Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270107053875/dn3069sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270107053875/dn3069Isup2.hkl |
CCDC reference: 672403
For related literature, see: Hueso-Ureña Moreno-Carretero Quirós-Olozábal Salas-Peregrín Faure Cienfuegos-López (1996); Baran et al. (1996); Dincă et al. (2006); Han & Goddard (2007); Kesanli et al. (2005); Li & Yang (2006); Lin et al. (2006); Luo et al. (2002); Rosi et al. (2003); Sun & Jin (2004a, 2004b); Sun et al. (2006); Surblé et al. (2006); Wong-Foy, Matzger & Yaghi (2006); Zhao et al. (2004).
A mixture of 2,4-dihydroxypyrimidine-5-carboxylic acid (0.0870 g, 0.5 mmol), Mn(ClO4)2·6H2O (0.0905 g, 0.25 mmol), NaOH (0.0200 g, 0.5 mmol) and water (15 ml) was placed in a 22 ml Teflon-lined stainless steel reactor and heated to 383 K for 144 h. The mixture was then cooled over a period of 48 h, giving yellow crystals in 30% yield. Analysis calculated for C5H6MnN2O6: C 24.51, H 2.47, N 11.43%; found: C 24.66, H 2.41, N 11.33%. IR (KBr): 3452 (s), 3321 (s), 3177 (s), 3060 (s), 2509 (w), 2455 (w), 2263 (w), 1987 (w), 1666 (s), 1639 (s), 1574 (s), 1493 (s), 1456 (s), 1392 (s), 1360 (s), 1182 (s), 1131 (m), 1013 (w), 1002 (w), 849 (m), 818 (s), 801 (m), 720 (m), 677 (m), 641 (s), 595 (m), 490 (m) cm-1.
H atoms on C and N atoms were placed in calculated positions (C—H = 0.93 Å and N—H = 0.86 Å) and refined in riding mode [Uiso(H) = 1.2Ueq(C,N)]. H atoms in water molecules were located in a difference Fourier map and refined as riding on their parent atoms [Uiso(H) = 1.5Ueq(O)].
Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg & Putz, 2004); software used to prepare material for publication: SHELXTL (Bruker, 1998).
[Mn(C5H2N2O4)(H2O)2] | F(000) = 984 |
Mr = 245.06 | Dx = 2.197 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 2468 reflections |
a = 12.9325 (17) Å | θ = 2.4–27.2° |
b = 6.7317 (9) Å | µ = 1.79 mm−1 |
c = 17.018 (2) Å | T = 273 K |
V = 1481.5 (3) Å3 | Block, yellow |
Z = 8 | 0.20 × 0.10 × 0.10 mm |
Bruker SMART CCD area-detector diffractometer | 1303 independent reflections |
Radiation source: fine-focus sealed tube | 1132 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.034 |
ϕ and ω scans | θmax = 25.1°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −14→15 |
Tmin = 0.716, Tmax = 0.841 | k = −7→8 |
7030 measured reflections | l = −20→18 |
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)] = 0.024 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.063 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0297P)2 + 0.7981P] where P = (Fo2 + 2Fc2)/3 |
1303 reflections | (Δ/σ)max = 0.001 |
127 parameters | Δρmax = 0.32 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
[Mn(C5H2N2O4)(H2O)2] | V = 1481.5 (3) Å3 |
Mr = 245.06 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 12.9325 (17) Å | µ = 1.79 mm−1 |
b = 6.7317 (9) Å | T = 273 K |
c = 17.018 (2) Å | 0.20 × 0.10 × 0.10 mm |
