Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270111008110/sk3402sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270111008110/sk3402Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270111008110/sk3402IIsup3.hkl |
CCDC references: 824044; 824045
For the preparation of compound (I), 4-oxo-4H-pyran-2,6-dicarboxylic acid (2.02 g, 10 mmol, Acros, chelidonic acid) was dissolved in methanol (200 ml) by heating. To this solution was added a solution of piperazine (0.86 ml, 10 mmol) in methanol (10 ml). After cooling, a light-yellow precipitate was collected. The precipitate was redissolved in water and allowed to evaporate slowly, producing crystals suitable for X-ray diffraction [m.p. 467 K (decomposition)]. Elemental analysis, calculated for C18H18N2O12: C 47.54, H3.96, N 6.16%; found: C 47.09, H 3.91, N 6.08%. Spectroscopic analysis: IR (KBr, ν, cm-1): 1339 (s), 1397 (s), 1644 (s), 2446 (br), 2999 (br), 3075 (w), 3236 (s), 3424 (s), 3620 (s); 1H NMR (D2O, δ, p.p.m.): 3.439 (3H, pipH2), 6.939 (2H, cdo); 13C NMR (D2O, δ, p.p.m.): 184.5, 159.1, 115.8, 40.2; UV: 223 nm.
Compound (II) was obtained when we attempted to obtain a nickel(II) complex with (cdo)2-. To a solution of (I) (1 mmol, 0.27 g) in water was added a solution of Ni(NO3)2.6H2O (0.14 g, 0.5 mmol) (molar ratio of 2:1) in water (25 ml). After one week, a light-yellow precipitate was collected. This was redissolved in water and allowed to evaporate slowly, yielding the crystals used for data collection [m.p. 489 K (decomposition)]. Spectroscopic analysis: IR (KBr, ν, cm-1): 1338 (br), 1383 (s), 1459 (w), 1642 (br), 2489 (br), 3075 (w), 3238 (w), 3622 (br).
For (I), the crystal was a three-component rotational twin. Twin integration was carried out using SAINT (Bruker, 2010) and the absorption correction applied using TWINABS (Sheldrick, 2006). The final reflection file used all components and composites. The excess 447 reflections were discounted in the least-squares instruction in order not to underestimate the s.u. values. In addition, 33 reflections were specifically omitted that were likely affected by overlap of twin domains. The twin laws were as follows: Transforms h1.1(1)->h1.2(2) (-0.99994 0.00089 0.00046/ -0.00252 -1.00000 -0.00009/ 0.24863 -0.00003 0.99994); Transforms h1.1(1)->h1.3(3) (-1.00020 -0.00071 -0.04193/ 0.00208 -1.00000 -0.00066/ 0.00948 -0.00126 1.00020); Transforms h1.2(2)->h1.3(3) (0.98972 0.00160 -0.04239/ -0.00474 0.99999 -0.00057/ 0.23919 0.00144 1.00015). Refined twin parameters for the three components are: 0.6036 (10)/0.2707 (10)/0.1257 (11).
For both (I) and (II), H atoms bonded to C and N atoms were refined as riding, with C—H = 0.95–0.99 Å and N—H = 0.92 Å, and Uiso(H) = 1.2Ueq(C,N). For (I), the H atoms of the hydrate molecule were located in a difference map and subsequently refined with restraints of O—H = 0.84 (2) Å and H···H = 1.34 (4) Å, and with Uiso(H) = 1.5Ueq(O). In the structure of (II), there are two short hydrogen bonds between the protonated carboxyl groups and the unprotonated carboxylate groups of an inversion-related molecule of (cdoH)-. Electron-density maps show that these are assymmetric hydrogen bonds and the H atom does not reside on the centre of symmetry. Each of these H atoms (H2 and H6) is at half-occupancy for charge balance and in order to model the disorder. These two H atoms were freely refined.
