Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102009010/gd1192sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102009010/gd1192Isup2.hkl |
CCDC reference: 192939
Compound (I) was synthesized as described by Lis (1980). Crystals were obtained from solution in which solvent?
The space-group assignment based on RT data (I4) was confirmed at 83 (2) K by the Laue symmetry of the diffraction pattern, the systematic absences and the successful solution and refinement of the structure. An anisotropic model including all non-H atoms in the cluster, along with the crystallization water molecule, was used to determine the correct absolute structure. The R1 and Flack parameters (Flack, 1983) were 0.0592 and 0.11 (3), respectively, compared with 0.0638 and 0.87 (4), respectively, for the inverted structure (x' = x, y' = y, z' = -z). A rigid-group refinement with isotropic displacement parameters, based on the molecular structure of acetic acid at the same temperature (Nahringbauer, 1970), was used for the disordered acetic acid of solvation. The two components (A and B) of the disordered acetate ligand were restrained to have the same geometry as O8—O9—C5—C6. The same isotropic displacement parameters were assigned to corresponding atoms in the two fragments, A and B. The final site occupancy factors were 0.457 (7) and 0.543 (7) for A and B, respectively. The H atoms of the coordinated water molecule (O12) were located in difference Fourier maps and refined isotropically with restrained O—H distances, while those of the extra-cluster water molecule (O13) were set in the positions determined by neutron diffraction (Langan et al., 2001). The H atoms in the methyl groups were treated as riding in the tetrahedral approximation with torsion angle refinement.
Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
[Mn12O12(C2H3O2)16(H2O)4]·4H2O·2C2H4O2 | Dx = 1.895 Mg m−3 |
Mr = 2060.22 | Melting point: not measured K |
Tetragonal, I4 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: I -4 | Cell parameters from 70298 reflections |
a = 17.1668 (3) Å | θ = 1.0–27.5° |
c = 12.2545 (3) Å | µ = 2.13 mm−1 |
V = 3611.39 (13) Å3 | T = 83 K |
Z = 2 | Parallelepiped, black |
F(000) = 2072 | 0.18 × 0.12 × 0.08 mm |
Nonius KappaCCD area-detector diffractometer | 4151 independent reflections |
Radiation source: fine-focus sealed tube | 3980 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.053 |
Detector resolution: 9 pixels mm-1 | θmax = 27.5°, θmin = 2.0° |
Absorption correction: multi-scan (SORTAV; Blessing, 1995) | h = −22→22 |
Tmin = 0.718, Tmax = 0.849 | k = −22→22 |