Bruker SMART CCD area-detector diffractometer | 1303 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 1132 reflections with I > 2σ(I) |
Tmin = 0.716, Tmax = 0.841 | Rint = 0.034 |
7030 measured reflections |
R[F2 > 2σ(F2)] = 0.024 | 0 restraints |
wR(F2) = 0.063 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.32 e Å−3 |
1303 reflections | Δρmin = −0.25 e Å−3 |
127 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 F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ 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 | ||
Mn1 | 0.46146 (2) | 0.66790 (5) | 0.57158 (2) | 0.01867 (13) | |
C1 | 0.69138 (16) | 0.7457 (3) | 0.67430 (13) | 0.0158 (5) | |
C2 | 0.68969 (16) | 0.7992 (3) | 0.59174 (13) | 0.0159 (5) | |
C3 | 0.86893 (17) | 0.8237 (3) | 0.59028 (13) | 0.0165 (5) | |
C4 | 0.78584 (16) | 0.7290 (3) | 0.70827 (13) | 0.0172 (5) | |
H4 | 0.7905 | 0.6939 | 0.7610 | 0.021* | |
C5 | 0.59655 (17) | 0.7098 (3) | 0.72311 (13) | 0.0193 (5) | |
N1 | 0.77882 (14) | 0.8396 (3) | 0.55353 (11) | 0.0179 (4) | |
N2 | 0.87285 (14) | 0.7625 (3) | 0.66708 (11) | 0.0193 (4) | |
H2 | 0.9319 | 0.7452 | 0.6893 | 0.023* | |
O1 | 0.50967 (13) | 0.6861 (3) | 0.69090 (9) | 0.0267 (4) | |
O2 | 0.60727 (13) | 0.7022 (2) | 0.79643 (9) | 0.0266 (4) | |
O3 | 0.60651 (11) | 0.8146 (2) | 0.55292 (9) | 0.0223 (4) | |
O4 | 0.95410 (11) | 0.8632 (2) | 0.55584 (9) | 0.0204 (4) | |
O1W | 0.38407 (12) | 0.9545 (2) | 0.57592 (9) | 0.0235 (4) | |
H1WA | 0.3976 | 1.0236 | 0.6162 | 0.035* | |
H1WB | 0.3857 | 1.0273 | 0.5354 | 0.035* | |
O2W | 0.33088 (11) | 0.5072 (3) | 0.61325 (10) | 0.0288 (4) | |
H2WA | 0.2783 | 0.4854 | 0.5851 | 0.043* | |
H2WB | 0.3467 | 0.3998 | 0.6364 | 0.043* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Mn1 | 0.0158 (2) | 0.0237 (2) | 0.0164 (2) | 0.00110 (14) | 0.00145 (13) | 0.00042 (14) |
C1 | 0.0184 (11) | 0.0144 (11) | 0.0145 (11) | 0.0003 (9) | 0.0012 (9) | −0.0001 (9) |
C2 | 0.0167 (11) | 0.0146 (12) | 0.0164 (11) | −0.0006 (9) | −0.0003 (9) | −0.0003 (9) |
C3 | 0.0182 (12) | 0.0143 (12) | 0.0170 (12) | −0.0006 (9) | 0.0028 (9) | −0.0032 (9) |
C4 | 0.0227 (12) | 0.0150 (12) | 0.0137 (11) | −0.0006 (9) | 0.0013 (9) | 0.0013 (9) |
C5 | 0.0246 (13) | 0.0149 (12) | 0.0184 (13) | −0.0010 (9) | 0.0021 (10) | −0.0003 (9) |
N1 | 0.0166 (10) | 0.0222 (11) | 0.0149 (9) | −0.0033 (8) | 0.0001 (7) | 0.0005 (8) |
N2 | 0.0156 (9) | 0.0252 (11) | 0.0170 (10) | −0.0002 (8) | −0.0032 (8) | 0.0032 (8) |
O1 | 0.0189 (9) | 0.0421 (11) | 0.0191 (9) | −0.0032 (7) | 0.0012 (7) | 0.0011 (7) |
O2 | 0.0337 (10) | 0.0345 (10) | 0.0117 (9) | −0.0057 (8) | 0.0012 (7) | 0.0007 (7) |
O3 | 0.0153 (8) | 0.0331 (10) | 0.0184 (8) | −0.0035 (7) | −0.0044 (7) | 0.0077 (7) |
O4 | 0.0150 (8) | 0.0271 (9) | 0.0190 (9) | −0.0046 (6) | 0.0040 (6) | −0.0006 (7) |
O1W | 0.0287 (9) | 0.0248 (9) | 0.0168 (8) | 0.0021 (7) | −0.0012 (7) | 0.0008 (7) |
O2W | 0.0183 (8) | 0.0370 (11) | 0.0310 (10) | −0.0036 (8) | −0.0047 (7) | 0.0074 (8) |
Mn1—O2W | 2.1271 (16) | C3—N1 | 1.327 (3) |
