Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270111043587/gz3201sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270111043587/gz3201Isup2.hkl | |
Chemdraw file https://doi.org/10.1107/S0108270111043587/gz3201Isup3.cdx |
CCDC reference: 855954
All reagents were commercial and were used as received. The title compound, (I), was prepared by adding an aqueous solution of CsOH (1.2 M) to an aqueous solution of {[Co(H2O)4][Co2(C6H5O7)2(H2O)4].6H2O}n (Zhou et al., 2005) (0.81 g, 1.00 mmol) until the pH reached 7–8. The resulting mixture was stirred for 30 min and filtered. The addition of 3,3'-thiodipropanol (98%) to the solution produced small quantities of red [Please clarify - pink given in CIF tables] crystals of (I) with cubic morphology after several months at room temperature.
The caesium site, Cs1, was refined with an occupancy of 0.5, which gives charge balance for the structure as a whole and results in displacement parameters for Cs1 in line with those of the rest of the structure. Citrate methylene H atoms were added at calculated positions (C—H = 0.99 Å) and refined as riding, with Uiso(H) = 1.2Ueq(C). For the seven water sites present in the asymmetric unit, of which four are bound to Co, a total of ten H atoms were located in difference maps and included as riding, with Uiso(H) = 1.2Ueq(O). We did not force or otherwise attempt to idealize the O—H distances. Atom O4W is located on a twofold axis and its unique H atom was located. Three H atoms were omitted, namely the two on O2W and one on O6W. The two H atoms attached to O6W were initially placed at positions calculated for donor H atoms in the two interactions in which O6W must be donor. Specifically, O6W must be the donor in hydrogen bonds to O2W [D···A = 2.882 (5) Å] and O7Wiv [symmetry code: (iv) x - 1/3, -y + 1/2, -z + 3/2; D···A = 2.785 (7) Å], because O2W and O7W have two clear hydrogen-bonding contacts each to unprotonated O atoms, and so O2W and O7Wiv must be the acceptors in their interactions with O6W. Nevertheless, the position of the H atom involved in a putative hydrogen bond from O6W to O2W could not be verified in an omit map, and so this H atom was removed from the model. One H atom attached to O2W, and which is likely the donor in an interaction with O7 [D···A = 2.782 (5) Å], was neither observed in a difference map nor placed at a calculated position, because there exists the possibility of minor disorder components in which the second H atom on O2W donates to O1W [2.991 (5) Å] or to O2Wv [symmetry code: (v) -x + 1, -y, z; D···A = 2.919 (8) Å]. Following refinement, two difference peaks with densities of 1.58 and 1.15 e Å-3 were found at 0.79 and 1.06 Å, respectively, from Cs1.
Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, (2007); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
Cs2[Co(H2O)6][Co6(C6H4O7)4(H2O)8]·12H2O | Dx = 2.036 Mg m−3 |
Mr = 1899.11 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, P421c | Cell parameters from 8136 reflections |
a = 12.5738 (1) Å | θ = 4.2–28.8° |
c = 19.5895 (3) Å | µ = 3.11 mm−1 |
V = 3097.11 (6) Å3 | T = 100 K |
Z = 2 | Block, pink |
F(000) = 1886 | 0.16 × 0.14 × 0.10 mm |
Oxford Xcalibur, Sapphire3 diffractometer | 3677 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 3128 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.038 |
Detector resolution: 16.0655 pixels mm-1 | θmax = 28.8°, θmin = 4.2° |
ω scans | h = −13→16 |
Absorption correction: multi-scan (multi-scan absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm; Oxford Diffraction, 2010) | k = −15→16 |