For both compounds, data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
C4H12N22+·C7H2O62−·H2O | F(000) = 608 |
Mr = 288.26 | Dx = 1.531 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 9971 reflections |
a = 6.8003 (3) Å | θ = 2.2–31.5° |
b = 11.3961 (5) Å | µ = 0.13 mm−1 |
c = 16.1548 (7) Å | T = 87 K |
β = 92.968 (2)° | Needle, colourless |
V = 1250.27 (9) Å3 | 0.42 × 0.14 × 0.06 mm |
Z = 4 |
Bruker SMART APEX DUO diffractometer | 4609 independent reflections |
Radiation source: fine-focus sealed tube | 4303 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.046 |
Detector resolution: 8.3 pixels mm-1 | θmax = 31.5°, θmin = 2.2° |
ω scans | h = −10→9 |
Absorption correction: multi-scan (TWINABS; Sheldrick, 2006) | k = −16→16 |
Tmin = 0.948, Tmax = 0.993 | l = −23→23 |
59584 measured reflections |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.099 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.12 | w = 1/[σ2(Fo2) + (0.052P)2 + 0.3187P] where P = (Fo2 + 2Fc2)/3 |
4609 reflections | (Δ/σ)max < 0.001 |
189 parameters | Δρmax = 0.52 e Å−3 |
3 restraints | Δρmin = −0.24 e Å−3 |
C4H12N22+·C7H2O62−·H2O | V = 1250.27 (9) Å3 |
Mr = 288.26 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 6.8003 (3) Å | µ = 0.13 mm−1 |
b = 11.3961 (5) Å | T = 87 K |
c = 16.1548 (7) Å | 0.42 × 0.14 × 0.06 mm |
β = 92.968 (2)° |
Bruker SMART APEX DUO diffractometer | 4609 independent reflections |
Absorption correction: multi-scan (TWINABS; Sheldrick, 2006) | 4303 reflections with I > 2σ(I) |
Tmin = 0.948, Tmax = 0.993 | Rint = 0.046 |
59584 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 3 restraints |
wR(F2) = 0.099 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.12 | Δρmax = 0.52 e Å−3 |
4609 reflections | Δρmin = −0.24 e Å−3 |
189 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. H atoms bonded to C and N were refined as riding on their bonded atoms with U(iso)= 1.2U(eq) of the bonded atom and C—H in the range 0.95 to 0.99 Å, N—H = 0.92 Å. H atoms of the hydrate molecule were located in a difference map and subsequently refined with restraints of O—H = 0.84 (2); H···H = 1.34 (4) Å and U(iso)= 1.5U(eq) of the bonded O atom. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.22695 (13) | 0.40793 (6) | 0.04088 (5) | 0.00950 (16) | |
O2 | 0.14864 (15) | 0.20189 (7) | 0.10764 (5) | 0.01377 (17) | |
O3 | 0.20665 (15) | 0.10755 (7) | −0.01012 (5) | 0.01377 (17) | |
O4 | 0.27759 (15) | 0.44996 (7) | −0.20777 (5) | 0.01450 (17) | |
O5 | 0.23249 (15) | 0.71644 (7) | 0.03859 (5) | 0.01442 (17) | |
O6 | 0.22009 (15) | 0.58961 (7) | 0.14485 (5) | 0.01470 (18) | |
O7 | 0.22073 (18) | 0.29837 (9) | −0.34369 (7) | 0.0244 (2) | |
H7A | 0.249 (4) | 0.3417 (18) | −0.3004 (11) | 0.037* | |
H7B | 0.320 (3) | 0.3116 (19) | −0.3761 (12) | 0.037* | |
C1 | 0.22805 (17) | 0.31350 (9) | −0.01049 (7) | 0.00905 (19) | |
C2 | 0.24851 (18) | 0.32309 (9) | −0.09277 (7) | 0.0101 (2) | |
H2 | 0.2512 | 0.2541 | −0.1257 | 0.012* | |
C3 | 0.26651 (18) | 0.43672 (9) | −0.13186 (7) | 0.00998 (19) | |
C4 | 0.26509 (19) | 0.53455 (9) | −0.07451 (7) | 0.0107 (2) | |
H4 | 0.2792 | 0.6122 | −0.0947 | 0.013* | |
C5 | 0.24398 (17) | 0.51683 (9) | 0.00712 (7) | 0.00900 (19) | |
C6 | 0.23172 (18) | 0.61606 (9) | 0.07004 (7) | 0.01027 (19) | |