Mn1—O1 | 2.1278 (16) | C3—N2 | 1.371 (3) |
Mn1—O3 | 2.1437 (16) | C4—N2 | 1.345 (3) |
Mn1—O1W | 2.1748 (17) | C4—H4 | 0.9300 |
Mn1—O4i | 2.1804 (16) | C5—O2 | 1.257 (3) |
Mn1—O4ii | 2.3392 (16) | C5—O1 | 1.260 (3) |
C1—C4 | 1.356 (3) | N2—H2 | 0.8600 |
C1—C2 | 1.451 (3) | O1W—H1WA | 0.8471 |
C1—C5 | 1.501 (3) | O1W—H1WB | 0.8458 |
C2—O3 | 1.267 (3) | O2W—H2WA | 0.8440 |
C2—N1 | 1.351 (3) | O2W—H2WB | 0.8481 |
C3—O4 | 1.276 (3) | ||
O2W—Mn1—O1 | 86.77 (6) | N1—C3—N2 | 120.39 (19) |
O2W—Mn1—O3 | 168.07 (6) | N2—C4—C1 | 121.2 (2) |
O1—Mn1—O3 | 81.86 (6) | N2—C4—H4 | 119.4 |
O2W—Mn1—O1W | 94.27 (6) | C1—C4—H4 | 119.4 |
O1—Mn1—O1W | 92.94 (6) | O2—C5—O1 | 121.7 (2) |
O3—Mn1—O1W | 89.94 (6) | O2—C5—C1 | 117.8 (2) |
O2W—Mn1—O4i | 104.37 (6) | O1—C5—C1 | 120.5 (2) |
O1—Mn1—O4i | 165.32 (6) | C3—N1—C2 | 120.41 (19) |
O3—Mn1—O4i | 86.28 (6) | C4—N2—C3 | 121.08 (19) |
O1W—Mn1—O4i | 95.67 (6) | C4—N2—H2 | 119.5 |
O2W—Mn1—O4ii | 87.87 (6) | C3—N2—H2 | 119.5 |
O1—Mn1—O4ii | 91.32 (6) | C5—O1—Mn1 | 133.12 (15) |
O3—Mn1—O4ii | 88.77 (6) | C2—O3—Mn1 | 128.91 (14) |
O1W—Mn1—O4ii | 175.33 (6) | C3—O4—Mn1iii | 118.34 (14) |
O4i—Mn1—O4ii | 79.77 (6) | C3—O4—Mn1iv | 122.21 (13) |
C4—C1—C2 | 116.5 (2) | Mn1iii—O4—Mn1iv | 100.23 (6) |
C4—C1—C5 | 119.1 (2) | Mn1—O1W—H1WA | 114.8 |
C2—C1—C5 | 124.32 (19) | Mn1—O1W—H1WB | 118.4 |
O3—C2—N1 | 117.19 (19) | H1WA—O1W—H1WB | 109.7 |
O3—C2—C1 | 122.57 (19) | Mn1—O2W—H2WA | 122.6 |
N1—C2—C1 | 120.22 (19) | Mn1—O2W—H2WB | 113.4 |
O4—C3—N1 | 121.7 (2) | H2WA—O2W—H2WB | 108.0 |
O4—C3—N2 | 117.9 (2) |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) −x+3/2, y−1/2, z; (iii) x+1/2, −y+3/2, −z+1; (iv) −x+3/2, y+1/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2v | 0.86 | 2.30 | 3.121 (2) | 160 |
N2—H2···O1v | 0.86 | 2.31 | 3.039 (2) | 143 |
O1W—H1WA···O2vi | 0.85 | 1.91 | 2.741 (2) | 165 |
O1W—H1WB···O3vii | 0.85 | 1.84 | 2.690 (2) | 178 |
O2W—H2WA···O1Wviii | 0.84 | 2.12 | 2.874 (2) | 149 |
O2W—H2WA···N1i | 0.84 | 2.64 | 3.094 (2) | 115 |
O2W—H2WB···O2ix | 0.85 | 1.85 | 2.687 (2) | 167 |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (v) x+1/2, y, −z+3/2; (vi) −x+1, y+1/2, −z+3/2; (vii) −x+1, −y+2, −z+1; (viii) −x+1/2, y−1/2, z; (ix) −x+1, y−1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | [Mn(C5H2N2O4)(H2O)2] |
Mr | 245.06 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 273 |
a, b, c (Å) | 12.9325 (17), 6.7317 (9), 17.018 (2) |
V (Å3) | 1481.5 (3) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 1.79 |
Crystal size (mm) | 0.20 × 0.10 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.716, 0.841 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7030, 1303, 1132 |
Rint | 0.034 |
(sin θ/λ)max (Å−1) | 0.596 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.024, 0.063, 1.07 |
No. of reflections | 1303 |
No. of parameters | 127 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.32, −0.25 |
Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg & Putz, 2004), SHELXTL (Bruker, 1998).
