084 (7) | 0.510 (5) | 0.618 (7) | 0.033 (5)* | |
H3A | 0.255 (8) | 0.174 (6) | 1.143 (8) | 0.033 (5)* | |
H3B | 0.136 (5) | 0.052 (8) | 1.175 (7) | 0.033 (5)* | |
H4A | 0.601 (6) | 0.152 (6) | 0.844 (8) | 0.033 (5)* | |
H4B | 0.562 (8) | 0.309 (6) | 0.855 (8) | 0.033 (5)* | |
H5A | 0.462 (8) | −0.117 (3) | 0.739 (7) | 0.033 (5)* | |
H5B | 0.537 (6) | 0.025 (8) | 0.622 (5) | 0.033 (5)* | |
H6A | 0.357 (8) | 0.372 (8) | 0.463 (5) | 0.033 (5)* | |
H6B | 0.494 (3) | 0.361 (2) | 0.523 (8) | 0.033 (5)* | |
H7A | 0.197 (8) | 0.548 (5) | 0.816 (6) | 0.033 (5)* | |
H7B | 0.255 (8) | 0.455 (9) | 0.966 (5) | 0.033 (5)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ce1 | 0.0038 (2) | 0.0089 (2) | 0.0061 (2) | −0.00300 (11) | −0.00032 (12) | −0.00166 (13) |
Cl1 | 0.0066 (5) | 0.0099 (5) | 0.0106 (5) | −0.0021 (4) | 0.0003 (4) | −0.0018 (4) |
Cl2 | 0.0081 (5) | 0.0132 (5) | 0.0167 (6) | −0.0018 (4) | −0.0023 (4) | −0.0056 (4) |
Cl3 | 0.0117 (5) | 0.0149 (5) | 0.0132 (5) | −0.0017 (4) | −0.0040 (4) | −0.0050 (4) |
O1 | 0.0109 (15) | 0.0137 (16) | 0.0168 (17) | 0.0020 (12) | −0.0070 (12) | −0.0073 (13) |
O2 | 0.0088 (15) | 0.0128 (16) | 0.0127 (16) | −0.0019 (12) | −0.0003 (12) | 0.0011 (13) |
O3 | 0.0108 (15) | 0.0176 (17) | 0.0096 (16) | −0.0082 (12) | −0.0014 (12) | −0.0038 (13) |
O4 | 0.0075 (15) | 0.0186 (17) | 0.0208 (17) | −0.0031 (12) | −0.0045 (13) | −0.0082 (14) |
O5 | 0.0066 (15) | 0.0120 (15) | 0.0171 (17) | −0.0029 (12) | 0.0022 (12) | −0.0030 (13) |
O6 | 0.0064 (15) | 0.0200 (17) | 0.0104 (16) | −0.0042 (12) | 0.0002 (12) | −0.0018 (13) |
O7 | 0.0189 (17) | 0.0144 (16) | 0.0201 (19) | −0.0005 (13) | −0.0094 (14) | −0.0061 (14) |
Ce1—O1 | 2.520 (3) | O2—H2B | 0.83 (2) |
Ce1—O2 | 2.524 (3) | O3—H3A | 0.84 (2) |
Ce1—O3 | 2.554 (3) | O3—H3B | 0.83 (2) |
Ce1—O4 | 2.523 (3) | O4—H4A | 0.84 (2) |
Ce1—O5 | 2.540 (3) | O4—H4B | 0.83 (2) |
Ce1—O6 | 2.494 (3) | O5—H5A | 0.84 (2) |
Ce1—O7 | 2.505 (3) | O5—H5B | 0.83 (2) |
Ce1—Cl1i | 2.8979 (10) | O6—H6A | 0.85 (2) |
Ce1—Cl1 | 2.9264 (10) | O6—H6B | 0.83 (2) |
O1—H1A | 0.83 (2) | O7—H7A | 0.84 (2) |
O1—H1B | 0.83 (2) | O7—H7B | 0.84 (2) |
O2—H2A | 0.83 (2) | ||
O6—Ce1—O7 | 84.21 (11) | O1—Ce1—Cl1 | 70.99 (8) |
O6—Ce1—O1 | 81.02 (10) | O4—Ce1—Cl1 | 107.49 (8) |
O7—Ce1—O1 | 137.56 (10) | O2—Ce1—Cl1 | 128.49 (7) |
O6—Ce1—O4 | 72.83 (11) | O5—Ce1—Cl1 | 68.40 (7) |
O7—Ce1—O4 | 68.64 (11) | O3—Ce1—Cl1 | 68.24 (7) |
O1—Ce1—O4 | 140.84 (10) | Cl1i—Ce1—Cl1 | 73.92 (3) |
O6—Ce1—O2 | 66.65 (10) | Ce1i—Cl1—Ce1 | 106.08 (3) |