24331 measured reflections | l = −15→15 |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.030 | w = 1/[σ2(Fo2) + (0.0379P)2 + 2.657P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.073 | (Δ/σ)max < 0.001 |
S = 1.13 | Δρmax = 0.51 e Å−3 |
4151 reflections | Δρmin = −0.57 e Å−3 |
235 parameters | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
31 restraints | Extinction coefficient: 0.00236 (18) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983), 1976 Friedel pairs Query |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.102 (16) |
[Mn12O12(C2H3O2)16(H2O)4]·4H2O·2C2H4O2 | Z = 2 |
Mr = 2060.22 | Mo Kα radiation |
Tetragonal, I4 | µ = 2.13 mm−1 |
a = 17.1668 (3) Å | T = 83 K |
c = 12.2545 (3) Å | 0.18 × 0.12 × 0.08 mm |
V = 3611.39 (13) Å3 |
Nonius KappaCCD area-detector diffractometer | 4151 independent reflections |
Absorption correction: multi-scan (SORTAV; Blessing, 1995) | 3980 reflections with I > 2σ(I) |
Tmin = 0.718, Tmax = 0.849 | Rint = 0.053 |
24331 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.073 | Δρmax = 0.51 e Å−3 |
S = 1.13 | Δρmin = −0.57 e Å−3 |
4151 reflections | Absolute structure: Flack (1983), 1976 Friedel pairs Query |
235 parameters | Absolute structure parameter: 0.102 (16) |
31 restraints |
Experimental. Data collection was performed at the Centre de Diffractométrie, Université de Rennes, France. A crystal-to-detector distance of 25 mm was used and a total of 309 frames were recorded, using Δω 1° rotation scans, with exposure time = 40 sec/°.). 95 mm CCD camera on κ goniostat |
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) | |
Mn1 | −0.08339 (2) | 0.01783 (2) | 0.07815 (4) | 0.01272 (10) | |
Mn2 | −0.24182 (2) | 0.04803 (2) | 0.08026 (4) | 0.01491 (10) | |
Mn3 | −0.19841 (2) | −0.14079 (2) | 0.01641 (3) | 0.01604 (11) | |
O1 | −0.07053 (10) | 0.01528 (10) | −0.07593 (16) | 0.0129 (4) | |
O2 | −0.10585 (11) | −0.14810 (11) | −0.06681 (15) | 0.0147 (4) | |
O3 | −0.17552 (10) | −0.03871 (10) | 0.06645 (15) | 0.0142 (4) | |
O12 | −0.26415 (15) | −0.10336 (14) | −0.1261 (2) | 0.0315 (6) | |
H12A | −0.250 (3) | −0.126 (3) | −0.184 (3) | 0.082 (15)* | |
H12B | −0.277 (3) | −0.0561 (15) | −0.131 (6) | 0.082 (15)* | |
O13 | −0.21629 (14) | −0.18889 (15) | −0.3008 (2) | 0.0341 (6) | |
H13A | −0.1696 | −0.2161 | −0.2886 | 0.082* | |
H13B | −0.2450 | −0.2200 | −0.3346 | 0.082* | |
O4 | −0.08534 (11) | 0.01962 (11) | 0.23458 (16) | 0.0171 (4) | |
O5 | −0.21272 (11) | 0.04686 (12) | 0.25772 (17) | 0.0196 (4) | |
C1 | −0.14510 (17) | 0.03571 (16) | 0.2929 (2) | 0.0184 (6) | |
C2 | −0.12864 (19) | 0.04385 (19) | 0.4134 (3) | 0.0256 (6) | |
H2A | −0.0879 | 0.0069 | 0.4346 | 0.057 (4)* | |