Mn1—O2W | 2.1271 (16) | Mn1—O1W | 2.1748 (17) |
Mn1—O1 | 2.1278 (16) | Mn1—O4i | 2.1804 (16) |
Mn1—O3 | 2.1437 (16) | Mn1—O4ii | 2.3392 (16) |
O2W—Mn1—O1 | 86.77 (6) | O3—Mn1—O4i | 86.28 (6) |
O2W—Mn1—O3 | 168.07 (6) | O1W—Mn1—O4i | 95.67 (6) |
O1—Mn1—O3 | 81.86 (6) | O2W—Mn1—O4ii | 87.87 (6) |
O2W—Mn1—O1W | 94.27 (6) | O1—Mn1—O4ii | 91.32 (6) |
O1—Mn1—O1W | 92.94 (6) | O3—Mn1—O4ii | 88.77 (6) |
O3—Mn1—O1W | 89.94 (6) | O1W—Mn1—O4ii | 175.33 (6) |
O2W—Mn1—O4i | 104.37 (6) | O4i—Mn1—O4ii | 79.77 (6) |
O1—Mn1—O4i | 165.32 (6) | Mn1iii—O4—Mn1iv | 100.23 (6) |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) −x+3/2, y−1/2, z; (iii) x+1/2, −y+3/2, −z+1; (iv) −x+3/2, y+1/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2v | 0.86 | 2.30 | 3.121 (2) | 160.0 |
N2—H2···O1v | 0.86 | 2.31 | 3.039 (2) | 142.9 |
O1W—H1WA···O2vi | 0.85 | 1.91 | 2.741 (2) | 165.4 |
O1W—H1WB···O3vii | 0.85 | 1.84 | 2.690 (2) | 178.2 |
O2W—H2WA···O1Wviii | 0.84 | 2.12 | 2.874 (2) | 149.1 |
O2W—H2WA···N1i | 0.84 | 2.64 | 3.094 (2) | 115.3 |
O2W—H2WB···O2ix | 0.85 | 1.85 | 2.687 (2) | 167.4 |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (v) x+1/2, y, −z+3/2; (vi) −x+1, y+1/2, −z+3/2; (vii) −x+1, −y+2, −z+1; (viii) −x+1/2, y−1/2, z; (ix) −x+1, y−1/2, −z+3/2. |
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Construction of porous metal-organic frameworks (MOFs) for hydrogen storage has been intensively studied in recent years, because of their potential for helping to meet targets of safe commercial application of hydrogen gas fuel in all kinds of vehicles (Zhao et al., 2004; Kesanli et al., 2005; Rosi et al., 2003; Li & Yang, 2006; Han & Goddard, 2007). To achieve this goal the designed MOFs must have both enough space to hold hydrogen gas and large surface areas and some special functional groups to bind hydrogen molecules. However, the reported MOFs at present undergo a relatively low enthalpy of adsorption change associated with the H2 uptake, which is significantly lower than that required for fuel cells under operating temperatures and pressures (Dincă et al., 2006). One strategy for solving this problem is to select appropriate organic linkers to increase the H2 binding energy. The linkers used at present are usually organic carboxylic acids bearing aromatic rings, such as benzendicarboxylic acid, benzene tricarboxylic acid, biphenyl-3,3',5,5'-tetracarboxylic acid and naphthalene-1,4,5,8-tetracarboxylate (Han & Goddard, 2007; Wong-Foy et al., 2006; Surblé et al., 2006; Sun et al., 2006; Lin et al., 2006). Organic acids with heteroatomic rings bearing other groups, such as hydroxyl and amino groups, are used much less frequently. This encourages us to use 2,4-dihydroxypyrimidine-5-carboxylic acid as the linker to build MOFs. Therefore, we report here the synthesis and X-ray structure of the title complex, [Mn(H2O)2(Hiso)]n (Hiso2- is 2-oxo-4-oxido-1,2-dihydropyrimidine-5-carboxylate), which exhibits a two-dimensional coordination framework structure assembled by MnII ions and Hiso2-.