O7—Ce1—O2 | 70.18 (11) | Ce1—O1—H1A | 121 (5) |
O1—Ce1—O2 | 67.42 (10) | Ce1—O1—H1B | 114 (5) |
O4—Ce1—O2 | 123.90 (10) | H1A—O1—H1B | 119 (7) |
O6—Ce1—O5 | 69.09 (10) | Ce1—O2—H2A | 118 (5) |
O7—Ce1—O5 | 135.21 (10) | Ce1—O2—H2B | 114 (5) |
O1—Ce1—O5 | 74.32 (10) | H2A—O2—H2B | 102 (6) |
O4—Ce1—O5 | 69.39 (10) | Ce1—O3—H3A | 114 (5) |
O2—Ce1—O5 | 124.57 (11) | Ce1—O3—H3B | 110 (5) |
O6—Ce1—O3 | 141.08 (10) | H3A—O3—H3B | 110 (6) |
O7—Ce1—O3 | 74.08 (11) | Ce1—O4—H4A | 123 (4) |
O4—Ce1—O3 | 69.30 (10) | Ce1—O4—H4B | 133 (4) |
O2—Ce1—O3 | 130.68 (10) | H4A—O4—H4B | 104 (6) |
O5—Ce1—O3 | 104.73 (10) | Ce1—O5—H5A | 124 (5) |
O6—Ce1—Cl1i | 136.56 (7) | Ce1—O5—H5B | 125 (4) |
O7—Ce1—Cl1i | 84.37 (8) | H5A—O5—H5B | 110 (6) |
O1—Ce1—Cl1i | 79.75 (7) | Ce1—O6—H6A | 128 (5) |
O4—Ce1—Cl1i | 138.74 (8) | Ce1—O6—H6B | 124 (4) |
O2—Ce1—Cl1i | 70.04 (7) | H6A—O6—H6B | 104 (6) |
O5—Ce1—Cl1i | 139.40 (7) | Ce1—O7—H7A | 112 (5) |
O3—Ce1—Cl1i | 73.70 (7) | Ce1—O7—H7B | 119 (5) |
O6—Ce1—Cl1 | 133.84 (8) | H7A—O7—H7B | 128 (7) |
O7—Ce1—Cl1 | 140.38 (8) |
Symmetry code: (i) −x, −y, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···Cl2ii | 0.83 (2) | 2.36 (3) | 3.139 (3) | 155 (6) |
O1—H1B···Cl2iii | 0.83 (2) | 2.22 (3) | 3.034 (3) | 165 (6) |
O2—H2A···Cl3iv | 0.83 (2) | 2.41 (3) | 3.196 (3) | 159 (6) |
O2—H2B···Cl2v | 0.83 (2) | 2.35 (3) | 3.141 (3) | 162 (6) |
O3—H3A···Cl3vi | 0.84 (2) | 2.30 (2) | 3.147 (3) | 176 (6) |
O3—H3B···O1i | 0.83 (2) | 2.04 (2) | 2.860 (4) | 172 (6) |
O4—H4A···O3vii | 0.84 (2) | 2.23 (2) | 3.050 (5) | 167 (6) |
O4—H4A···Cl1vii | 0.84 (2) | 2.94 (6) | 3.364 (3) | 114 (5) |
O4—H4B···Cl3v | 0.83 (2) | 2.53 (3) | 3.315 (3) | 157 (6) |
O5—H5A···Cl3iii | 0.84 (2) | 2.50 (4) | 3.247 (3) | 149 (6) |
O5—H5B···Cl2 | 0.83 (2) | 2.53 (3) | 3.284 (3) | 153 (6) |
O6—H6A···Cl3 | 0.85 (2) | 2.30 (3) | 3.128 (3) | 166 (6) |
O6—H6B···O6v | 0.83 (2) | 2.49 (1) | 2.993 (6) | 120 (1) |
O6—H6B···Cl2 | 0.83 (2) | 2.44 (2) | 3.174 (3) | 148 (1) |
O7—H7A···Cl2v | 0.84 (2) | 2.62 (3) | 3.426 (4) | 161 (6) |
O7—H7B···Cl3vi | 0.84 (2) | 2.43 (2) | 3.252 (4) | 170 (6) |
Symmetry codes: (i) −x, −y, −z+2; (ii) x−1, y, z; (iii) −x+1, −y, −z+1; (iv) −x, −y+1, −z+1; (v) −x+1, −y+1, −z+1; (vi) x, y, z+1; (vii) −x+1, −y, −z+2. |
Experimental details
Crystal data | |
Chemical formula | [Ce2Cl2(H2O)14]Cl4 |
Mr | 745.16 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 120 |
a, b, c (Å) | 7.9018 (5), 8.2096 (10), 9.1877 (10) |
α, β, γ (°) | 70.521 (7), 73.142 (6), 81.660 (5) |
