Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270109014693/eg3016sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270109014693/eg3016Isup2.hkl |
CCDC reference: 742164
[Mn3(OAc)6(py)3](ClO4) was synthesized according to the published procedure (Vincent et al., 1987). (S)-H2PEDEA was synthesized by reacting (S)-N-phenylethylamine with ethylene oxide in ethanol. Full details will be published elsewhere. All other reagents were obtained commercially as ACS reagent grade and used as supplied. IR spectra were recorded on a Bruker TENSOR 27 spectrometer.
(S)-H2PEDEA (0.078 g, 0.373 mmol) in methanol (3 ml) was added to a solution of [Mn3(OAc)6(py)3](ClO4) (0.27 g, 0.310 mmol) in acetonitrile (7 ml). The resulting dark-brown mixture was stirred for 16 h at room temperature before filtration. Slow evaporation of the solvent produced a dark-brown microcrystalline solid (0.092 g). The X-ray powder pattern of this material matched neither compound (I) nor β/γ-Mn(OAc)2. However, elemental analysis on dried material indicated that it was a form of manganese(II) acetate. Further evaporation produced a small quantity of pale-yellow single-crystal X-ray diffraction quality crystals of compound (I). FT–IR (KBr disc, ν, cm-1): 3386 (s), 2936 (w), 2255 (w), 1577 (v), 1418 (v), 1344 (s), 1049 (m), 1026 (m), 940 (w), 660 (s), 615 (m), 502 (w).
All H atoms are bound to methyl C atoms and were placed in geometrically idealized positions. For both acetate ligands and acetonitrile solvent they were constrained to ride and rotate on their parent atoms, with C—H = 0.98 Å and Uiso = 1.5Ueq(C). The relatively large Ueq(max)/Ueq(min) for carbon on both acetate framework and acetonitrile solvent atoms is a consequence of slight thermal disorder on the terminal methyl positions.
Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2009).
[Mn3(C2H3O2)6]·C2H3N | Dx = 1.720 Mg m−3 |
Mr = 560.14 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pnma | Cell parameters from 926 reflections |
a = 10.788 (2) Å | θ = 3.0–28.2° |
b = 12.702 (2) Å | µ = 1.78 mm−1 |
c = 15.784 (3) Å | T = 193 K |
V = 2163.0 (7) Å3 | Prism, yellow |
Z = 4 | 0.15 × 0.08 × 0.05 mm |
F(000) = 1132 |
Bruker SMART ? CCD area-detector diffractometer | 2763 independent reflections |
Radiation source: fine-focus sealed tube | 2307 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
ϕ and ω scans | θmax = 28.3°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | h = −13→14 |