As shown in Fig. 1, the MnII ion is coordinated in a distorted octahedral geometry by two water molecules, two oxo O atoms from two different Hiso2– anions, and one carboxylate O atom and one oxido O atom from a third Hiso2– anion. The Mn—O bond lengths range from 2.1271 (16) to 2.3392 (16) Å, and the O—Mn—O bond angles are in the ranges 79.77 (6)–104.37 (6)° and 165.32 (6)–175.33 (6)° (Table 1). Thus, each MnII ion is coordinated to three Hiso2–anions, and each Hiso2– anion acts as a µ3:η4-bridge using the oxo O atom to bridge two MnII ions with a Mn—O—Mn bond angle of 100.23 (6)° and the oxido O atom and one carboxylate O atom to chelate to another MnII ion. To the best of our knowledge, this coordination mode for the Hiso2– ion is unprecedented. The only reported tetradentate case is Pr2(Hiso)(H2iso)4(phen)2(H2O)2·5H2O, in which the Hiso2– anion bridges only two metal ions (Sun & Jin, 2004a).
Two MnII ions are bridged by the oxo groups of two Hiso2– ions, constructing a centrosymmetric dinuclear [Mn2(H2O)4(Hiso)2] building block with an Mn···Mn separation of 3.4697 (3) Å. Each dinuclear building block acts as a four-connected node to connect another four dinuclear building blocks by the coordination of the oxido groups and carboxylate O atoms to the MnII ions from the adjacent dinuclear building blocks. The MnII ions bridged by Hiso2– ions have Mn···Mn separations of 6.9978 (8) and 8.1870 (9) Å, respectively. This leads to the construction of a two-dimensional framework (Fig. 2a) parallel to the ab plane, which presents an s-like appearance viewed down the b axis (Fig. 2b). The pyrimidine rings aligned along the b axis are almost parallel to each other, with a dihedral angle of 5.546° and a center-to-center distance of 3.4617 (4) Å between the two adjacent pyrimidine rings. The center-to-plane distances are 3.194 and 3.273 Å with offset angles of 22.67 and 19.03°, respectively. This indicates the presence of significant π–π interactions between the adjacent pyrimidine rings. The two-dimensional framework also contains O2W—H2WA···O1Wviii, O2W—H2WA···N1i and O1W—H1WB···O3vii hydrogen bonds (details are given in Table 2). These π–π interactions and hydrogen bonds further stabilize the two-dimensional network. The construction of a two-dimensional framework from transition metal ions and 2,4-dihydroxypyrimidine-5-carboxylic acid is unprecedented. The reported cases are usually mononuclear compounds (Luo et al., 2002; Baran et al., 1996). Only a few were obtained as polynuclear complexes (Hueso-Ureña et al., 1996) or one-dimension coordination polymers (Sun & Jin, 2004b).
The two-dimensional sheets pack along the c axis by the propagation of O1W—H1WA···O2vi, O2W—H2WB···O2ix, N2—H2···O1v and N2—H2···O2v hydrogen bonds between two adjacent sheets (Table 2), constructing a three-dimensional supramolecular framework (Fig. 3).