H2B | −0.1762 | 0.0329 | 0.4548 | 0.057 (4)* | |
H2C | −0.1112 | 0.0971 | 0.4289 | 0.057 (4)* | |
O8 | −0.33490 (11) | −0.01406 (12) | 0.10130 (17) | 0.0191 (4) | |
O9 | −0.29783 (12) | −0.13967 (12) | 0.09568 (19) | 0.0235 (5) | |
C5 | −0.34687 (16) | −0.08623 (16) | 0.1120 (2) | 0.0171 (5) | |
C6 | −0.42692 (17) | −0.10966 (17) | 0.1491 (3) | 0.0239 (6) | |
H6A | −0.4390 | −0.1618 | 0.1212 | 0.057 (4)* | |
H6B | −0.4652 | −0.0723 | 0.1212 | 0.057 (4)* | |
H6C | −0.4287 | −0.1102 | 0.2290 | 0.057 (4)* | |
O10 | −0.30780 (12) | 0.13681 (12) | 0.1125 (2) | 0.0269 (5) | |
O11 | −0.24671 (12) | 0.23385 (12) | 0.0278 (2) | 0.0246 (5) | |
C7 | −0.30302 (16) | 0.20626 (15) | 0.0799 (2) | 0.0171 (5) | |
C8 | −0.36954 (17) | 0.25892 (17) | 0.1077 (2) | 0.0218 (6) | |
H8A | −0.3749 | 0.2989 | 0.0511 | 0.057 (4)* | |
H8B | −0.3596 | 0.2840 | 0.1782 | 0.057 (4)* | |
H8C | −0.4177 | 0.2284 | 0.1120 | 0.057 (4)* | |
O6A | −0.2797 (3) | 0.0690 (3) | −0.0832 (4) | 0.0188 (6)* | 0.457 (7) |
O7A | −0.1875 (4) | 0.1434 (4) | −0.1609 (6) | 0.0201 (6)* | 0.457 (7) |
C3A | −0.2442 (4) | 0.0945 (4) | −0.1654 (7) | 0.0204 (8)* | 0.457 (7) |
C4A | −0.2673 (6) | 0.0679 (5) | −0.2792 (6) | 0.0363 (12)* | 0.457 (7) |
H4A1 | −0.2253 | 0.0362 | −0.3104 | 0.057 (4)* | 0.457 (7) |
H4A2 | −0.2764 | 0.1134 | −0.3256 | 0.057 (4)* | 0.457 (7) |
H4A3 | −0.3150 | 0.0367 | −0.2749 | 0.057 (4)* | 0.457 (7) |
O6B | −0.2596 (3) | 0.0476 (3) | −0.0997 (3) | 0.0188 (6)* | 0.543 (7) |
O7B | −0.1970 (3) | 0.1547 (3) | −0.1572 (5) | 0.0201 (6)* | 0.543 (7) |
C3B | −0.2293 (3) | 0.0897 (4) | −0.1738 (6) | 0.0204 (8)* | 0.543 (7) |
C4B | −0.2337 (5) | 0.0578 (4) | −0.2869 (5) | 0.0363 (12)* | 0.543 (7) |
H4B1 | −0.2467 | 0.0998 | −0.3378 | 0.057 (4)* | 0.543 (7) |
H4B2 | −0.2739 | 0.0173 | −0.2901 | 0.057 (4)* | 0.543 (7) |
H4B3 | −0.1832 | 0.0352 | −0.3069 | 0.057 (4)* | 0.543 (7) |
O14 | −0.4148 (3) | −0.0726 (2) | −0.1212 (5) | 0.0482 (14)* | 0.50 |
O15 | −0.4352 (3) | 0.0537 (2) | −0.0962 (5) | 0.0446 (13)* | 0.50 |
H15 | −0.3760 | 0.0558 | −0.0997 | 0.053* | 0.50 |
C9 | −0.4605 (2) | −0.01792 (19) | −0.1119 (3) | 0.0369 (16)* | 0.50 |
C10 | −0.5463 (2) | −0.0248 (3) | −0.1120 (7) | 0.052 (2)* | 0.50 |
H10A | −0.5618 | −0.0696 | −0.1567 | 0.077* | 0.50 |
H10B | −0.5692 | 0.0228 | −0.1424 | 0.077* | 0.50 |
H10C | −0.5649 | −0.0322 | −0.0371 | 0.077* | 0.50 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Mn1 | 0.01215 (19) | 0.01262 (19) | 0.01338 (18) | −0.00033 (14) | 0.00068 (14) | −0.00004 (15) |
Mn2 | 0.01247 (19) | 0.0129 (2) | 0.0194 (2) | 0.00037 (14) | 0.00188 (16) | 0.00100 (16) |
Mn3 | 0.0134 (2) | 0.0136 (2) | 0.0211 (2) | −0.00063 (16) | 0.00259 (16) | −0.00320 (16) |