Tmin = 0.790, Tmax = 1.000 | l = −25→21 |
14807 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.037 | H-atom parameters constrained |
wR(F2) = 0.094 | w = 1/[σ2(Fo2) + (0.059P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max = 0.001 |
3677 reflections | Δρmax = 1.58 e Å−3 |
202 parameters | Δρmin = −0.45 e Å−3 |
0 restraints | Absolute structure: Flack (1983), with how many Friedel pairs? |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.04 (2) |
Cs2[Co(H2O)6][Co6(C6H4O7)4(H2O)8]·12H2O | Z = 2 |
Mr = 1899.11 | Mo Kα radiation |
Tetragonal, P421c | µ = 3.11 mm−1 |
a = 12.5738 (1) Å | T = 100 K |
c = 19.5895 (3) Å | 0.16 × 0.14 × 0.10 mm |
V = 3097.11 (6) Å3 |
Oxford Xcalibur, Sapphire3 diffractometer | 3677 independent reflections |
Absorption correction: multi-scan (multi-scan absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm; Oxford Diffraction, 2010) | 3128 reflections with I > 2σ(I) |
Tmin = 0.790, Tmax = 1.000 | Rint = 0.038 |
14807 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | H-atom parameters constrained |
wR(F2) = 0.094 | Δρmax = 1.58 e Å−3 |
S = 1.02 | Δρmin = −0.45 e Å−3 |
3677 reflections | Absolute structure: Flack (1983), with how many Friedel pairs? |
202 parameters | Absolute structure parameter: 0.04 (2) |
0 restraints |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Co1 | 0.43328 (4) | 0.39047 (4) | 0.55493 (3) | 0.01208 (13) | |
O1 | 0.5910 (2) | 0.4417 (2) | 0.55095 (14) | 0.0131 (5) | |
C1 | 0.6707 (3) | 0.3870 (3) | 0.5883 (2) | 0.0140 (8) | |
C2 | 0.7240 (3) | 0.3037 (3) | 0.5415 (2) | 0.0149 (8) | |
O2 | 0.6967 (2) | 0.2990 (2) | 0.47954 (14) | 0.0170 (6) | |
O3 | 0.7891 (3) | 0.2410 (3) | 0.56827 (15) | 0.0234 (7) | |
C3 | 0.7557 (3) | 0.4652 (3) | 0.6125 (2) | 0.0179 (9) | |
H3A | 0.7840 | 0.5045 | 0.5726 | 0.021* | |
H3B | 0.8152 | 0.4252 | 0.6333 | 0.021* | |
C4 | 0.7115 (4) | 0.5447 (4) | 0.6647 (2) | 0.0215 (10) | |
O4 | 0.6366 (2) | 0.6046 (2) | 0.64869 (16) | 0.0182 (6) | |
O5 | 0.7518 (3) | 0.5467 (4) | 0.7231 (2) | 0.0537 (13) | |
C5 | 0.6226 (3) | 0.3269 (3) | 0.6496 (2) | 0.0153 (8) | |
H5A | 0.6805 | 0.3054 | 0.6810 | 0.018* | |
H5B | 0.5744 | 0.3752 | 0.6749 | 0.018* | |
C6 | 0.5616 (3) | 0.2295 (3) | 0.6279 (2) | 0.0157 (8) | |
O6 | 0.4933 (2) | 0.2400 (2) | 0.57999 (14) | 0.0173 (6) | |
O7 | 0.5827 (2) | 0.1428 (2) | 0.65632 (17) | 0.0217 (7) | |
Co2 | 0.5000 | 0.0000 | 0.65049 (4) | 0.02063 (19) | |
O1W | 0.3958 (3) | 0.0553 (3) | 0.57394 (18) | 0.0325 (8) | |
H1WA | 0.4191 | 0.1212 | 0.5556 | 0.039* | |
H1WB | 0.3903 | 0.0117 | 0.5339 | 0.039* | |
O2W | 0.4055 (3) | 0.0674 (3) | 0.72630 (19) | 0.0393 (10) | |
Co3 | 0.0000 | 0.0000 | 0.5000 | 0.0159 (2) | |
O3W | 0.1570 (2) | 0.0513 (2) | 0.50292 (17) | 0.0231 (7) | |
H3WA | 0.1912 | 0.1000 | 0.4841 | 0.028* | |
H3WB | 0.2027 | 0.0033 | 0.4977 | 0.028* | |
O4W | 0.0000 | 0.0000 | 0.3925 (2) | 0.0383 (12) | |
H4WA | 0.0561 | 0.0371 | 0.3653 | 0.046* | |
Cs1 | 0.22000 (5) | 0.17011 (5) | 0.65067 (3) | 0.03163 (16) | 0.50 |
O5W | 0.3296 (3) | −0.0710 (3) | 0.46224 (17) | 0.0300 (8) | |
H5WA | 0.3369 | −0.0520 | 0.4178 | 0.036* | |
H5WB | 0.3294 | −0.1432 | 0.4731 | 0.036* | |
O6W | 0.5222 (3) | 0.1987 (3) | 0.82087 (17) | 0.0420 (10) | |
H6WA | 0.4767 | 0.2486 | 0.8214 | 0.050* | |
O7W | 0.8722 (4) | 0.1384 (3) | 0.6775 (2) | 0.0514 (12) | |
H7WA | 0.8197 | 0.1757 | 0.6493 | 0.062* | |