C7 | 0.19263 (18) | 0.19811 (9) | 0.03303 (7) | 0.0100 (2) | |
C8 | 0.08090 (18) | 0.44868 (10) | 0.35334 (7) | 0.0120 (2) | |
H8A | 0.0661 | 0.5298 | 0.3320 | 0.014* | |
H8B | −0.0162 | 0.4368 | 0.3962 | 0.014* | |
C9 | 0.04210 (19) | 0.36210 (10) | 0.28322 (7) | 0.0121 (2) | |
H9A | 0.0450 | 0.2812 | 0.3056 | 0.015* | |
H9B | −0.0904 | 0.3764 | 0.2569 | 0.015* | |
C10 | 0.39414 (19) | 0.35568 (10) | 0.25834 (7) | 0.0117 (2) | |
H10A | 0.4927 | 0.3649 | 0.2158 | 0.014* | |
H10B | 0.4058 | 0.2752 | 0.2812 | 0.014* | |
C11 | 0.43271 (18) | 0.44460 (10) | 0.32688 (7) | 0.0113 (2) | |
H11A | 0.5663 | 0.4325 | 0.3528 | 0.014* | |
H11B | 0.4262 | 0.5249 | 0.3035 | 0.014* | |
N1 | 0.28378 (16) | 0.43184 (8) | 0.39064 (6) | 0.01027 (17) | |
H1A | 0.3079 | 0.4864 | 0.4319 | 0.012* | |
H1B | 0.2941 | 0.3584 | 0.4141 | 0.012* | |
N2 | 0.19266 (16) | 0.37408 (8) | 0.22020 (6) | 0.01145 (18) | |
H2A | 0.1844 | 0.4477 | 0.1969 | 0.014* | |
H2B | 0.1684 | 0.3199 | 0.1787 | 0.014* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0140 (4) | 0.0052 (3) | 0.0094 (3) | −0.0004 (3) | 0.0017 (3) | −0.0002 (2) |
O2 | 0.0229 (5) | 0.0094 (3) | 0.0092 (4) | −0.0020 (3) | 0.0028 (3) | 0.0003 (3) |
O3 | 0.0233 (5) | 0.0073 (3) | 0.0108 (4) | −0.0001 (3) | 0.0017 (3) | −0.0005 (3) |
O4 | 0.0205 (5) | 0.0133 (4) | 0.0098 (4) | −0.0012 (3) | 0.0030 (3) | 0.0016 (3) |
O5 | 0.0219 (5) | 0.0067 (3) | 0.0149 (4) | −0.0001 (3) | 0.0035 (3) | −0.0002 (3) |
O6 | 0.0230 (5) | 0.0101 (3) | 0.0110 (4) | 0.0001 (3) | 0.0010 (3) | −0.0010 (3) |
O7 | 0.0283 (6) | 0.0199 (4) | 0.0258 (5) | −0.0050 (4) | 0.0100 (4) | −0.0078 (4) |
C1 | 0.0107 (5) | 0.0061 (4) | 0.0104 (4) | −0.0002 (4) | 0.0013 (4) | −0.0006 (3) |
C2 | 0.0122 (5) | 0.0081 (4) | 0.0102 (4) | 0.0000 (4) | 0.0015 (4) | 0.0001 (3) |
C3 | 0.0103 (5) | 0.0094 (4) | 0.0103 (5) | −0.0004 (4) | 0.0016 (4) | 0.0006 (3) |
C4 | 0.0130 (5) | 0.0076 (4) | 0.0115 (5) | −0.0002 (4) | 0.0009 (4) | 0.0008 (3) |
C5 | 0.0095 (5) | 0.0054 (4) | 0.0120 (4) | 0.0006 (4) | 0.0005 (4) | 0.0003 (3) |
C6 | 0.0094 (5) | 0.0088 (4) | 0.0126 (5) | 0.0002 (4) | 0.0008 (4) | −0.0018 (3) |
C7 | 0.0124 (5) | 0.0082 (4) | 0.0095 (4) | −0.0007 (4) | 0.0003 (4) | 0.0007 (3) |
C8 | 0.0129 (5) | 0.0109 (5) | 0.0123 (5) | 0.0015 (4) | 0.0019 (4) | −0.0012 (4) |
C9 | 0.0120 (5) | 0.0126 (5) | 0.0117 (5) | −0.0013 (4) | 0.0006 (4) | −0.0003 (4) |
C10 | 0.0138 (5) | 0.0099 (4) | 0.0118 (5) | 0.0002 (4) | 0.0032 (4) | −0.0015 (4) |
C11 | 0.0126 (5) | 0.0098 (4) | 0.0116 (5) | −0.0007 (4) | 0.0016 (4) | −0.0008 (4) |
N1 | 0.0150 (5) | 0.0074 (3) | 0.0084 (4) | −0.0003 (3) | 0.0010 (3) | −0.0001 (3) |
N2 | 0.0168 (5) | 0.0091 (4) | 0.0084 (4) | −0.0012 (4) | 0.0003 (3) | −0.0003 (3) |
O1—C1 | 1.3592 (12) | C8—C9 | 1.5150 (16) |
O1—C5 | 1.3630 (12) | C8—H8A | 0.9900 |
O2—C7 | 1.2575 (13) | C8—H8B | 0.9900 |
O3—C7 | 1.2518 (13) | C9—N2 | 1.4871 (16) |
O4—C3 | 1.2417 (14) | C9—H9A | 0.9900 |
O5—C6 | 1.2518 (13) | C9—H9B | 0.9900 |
O6—C6 | 1.2520 (14) | C10—N2 | 1.4878 (17) |
O7—H7A | 0.870 (15) | C10—C11 | 1.5137 (16) |
O7—H7B | 0.891 (16) | C10—H10A | 0.9900 |
C1—C2 | 1.3480 (15) | C10—H10B | 0.9900 |
C1—C7 | 1.5163 (15) | C11—N1 | 1.4886 (15) |
C2—C3 | 1.4486 (15) | C11—H11A | 0.9900 |
C2—H2 | 0.9500 | C11—H11B | 0.9900 |
C3—C4 | 1.4500 (15) | N1—H1A | 0.9200 |
C4—C5 | 1.3490 (15) | N1—H1B | 0.9200 |
