In the title compound, C
4H
12N
22+·2C
7H
5O
5−·2H
2O, the cation lies on a centre of symmetry. The crystal structure is stabilized by various intermolecular O—H
O and N—H
O hydrogen bonds, and by intermolecular aromatic π–π interactions, with a centroid-to-centroid distance of 3.348 (2) Å between the benzene rings of neighbouring anions.
Supporting information
CCDC reference: 672792
Key indicators
- Single-crystal X-ray study
- T = 294 K
- Mean (C-C) = 0.002 Å
- R factor = 0.039
- wR factor = 0.107
- Data-to-parameter ratio = 11.9
checkCIF/PLATON results
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Gallic acid monohydrate (3.76 g, 20 mmol) and piperazine (0.86 g, 10 mmol) were
loaded into a 100 ml roundbottom flask, and then 50 ml H2O were droped into
above mixture. After reaction the solid gallic acid and piperazine dissolved
into solution under heater. Crystals of the title compound were obtained by
slow evaporation of deionic H2O solution.
The H atoms of the water molecule and the hydrogen atoms on the N atom were
positioned in a different Fourier maps, there the parameters were freely
refined. All other H atoms were positioned geometrically and refined using a
riding model, with O—H = 0.82 Å for hydroxy H atoms, C—H = 0.93 Å for
aromatic H atoms, and 0.97 Å for methylene H atoms, respectively, and with
Uiso(H) = 1.5Ueq(O) for hydroxy, Uiso(H) = 1.2Ueq(C) for
aromatic and methylene H atoms.
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2001); software used to prepare material for publication: SHELXTL (Sheldrick, 2001).
Piperazindiium bis(3,4,5-trihydroxybenzoate) dihydrate
top
Crystal data top
C4H12N22+·2C7H5O5−·2H2O | F(000) = 488 |
Mr = 462.41 | Dx = 1.634 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 2556 reflections |
a = 8.197 (2) Å | θ = 2.7–26.4° |
b = 9.449 (2) Å | µ = 0.14 mm−1 |
c = 12.655 (2) Å | T = 294 K |
β = 106.516 (3)° | Block, colorless |
V = 939.7 (3) Å3 | 0.20 × 0.16 × 0.12 mm |
Z = 2 | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1591 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.028 |
Graphite monochromator | θmax = 26.4°, θmin = 2.7° |
Detector resolution: 10.0 pixels mm-1 | h = −10→9 |
ϕ and ω scans | k = −11→11 |
5263 measured reflections | l = −11→15 |
1922 independent reflections | |
Refinement top
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)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.107 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0541P)2 + 0.3692P] where P = (Fo2 + 2Fc2)/3 |
1922 reflections | (Δ/σ)max < 0.001 |
161 parameters | Δρmax = 0.23 e Å−3 |
4 restraints | Δρmin = −0.42 e Å−3 |
Crystal data top
C4H12N22+·2C7H5O5−·2H2O | V = 939.7 (3) Å3 |
Mr = 462.41 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.197 (2) Å | µ = 0.14 mm−1 |
b = 9.449 (2) Å | T = 294 K |
c = 12.655 (2) Å | 0.20 × 0.16 × 0.12 mm |