H7WB | 0.8353 | 0.1284 | 0.7172 | 0.062* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Co1 | 0.0120 (3) | 0.0134 (3) | 0.0108 (2) | −0.0008 (2) | −0.0003 (2) | 0.0009 (2) |
O1 | 0.0115 (13) | 0.0163 (14) | 0.0115 (12) | 0.0000 (11) | −0.0021 (11) | 0.0018 (12) |
C1 | 0.014 (2) | 0.0128 (19) | 0.0155 (19) | 0.0017 (17) | 0.0009 (16) | 0.0034 (16) |
C2 | 0.0135 (19) | 0.015 (2) | 0.016 (2) | 0.0018 (16) | 0.0026 (16) | 0.0034 (15) |
O2 | 0.0202 (16) | 0.0164 (15) | 0.0143 (14) | 0.0054 (12) | 0.0006 (11) | −0.0001 (11) |
O3 | 0.0242 (16) | 0.0291 (17) | 0.0167 (16) | 0.0117 (14) | 0.0021 (12) | 0.0027 (13) |
C3 | 0.014 (2) | 0.023 (2) | 0.016 (2) | −0.0031 (18) | −0.0032 (16) | 0.0016 (16) |
C4 | 0.021 (2) | 0.022 (2) | 0.021 (2) | −0.001 (2) | −0.0058 (18) | −0.0035 (17) |
O4 | 0.0209 (15) | 0.0155 (14) | 0.0181 (15) | 0.0002 (12) | −0.0028 (13) | −0.0017 (13) |
O5 | 0.057 (3) | 0.071 (3) | 0.033 (2) | 0.039 (2) | −0.033 (2) | −0.030 (2) |
C5 | 0.020 (2) | 0.0152 (19) | 0.0106 (17) | 0.0002 (16) | −0.0015 (17) | −0.0016 (17) |
C6 | 0.015 (2) | 0.019 (2) | 0.0133 (18) | 0.0010 (18) | 0.0055 (16) | 0.0003 (16) |
O6 | 0.0168 (14) | 0.0178 (14) | 0.0174 (14) | 0.0033 (13) | −0.0045 (12) | 0.0009 (11) |
O7 | 0.0262 (17) | 0.0156 (14) | 0.0231 (16) | −0.0028 (13) | −0.0086 (14) | 0.0086 (13) |
Co2 | 0.0311 (4) | 0.0171 (4) | 0.0137 (4) | −0.0077 (4) | 0.000 | 0.000 |
O1W | 0.043 (2) | 0.0254 (17) | 0.0294 (19) | −0.0150 (17) | −0.0103 (16) | 0.0054 (14) |
O2W | 0.055 (3) | 0.0301 (19) | 0.033 (2) | −0.0101 (19) | 0.0152 (18) | −0.0113 (16) |
Co3 | 0.0145 (3) | 0.0145 (3) | 0.0185 (5) | 0.000 | 0.000 | 0.000 |
O3W | 0.0152 (15) | 0.0196 (15) | 0.0344 (18) | −0.0039 (13) | −0.0005 (14) | 0.0032 (15) |
O4W | 0.052 (3) | 0.043 (3) | 0.019 (2) | −0.020 (3) | 0.000 | 0.000 |
Cs1 | 0.0369 (3) | 0.0339 (3) | 0.0241 (3) | 0.0018 (3) | 0.0074 (3) | 0.0039 (3) |
O5W | 0.0390 (19) | 0.0255 (17) | 0.0257 (19) | 0.0083 (16) | 0.0026 (15) | 0.0013 (14) |
O6W | 0.064 (3) | 0.041 (2) | 0.0208 (18) | −0.002 (2) | −0.0087 (17) | −0.0089 (15) |
O7W | 0.073 (3) | 0.054 (3) | 0.027 (2) | 0.032 (2) | 0.011 (2) | 0.0128 (18) |
Co1—O4i | 2.037 (3) | C6—O7 | 1.253 (5) |
Co1—O1 | 2.087 (3) | C6—O6 | 1.279 (5) |
Co1—O1ii | 2.090 (3) | O7—Co2 | 2.078 (3) |
Co1—O6 | 2.096 (3) | Co2—O7iv | 2.078 (3) |
Co1—O2ii | 2.124 (3) | Co2—O2W | 2.082 (4) |
Co1—O1i | 2.134 (3) | Co2—O1W | 2.109 (4) |
O1—C1 | 1.419 (5) | O1W—Cs1 | 3.038 (4) |
O1—Co1iii | 2.090 (3) | O1W—H1WA | 0.9497 |
O1—Co1i | 2.134 (3) | O1W—H1WB | 0.9600 |
C1—C3 | 1.527 (6) | O2W—Cs1 | 3.050 (4) |
C1—C5 | 1.542 (6) | Co3—O3W | 2.078 (3) |
C1—C2 | 1.545 (6) | Co3—O4W | 2.106 (5) |
C2—O3 | 1.252 (5) | O3W—Cs1 | 3.352 (3) |
C2—O2 | 1.262 (5) | O3W—H3WA | 0.8339 |
O2—Co1iii | 2.124 (3) | O3W—H3WB | 0.8401 |
O2—Cs1iii | 3.209 (3) | O4W—H4WA | 0.9993 |
C3—C4 | 1.534 (6) | Cs1—O6Wv | 3.036 (4) |
C3—H3A | 0.9900 | Cs1—O2ii | 3.209 (3) |
C3—H3B | 0.9900 | Cs1—O4i | 3.358 (3) |
C4—O4 | 1.247 (5) | O5W—H5WA | 0.9076 |
C4—O5 | 1.251 (6) | O5W—H5WB | 0.9314 |
O4—Co1i | 2.037 (3) | O6W—Cs1vi | 3.036 (4) |
O4—Cs1i | 3.358 (3) | O6W—H6WA | 0.8495 |
C5—C6 | 1.506 (6) | O7W—H7WA | 0.9800 |
C5—H5A | 0.9900 | O7W—H7WB | 0.9150 |
C5—H5B | 0.9900 | ||
O4i—Co1—O1 | 115.75 (12) | O7—C6—C5 | 118.3 (4) |
O4i—Co1—O1ii | 155.97 (11) | O6—C6—C5 | 117.7 (4) |
O1—Co1—O1ii | 83.14 (12) | C6—O6—Co1 | 120.4 (3) |
O4i—Co1—O6 | 88.35 (11) | C6—O6—Cs1 | 108.4 (2) |
O1—Co1—O6 | 86.86 (11) | Co1—O6—Cs1 | 88.20 (10) |
O1ii—Co1—O6 | 108.35 (11) | C6—O7—Co2 | 128.4 (3) |
O4i—Co1—O2ii | 87.66 (12) | O7—Co2—O7iv | 173.69 (19) |