O1 | 0.0129 (9) | 0.0118 (8) | 0.0139 (8) | 0.0017 (7) | −0.0008 (7) | −0.0003 (8) |
O2 | 0.0143 (9) | 0.0121 (8) | 0.0176 (9) | −0.0008 (7) | −0.0001 (8) | −0.0007 (8) |
O3 | 0.0123 (8) | 0.0145 (9) | 0.0159 (9) | −0.0010 (7) | 0.0004 (7) | −0.0003 (7) |
O12 | 0.0353 (14) | 0.0251 (12) | 0.0341 (12) | 0.0083 (10) | −0.0137 (10) | −0.0095 (10) |
O13 | 0.0261 (12) | 0.0397 (14) | 0.0364 (13) | 0.0027 (10) | −0.0095 (10) | −0.0137 (11) |
O4 | 0.0182 (10) | 0.0188 (10) | 0.0144 (9) | −0.0016 (8) | 0.0010 (7) | −0.0007 (7) |
O5 | 0.0192 (10) | 0.0191 (9) | 0.0206 (10) | 0.0004 (8) | 0.0045 (8) | 0.0000 (8) |
C1 | 0.0217 (14) | 0.0151 (13) | 0.0183 (13) | −0.0021 (10) | 0.0007 (11) | −0.0006 (10) |
C2 | 0.0292 (16) | 0.0302 (16) | 0.0174 (13) | −0.0016 (12) | 0.0017 (12) | −0.0028 (12) |
O8 | 0.0156 (9) | 0.0162 (9) | 0.0256 (12) | 0.0005 (7) | 0.0029 (8) | 0.0035 (8) |
O9 | 0.0178 (10) | 0.0185 (10) | 0.0343 (12) | 0.0007 (8) | 0.0070 (9) | −0.0055 (9) |
C5 | 0.0162 (13) | 0.0196 (14) | 0.0156 (12) | −0.0008 (11) | 0.0011 (10) | 0.0009 (10) |
C6 | 0.0146 (14) | 0.0193 (14) | 0.0379 (17) | −0.0004 (11) | 0.0079 (12) | 0.0037 (13) |
O10 | 0.0167 (10) | 0.0176 (10) | 0.0464 (14) | 0.0049 (8) | 0.0114 (9) | 0.0079 (9) |
O11 | 0.0201 (10) | 0.0186 (10) | 0.0352 (12) | 0.0033 (8) | 0.0084 (9) | 0.0057 (9) |
C7 | 0.0170 (12) | 0.0174 (12) | 0.0168 (12) | 0.0022 (10) | 0.0014 (11) | 0.0000 (11) |
C8 | 0.0220 (14) | 0.0178 (14) | 0.0256 (16) | 0.0017 (11) | 0.0036 (11) | 0.0010 (11) |
Mn1—Mn2 | 2.7687 (6) | C2—H2C | 0.9800 |
Mn1—Mn1i | 2.8204 (7) | O8—C5 | 1.263 (3) |
Mn1—Mn1ii | 2.9280 (8) | O9—C5 | 1.261 (3) |
Mn1—O3 | 1.8611 (18) | C5—C6 | 1.502 (4) |
Mn1—O2iii | 1.8804 (18) | C6—H6A | 0.9800 |
Mn1—O1 | 1.902 (2) | C6—H6B | 0.9800 |
Mn1—O1i | 1.9154 (18) | C6—H6C | 0.9800 |
Mn1—O1iii | 1.9206 (17) | O10—C7 | 1.260 (3) |
Mn1—O4 | 1.918 (2) | O11—C7 | 1.251 (4) |
Mn2—O3 | 1.8818 (18) | C7—C8 | 1.496 (4) |
Mn2—O2iii | 1.8975 (19) | C8—H8A | 0.9800 |
Mn2—O8 | 1.938 (2) | C8—H8B | 0.9800 |
Mn2—O10 | 1.940 (2) | C8—H8C | 0.9800 |
Mn2—O6A | 2.137 (5) | O6A—C3A | 1.257 (9) |
Mn2—O6B | 2.227 (4) | O7A—C3A | 1.286 (10) |
Mn2—O5 | 2.231 (2) | C3A—C4A | 1.520 (10) |
Mn3—O2 | 1.8923 (19) | C4A—H4A1 | 0.9800 |
Mn3—O3 | 1.8977 (18) | C4A—H4A2 | 0.9800 |
Mn3—O9 | 1.964 (2) | C4A—H4A3 | 0.9800 |
Mn3—O11i | 1.993 (2) | O6B—C3B | 1.271 (7) |
Mn3—O7Ai | 2.161 (7) | O7B—C3B | 1.264 (8) |
Mn3—O7Bi | 2.114 (6) | C3B—C4B | 1.492 (9) |
Mn3—O12 | 2.177 (2) | C4B—H4B1 | 0.9800 |
O12—H12A | 0.85 (2) | C4B—H4B2 | 0.9800 |
O12—H12B | 0.843 (19) | C4B—H4B3 | 0.9800 |
O13—H13A | 0.9396 | O14—C9 | 1.2281 |