Tmin = 0.692, Tmax = 0.915 | k = −16→16 |
18714 measured reflections | l = −21→20 |
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)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0293P)2 + 1.7643P] where P = (Fo2 + 2Fc2)/3 |
2763 reflections | (Δ/σ)max = 0.001 |
159 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.40 e Å−3 |
[Mn3(C2H3O2)6]·C2H3N | V = 2163.0 (7) Å3 |
Mr = 560.14 | Z = 4 |
Orthorhombic, Pnma | Mo Kα radiation |
a = 10.788 (2) Å | µ = 1.78 mm−1 |
b = 12.702 (2) Å | T = 193 K |
c = 15.784 (3) Å | 0.15 × 0.08 × 0.05 mm |
Bruker SMART ? CCD area-detector diffractometer | 2763 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | 2307 reflections with I > 2σ(I) |
Tmin = 0.692, Tmax = 0.915 | Rint = 0.037 |
18714 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.09 | Δρmax = 0.48 e Å−3 |
2763 reflections | Δρmin = −0.40 e Å−3 |
159 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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
C1 | −0.0434 (2) | 0.2500 | 0.47600 (16) | 0.0182 (5) | |
C2 | −0.0952 (4) | 0.2500 | 0.38807 (18) | 0.0380 (8) | |
H2A | −0.0960 | 0.3221 | 0.3660 | 0.057* | 0.50 |
H2B | −0.1800 | 0.2223 | 0.3891 | 0.057* | 0.50 |
H2C | −0.0437 | 0.2056 | 0.3515 | 0.057* | 0.50 |
C3 | 0.0836 (3) | 0.2500 | 0.84620 (16) | 0.0257 (6) | |
C4 | 0.1704 (3) | 0.2500 | 0.92162 (19) | 0.0502 (11) | |
H4A | 0.2476 | 0.2140 | 0.9065 | 0.075* | 0.50 |
H4B | 0.1310 | 0.2133 | 0.9691 | 0.075* | 0.50 |
H4C | 0.1887 | 0.3227 | 0.9381 | 0.075* | 0.50 |
C5 | 0.25158 (19) | 0.06295 (16) | 0.58784 (13) | 0.0272 (4) | |
C6 | 0.3797 (2) | 0.0202 (2) | 0.6025 (2) | 0.0538 (8) | |
H6A | 0.3764 | −0.0568 | 0.6048 | 0.081* | |
H6B | 0.4120 | 0.0475 | 0.6562 | 0.081* | |
H6C | 0.4341 | 0.0422 | 0.5560 | 0.081* | |
C7 | −0.1231 (2) | 0.04699 (16) | 0.67196 (12) | 0.0288 (4) | |
C8 | −0.2484 (3) | 0.0016 (2) | 0.6921 (2) | 0.0599 (9) | |
H8A | −0.2951 | −0.0086 | 0.6395 | 0.090* | |
H8B | −0.2937 | 0.0500 | 0.7292 | 0.090* | |
H8C | −0.2381 | −0.0663 | 0.7208 | 0.090* | |
Mn1 | 0.04447 (3) | 0.2500 | 0.63752 (2) | 0.01546 (10) | |
Mn2 | 0.31414 (3) | 0.2500 | 0.71722 (2) | 0.01686 (10) | |
Mn3 | 0.0000 | 0.0000 | 0.5000 | 0.01945 (10) | |
O1 | 0.12887 (17) | 0.2500 | 0.77135 (11) | 0.0240 (4) | |
O2 | 0.21410 (12) | 0.14233 (11) | 0.63072 (8) | 0.0230 (3) | |
O3 | −0.04932 (16) | −0.00827 (11) | 0.63187 (9) | 0.0339 (4) | |