O1—Co1—O2ii | 154.59 (11) | O7—Co2—O2Wiv | 91.55 (13) |
O1ii—Co1—O2ii | 77.41 (11) | O7—Co2—O2W | 83.94 (14) |
O6—Co1—O2ii | 83.95 (12) | O2Wiv—Co2—O2W | 89.0 (2) |
O4i—Co1—O1i | 86.63 (11) | O7—Co2—O1W | 93.75 (12) |
O1—Co1—O1i | 80.19 (11) | O2W—Co2—O1W | 91.06 (15) |
O1ii—Co1—O1i | 82.01 (11) | O7—Co2—O1Wiv | 90.74 (13) |
O6—Co1—O1i | 162.42 (11) | O2W—Co2—O1Wiv | 174.68 (14) |
O2ii—Co1—O1i | 112.64 (11) | O1W—Co2—O1Wiv | 89.4 (2) |
C1—O1—Co1 | 120.1 (2) | Co2—O1W—Cs1 | 104.88 (14) |
C1—O1—Co1iii | 114.2 (2) | Co2—O1W—H1WA | 111.4 |
Co1—O1—Co1iii | 97.31 (11) | Cs1—O1W—H1WA | 89.8 |
C1—O1—Co1i | 124.2 (2) | Co2—O1W—H1WB | 115.9 |
Co1—O1—Co1i | 99.65 (11) | Cs1—O1W—H1WB | 128.6 |
Co1iii—O1—Co1i | 95.87 (11) | H1WA—O1W—H1WB | 102.2 |
O1—C1—C3 | 110.0 (3) | Co2—O2W—Cs1 | 105.20 (15) |
O1—C1—C5 | 111.2 (3) | O3W—Co3—O3Wvii | 176.85 (18) |
C3—C1—C5 | 110.4 (3) | O3W—Co3—O3Wviii | 90.043 (5) |
O1—C1—C2 | 109.1 (3) | O3W—Co3—O4Wix | 88.42 (9) |
C3—C1—C2 | 108.5 (3) | O3W—Co3—O4W | 91.58 (9) |
C5—C1—C2 | 107.5 (3) | O4Wix—Co3—O4W | 180.0 |
O3—C2—O2 | 123.4 (4) | Co3—O3W—Cs1 | 112.75 (12) |
O3—C2—C1 | 117.5 (4) | Co3—O3W—H3WA | 134.9 |
O2—C2—C1 | 119.0 (4) | Cs1—O3W—H3WA | 86.2 |
C2—O2—Co1iii | 114.1 (3) | Co3—O3W—H3WB | 115.0 |
C2—O2—Cs1iii | 129.6 (3) | Cs1—O3W—H3WB | 105.3 |
Co1iii—O2—Cs1iii | 105.23 (10) | H3WA—O3W—H3WB | 96.9 |
C1—C3—C4 | 111.9 (4) | Co3—O4W—H4WA | 122.2 |
C1—C3—H3A | 109.2 | O6Wv—Cs1—O1W | 160.92 (9) |
C4—C3—H3A | 109.2 | O6Wv—Cs1—O2W | 140.11 (10) |
C1—C3—H3B | 109.2 | O1W—Cs1—O2W | 58.85 (9) |
C4—C3—H3B | 109.2 | O6Wv—Cs1—O2ii | 96.65 (9) |
H3A—C3—H3B | 107.9 | O1W—Cs1—O2ii | 68.25 (8) |
O4—C4—O5 | 121.5 (4) | O2W—Cs1—O2ii | 111.74 (9) |
O4—C4—C3 | 120.0 (4) | O6Wv—Cs1—O3W | 101.96 (9) |
O5—C4—C3 | 118.5 (4) | O1W—Cs1—O3W | 62.16 (8) |
C4—O4—Co1i | 124.8 (3) | O2W—Cs1—O3W | 114.31 (9) |
C4—O4—Cs1i | 95.8 (3) | O2ii—Cs1—O3W | 67.62 (8) |
Co1i—O4—Cs1i | 102.51 (11) | O6Wv—Cs1—O4i | 89.05 (10) |
C4—O5—Cs1vi | 123.5 (3) | O1W—Cs1—O4i | 90.25 (8) |
C6—C5—C1 | 112.2 (3) | O2W—Cs1—O4i | 87.24 (8) |
C6—C5—H5A | 109.2 | O2ii—Cs1—O4i | 52.01 (8) |
C1—C5—H5A | 109.2 | O3W—Cs1—O4i | 119.52 (8) |
C6—C5—H5B | 109.2 | H5WA—O5W—H5WB | 118.5 |
C1—C5—H5B | 109.2 | Cs1vi—O6W—H6WA | 98.5 |
H5A—C5—H5B | 107.9 | H7WA—O7W—H7WB | 101.7 |
O7—C6—O6 | 123.9 (4) | ||
O4i—Co1—O1—C1 | 62.1 (3) | O4i—Co1—O6—C6 | −65.7 (3) |
O1ii—Co1—O1—C1 | −133.5 (3) | O1—Co1—O6—C6 | 50.2 (3) |
O6—Co1—O1—C1 | −24.5 (3) | O1ii—Co1—O6—C6 | 131.9 (3) |
O2ii—Co1—O1—C1 | −93.4 (4) | O2ii—Co1—O6—C6 | −153.5 (3) |
O1i—Co1—O1—C1 | 143.5 (2) | O1i—Co1—O6—C6 | 7.7 (6) |
O4i—Co1—O1—Co1iii | −174.41 (10) | O4i—Co1—O6—Cs1 | 44.62 (9) |
O1ii—Co1—O1—Co1iii | −9.98 (11) | O1—Co1—O6—Cs1 | 160.52 (9) |
O6—Co1—O1—Co1iii | 98.93 (11) | O1ii—Co1—O6—Cs1 | −117.77 (9) |
O2ii—Co1—O1—Co1iii | 30.1 (3) | O2ii—Co1—O6—Cs1 | −43.21 (8) |
O1i—Co1—O1—Co1iii | −93.01 (10) | O1i—Co1—O6—Cs1 | 118.0 (4) |
O4i—Co1—O1—Co1i | −77.16 (14) | O6—C6—O7—Co2 | −12.7 (6) |
O1ii—Co1—O1—Co1i | 87.28 (11) | C5—C6—O7—Co2 | 169.5 (3) |
O6—Co1—O1—Co1i | −163.81 (12) | C6—O7—Co2—O2Wiv | −171.9 (4) |
O2ii—Co1—O1—Co1i | 127.4 (2) | C6—O7—Co2—O2W | −83.1 (4) |
O1i—Co1—O1—Co1i | 4.24 (16) | C6—O7—Co2—O1W | 7.6 (4) |
Co1—O1—C1—C3 | −146.9 (3) | C6—O7—Co2—O1Wiv | 97.0 (4) |
Co1iii—O1—C1—C3 | 98.2 (3) | O7—Co2—O1W—Cs1 | −84.63 (13) |
Co1i—O1—C1—C3 | −17.9 (4) | O7iv—Co2—O1W—Cs1 | 90.94 (12) |
Co1—O1—C1—C5 | −24.2 (4) | O2W—Co2—O1W—Cs1 | −0.63 (13) |
Co1iii—O1—C1—C5 | −139.1 (3) | O1Wiv—Co2—O1W—Cs1 | −175.32 (18) |
Co1i—O1—C1—C5 | 104.7 (3) | O7—Co2—O2W—Cs1 | 94.28 (13) |