O13—H13B | 0.8366 | O15—C9 | 1.3188 |
O4—C1 | 1.280 (4) | O15—H15 | 1.0182 |
O5—C1 | 1.253 (4) | C9—C10 | 1.4781 |
C1—C2 | 1.510 (4) | C10—H10A | 0.9800 |
C2—H2A | 0.9800 | C10—H10B | 0.9800 |
C2—H2B | 0.9800 | C10—H10C | 0.9800 |
Mn2—Mn1—Mn1i | 120.91 (2) | Mn3—O2—Mn2i | 122.84 (10) |
Mn2—Mn1—Mn1iii | 122.47 (2) | Mn1—O3—Mn2 | 95.41 (8) |
Mn1i—Mn1—Mn1iii | 62.539 (17) | Mn1—O3—Mn3 | 133.04 (10) |
Mn2—Mn1—Mn1ii | 178.61 (2) | Mn2—O3—Mn3 | 129.38 (10) |
Mn1i—Mn1—Mn1ii | 58.730 (9) | Mn3—O12—H12A | 113 (4) |
O3—Mn1—O2iii | 84.92 (8) | Mn3—O12—H12B | 119 (5) |
O3—Mn1—O1 | 90.59 (8) | H12A—O12—H12B | 117 (6) |
O2iii—Mn1—O1 | 90.79 (8) | H13A—O13—H13B | 105.3 |
O3—Mn1—O1i | 96.00 (8) | C1—O4—Mn1 | 125.11 (18) |
O2iii—Mn1—O1i | 174.79 (8) | C1—O5—Mn2 | 122.94 (18) |
O1—Mn1—O1i | 84.08 (9) | O5—C1—O4 | 125.7 (3) |
O3—Mn1—O4 | 94.04 (8) | O5—C1—C2 | 119.7 (3) |
O2iii—Mn1—O4 | 92.91 (8) | O4—C1—C2 | 114.6 (3) |
O1—Mn1—O4 | 174.31 (8) | C1—C2—H2A | 109.5 |
O1i—Mn1—O4 | 92.14 (8) | C1—C2—H2B | 109.5 |
O3—Mn1—O1iii | 173.75 (8) | C1—C2—H2C | 109.5 |
O2iii—Mn1—O1iii | 98.14 (8) | H2A—C2—H2B | 109.5 |
O1—Mn1—O1iii | 83.94 (9) | H2A—C2—H2C | 109.5 |
O1i—Mn1—O1iii | 80.47 (8) | H2B—C2—H2C | 109.5 |
O4—Mn1—O1iii | 91.26 (8) | C5—O8—Mn2 | 133.44 (19) |
O3—Mn2—O2iii | 83.87 (8) | C5—O9—Mn3 | 131.74 (19) |
O3—Mn2—O8 | 94.33 (8) | O9—C5—O8 | 126.1 (3) |
O2iii—Mn2—O8 | 176.66 (8) | O9—C5—C6 | 117.6 (2) |
O3—Mn2—O10 | 173.35 (10) | O8—C5—C6 | 116.3 (2) |
O2iii—Mn2—O10 | 95.85 (8) | C5—C6—H6A | 109.5 |
O8—Mn2—O10 | 85.61 (9) | C5—C6—H6B | 109.5 |
O3—Mn2—O6A | 103.47 (19) | C5—C6—H6C | 109.5 |
O2iii—Mn2—O6A | 95.10 (13) | H6A—C6—H6B | 109.5 |
O8—Mn2—O6A | 88.05 (13) | H6A—C6—H6C | 109.5 |
O10—Mn2—O6A | 83.18 (19) | H6B—C6—H6C | 109.5 |
O3—Mn2—O6B | 89.50 (16) | C7—O10—Mn2 | 129.83 (19) |
O2iii—Mn2—O6B | 91.83 (12) | C7—O11—Mn3iii | 136.72 (18) |
O8—Mn2—O6B | 90.97 (12) | O11—C7—O10 | 124.8 (2) |
O10—Mn2—O6B | 97.15 (16) | O11—C7—C8 | 118.5 (2) |
O6A—Mn2—O6B | 14.10 (14) | O10—C7—C8 | 116.7 (2) |
O3—Mn2—O5 | 86.85 (8) | C7—C8—H8A | 109.5 |
O2iii—Mn2—O5 | 84.23 (8) | C7—C8—H8B | 109.5 |
O8—Mn2—O5 | 92.86 (8) | C7—C8—H8C | 109.5 |
O10—Mn2—O5 | 86.50 (9) | H8A—C8—H8B | 109.5 |
O6A—Mn2—O5 | 169.54 (18) | H8A—C8—H8C | 109.5 |
O6B—Mn2—O5 | 174.90 (15) | H8B—C8—H8C | 109.5 |
O2—Mn3—O3 | 93.52 (8) | C3A—O6A—Mn2 | 131.4 (4) |
O2—Mn3—O9 | 175.55 (9) | C3A—O7A—Mn3iii | 126.9 (6) |
O3—Mn3—O9 | 90.64 (8) | O6A—C3A—O7A | 124.2 (7) |
O2—Mn3—O11i | 92.83 (8) | O6A—C3A—C4A | 120.2 (7) |
O3—Mn3—O11i | 173.62 (8) | O7A—C3A—C4A | 115.7 (7) |
O9—Mn3—O11i | 82.99 (9) | C3B—O6B—Mn2 | 130.5 (4) |
O2—Mn3—O7Bi | 96.42 (16) | C3B—O7B—Mn3iii | 130.2 (5) |