O4 | 0.19026 (14) | 0.01826 (14) | 0.53218 (11) | 0.0397 (4) | |
O5 | 0.40082 (13) | 0.14224 (11) | 0.80605 (8) | 0.0238 (3) | |
O6 | 0.47080 (18) | 0.2500 | 0.63844 (12) | 0.0278 (5) | |
O7 | −0.02185 (16) | 0.16621 (11) | 0.51492 (8) | 0.0298 (3) | |
C9 | 0.2874 (9) | 0.2500 | 0.4265 (4) | 0.147 (4) | |
H9A | 0.2284 | 0.2073 | 0.3942 | 0.220* | 0.50 |
H9B | 0.2565 | 0.3223 | 0.4308 | 0.220* | 0.50 |
H9C | 0.2970 | 0.2204 | 0.4835 | 0.220* | 0.50 |
C10 | 0.4023 (8) | 0.2500 | 0.3853 (4) | 0.090 (2) | |
N1 | 0.4963 (7) | 0.2500 | 0.3513 (6) | 0.139 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0192 (12) | 0.0175 (12) | 0.0179 (11) | 0.000 | 0.0009 (10) | 0.000 |
C2 | 0.058 (2) | 0.0354 (17) | 0.0204 (13) | 0.000 | −0.0130 (14) | 0.000 |
C3 | 0.0185 (13) | 0.0415 (17) | 0.0171 (12) | 0.000 | 0.0001 (10) | 0.000 |
C4 | 0.0200 (16) | 0.112 (4) | 0.0184 (14) | 0.000 | −0.0016 (12) | 0.000 |
C5 | 0.0236 (10) | 0.0285 (10) | 0.0294 (10) | 0.0004 (8) | 0.0011 (8) | −0.0070 (8) |
C6 | 0.0403 (15) | 0.0498 (16) | 0.0714 (18) | 0.0168 (12) | −0.0143 (13) | −0.0315 (14) |
C7 | 0.0395 (12) | 0.0260 (10) | 0.0210 (9) | −0.0076 (9) | 0.0060 (8) | −0.0034 (8) |
C8 | 0.0626 (19) | 0.0505 (16) | 0.0665 (18) | −0.0311 (14) | 0.0263 (15) | −0.0269 (14) |
Mn1 | 0.01396 (19) | 0.01953 (19) | 0.01290 (17) | 0.000 | −0.00045 (14) | 0.000 |
Mn2 | 0.01382 (19) | 0.0227 (2) | 0.01407 (18) | 0.000 | −0.00219 (14) | 0.000 |
Mn3 | 0.0275 (2) | 0.01335 (19) | 0.01746 (18) | 0.00050 (15) | −0.00011 (16) | −0.00320 (14) |
O1 | 0.0155 (9) | 0.0415 (11) | 0.0151 (8) | 0.000 | −0.0006 (7) | 0.000 |
O2 | 0.0209 (7) | 0.0251 (7) | 0.0230 (6) | −0.0001 (5) | −0.0021 (5) | −0.0070 (5) |
O3 | 0.0579 (11) | 0.0222 (7) | 0.0217 (7) | 0.0053 (7) | 0.0092 (7) | −0.0007 (6) |
O4 | 0.0292 (9) | 0.0476 (10) | 0.0425 (9) | 0.0014 (7) | −0.0036 (7) | −0.0265 (8) |
O5 | 0.0250 (7) | 0.0227 (7) | 0.0236 (6) | −0.0047 (5) | −0.0069 (5) | 0.0059 (5) |
O6 | 0.0162 (10) | 0.0497 (13) | 0.0175 (9) | 0.000 | −0.0011 (7) | 0.000 |
O7 | 0.0547 (10) | 0.0147 (7) | 0.0199 (7) | 0.0052 (6) | −0.0035 (6) | −0.0003 (5) |
C9 | 0.278 (12) | 0.061 (4) | 0.102 (5) | 0.000 | 0.108 (7) | 0.000 |
C10 | 0.148 (7) | 0.053 (3) | 0.069 (4) | 0.000 | −0.019 (4) | 0.000 |
N1 | 0.114 (6) | 0.129 (6) | 0.174 (8) | 0.000 | −0.032 (5) | 0.000 |
C1—O7i | 1.2506 (19) | Mn1—O2i | 2.2871 (14) |
C1—O7 | 1.2506 (19) | Mn1—O5iii | 2.2514 (13) |