V (Å3) | 536.98 (10) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 4.98 |
Crystal size (mm) | 0.26 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (SORTAV; Blessing, 1997) |
Tmin, Tmax | 0.287, 0.369 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7877, 1879, 1849 |
Rint | 0.053 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.080, 1.17 |
No. of reflections | 1879 |
No. of parameters | 144 |
No. of restraints | 15 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 2.28, −2.39 |
Computer programs: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997), COLLECT and DENZO, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976).
Ce1—O1 | 2.520 (3) | Ce1—O6 | 2.494 (3) |
Ce1—O2 | 2.524 (3) | Ce1—O7 | 2.505 (3) |
Ce1—O3 | 2.554 (3) | Ce1—Cl1i | 2.8979 (10) |
Ce1—O4 | 2.523 (3) | Ce1—Cl1 | 2.9264 (10) |
Ce1—O5 | 2.540 (3) | ||
O6—Ce1—O2 | 66.65 (10) | O2—Ce1—O3 | 130.68 (10) |
O7—Ce1—O2 | 70.18 (11) | O2—Ce1—Cl1i | 70.04 (7) |
O1—Ce1—O2 | 67.42 (10) | O2—Ce1—Cl1 | 128.49 (7) |
O4—Ce1—O2 | 123.90 (10) | Cl1i—Ce1—Cl1 | 73.92 (3) |
O2—Ce1—O5 | 124.57 (11) |
Symmetry code: (i) −x, −y, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···Cl2ii | 0.83 (2) | 2.36 (3) | 3.139 (3) | 155 (6) |
O1—H1B···Cl2iii | 0.83 (2) | 2.22 (3) | 3.034 (3) | 165 (6) |
O2—H2A···Cl3iv | 0.83 (2) | 2.41 (3) | 3.196 (3) | 159 (6) |
O2—H2B···Cl2v | 0.83 (2) | 2.35 (3) | 3.141 (3) | 162 (6) |
O3—H3A···Cl3vi | 0.84 (2) | 2.30 (2) | 3.147 (3) | 176 (6) |
O3—H3B···O1i | 0.83 (2) | 2.04 (2) | 2.860 (4) | 172 (6) |
O4—H4A···O3vii | 0.84 (2) | 2.23 (2) | 3.050 (5) | 167 (6) |
O4—H4B···Cl3v | 0.83 (2) | 2.53 (3) | 3.315 (3) | 157 (6) |
O5—H5A···Cl3iii | 0.84 (2) | 2.50 (4) | 3.247 (3) | 149 (6) |
O5—H5B···Cl2 | 0.83 (2) | 2.53 (3) | 3.284 (3) | 153 (6) |
O6—H6A···Cl3 | 0.85 (2) | 2.30 (3) | 3.128 (3) | 166 (6) |
O6—H6B···O6v | 0.83 (2) | 2.489 (12) | 2.993 (6) | 120.1 (11) |
O6—H6B···Cl2 | 0.83 (2) | 2.44 (2) | 3.174 (3) | 147.7 (10) |
O7—H7B···Cl3vi | 0.84 (2) | 2.43 (2) | 3.252 (4) | 170 (6) |
Symmetry codes: (i) −x, −y, −z+2; (ii) x−1, y, z; (iii) −x+1, −y, −z+1; (iv) −x, −y+1, −z+1; (v) −x+1, −y+1, −z+1; (vi) x, y, z+1; (vii) −x+1, −y, −z+2. |