β = 106.516 (3)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1591 reflections with I > 2σ(I) |
5263 measured reflections | Rint = 0.028 |
1922 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.039 | 4 restraints |
wR(F2) = 0.107 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | Δρmax = 0.23 e Å−3 |
1922 reflections | Δρmin = −0.42 e Å−3 |
161 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.58286 (17) | 0.49827 (12) | 0.69747 (9) | 0.0276 (3) | |
O2 | 0.53936 (15) | 0.33368 (12) | 0.81110 (9) | 0.0270 (3) | |
O3 | 0.83718 (16) | 0.49981 (12) | 1.19238 (9) | 0.0279 (3) | |
H3 | 0.7719 | 0.4333 | 1.1896 | 0.042* | |
O4 | 1.02059 (15) | 0.72094 (12) | 1.17301 (9) | 0.0277 (3) | |
H4 | 1.0744 | 0.7876 | 1.1583 | 0.042* | |
O5 | 1.02560 (14) | 0.82015 (12) | 0.96955 (9) | 0.0249 (3) | |
H5 | 1.0160 | 0.8417 | 0.9053 | 0.037* | |
O6 | 0.2251 (2) | 0.26564 (15) | 0.68561 (10) | 0.0325 (3) | |
H6A | 0.325 (4) | 0.295 (3) | 0.717 (2) | 0.067 (9)* | |
H6B | 0.161 (3) | 0.282 (3) | 0.724 (2) | 0.064 (8)* | |
N | 0.58220 (17) | 0.12224 (14) | 0.97017 (12) | 0.0215 (3) | |
H1A | 0.651 (2) | 0.151 (2) | 1.0349 (18) | 0.030 (5)* | |
H1B | 0.592 (3) | 0.186 (2) | 0.9169 (19) | 0.042 (6)* | |
C1 | 0.6055 (2) | 0.44903 (16) | 0.79314 (12) | 0.0196 (3) | |
C2 | 0.71553 (19) | 0.52807 (16) | 0.89041 (12) | 0.0179 (3) | |
C3 | 0.7195 (2) | 0.48134 (16) | 0.99537 (12) | 0.0194 (3) | |
H3A | 0.6495 | 0.4071 | 1.0033 | 0.023* | |
C4 | 0.8266 (2) | 0.54420 (16) | 1.08790 (12) | 0.0187 (3) | |
C5 | 0.92582 (19) | 0.65932 (16) | 1.07747 (12) | 0.0185 (3) | |
C6 | 0.92217 (19) | 0.70748 (16) | 0.97240 (13) | 0.0179 (3) | |
C7 | 0.81769 (19) | 0.64194 (16) | 0.87896 (12) | 0.0186 (3) | |
H7 | 0.8160 | 0.6739 | 0.8092 | 0.022* | |
C8 | 0.6298 (2) | −0.02284 (17) | 0.94383 (14) | 0.0257 (4) | |
H8A | 0.7493 | −0.0248 | 0.9467 | 0.031* | |
H8B | 0.5638 | −0.0484 | 0.8698 | 0.031* | |
C9 | 0.4030 (2) | 0.12800 (18) | 0.97492 (15) | 0.0268 (4) | |
H9A | 0.3271 | 0.1084 | 0.9023 | 0.032* | |
H9B | 0.3784 | 0.2226 | 0.9959 | 0.032* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0437 (7) | 0.0207 (6) | 0.0155 (6) | −0.0033 (5) | 0.0037 (5) | 0.0001 (4) |
O2 | 0.0343 (7) | 0.0218 (6) | 0.0215 (6) | −0.0079 (5) | 0.0024 (5) | 0.0016 (5) |
O3 | 0.0448 (8) | 0.0233 (6) | 0.0148 (6) | −0.0069 (5) | 0.0072 (5) | 0.0005 (4) |
O4 | 0.0376 (7) | 0.0228 (6) | 0.0180 (6) | −0.0087 (5) | 0.0002 (5) | −0.0020 (5) |
O5 | 0.0268 (6) | 0.0243 (6) | 0.0210 (6) | −0.0077 (5) | 0.0026 (5) | 0.0036 (5) |
O6 | 0.0358 (8) | 0.0343 (7) | 0.0252 (7) | 0.0079 (6) | 0.0050 (6) | −0.0087 (5) |
N | 0.0236 (7) | 0.0196 (7) | 0.0214 (7) | −0.0013 (5) | 0.0067 (6) | 0.0028 (6) |
C1 | 0.0221 (8) | 0.0173 (7) | 0.0191 (7) | 0.0017 (6) | 0.0053 (6) | 0.0001 (6) |
C2 | 0.0183 (7) | 0.0171 (7) | 0.0174 (7) | 0.0020 (6) | 0.0034 (6) | −0.0011 (6) |