C4—H4 | 0.9500 | N2—H2A | 0.9200 |
C5—C6 | 1.5257 (15) | N2—H2B | 0.9200 |
C8—N1 | 1.4891 (16) | ||
C1—O1—C5 | 118.25 (8) | N2—C9—H9A | 109.5 |
H7A—O7—H7B | 103.6 (19) | C8—C9—H9A | 109.5 |
C2—C1—O1 | 122.82 (9) | N2—C9—H9B | 109.5 |
C2—C1—C7 | 123.67 (9) | C8—C9—H9B | 109.5 |
O1—C1—C7 | 113.42 (9) | H9A—C9—H9B | 108.1 |
C1—C2—C3 | 121.17 (10) | N2—C10—C11 | 109.24 (10) |
C1—C2—H2 | 119.4 | N2—C10—H10A | 109.8 |
C3—C2—H2 | 119.4 | C11—C10—H10A | 109.8 |
O4—C3—C2 | 123.36 (10) | N2—C10—H10B | 109.8 |
O4—C3—C4 | 122.71 (10) | C11—C10—H10B | 109.8 |
C2—C3—C4 | 113.91 (9) | H10A—C10—H10B | 108.3 |
C5—C4—C3 | 120.94 (9) | N1—C11—C10 | 110.03 (10) |
C5—C4—H4 | 119.5 | N1—C11—H11A | 109.7 |
C3—C4—H4 | 119.5 | C10—C11—H11A | 109.7 |
C4—C5—O1 | 122.89 (9) | N1—C11—H11B | 109.7 |
C4—C5—C6 | 123.55 (9) | C10—C11—H11B | 109.7 |
O1—C5—C6 | 113.55 (9) | H11A—C11—H11B | 108.2 |
O5—C6—O6 | 127.85 (10) | C11—N1—C8 | 110.90 (9) |
O5—C6—C5 | 113.91 (10) | C11—N1—H1A | 109.5 |
O6—C6—C5 | 118.23 (9) | C8—N1—H1A | 109.5 |
O3—C7—O2 | 126.21 (10) | C11—N1—H1B | 109.5 |
O3—C7—C1 | 115.99 (9) | C8—N1—H1B | 109.5 |
O2—C7—C1 | 117.78 (9) | H1A—N1—H1B | 108.0 |
N1—C8—C9 | 109.90 (9) | C9—N2—C10 | 110.82 (9) |
N1—C8—H8A | 109.7 | C9—N2—H2A | 109.5 |
C9—C8—H8A | 109.7 | C10—N2—H2A | 109.5 |
N1—C8—H8B | 109.7 | C9—N2—H2B | 109.5 |
C9—C8—H8B | 109.7 | C10—N2—H2B | 109.5 |
H8A—C8—H8B | 108.2 | H2A—N2—H2B | 108.1 |
N2—C9—C8 | 110.65 (10) | ||
C5—O1—C1—C2 | 1.14 (17) | O1—C5—C6—O5 | −174.96 (10) |
C5—O1—C1—C7 | −175.61 (10) | C4—C5—C6—O6 | −177.18 (12) |
O1—C1—C2—C3 | −1.36 (19) | O1—C5—C6—O6 | 4.27 (15) |
C7—C1—C2—C3 | 175.05 (11) | C2—C1—C7—O3 | 8.39 (18) |
C1—C2—C3—O4 | −176.98 (12) | O1—C1—C7—O3 | −174.90 (10) |
C1—C2—C3—C4 | 1.43 (17) | C2—C1—C7—O2 | −170.26 (12) |
O4—C3—C4—C5 | 177.00 (12) | O1—C1—C7—O2 | 6.45 (16) |
C2—C3—C4—C5 | −1.42 (17) | N1—C8—C9—N2 | −56.35 (12) |
C3—C4—C5—O1 | 1.36 (18) | N2—C10—C11—N1 | 58.96 (12) |
C3—C4—C5—C6 | −177.06 (11) | C10—C11—N1—C8 | −58.88 (12) |
C1—O1—C5—C4 | −1.14 (17) | C9—C8—N1—C11 | 57.12 (12) |
C1—O1—C5—C6 | 177.42 (10) | C8—C9—N2—C10 | 57.94 (12) |
C4—C5—C6—O5 | 3.59 (17) | C11—C10—N2—C9 | −58.80 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
O7—H7A···O4 | 0.87 (2) | 1.94 (2) | 2.8049 (14) | 172 (2) |
O7—H7B···O2i | 0.89 (2) | 2.27 (2) | 3.0533 (16) | 147 (2) |
N1—H1A···O3ii | 0.92 | 1.88 | 2.7796 (12) | 166 |
N1—H1B···O5iii | 0.92 | 1.80 | 2.7126 (12) | 170 |
N2—H2B···O2 | 0.92 | 1.77 | 2.6815 (12) | 171 |
N2—H2A···O6 | 0.92 | 1.84 | 2.7519 (13) | 168 |
N1—H1A···O2ii | 0.92 | 2.56 | 3.1115 (13) | 119 |
N2—H2B···O1 | 0.92 | 2.49 | 2.9436 (12) | 110 |
Symmetry codes: (i) x+1/2, −y+1/2, z−1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+1/2, y−1/2, −z+1/2. |
C4H12N22+·2C7H3O6− | Z = 1 |
Mr = 454.34 | F(000) = 236 |
Triclinic, P1 | Dx = 1.667 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.7880 (3) Å | Cell parameters from 5711 reflections |
b = 8.0650 (4) Å | θ = 2.6–31.5° |
c = 8.5675 (4) Å | µ = 0.14 mm−1 |
α = 90.377 (2)° | T = 87 K |
β = 94.110 (2)° | Block, colourless |
γ = 104.538 (3)° | 0.36 × 0.34 × 0.22 mm |
V = 452.70 (4) Å3 |
Bruker SMART APEXII diffractometer | 2971 independent reflections |
Radiation source: fine-focus sealed tube | 2806 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.011 |