The structure of CeCl3·7H2O has been reported (Peterson et al., 1979) along with the isomorphous La (Habenschuss & Spedding, 1979) and Pr compounds (Habenschuss & Spedding, 1978). These heptahydrates are only found for the early rare earths; the later rare earths form hexahydrates. The La and Pr compounds were refined in space group P1 (No. 2), whereas the Ce compound was refined in P1 (No. 1), this latter decision being heavily influenced by the observation of a piezoelectric effect in the La compound (Bakakin et al., 1974). The structures of MCl3·7H2O all contain nine-coordinate M derived from seven water molecules and two bridging Cl atoms forming a dimeric 4+ cation. Inspection of the non-H coordinates of the Ce compound clearly shows that those related by the (pseudo) `centre of symmetry' lie within 3σ for many of the atoms (approximately 2/3 of the 30 non-H x, y, and z pairs).
The problem of whether to refine in a centrosymmetric space group or not, as well as identifying the crystal system and Laue group, has been well addressed: `··· it simply cannot be determined, by diffraction methods alone, whether a particular structure is centrosymmetric or only approximately so' (Marsh, 1995, 1999). Marsh adopts a pragmatic view in which a centrosymmetric space group should be used if at all possible; only if it is found to be unsatisfactory should the noncentrosymmetric space group be explored, recognizing the well known problems that will probably occur. Warnings against the Hamilton R ratio test (Hamilton, 1965) to resolve the centre of symmetry problem have also been voiced (Baur & Tillmanns, 1986; Marsh, 1995, 1997).
The redetermined structure was solved in space group P1. Note that the unit cell is a reduced cell (type I with all angles acute). The coordination around Ce is a capped square antiprism, with O2 as the capping atom (Fig. 1). All the H atoms are involved in either O—H···O [shortest 2.860 (4) Å] or mainly O—H···Cl [shortest 3.034 (3) Å] hydrogen bonding. Peterson et al. (1979) also commented on short H···H contacts.
In the corresponding refinement in the noncentrosymmetric space group P1, the s.u. values for Ce—O were ca 0.01 Å, with the difference between (pseudo)symmetry related Ce—O distances ranging from 0.01 (O3/O4) to 0.13 Å (O13/O14) [Peterson et al. (1979) atom labelling scheme]. As noted before (Marsh, 1995), the mean of the pairs of (pseudo)centrosymmetric bond lengths in P1 are close to the single value in P1. For example, using our data, the mean of Ce1—O1 [2.549 (12) Å] and Ce2—O2 [2.449 (11) Å] in P1 is similar to the corresponding Ce1—O6 distance [2.494 (3) Å] in P1.
Taking the crystallographic data in isolation, it is clear that the refinement in P1 is more satisfactory, providing as good a fit to the data without the refinement problems encountered in P1.