Co1—O1—C1—C2 | 94.3 (3) | O7iv—Co2—O2W—Cs1 | −90.14 (14) |
Co1iii—O1—C1—C2 | −20.7 (4) | O2Wiv—Co2—O2W—Cs1 | −174.1 (2) |
Co1i—O1—C1—C2 | −136.8 (3) | O1W—Co2—O2W—Cs1 | 0.62 (13) |
O1—C1—C2—O3 | −173.1 (3) | O3Wviii—Co3—O3W—Cs1 | 69.27 (10) |
C3—C1—C2—O3 | 67.1 (5) | O3Wix—Co3—O3W—Cs1 | −113.88 (15) |
C5—C1—C2—O3 | −52.4 (5) | O4W—Co3—O3W—Cs1 | 157.69 (9) |
O1—C1—C2—O2 | 3.7 (5) | O3W—Co3—O4W—Cs1viii | −109.61 (9) |
C3—C1—C2—O2 | −116.0 (4) | O3Wvii—Co3—O4W—Cs1viii | 70.39 (9) |
C5—C1—C2—O2 | 124.5 (4) | O3Wviii—Co3—O4W—Cs1viii | −19.61 (9) |
O3—C2—O2—Co1iii | −168.6 (3) | O3Wix—Co3—O4W—Cs1viii | 160.39 (9) |
C1—C2—O2—Co1iii | 14.7 (4) | O3W—Co3—O4W—Cs1ix | 70.39 (9) |
O3—C2—O2—Cs1iii | −30.6 (6) | O3Wvii—Co3—O4W—Cs1ix | −109.61 (9) |
C1—C2—O2—Cs1iii | 152.7 (3) | O3Wviii—Co3—O4W—Cs1ix | 160.39 (9) |
O1—C1—C3—C4 | 66.0 (4) | O3Wix—Co3—O4W—Cs1ix | −19.61 (9) |
C5—C1—C3—C4 | −57.1 (5) | Co2—O1W—Cs1—O6Wv | 175.0 (3) |
C2—C1—C3—C4 | −174.7 (3) | Co2—O1W—Cs1—O2W | 0.50 (10) |
C1—C3—C4—O4 | −59.9 (5) | Co2—O1W—Cs1—O2ii | 135.48 (14) |
C1—C3—C4—O5 | 119.5 (5) | Co2—O1W—Cs1—O3W | −149.17 (15) |
C1—C3—C4—Cs1i | −136.0 (3) | Co2—O1W—Cs1—O4i | 87.12 (13) |
O5—C4—O4—Co1i | 179.0 (4) | Co2—O1W—Cs1—O5Wviii | 164.78 (11) |
C3—C4—O4—Co1i | −1.6 (6) | Co2—O1W—Cs1—O4Wix | −115.29 (12) |
Cs1i—C4—O4—Co1i | 109.6 (3) | Co2—O2W—Cs1—O6Wv | −177.69 (13) |
O5—C4—O4—Cs1i | 69.4 (5) | Co2—O2W—Cs1—O1W | −0.51 (10) |
C3—C4—O4—Cs1i | −111.2 (4) | Co2—O2W—Cs1—O2ii | −45.52 (15) |
O4—C4—O5—Cs1vi | 110.0 (4) | Co2—O2W—Cs1—O3W | 28.83 (16) |
C3—C4—O5—Cs1vi | −69.4 (5) | Co2—O2W—Cs1—O4i | −92.47 (13) |
Cs1i—C4—O5—Cs1vi | 167.8 (2) | Co2—O2W—Cs1—O5Wviii | −56.7 (4) |
O1—C1—C5—C6 | 73.3 (4) | Co2—O2W—Cs1—O4Wix | 84.06 (15) |
C3—C1—C5—C6 | −164.3 (3) | Co3—O3W—Cs1—O6Wv | −40.66 (14) |
C2—C1—C5—C6 | −46.2 (4) | Co3—O3W—Cs1—O1W | 150.63 (16) |
C1—C5—C6—O7 | 128.7 (4) | Co3—O3W—Cs1—O2W | 122.32 (13) |
C1—C5—C6—O6 | −49.3 (5) | Co3—O3W—Cs1—O2ii | −133.00 (14) |
O7—C6—O6—Co1 | 162.9 (3) | Co3—O3W—Cs1—O4i | −136.43 (11) |
C5—C6—O6—Co1 | −19.3 (5) | Co3—O3W—Cs1—O5Wviii | −77.25 (13) |
O7—C6—O6—Cs1 | 63.9 (4) | Co3—O3W—Cs1—O4Wix | 16.99 (8) |
C5—C6—O6—Cs1 | −118.3 (3) |
Symmetry codes: (i) −x+1, −y+1, z; (ii) y, −x+1, −z+1; (iii) −y+1, x, −z+1; (iv) −x+1, −y, z; (v) x−1/2, −y+1/2, −z+3/2; (vi) x+1/2, −y+1/2, −z+3/2; (vii) −x, −y, z; (viii) −y, x, −z+1; (ix) y, −x, −z+1. |
Experimental details
Crystal data | |
Chemical formula | Cs2[Co(H2O)6][Co6(C6H4O7)4(H2O)8]·12H2O |
Mr | 1899.11 |
Crystal system, space group | Tetragonal, P421c |
Temperature (K) | 100 |
a, c (Å) | 12.5738 (1), 19.5895 (3) |
V (Å3) | 3097.11 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 3.11 |
Crystal size (mm) | 0.16 × 0.14 × 0.10 |
Data collection | |
Diffractometer | Oxford Xcalibur, Sapphire3 diffractometer |
Absorption correction | Multi-scan (multi-scan absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm; Oxford Diffraction, 2010) |
Tmin, Tmax | 0.790, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14807, 3677, 3128 |
Rint | 0.038 |
(sin θ/λ)max (Å−1) | 0.678 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.094, 1.02 |
No. of reflections | 3677 |
No. of parameters | 202 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.58, −0.45 |
Absolute structure | Flack (1983), with how many Friedel pairs? |
Absolute structure parameter | 0.04 (2) |
Computer programs: CrysAlis PRO (Oxford Diffraction, 2010), SUPERFLIP (Palatinus & Chapuis, (2007), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005).