O3—Mn3—O7Bi | 94.84 (17) | O7B—C3B—O6B | 124.6 (6) |
O9—Mn3—O7Bi | 84.77 (16) | O7B—C3B—C4B | 119.7 (6) |
O11i—Mn3—O7Bi | 85.05 (17) | O6B—C3B—C4B | 115.7 (6) |
O2—Mn3—O7Ai | 92.89 (19) | C3B—C4B—H4B1 | 109.5 |
O3—Mn3—O7Ai | 89.27 (18) | C3B—C4B—H4B2 | 109.5 |
O9—Mn3—O7Ai | 88.73 (19) | C3B—C4B—H4B3 | 109.5 |
O11i—Mn3—O7Ai | 91.02 (19) | H4B1—C4B—H4B2 | 109.5 |
O7Bi—Mn3—O7Ai | 6.8 (3) | H4B1—C4B—H4B3 | 109.5 |
O2—Mn3—O12 | 91.29 (9) | H4B2—C4B—H4B3 | 109.5 |
O3—Mn3—O12 | 95.40 (8) | C9—O15—H15 | 110.8 |
O9—Mn3—O12 | 86.76 (10) | O14—C9—O15 | 121.1 |
O11i—Mn3—O12 | 83.85 (10) | O14—C9—C10 | 125.1 |
O7Bi—Mn3—O12 | 166.77 (16) | O15—C9—C10 | 113.8 |
O7Ai—Mn3—O12 | 173.54 (19) | C9—C10—H10A | 109.5 |
Mn1—O1—Mn1iii | 95.28 (8) | C9—C10—H10B | 109.5 |
Mn1—O1—Mn1i | 95.11 (8) | C9—C10—H10C | 109.5 |
Mn1iii—O1—Mn1i | 99.51 (8) | H10A—C10—H10B | 109.5 |
Mn1i—O2—Mn3 | 132.48 (10) | H10A—C10—H10C | 109.5 |
Mn1i—O2—Mn2i | 94.25 (8) | H10B—C10—H10C | 109.5 |
Symmetry codes: (i) −y, x, −z; (ii) −x, −y, z; (iii) y, −x, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12a···O13 | 0.85 (4) | 1.88 (5) | 2.722 (4) | 172 (4) |
O12—H12b···O6A | 0.84 (3) | 2.23 (3) | 3.016 (6) | 156 (2) |
O12—H12b···O6B | 0.84 (3) | 1.85 (3) | 2.613 (5) | 150 (2) |
O13—H13a···O5i | 0.94 | 2.14 | 2.984 (3) | 149 |
O13—H13b···O7Aiv | 0.84 | 2.49 | 3.244 (7) | 151 |
O13—H13b···O7Biv | 0.84 | 2.24 | 3.001 (6) | 152 |
O13—H13b···O11iv | 0.84 | 2.46 | 3.114 (3) | 135 |
O13—H13b···O9v | 0.84 | 2.66 | 3.214 (3) | 125 |
O15—H15···O6A | 1.02 | 1.68 | 2.687 (7) | 169 |
Symmetry codes: (i) −y, x, −z; (iv) y−1/2, −x−1/2, −z−1/2; (v) −x−1/2, −y−1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Mn12O12(C2H3O2)16(H2O)4]·4H2O·2C2H4O2 |
Mr | 2060.22 |
Crystal system, space group | Tetragonal, I4 |
Temperature (K) | 83 |
a, c (Å) | 17.1668 (3), 12.2545 (3) |
V (Å3) | 3611.39 (13) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.13 |
Crystal size (mm) | 0.18 × 0.12 × 0.08 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (SORTAV; Blessing, 1995) |
Tmin, Tmax | 0.718, 0.849 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 24331, 4151, 3980 |
Rint | 0.053 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.073, 1.13 |
No. of reflections | 4151 |
No. of parameters | 235 |
No. of restraints | 31 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.51, −0.57 |
Absolute structure | Flack (1983), 1976 Friedel pairs Query |
Absolute structure parameter | 0.102 (16) |
Computer programs: COLLECT (Nonius, 1998), HKL SCALEPACK (Otwinowski & Minor 1997), HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK, SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).