Detector resolution: 8.3 pixels mm-1 | θmax = 31.5°, θmin = 2.4° |
ω scans | h = −9→9 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | k = −11→11 |
Tmin = 0.956, Tmax = 0.976 | l = −12→12 |
7496 measured reflections |
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)] = 0.031 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.092 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0569P)2 + 0.1111P] where P = (Fo2 + 2Fc2)/3 |
2971 reflections | (Δ/σ)max = 0.001 |
153 parameters | Δρmax = 0.53 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C4H12N22+·2C7H3O6− | γ = 104.538 (3)° |
Mr = 454.34 | V = 452.70 (4) Å3 |
Triclinic, P1 | Z = 1 |
a = 6.7880 (3) Å | Mo Kα radiation |
b = 8.0650 (4) Å | µ = 0.14 mm−1 |
c = 8.5675 (4) Å | T = 87 K |
α = 90.377 (2)° | 0.36 × 0.34 × 0.22 mm |
β = 94.110 (2)° |
Bruker SMART APEXII diffractometer | 2971 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2806 reflections with I > 2σ(I) |
Tmin = 0.956, Tmax = 0.976 | Rint = 0.011 |
7496 measured reflections |
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.092 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.53 e Å−3 |
2971 reflections | Δρmin = −0.24 e Å−3 |
153 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) | |
O1 | 0.74410 (8) | 0.54080 (6) | 0.11379 (6) | 0.01081 (11) | |
O2 | 0.91492 (9) | 0.85356 (7) | 0.03521 (6) | 0.01557 (12) | |
H2 | 0.977 (8) | 0.964 (6) | 0.006 (7) | 0.056 (11)* | 0.50 |
O3 | 0.86543 (9) | 0.78085 (7) | −0.22173 (6) | 0.01539 (12) | |
O4 | 0.62761 (9) | 0.13354 (7) | −0.19429 (7) | 0.01478 (12) | |
O5 | 0.58838 (9) | 0.23123 (7) | 0.39606 (6) | 0.01451 (12) | |
O6 | 0.60388 (9) | 0.51366 (7) | 0.38810 (7) | 0.01521 (12) | |
H6 | 0.523 (7) | 0.502 (6) | 0.469 (5) | 0.046 (9)* | 0.50 |
C1 | 0.77985 (10) | 0.56304 (9) | −0.03965 (8) | 0.01025 (13) | |
C2 | 0.74579 (11) | 0.43258 (9) | −0.14573 (8) | 0.01153 (13) | |
H2A | 0.7744 | 0.4561 | −0.2514 | 0.014* | |
C3 | 0.66578 (10) | 0.25639 (9) | −0.10008 (8) | 0.01113 (13) | |
C4 | 0.63217 (11) | 0.23805 (9) | 0.06593 (8) | 0.01156 (13) | |
H4 | 0.5836 | 0.1273 | 0.1068 | 0.014* | |
C5 | 0.66982 (10) | 0.37790 (9) | 0.16164 (8) | 0.01017 (13) | |
C6 | 0.61799 (10) | 0.36981 (9) | 0.33080 (8) | 0.01090 (13) | |
C7 | 0.85932 (10) | 0.74826 (9) | −0.08149 (8) | 0.01129 (13) | |
N1 | 0.81573 (9) | 1.02489 (8) | −0.44256 (7) | 0.01217 (12) | |
H1A | 0.7998 | 0.9521 | −0.3596 | 0.015* | |
H1B | 0.7091 | 1.0766 | −0.4481 | 0.015* | |
C8 | 0.80952 (11) | 0.92372 (9) | −0.59066 (8) | 0.01256 (13) | |
H8A | 0.8168 | 1.0002 | −0.6811 | 0.015* | |
H8B | 0.6793 | 0.8341 | −0.6042 | 0.015* | |
C9 | 1.01302 (11) | 1.15908 (9) | −0.41500 (8) | 0.01219 (13) | |
H9A | 1.0144 | 1.2216 | −0.3149 | 0.015* | |
H9B | 1.0264 | 1.2426 | −0.5002 | 0.015* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0142 (2) | 0.0079 (2) | 0.0094 (2) | 0.00030 (17) | 0.00286 (17) | 0.00102 (17) |
O2 | 0.0219 (3) | 0.0097 (2) | 0.0120 (2) | −0.00178 (19) | 0.00101 (19) | −0.00019 (19) |
O3 | 0.0214 (3) | 0.0126 (2) | 0.0111 (2) | 0.0018 (2) | 0.00261 (19) | 0.00244 (18) |
O4 | 0.0184 (3) | 0.0117 (2) | 0.0131 (2) | 0.00134 (19) | 0.00252 (19) | −0.00338 (19) |
O5 | 0.0189 (3) | 0.0120 (2) | 0.0132 (2) | 0.00420 (19) | 0.00339 (19) | 0.00338 (19) |