C1—C2 | 1.496 (4) | Mn1—O5ii | 2.2514 (14) |
C2—H2A | 0.9800 | Mn1—O7 | 2.3215 (14) |
C2—H2B | 0.9800 | Mn1—O7i | 2.3215 (14) |
C2—H2C | 0.9800 | Mn1—Mn2 | 3.1697 (7) |
C3—O6ii | 1.241 (3) | Mn2—O1 | 2.1737 (19) |
C3—O1 | 1.278 (3) | Mn2—O2 | 2.2134 (13) |
C3—C4 | 1.514 (4) | Mn2—O2i | 2.2135 (13) |
C4—H4A | 0.9800 | Mn2—O5 | 2.1711 (13) |
C4—H4B | 0.9800 | Mn2—O5i | 2.1710 (13) |
C4—H4C | 0.9800 | Mn2—O6 | 2.0983 (19) |
C5—O4 | 1.238 (2) | Mn3—O3 | 2.1509 (14) |
C5—O2 | 1.280 (2) | Mn3—O3iv | 2.1510 (14) |
C5—C6 | 1.502 (3) | Mn3—O4 | 2.1273 (16) |
C6—H6A | 0.9800 | Mn3—O4iv | 2.1273 (16) |
C6—H6B | 0.9800 | Mn3—O7 | 2.1374 (14) |
C6—H6C | 0.9800 | Mn3—O7iv | 2.1373 (14) |
C7—O3 | 1.236 (3) | O5—C7v | 1.285 (2) |
C7—O5ii | 1.285 (2) | O5—Mn1v | 2.2513 (13) |
C7—C8 | 1.503 (3) | O6—C3v | 1.241 (3) |
C8—H8A | 0.9800 | C9—C10 | 1.400 (11) |
C8—H8B | 0.9800 | C9—H9A | 0.9800 |
C8—H8C | 0.9800 | C9—H9B | 0.9800 |
Mn1—O1 | 2.3004 (18) | C9—H9C | 0.9800 |
Mn1—O2 | 2.2871 (14) | C10—N1 | 1.147 (10) |
O7i—C1—O7 | 116.6 (2) | O1—Mn1—Mn2 | 43.30 (5) |
O7i—C1—C2 | 121.67 (12) | O7—Mn1—Mn2 | 127.86 (4) |
O7—C1—C2 | 121.67 (12) | O7i—Mn1—Mn2 | 127.86 (4) |
C1—C2—H2A | 109.5 | O6—Mn2—O5i | 92.05 (6) |
C1—C2—H2B | 109.5 | O6—Mn2—O5 | 92.05 (6) |
H2A—C2—H2B | 109.5 | O5i—Mn2—O5 | 78.17 (7) |
C1—C2—H2C | 109.5 | O6—Mn2—O1 | 166.80 (7) |
H2A—C2—H2C | 109.5 | O5i—Mn2—O1 | 98.18 (5) |
H2B—C2—H2C | 109.5 | O5—Mn2—O1 | 98.18 (5) |
O6ii—C3—O1 | 123.7 (2) | O6—Mn2—O2 | 91.56 (6) |
O6ii—C3—C4 | 116.9 (2) | O5i—Mn2—O2 | 176.27 (5) |
O1—C3—C4 | 119.4 (2) | O5—Mn2—O2 | 102.64 (5) |
C3—C4—H4A | 109.5 | O1—Mn2—O2 | 78.12 (5) |
C3—C4—H4B | 109.5 | O6—Mn2—O2i | 91.56 (6) |
H4A—C4—H4B | 109.5 | O5i—Mn2—O2i | 102.64 (5) |
C3—C4—H4C | 109.5 | O5—Mn2—O2i | 176.27 (5) |
H4A—C4—H4C | 109.5 | O1—Mn2—O2i | 78.12 (5) |
H4B—C4—H4C | 109.5 | O2—Mn2—O2i | 76.32 (7) |
O4—C5—O2 | 124.60 (19) | O6—Mn2—Mn1 | 120.27 (5) |
O4—C5—C6 | 115.80 (19) | O5i—Mn2—Mn1 | 130.67 (4) |
O2—C5—C6 | 119.58 (19) | O5—Mn2—Mn1 | 130.67 (4) |
C5—C6—H6A | 109.5 | O1—Mn2—Mn1 | 46.53 (5) |
C5—C6—H6B | 109.5 | O2—Mn2—Mn1 | 46.18 (4) |
H6A—C6—H6B | 109.5 | O2i—Mn2—Mn1 | 46.18 (4) |
C5—C6—H6C | 109.5 | O4—Mn3—O4iv | 180.0 |
H6A—C6—H6C | 109.5 | O4—Mn3—O7iv | 91.58 (6) |
H6B—C6—H6C | 109.5 | O4iv—Mn3—O7iv | 88.42 (6) |
O3—C7—O5ii | 122.9 (2) | O4—Mn3—O7 | 88.42 (6) |
O3—C7—C8 | 118.0 (2) | O4iv—Mn3—O7 | 91.58 (6) |
O5ii—C7—C8 | 119.0 (2) | O7iv—Mn3—O7 | 180.0 |