Mn1—O3 | 1.8611 (18) | Mn2—O6A | 2.137 (5) |
Mn1—O2i | 1.8804 (18) | Mn2—O6B | 2.227 (4) |
Mn1—O1 | 1.902 (2) | Mn2—O5 | 2.231 (2) |
Mn1—O1ii | 1.9154 (18) | Mn3—O2 | 1.8923 (19) |
Mn1—O1i | 1.9206 (17) | Mn3—O3 | 1.8977 (18) |
Mn1—O4 | 1.918 (2) | Mn3—O9 | 1.964 (2) |
Mn2—O3 | 1.8818 (18) | Mn3—O11ii | 1.993 (2) |
Mn2—O2i | 1.8975 (19) | Mn3—O7Aii | 2.161 (7) |
Mn2—O8 | 1.938 (2) | Mn3—O7Bii | 2.114 (6) |
Mn2—O10 | 1.940 (2) | Mn3—O12 | 2.177 (2) |
Symmetry codes: (i) y, −x, −z; (ii) −y, x, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12a···O13 | 0.85 (4) | 1.88 (5) | 2.722 (4) | 172 (4) |
O12—H12b···O6A | 0.84 (3) | 2.23 (3) | 3.016 (6) | 156 (2) |
O12—H12b···O6B | 0.84 (3) | 1.85 (3) | 2.613 (5) | 150 (2) |
O13—H13a···O5ii | 0.94 | 2.14 | 2.984 (3) | 149 |
O13—H13b···O7Aiii | 0.84 | 2.49 | 3.244 (7) | 151 |
O13—H13b···O7Biii | 0.84 | 2.24 | 3.001 (6) | 152 |
O13—H13b···O11iii | 0.84 | 2.46 | 3.114 (3) | 135 |
O13—H13b···O9iv | 0.84 | 2.66 | 3.214 (3) | 125 |
O15—H15···O6A | 1.02 | 1.68 | 2.687 (7) | 169 |
Symmetry codes: (ii) −y, x, −z; (iii) y−1/2, −x−1/2, −z−1/2; (iv) −x−1/2, −y−1/2, z−1/2. |
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The compound [Mn12O12(CH3COO)16(H2O)4]·4H2O·2CH3COOH, known as Mn12-acetate, (I), is the prototype of a class of magnetic materials referred to as `single-molecule magnets' (Sessoli et al., 1993). The acronym reflects the exceedingly slow relaxation of the magnetization at low temperature (LT), which is reminiscent of bulk magnets. In (I), however, the slow magnetic relaxation has a purely molecular origin, as established by measurements in solution (Cheesman et al., 1997) and in polymer films (Eppley et al., 1995). It arises from the huge easy-axis magnetic anisotropy in the ground spin state (S = 10), and from the energy barrier (60 K) to be overcome for the reversal of the magnetization. In addition, due to the intrinsic quantum nature of the system, underbarrier tunnelling processes are possible which lead to characteristic steps in the hysteresis loops at LT (Friedman et al., 1996). \sch
Compound (I) was first synthesized and structurally characterized by room temperature (RT) methods in 1980 (Reference?). The crystal lattice (tetragonal space group I4) comprises [Mn12O12(CH3COO)16(H2O)4] cluster units which develop around 4 axes. These units feature a central cubane-like tetramanganese(IV)-oxo moiety linked to eight peripheral manganese(III) centres by eight µ3-O and four µ-acetato ligands. Twelve additional µ-acetates and four water ligands complete the Jahn–Teller distorted coordination sphere of the manganese(III) ions (Lis, 1980).