Co1-O4i | 2.037 (3) | O1-O1i | 2.719 (5) |
Co1-O1 | 2.087 (3) | O1-O1iii | 2.772 (5) |
Co1-O1iii | 2.090 (3) | O7-Co2 | 2.078 (3) |
Co1-O6 | 2.096 (3) | Co2-O2W | 2.082 (4) |
Co1-O2iii | 2.124 (3) | Co2-O1W | 2.109 (4) |
Co1-O1i | 2.134 (3) | Co3-O3W | 2.078 (3) |
Co1···Co1i | 3.2252 (11) | Co3-O4W | 2.106 (5) |
Co1···Co1iii | 3.1357 (9) | ||
O4i-Co1-O1 | 115.75 (12) | O6-Co1-O2iii | 83.95 (12) |
O4i-Co1-O1iii | 155.97 (11) | O4i-Co1-O1i | 86.63 (11) |
O1-Co1-O1iii | 83.14 (12) | O1-Co1-O1i | 80.19 (11) |
O4i-Co1-O6 | 88.35 (11) | O1iii-Co1-O1i | 82.01 (11) |
O1-Co1-O6 | 86.86 (11) | O6-Co1-O1i | 162.42 (11) |
O1iii-Co1-O6 | 108.35 (11) | O2iii-Co1-O1i | 112.64 (11) |
O4i-Co1-O2iii | 87.66 (12) | Co1-O1-Co1ii | 97.31 (11) |
O1-Co1-O2iii | 154.59 (11) | Co1-O1-Co1i | 99.65 (11) |
O1iii-Co1-O2iii | 77.41 (11) | Co1ii-O1-Co1i | 95.87 (11) |
Symmetry codes: (i) -x + 1, -y + 1, z; (ii) -y + 1, x, -z + 1; (iii) y, -x + 1, -z + 1. |
D | H | A | D-H | H···A | D···A | D—H···A |
O1W | H1WA | O6 | 0.95 | 1.82 | 2.628 (5) | 141 |
O1W | H1WB | O5W | 0.96 | 1.91 | 2.829 (5) | 160 |
O2W | O5iv | 2.604 (5) | ||||
O2W | O7 | 2.782 (5) | ||||
O3W | H3WA | O3iii | 0.83 | 1.84 | 2.662 (4) | 168 |
O3W | H3WB | O5W | 0.84 | 1.98 | 2.778 (4) | 159 |
O4W | H4WA | O7Wiii | 1.00 | 1.75 | 2.736 (5) | 167 |
O5W | H5WA | O6Wvi | 0.91 | 1.99 | 2.859 (5) | 161 |
O5W | H5WB | O2v | 0.93 | 1.99 | 2.905 (5) | 167 |
O6W | H6WA | O7Wiv | 0.85 | 1.94 | 2.785 (7) | 180 |
O6W | O2W | 2.882 (5) | ||||
O7W | H7WA | O3 | 0.98 | 1.83 | 2.708 (5) | 148 |
O7W | H7WB | O5vii | 0.91 | 1.90 | 2.749 (6) | 153 |
Symmetry codes: (iii) y, -x + 1, -z + 1; (iv) x - 1/2, -y + 1/2, -z + 3/2; (v) 1 - x, -y, z; (vi) 1/2 - y, 1/2 - x, -1/2 + z; (vii) -x + 3/2, y - 1/2, -z + 3/2. |
Polynuclear transition metal complexes with cube-shaped cores, generically called cubanes, have been studied for a variety of metals and in a variety of contexts. In recent years, the magnetic properties of cubane complexes of first-row transition elements have been studied, not in small part because the seminal single-molecule magnet (SMM), [Mn12O12(CH3CO2)16(H2O)4], has a cubane Mn4O4 centre (Lis, 1980; Sessoli, Gatteschi et al., 1993; Sessoli, Tsai et al., 1993). The first cobalt-based SMM (Yang et al., 2002) was a cubane, with deprotonated hydroxymethylpyridine ligands. Murrie et al. (2003a,b) described a Co-based SMM with citrate ligands. Citrate cubanes of six different transition metals were described by Hudson et al. (2006) and by Moubaraki et al. (2008) [Galloway et al. (2008) here too?]. The citrate cubanes in these studies were discrete molecules, either with the basic [Co4(citr)4]8- structure (where citr denotes quadruply deprotonated citric acid, C6H4O74-), or with two additional CoII centres covalently bound at the periphery of the [Co4(citr)4]8- unit to give a tetra-anion. We have reported a serrated one-dimensional polymer whose structural building block is the [Co4(citr)4]8- cubane, and which undergoes an unprecedented reversible crosslinking in the crystal structure to form a rhombic two-dimensional cubane polymer (Campo et al., 2008). In the resulting two-dimensional polymer, a CoII centre within the crosslink fragment possesses an uncommon CoO7 coordination environment. The first three-dimensional network based on the same building block was reported recently (Galloway et al., 2010).