C7—C8—H8A | 109.5 | O4—Mn3—O3 | 90.74 (7) |
C7—C8—H8B | 109.5 | O4iv—Mn3—O3 | 89.26 (7) |
H8A—C8—H8B | 109.5 | O7iv—Mn3—O3 | 94.91 (5) |
C7—C8—H8C | 109.5 | O7—Mn3—O3 | 85.09 (5) |
H8A—C8—H8C | 109.5 | O4—Mn3—O3iv | 89.26 (7) |
H8B—C8—H8C | 109.5 | O4iv—Mn3—O3iv | 90.74 (7) |
O5ii—Mn1—O5iii | 74.88 (7) | O7iv—Mn3—O3iv | 85.09 (5) |
O5ii—Mn1—O2i | 158.89 (5) | O7—Mn3—O3iv | 94.91 (5) |
O5iii—Mn1—O2i | 101.88 (5) | O3—Mn3—O3iv | 180.0 |
O5ii—Mn1—O2 | 101.88 (5) | C3—O1—Mn2 | 135.60 (17) |
O5iii—Mn1—O2 | 158.89 (5) | C3—O1—Mn1 | 134.22 (17) |
O2i—Mn1—O2 | 73.45 (7) | Mn2—O1—Mn1 | 90.17 (7) |
O5ii—Mn1—O1 | 84.79 (5) | C5—O2—Mn2 | 131.21 (13) |
O5iii—Mn1—O1 | 84.79 (5) | C5—O2—Mn1 | 138.47 (13) |
O2i—Mn1—O1 | 74.12 (5) | Mn2—O2—Mn1 | 89.53 (5) |
O2—Mn1—O1 | 74.12 (5) | C7—O3—Mn3 | 128.84 (14) |
O5ii—Mn1—O7 | 80.73 (5) | C5—O4—Mn3 | 137.33 (14) |
O5iii—Mn1—O7 | 113.35 (6) | C7v—O5—Mn2 | 132.96 (13) |
O2i—Mn1—O7 | 118.79 (5) | C7v—O5—Mn1v | 127.16 (12) |
O2—Mn1—O7 | 86.18 (5) | Mn2—O5—Mn1v | 99.71 (5) |
O1—Mn1—O7 | 152.56 (3) | C3v—O6—Mn2 | 132.40 (17) |
O5ii—Mn1—O7i | 113.35 (6) | C1—O7—Mn3 | 143.80 (13) |
O5iii—Mn1—O7i | 80.73 (5) | C1—O7—Mn1 | 94.39 (12) |
O2i—Mn1—O7i | 86.18 (5) | Mn3—O7—Mn1 | 120.71 (6) |
O2—Mn1—O7i | 118.79 (5) | C10—C9—H9A | 109.5 |
O1—Mn1—O7i | 152.56 (3) | C10—C9—H9B | 109.5 |
O7—Mn1—O7i | 54.57 (7) | H9A—C9—H9B | 109.5 |
O5ii—Mn1—Mn2 | 118.35 (4) | C10—C9—H9C | 109.5 |
O5iii—Mn1—Mn2 | 118.34 (4) | H9A—C9—H9C | 109.5 |
O2i—Mn1—Mn2 | 44.29 (3) | H9B—C9—H9C | 109.5 |
O2—Mn1—Mn2 | 44.29 (3) | N1—C10—C9 | 179.8 (9) |
Symmetry codes: (i) x, −y+1/2, z; (ii) x−1/2, y, −z+3/2; (iii) x−1/2, −y+1/2, −z+3/2; (iv) −x, −y, −z+1; (v) x+1/2, y, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | [Mn3(C2H3O2)6]·C2H3N |
Mr | 560.14 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 193 |
a, b, c (Å) | 10.788 (2), 12.702 (2), 15.784 (3) |
V (Å3) | 2163.0 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.78 |
Crystal size (mm) | 0.15 × 0.08 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART ? CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.692, 0.915 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 18714, 2763, 2307 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.071, 1.09 |
No. of reflections | 2763 |
No. of parameters | 159 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.48, −0.40 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), publCIF (Westrip, 2009).