O6 | 0.0221 (3) | 0.0102 (2) | 0.0131 (2) | 0.00213 (19) | 0.00652 (19) | −0.00104 (18) |
C1 | 0.0109 (3) | 0.0097 (3) | 0.0096 (3) | 0.0012 (2) | 0.0017 (2) | 0.0013 (2) |
C2 | 0.0129 (3) | 0.0109 (3) | 0.0103 (3) | 0.0017 (2) | 0.0017 (2) | 0.0000 (2) |
C3 | 0.0115 (3) | 0.0102 (3) | 0.0113 (3) | 0.0018 (2) | 0.0016 (2) | −0.0005 (2) |
C4 | 0.0136 (3) | 0.0091 (3) | 0.0114 (3) | 0.0015 (2) | 0.0023 (2) | 0.0001 (2) |
C5 | 0.0114 (3) | 0.0086 (3) | 0.0102 (3) | 0.0013 (2) | 0.0021 (2) | 0.0012 (2) |
C6 | 0.0112 (3) | 0.0107 (3) | 0.0100 (3) | 0.0013 (2) | 0.0013 (2) | −0.0002 (2) |
C7 | 0.0110 (3) | 0.0099 (3) | 0.0123 (3) | 0.0011 (2) | 0.0016 (2) | 0.0010 (2) |
N1 | 0.0123 (3) | 0.0111 (3) | 0.0128 (3) | 0.0020 (2) | 0.0027 (2) | −0.0003 (2) |
C8 | 0.0128 (3) | 0.0122 (3) | 0.0118 (3) | 0.0016 (2) | −0.0001 (2) | −0.0012 (2) |
C9 | 0.0131 (3) | 0.0097 (3) | 0.0128 (3) | 0.0011 (2) | 0.0014 (2) | −0.0012 (2) |
O1—C1 | 1.3588 (8) | C4—C5 | 1.3502 (9) |
O1—C5 | 1.3610 (8) | C4—H4 | 0.9500 |
O2—C7 | 1.2794 (9) | C5—C6 | 1.5137 (10) |
O2—H2 | 0.93 (4) | N1—C8 | 1.4962 (9) |
O3—C7 | 1.2330 (9) | N1—C9 | 1.4981 (9) |
O4—C3 | 1.2373 (8) | N1—H1A | 0.9200 |
O5—C6 | 1.2303 (9) | N1—H1B | 0.9200 |
O6—C6 | 1.2850 (9) | C8—C9i | 1.5151 (10) |
O6—H6 | 0.91 (4) | C8—H8A | 0.9900 |
C1—C2 | 1.3496 (9) | C8—H8B | 0.9900 |
C1—C7 | 1.5104 (10) | C9—C8i | 1.5151 (10) |
C2—C3 | 1.4551 (10) | C9—H9A | 0.9900 |
C2—H2A | 0.9500 | C9—H9B | 0.9900 |
C3—C4 | 1.4592 (10) | ||
C1—O1—C5 | 117.73 (5) | O3—C7—O2 | 127.56 (7) |
C7—O2—H2 | 113 (3) | O3—C7—C1 | 117.31 (6) |
C6—O6—H6 | 113 (3) | O2—C7—C1 | 115.13 (6) |
C2—C1—O1 | 123.44 (6) | C8—N1—C9 | 111.47 (5) |
C2—C1—C7 | 122.85 (6) | C8—N1—H1A | 109.3 |
O1—C1—C7 | 113.71 (6) | C9—N1—H1A | 109.3 |
C1—C2—C3 | 120.76 (6) | C8—N1—H1B | 109.3 |
C1—C2—H2A | 119.6 | C9—N1—H1B | 109.3 |
C3—C2—H2A | 119.6 | H1A—N1—H1B | 108.0 |
O4—C3—C2 | 122.84 (6) | N1—C8—C9i | 110.03 (6) |
O4—C3—C4 | 123.14 (6) | N1—C8—H8A | 109.7 |
C2—C3—C4 | 114.02 (6) | C9i—C8—H8A | 109.7 |
C5—C4—C3 | 120.26 (6) | N1—C8—H8B | 109.7 |
C5—C4—H4 | 119.9 | C9i—C8—H8B | 109.7 |
C3—C4—H4 | 119.9 | H8A—C8—H8B | 108.2 |
C4—C5—O1 | 123.76 (6) | N1—C9—C8i | 109.96 (6) |
C4—C5—C6 | 122.98 (6) | N1—C9—H9A | 109.7 |
O1—C5—C6 | 113.10 (6) | C8i—C9—H9A | 109.7 |
O5—C6—O6 | 127.44 (7) | N1—C9—H9B | 109.7 |
O5—C6—C5 | 118.82 (6) | C8i—C9—H9B | 109.7 |
O6—C6—C5 | 113.70 (6) | H9A—C9—H9B | 108.2 |
C5—O1—C1—C2 | −0.09 (10) | C1—O1—C5—C6 | −174.80 (6) |
C5—O1—C1—C7 | 179.24 (6) | C4—C5—C6—O5 | 18.57 (11) |
O1—C1—C2—C3 | 0.31 (11) | O1—C5—C6—O5 | −165.82 (6) |
C7—C1—C2—C3 | −178.95 (6) | C4—C5—C6—O6 | −159.28 (7) |
C1—C2—C3—O4 | 178.15 (7) | O1—C5—C6—O6 | 16.33 (9) |
C1—C2—C3—C4 | −1.06 (10) | C2—C1—C7—O3 | 10.25 (11) |
O4—C3—C4—C5 | −177.53 (7) | O1—C1—C7—O3 | −169.08 (6) |
C2—C3—C4—C5 | 1.68 (10) | C2—C1—C7—O2 | −169.06 (7) |
C3—C4—C5—O1 | −1.62 (11) | O1—C1—C7—O2 | 11.62 (9) |
C3—C4—C5—C6 | 173.51 (6) | C9—N1—C8—C9i | 57.73 (8) |
C1—O1—C5—C4 | 0.77 (10) | C8—N1—C9—C8i | −57.69 (8) |
Symmetry code: (i) −x+2, −y+2, −z−1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O2ii | 0.93 (4) | 1.52 (4) | 2.4549 (11) | 177 (6) |
O6—H6···O6iii | 0.91 (4) | 1.53 (4) | 2.4395 (11) | 177 (5) |
N1—H1A···O3 | 0.92 | 1.94 | 2.8032 (8) | 156 |
N1—H1B···O5iv | 0.92 | 2.09 | 2.8419 (8) | 138 |