We have prepared a square anionic two-dimensional polymer, octaaqua-tetra-µ-citrato-hexacobalt(II), the structure of which is related to that of a previously reported two-dimensional polymer containing ethylene glycol, (II). The Rb+ and Cs+ salts of (II) suffer severe structural disorder but have interesting magnetic properties; these are the subject of another report (Burzurí et al., 2011). In what follows, we report the structure of the title hydrated double salt of this polymer, (I), {Cs2[Co(H2O)6]{[Co4(C6H4O7)4][µ-Co(H2O)4]2}.12H2O}n, which is the first of the square two-dimensional citrate cubane polymers to have crystallized without serious cation and hydrate disorder.
The structure of (I) is a stack of square two-dimensional polymeric layers (Fig. 1). Each layer is a regular array of cubanes located on sites of 4 symmetry, bridged by six-coordinate CoII centres which sit on twofold axes. The basic unit of the polymer consists of one cubane and two bridges, {[Co4(citr)4][µ-Co(H2O)4]2}4-; the crystallographic a and b axes are the propagation vectors. In chemical terms, it is perhaps better to view the cubane as sharing bridges with each of four neighbours, with the negative charge of one unit of the polymer arising from [Co4(citr)4]8- and one-half of each of the four [µ-Co(H2O)4]2+ bridges, giving a charge of 4- per node of the polymer; there are two nodes per unit cell. Charge is balanced by one [Co(H2O)6]2+ and two Cs+ cations per cubane; these cations are not part of the polymer. The octahedral cation is centred at Co3, which resides on 4, giving two per unit cell. Atom Cs1 resides on a set of general positions but is half-occupied, as determined both by the need for charge balance and by the refinement of the displacement parameters to values in line with those of the rest of the structure. There are thus four Cs+ cations per cell. One-quarter of the polymer repeat unit, and its associated cations and solvent water molecules, comprises the crystallographic asymmetric unit.
The geometries of cubanes containing Co and Ni have been reviewed by Isele et al. (2007). The Co4O4 core in (I) (Fig. 2 and Table 1) has internal geometry comparable with that observed in previously reported structures based on this unit. The Co···Co and O···O distances are well within the ranges found by Isele et al. (2007), and the acute and obtuse bond angles at Co1 and O1, respectively, have commonly observed values that can be related to the magnetic properties of the cubanes. The Co4O4 fragment in (I) is sufficiently distorted from a regular cubic shape that, for the purposes of describing its geometry, it is best viewed as a stellated octahedron (a distortion of the stella octangula) formed by the interleaved Co4 and O4 tetrahedra (Fig. 3). The unique Cg1—Co1 and Cg1—O1 distances are 1.9387 (5) and 1.687 (3) Å, respectively (Cg1 represents the centre of the cubane, located at the unweighted average position of the eight constituent atoms). If the two tetrahedra were considered to be distorted, the Co4 unit would be taken as very slightly compressed, with two Co—Cg1—Co angles greater than, and four less than, the ideal tetrahedral value. The O4 tetrahedron might similarly be considered as slightly elongated, although quantitatively the tetrahedral distortion is essentially negligible in both cases, with a Robinson tetrahedral angular variance σθ(tet)2 of 5.72°2 for Co4 and 2.51°2 for O4 (Robinson et al., 1971). Because of the 4 symmetry, the quadratic elongation <λtet> is 1.00. For the purposes of comparison, we have surveyed the geometries of 40 previously published CoII4O4 cubane fragments using the Cambridge Structural Database (Version 5.31; Allen, 2002). Structures that we considered to be chemically unrepresentative, such as fused cubanes, were excluded from this study. Eight of these published cubane structures displayed a slightly compressed Co4 tetrahedron together with a slightly elongated O4 unit, and three showed the opposite. None had both tetrahedra elongated. The calculated angular variances σθ(tet)2 for the cubanes surveyed varied in the ranges 0.01–52.9°2 for atom Co4 and 0.05–63.9°2 for atom O4. In no case did <λtet> vary by more than 0.02 from the symmetrical value of 1.00 for either of the tetrahedra.
The four citrate ligands of the cubane in (I) are related by 4 symmetry. Each citrate has its hydroxy O atom at one corner of the cubane. The three terminal carboxyl groups bind through one O atom each to a Co atom of the cube, thus forming one five-membered and two six-membered chelates (Figs. 2a and 2b). The five-membered ring Co1ii/O1/C1/C2/O2 has an envelope conformation with the fold at Co1ii [symmetry code: (ii) -y + 1, x, -z + 1]. Numbering from Co1ii as the 1 position, this would be rendered as E1. The six-membered rings Co1i/O1/C1/C3/C4/O4 [symmetry code: (i) -x + 1, -y + 1, z] and Co1/O1/C1/C5/C6/O6 have ring-puckering parameters (Cremer & Pople, 1975) of Q = 0.780 (3) and 0.867 (3) Å, θ = 87.9 (3) and 87.8 (2)°, and ϕ = 112.0 (3) and 343.7 (2)°, respectively. Thus, the former has a boat conformation, 1,4B using the given atom sequence, while the latter is a slightly twisted boat, based on 1,4B.