Mn1—O1 | 2.3004 (18) | Mn2—O2i | 2.2135 (13) |
Mn1—O2 | 2.2871 (14) | Mn2—O5 | 2.1711 (13) |
Mn1—O2i | 2.2871 (14) | Mn2—O5i | 2.1710 (13) |
Mn1—O5ii | 2.2514 (13) | Mn2—O6 | 2.0983 (19) |
Mn1—O5iii | 2.2514 (14) | Mn3—O3 | 2.1509 (14) |
Mn1—O7 | 2.3215 (14) | Mn3—O3iv | 2.1510 (14) |
Mn1—O7i | 2.3215 (14) | Mn3—O4 | 2.1273 (16) |
Mn1—Mn2 | 3.1697 (7) | Mn3—O4iv | 2.1273 (16) |
Mn2—O1 | 2.1737 (19) | Mn3—O7 | 2.1374 (14) |
Mn2—O2 | 2.2134 (13) | Mn3—O7iv | 2.1373 (14) |
Symmetry codes: (i) x, −y+1/2, z; (ii) x−1/2, −y+1/2, −z+3/2; (iii) x−1/2, y, −z+3/2; (iv) −x, −y, −z+1. |
Coordination networks constructed from rigid bis-carboxylate or amine ligand linkers, such as terephthalic acid (Li et al., 1999) or 4,4-dipyridyl (Zaworotko, 2000), have attracted great attention in recent years. In such substances, changing the length of the linker ligand allows adjustment of structural properties such as pore size (Zaworotko, 2000; Yaghi et al., 2003). However, simple mono-carboxylates, such as formate or acetate, are also able to generate complex extended structures, due to the many accessible carboxylate bridging coordination modes (Viertelhaus et al., 2003; Martin & Hess, 1996). Such structures more closely resemble metal oxides such as zeolites, as the small size of the ligands obliges the metal ions to play a structural role in the linkers as well as the nodes. The resulting short metal···metal distances can lead to interesting magnetic behaviour, driving investigation of a number of stable porous formate networks based on divalent metal ions (Wang, Zhang, Fujiwara et al., 2004; Wang, Zhang, Otsuka et al., 2004; Wang et al., 2005; Viertelhaus et al., 2005; Rood et al., 2006). Such formate-based materials can accommodate a range of guests and have potential as porous magnets (Wang, Zhang, Fujiwara et al., 2004; Dybtsev et al., 2004). However, anhydrous acetate-based frameworks have received less attention to date.
Our recent investigation of the coordination chemistry of the novel chiral ethanolamine ligand, (S)-N-phenylethyldiethanolamine [(S)-H2PEDEA], has resulted in the serendipitous isolation of a new anhydrous manganese(II) acetate coordination framework, the title compound, {[Mn3(O2CCH3)6].CH3CN}n, (I), which crystallizes in the space group Pnma. Compound (I) is the first structurally characterized porous anhydrous manganese(II) acetate phase, and was isolated as a minor product from the attempted reaction of the well known manganese(III) trimer, [Mn3O(O2CCH3)6(py)3](ClO4) (Vincent et al., 1987), with (S)-H2PEDEA in acetonitrile–methanol. In this way, reduction from MnIII to MnII occurs due to reaction with the alcohol groups provided by the solvent and (S)-H2PEDEA. Accommodation of acetonitrile molecules within the resulting framework leads to a porous structure with a substantially increased unit cell volume (by ca 9%) in comparison with the previously published densely packed β-Mn(OAc)2 (Martin & Hess, 1996) and γ-Mn(OAc)2 (Yang et al., 2005).
The three-dimensional network formed by compound (I) is based on assembly of an {Mn3} asymmetric unit, consisting of a central seven-coordinate Mn centre (Mn1) and two six-coordinate Mn atoms (Mn2 and Mn3), four crystallographically independent acetate ligands, and an acetonitrile molecule (Fig. 1). Two of the Mn atoms (Mn1 and Mn2), two acetate ligands (those containing atoms C1 and C3) and the acetonitrile molecule are located on a mirror plane, while atom Mn3 sits on an inversion centre. The C1 acetate ligand is bisected by the mirror, so that only C atoms C1 and C2 sit on the mirror plane and atom O7iii [symmetry code: (iii) x, 1/2 - y, z] is generated by mirror symmetry from atom O7. In the C3 acetate ligand, all four atoms are located on the mirror plane.