Symmetry codes: (ii) −x+2, −y+2, −z; (iii) −x+1, −y+1, −z+1; (iv) x, y+1, z−1. |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | C4H12N22+·C7H2O62−·H2O | C4H12N22+·2C7H3O6− |
Mr | 288.26 | 454.34 |
Crystal system, space group | Monoclinic, P21/n | Triclinic, P1 |
Temperature (K) | 87 | 87 |
a, b, c (Å) | 6.8003 (3), 11.3961 (5), 16.1548 (7) | 6.7880 (3), 8.0650 (4), 8.5675 (4) |
α, β, γ (°) | 90, 92.968 (2), 90 | 90.377 (2), 94.110 (2), 104.538 (3) |
V (Å3) | 1250.27 (9) | 452.70 (4) |
Z | 4 | 1 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.13 | 0.14 |
Crystal size (mm) | 0.42 × 0.14 × 0.06 | 0.36 × 0.34 × 0.22 |
Data collection | ||
Diffractometer | Bruker SMART APEX DUO diffractometer | Bruker SMART APEXII diffractometer |
Absorption correction | Multi-scan (TWINABS; Sheldrick, 2006) | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.948, 0.993 | 0.956, 0.976 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 59584, 4609, 4303 | 7496, 2971, 2806 |
Rint | 0.046 | 0.011 |
(sin θ/λ)max (Å−1) | 0.736 | 0.736 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.099, 1.12 | 0.031, 0.092, 1.06 |
No. of reflections | 4609 | 2971 |
No. of parameters | 189 | 153 |
No. of restraints | 3 | 0 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.52, −0.24 | 0.53, −0.24 |
Computer programs: APEX2 (Bruker, 2010), SAINT (Bruker, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).
O2—C7 | 1.2575 (13) | O5—C6 | 1.2518 (13) |
O3—C7 | 1.2518 (13) | O6—C6 | 1.2520 (14) |
O4—C3 | 1.2417 (14) |
D—H···A | D—H | H···A | D···A | D—H···A |
O7—H7A···O4 | 0.870 (15) | 1.941 (16) | 2.8049 (14) | 172 (2) |
O7—H7B···O2i | 0.891 (16) | 2.266 (19) | 3.0533 (16) | 147.2 (19) |
N1—H1A···O3ii | 0.92 | 1.88 | 2.7796 (12) | 166 |
N1—H1B···O5iii | 0.92 | 1.80 | 2.7126 (12) | 170 |
N2—H2B···O2 | 0.92 | 1.77 | 2.6815 (12) | 171 |
N2—H2A···O6 | 0.92 | 1.84 | 2.7519 (13) | 168 |
N1—H1A···O2ii | 0.92 | 2.56 | 3.1115 (13) | 119 |
N2—H2B···O1 | 0.92 | 2.49 | 2.9436 (12) | 110 |
Symmetry codes: (i) x+1/2, −y+1/2, z−1/2; (ii) −x+1/2, y+1/2, −z+1/2; (iii) −x+1/2, y−1/2, −z+1/2. |
O2—C7 | 1.2794 (9) | O5—C6 | 1.2303 (9) |
O3—C7 | 1.2330 (9) | O6—C6 | 1.2850 (9) |
O4—C3 | 1.2373 (8) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O2i | 0.93 (4) | 1.52 (4) | 2.4549 (11) | 177 (6) |
O6—H6···O6ii | 0.91 (4) | 1.53 (4) | 2.4395 (11) | 177 (5) |
N1—H1A···O3 | 0.92 | 1.94 | 2.8032 (8) | 156 |
N1—H1B···O5iii | 0.92 | 2.09 | 2.8419 (8) | 138 |
Symmetry codes: (i) −x+2, −y+2, −z; (ii) −x+1, −y+1, −z+1; (iii) x, y+1, z−1. |
4-Oxo-4H-pyran-2,6-dicarboxylic acid, also called chelidonic acid, is a weak acid extracted from the perennial herb celandine (Chelidonium majus) as a white crystalline substance (m.p. 538 K). The structures of several metal complexes containing the 4-oxo-4H-pyran-2,6-dicarboxylate dianion, (cdo)2-, illustrate the versatile ability of this ligand to coordinate in a monodentate, bidentate or bridging fashion. Crystal structures include complexes of Ag+, Be2+, Ca2+, Mn2+, Cu2+, Cd2+, Sn2+, Zn2+ and Tb3+ (Manojlovic-Muir et al., 1999; Ng et al., 2000; Olovsson et al., 2001; Fainerman-Melnikova et al., 2006; Yasodha, Govindarajan, Low & Glidewell, 2007; Chen, 2009; Zhang et al., 2009; Zhou et al. 2009). A salt of [Ni(H2O)6](cdo) (Yasodha, Govindarajan, Manivannan & Büyükgüngör , 2007) has also been reported.