An important topological feature of the [Co4(citr)4]8- building block is its periphery, at which 12 partially charged O atoms, namely the carboxylate O atoms not involved in chelation to Co of the cube, offer as many reactive nucleophilic sites, which serve as potential linkage points for forming an ample variety of extended structures in one, two and three dimensions. A number of the citrate cubanes characterized to date have transition metals coordinated by one or more of these peripheral O atoms. The 12 O atoms form an irregular icosahedron (Fig. 4), with Cg1-to-vertex distances of 5.061 (3), 5.428 (3) and 5.535 (3) Å for atoms O3, O5 and O7, respectively. The crystallographic 4 symmetry relates the vertices in groups of four. Each such group forms a distorted tetrahedron. That formed by atom O5 and its congeners is elongated along c, with a tetrahedral angular variance of 889°2; this shape, when it appears as a crystal form, is called a tetragonal disphenoid. The tetrahedron containing atom O3 is compressed, with a similar variance of 828°2. The O7 tetrahedron is nearly regular, with an angular variance of 6.7°2. Atom O7 and its equivalents are the linkage points for the extended structure, binding the `satellite' atom Co2 and its congeners, which sit on crystallographic twofold axes and bridge successive cubanes. In this way, the cubane/icosahedron and bridging atom Co2 form an unbounded two-dimensional net parallel to the crystallographic ab plane (Fig. 1). The O7 equivalents from neighbouring cubanes are trans to each other at Co2, the coordination of which is completed by four aqua ligands.
Similarities between (I) and previously reported structures with the same cubane building block end at the periphery of the cubane unit. In a previously reported structure of a one-dimensional polymer of Co citrate cubanes (Campo et al., 2008), the analogous icosahedron has similar geometry to that found for (I), with elongated, compressed and regular oxygen tetrahedra having angular variances of 467, 805 and 38.1°2, respectively. In that structure the cubane sits on a general position. Five of its peripheral O atoms bind Co, namely those that are analogous to atoms O3, O7, O5iii, O3ii and O5i in Fig. 4. The extended structure in that case does not have the symmetry shown by (I) and the chemical unit formed is a serrated one-dimensional polymer of cubanes. That structure undergoes a chemical reaction in the solid state to form a cross-linked two-dimensional polymer whose icosahedra of peripheral O atoms bind Co at the sites analogous to O3, O7, O5iii, O3ii and O7i, having lost the link to Co at the site analogous to O5i.
In (I), the gaps in the polymer mesh of one layer are covered by the cubanes of the two neighbouring layers. The ABAB stacking of the layers is propagated by 1/2[111], but alternate layers are actually related by n[110] and are thus mirror images of each other.
The stacking of the two-dimensional polymeric layers leaves channels in the structure parallel to the a and b axes. These are occupied by the Cs+ cations (two per polymer repeat unit) along with [Co(H2O)6]2+ cations, located on 4, and the solvent water molecules.
The hydrogen bonding in (I), although extensive, is not a structure-determining factor; rather, hydrogen bonds are formed within the channels left by the stacking of the anionic polymers, and also between water molecules within the channels and O atoms of the citrate and aqua ligands attached to the Co atoms of the polymer. The seven independent water fragments present (three of them unligated), along with atoms Co2 and Co3 (to which four of the unique water molecules are bound) and their congeners, form a cyclic structure mediated by coordination and hydrogen bonds and which girds the periphery of the icosahedral [Co4(citr)4]8- unit. The water molecules donate hydrogen bonds to the inner carboxylate O atoms, i.e. those that are bound to cubane Co, as well as to the peripheral carboxylate O atoms (Table 2).
This extensive ordered hydrogen-bonding arrangement is not necessary, however, for the stability of the structure. In other systems based on a closely related two-dimensional polymer but crystallized with other cations (Rb+, Cs+ or K+), we have observed an isomorphous crystal structure – the two-dimensional layer is stacked in the same arrangement as in (I), but the interlayer space is very different in all cases. Compound (I) is the first case we have observed in which there is no disorder in the non-H atoms of the interstitial residues. In the Rb+ and Cs+ salts (Burzurí et al., 2011), which are stable in the crystalline state, the cations are disordered over two and three independent sites, respectively, and the interlayer water molecules are severely disordered in the channels. In those structures, the channels account for 39% of the volume of the unit cell, while in (I) 42% of the volume is in the channels. We can speculate that the presence of a larger cation, [Co(H2O)6]2+, with its hydrogen-bonding capability, obviates the disordering of the channel contents in (I).
In conclusion, the structure of (I) presents a variety of geometric forms, from the central cubane formed by interleaved tetrahedra to the icosahedron composed of 12 O atoms at the periphery of the basic structural building block, to which are ligated four bridging octahedral CoII centres to form a square two-dimensional polymer. These anionic layers are stacked along the c axis, with independent octahedral [Co(H2O)6]2+, Cs+ and H2O in the interlayer spaces. The fact that the interlayer space is ordered in (I) and disordered in two previously reported structures of the same type indicates that the hydrogen-bonding pattern in (I) is not a structure-directing feature.