The four crystallographically independent acetate ligands show two different µ3 coordination modes. The C3, C5 and C7 acetates all have one O atom [O1, O2 and O5ii, respectively; symmetry code: (ii) x - 1/2, y, 3/2 - z] acting as a monoatomic bridge between two Mn sites, with the other connecting to a third Mn atom. For the C1 acetate, both O atoms (O7 and symmetry-related O7iii) act as monoatomic bridges coordinating to atom Mn1, so that atoms O7 and O7iii, respectively, link atom Mn1 to atom Mn3 and symmetry-related atom Mn3v (Fig. 3) [symmetry code: (v) -x, y + 1/2, 1 - z]. The overall result is that the Mn centres are connected through a mixture of Mn—O—Mn and Mn—OCO—Mn bridges, whereby atoms Mn1 and Mn2 are connected by three Mn—O—Mn bridges (e.g. face-sharing polyhedra), and atom Mn1 connects to atom Mn3 by a single Mn—O—Mn bridge supported by two Mn—OCO—Mn linkages (corner-sharing polyhedra). The Mn1···Mn2 face-sharing connection results in a short Mn···Mn contact of 3.170 (1) Å that may indicate a weak metal–metal interaction. This contrasts with the {Mn3} unit observed in β-Mn(OAc)2 [Martin & Hess, 1996; Cambridge Structural Database (Allen, 2002) refcode QQQFUV02], which exhibits one face-sharing and one edge-sharing interaction between the Mn centres (Fig. 1). However, both β-Mn(OAc)2 and compound (I) show the same overall level of condensation, as the four connections to other trimers comprise exclusively corner-sharing interactions in β-Mn(OAc)2, but two edge-sharing and two corner-sharing interactions in compound (I). The structure of γ-Mn(OAc)2 (Yang et al., 2005) is essentially the same as β-Mn(OAc)2. However, the presence of disorder in the acetate bridging ligands merges the Mn2 and Mn3 sites into one position. This results in an inversion centre at the seven-coordinate atom Mn1 and a higher symmetry space group (P41212, compared with P212121 for the β phase).
The simplest way of describing the network formed by compound (I) is as a diamondoid net of Mn centres (Fig. 2). Seven-coordinate atom Mn1 forms a tetrahedral node by connecting to four other Mn1 centres via two Mn2 and two Mn3 atoms, which combined with the acetate ligands act as linkers. As such, atom Mn1 sits at the centre of an {Mn5} tetrahedral unit with vertices described by two Mn2 and two Mn3 atoms (Figs. 2 and 4). This arrangement results in wavy chains of Mn1 and Mn2 atoms propagating parallel to the crystallographic a axis, formed by face-sharing intratrimer and edge-sharing intertrimer Mn1···Mn2 interactions. The chains are connected to form a three-dimensional network by the corner-sharing links provided by atom Mn3 between the Mn1 nodes, leading to pores which run along the crystallographic a axis and are occupied by the crystallographically located acetonitrile guests (one per {Mn3} formula unit; Fig. 3). Tight binding of the guest acetonitrile molecules is indicated by the zero solvent-accessible void space calculated by PLATON (Spek, 2003), and is illustrated by the space-filling diagram on the right-hand side of Fig. 3.
Note that the chiral literature compound β-Mn(OAc)2 (space group P212121; Martin & Hess, 1996) is also based on a diamondoid arrangement of Mn centres (Fig. 2). However, breaking the structure down again into chains of Mn1 and Mn2 connected by Mn3 atoms reveals that the nature of the intra- and interchain connections is different from that of compound (I). The Mn1···Mn2 chains in β-Mn(OAc)2 contain alternating face-sharing and corner-sharing connections [rather than the face-sharing and edge-sharing connections seen in compound (I)], and the Mn3 linkers connect to the chains through alternating edge-sharing and corner-sharing connections [compared with exclusively corner-sharing in compound (I)]. As a result, the β-Mn(OAc)2 network is less regular (as reflected in the chiral space group). This distortion probably occurs because it is `collapsed' compared with compound (I), filling the space left by the absent acetonitrile molecules. The chirality of β-Mn(OAc)2, observed in the helical axes described by Martin & Hess (1996), is also manifested in the subtly contrasting connectivity around the Mn1 node positions compared with compound (I) (Fig. 4). In compound (I), atom Mn1 and the two Mn2 atoms sit on a mirror plane between two crystallographically identical Mn3 positions (Fig. 3). In β-Mn(OAc)2, the equivalent Mn1 position is effectively a chiral centre, as all four combinations of connection mode (face-, edge- or corner-sharing) and linked atom (e.g. Mn2 or Mn3 sites) are different.