The relationship between tunnelling and molecular symmetry in (I) has recently become the focus of considerable interest, because the selection rules imposed by the S4 crystallographic symmetry are not obeyed. For this reason, symmetry-breaking effects arising from crystal dislocations have been suggested (Mertes et al., 2001). Close examination of the structural data, however, suggests a possible mechanism for symmetry-lowering at the molecular level. Each cluster is in fact surrounded by four water and two acetic acid molecules of solvation. The latter are located between adjacent Mn12 units in the ab plane and are disordered over two partially overlapping positions related by a twofold axis parallel to c. As confirmed by a very recent neutron diffraction study at LT (Langan et al., 2001), one of the acetate ligands (O6—O7—C3—C4) is involved in a strong hydrogen-bonding interaction with the disordered acetic acid molecule. Indeed, atom O6 and the neighbouring methyl atom C4 exhibit unusually large displacement parameters at RT compared with the remaining acetate ligands (Lis, 1980), possibly reflecting unresolved disorder.
To investigate this issue in more detail, we collected a new set of X-ray diffraction data at 83 (2) K. Preliminary structure refinement showed abnormal elongation of the displacement ellipsoids of atoms O6, C4 and, to a lesser extent, O7 and C3. We thus modelled the O6—O7—C3—C4 acetate ligand over two positions, A and B (Figs. 1 and 2). The resulting hydrogen-bonding geometry between atoms O15 and O6A [O15···O6A 2.687 (7) Å, H15···O6A 1.68 Å and O15—H15···O6A 169°] compares extremely well with that found in solid acetic acid at the same temperature (O···O' 2.624 Å, H···O' 1.628 Å and O—H···O' 164.9°; Reference?).
Notably, the coordination geometry of atoms Mn2 and Mn3 undergoes significant distortion upon hydrogen bonding, the Mn2—O6 and Mn3—O7 distances varying by -0.09 and 0.05 Å, respectively. Angular distortions are also meaningful, with O6A—Mn2—O6B 14.10 (14)° and O7A—Mn3i—O7B 6.8 (3)°.
These results definitely show that the disorder of the acetic acid molecule is supramolecularly transmitted to the Mn12 units via a strong hydrogen-bonding interaction. Since the number (n) of hydrogen-bonded acetic acid molecules which surround each Mn12 unit can, in principle, range from 0 to 4, up to six isomeric forms of the cluster can be envisaged. Two of them (n = 0 and 4) retain S4 point-group symmetry, while the remaining isomers have either C2 (n = 2, `trans') or C1 (n = 1, 2, `cis', and 3) symmetry. Ordered layers of alternating n = 0 and 4 isomers would clearly preserve S4 molecular symmetry, at the same time leading to doubled unit-cell vectors in the ab plane. Careful inspection of the diffraction pattern using a CCD device gave no hint as to the presence of a supercell, thus excluding an ordered structure in the ab plane. Nonaxial isomers must then be present in the lattice, which provides a possible explanation for the intriguing tunnelling behavior of (I) (Cornia et al., 2002).