As a continuation of our research on the synthesis of proton-transfer compounds by the use of different dicarboxylic acids and numerous amines [for a similar proton-transfer compound of pyridine-2,6-dicarboxylic acid with piperazine, see Aghabozorg, Ghadermazi et al. (2006) and for a proton-transfer compound of piperazine with oxalate, refer to Aghabozorg, Ghadermazi & Sheshmani (2006)], we report here the synthesis and structure determination of two proton-transfer compounds, (I) and (II), obtained from 4-oxo-4H-pyran-2,6-dicarboxylic acid (cdoH2) and piperazine (pipz).
In (pipzH2)(cdo).H2O, (I) (Fig. 1), both H atoms of cdoH2 are transferred to pipz, and the negative charge of (cdo)2- is balanced by the doubly protonated piperazine-1,4-diium ion. All possible N—H donors are engaged in hydrogen bonds to O atoms (see Table 2). The water molecule spans two different anions via a 4-oxo group of the pyranose ring (O4) and a carboxylate O atom (O2). Atom O2 is also hydrogen-bonded to an N—H donor. These hydrogen-bonding interactions form a motif that is two-dimensional (Fig. 3).
In (pipzH2)(cdoH)2, (II) (Fig. 2), the H atom of the (cdoH)- moiety is disordered with respect to exchange between the two carboxylic acid centres, as well as with respect to a centre of inversion. As shown in Fig. 4, the H-atom position is disordered between opposite sides of the centre of inversion with occupancies of 0.5. Thus, there are two assymmetric hydrogen bonds, O2—H2···O2' and O6—H6···O6'' (see Fig. 4 for symmetry codes). The O···O distances and linear geometry correspond to very short hydrogen bonds (Table 4). On average, each (cdoH)- anion acts as an acceptor, using either O2 or O6, and as a donor, using either H2 or H6. A similar but apparently symmetrically hydrogen-bonded species was reported in the structure of [Zn(phen)3]4[H(hpydc)2](NO3)7.26H2O (phen is 1,10-phenanthroline and Hpydc is 5-carboxypyridine-3-carboxylic acid [OK?]; Moghimi et al., 2005). In this case, the unique H atom resides on a centre of symmetry, bridging two carboxylates, and leads to the formation of a discrete anion with an O···O distance of 2.493 (3) Å. In (II), each of the N—H donor groups is hydrogen-bonded to a different C═O group of the anion (see Table 4 for details). The N—N vector of the (pipzH2)2+ cation is perpendicular to the chain of anions, yielding a three-dimensional hydrogen-bonding motif, different from the orientation in (I) where the N—N vector is in the plane of the anions.
There are several other notable differences between the two structures. Although both (I) and (II) feature alternating inversion-related π–π stacking interactions, these differ in their details, as viewed from top to bottom in Fig. 6. If the stacking planes are represented by the six-membered C1–C5/O1 ring, in (I), the perpendicular distances between stacking planes alternate between 3.2856 (5) and 3.4334 (5) Å, with slippage distances of 2.46 and 2.18 Å and centroid-to-centroid distances between 4.1071 (7) and 4.0644 (7) Å, respectively. In (II), the corresponding values are 3.2771 (3) and 3.3451 (3) Å for perpendicular distances, 1.35 and 2.04 Å for slippage distances and 3.5449 (4) and 3.9201 (4) Å for centroid-to-centroid distances.
The carbonyl bond lengths support the existence of deprotonated acid molecules. In particular, the C—O distances indicate full delocalization in (I) and are equal within the s.u. values. In (II), the C—O bond bearing the H atoms is ca 0.05 Å longer than the C═O bond (see Tables 1 and 3).
The 4-oxo group of the furan ring is expected to be a strong hydrogen-bond acceptor, but is only engaged in a classical hydrogen bond to water in the structure of (I). In the structure of (II), there are no remaining donors for this purpose and it remains only weakly involved in C—H interactions.