C3 | 0.0231 (8) | 0.0155 (7) | 0.0197 (8) | −0.0005 (6) | 0.0065 (6) | 0.0007 (6) |
C4 | 0.0240 (8) | 0.0171 (7) | 0.0150 (7) | 0.0043 (6) | 0.0057 (6) | 0.0012 (6) |
C5 | 0.0198 (7) | 0.0165 (7) | 0.0167 (7) | 0.0032 (6) | 0.0011 (6) | −0.0028 (6) |
C6 | 0.0158 (7) | 0.0153 (7) | 0.0224 (8) | 0.0022 (6) | 0.0052 (6) | 0.0014 (6) |
C7 | 0.0206 (7) | 0.0200 (8) | 0.0154 (7) | 0.0029 (6) | 0.0056 (6) | 0.0025 (6) |
C8 | 0.0250 (8) | 0.0244 (8) | 0.0311 (9) | 0.0010 (7) | 0.0135 (7) | −0.0023 (7) |
C9 | 0.0234 (8) | 0.0217 (8) | 0.0351 (9) | 0.0074 (7) | 0.0082 (7) | 0.0051 (7) |
Geometric parameters (Å, º) top
O1—C1 | 1.261 (2) | C2—C3 | 1.391 (2) |
O2—C1 | 1.266 (2) | C2—C7 | 1.396 (2) |
O3—C4 | 1.366 (2) | C3—C4 | 1.382 (2) |
O3—H3 | 0.8200 | C3—H3A | 0.9300 |
O4—C5 | 1.368 (2) | C4—C5 | 1.387 (2) |
O4—H4 | 0.8200 | C5—C6 | 1.398 (2) |
O5—C6 | 1.368 (2) | C6—C7 | 1.393 (2) |
O5—H5 | 0.8200 | C7—H7 | 0.9300 |
O6—H6A | 0.85 (3) | C8—C9i | 1.508 (2) |
O6—H6B | 0.83 (3) | C8—H8A | 0.9700 |
N—C9 | 1.488 (2) | C8—H8B | 0.9700 |
N—C8 | 1.489 (2) | C9—C8i | 1.508 (2) |
N—H1A | 0.89 (2) | C9—H9A | 0.9700 |
N—H1B | 0.92 (2) | C9—H9B | 0.9700 |
C1—C2 | 1.502 (2) | | |
| | | |
C4—O3—H3 | 109.5 | O4—C5—C4 | 116.8 (1) |
C5—O4—H4 | 109.5 | O4—C5—C6 | 123.8 (1) |
C6—O5—H5 | 109.5 | C4—C5—C6 | 119.4 (1) |
H6A—O6—H6B | 111 (3) | O5—C6—C7 | 124.1 (1) |
C9—N—C8 | 111.6 (1) | O5—C6—C5 | 115.6 (1) |
C9—N—H1A | 109 (1) | C7—C6—C5 | 120.3 (1) |
C8—N—H1A | 110 (1) | C6—C7—C2 | 119.8 (1) |
C9—N—H1B | 107 (1) | C6—C7—H7 | 120.1 |
C8—N—H1B | 111 (1) | C2—C7—H7 | 120.1 |
H1A—N—H1B | 108 (2) | N—C8—C9i | 110.17 (13) |
O1—C1—O2 | 122.4 (1) | N—C8—H8A | 109.6 |
O1—C1—C2 | 119.6 (1) | C9i—C8—H8A | 109.6 |
O2—C1—C2 | 118.0 (1) | N—C8—H8B | 109.6 |
C3—C2—C7 | 119.6 (1) | C9i—C8—H8B | 109.6 |
C3—C2—C1 | 118.1 (1) | H8A—C8—H8B | 108.1 |
C7—C2—C1 | 122.5 (1) | N—C9—C8i | 111.90 (13) |
C4—C3—C2 | 120.6 (2) | N—C9—H9A | 109.2 |
C4—C3—H3A | 119.7 | C8i—C9—H9A | 109.2 |
C2—C3—H3A | 119.7 | N—C9—H9B | 109.2 |
O3—C4—C3 | 122.6 (1) | C8i—C9—H9B | 109.2 |
O3—C4—C5 | 117.1 (1) | H9A—C9—H9B | 107.9 |
C3—C4—C5 | 120.3 (1) | | |
| | | |
O1—C1—C2—C3 | 171.50 (14) | C3—C4—C5—C6 | −2.8 (2) |
O2—C1—C2—C3 | −8.9 (2) | O4—C5—C6—O5 | 2.1 (2) |
O1—C1—C2—C7 | −11.1 (2) | C4—C5—C6—O5 | −179.08 (13) |
O2—C1—C2—C7 | 168.51 (14) | O4—C5—C6—C7 | −177.75 (14) |
C7—C2—C3—C4 | −1.7 (2) | C4—C5—C6—C7 | 1.1 (2) |
C1—C2—C3—C4 | 175.86 (14) | O5—C6—C7—C2 | −179.52 (13) |
C2—C3—C4—O3 | −178.62 (14) | C5—C6—C7—C2 | 0.3 (2) |
C2—C3—C4—C5 | 3.1 (2) | C3—C2—C7—C6 | 0.0 (2) |
O3—C4—C5—O4 | −2.3 (2) | C1—C2—C7—C6 | −177.44 (14) |
C3—C4—C5—O4 | 176.13 (14) | C9—N—C8—C9i | −55.1 (2) |
O3—C4—C5—C6 | 178.85 (13) | C8—N—C9—C8i | 56.0 (2) |
Symmetry code: (i) −x+1, −y, −z+2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O6ii | 0.82 | 1.92 | 2.664 (2) | 151 |
O4—H4···O1iii | 0.82 | 2.08 | 2.703 (2) | 133 |
O5—H5···O1iv | 0.82 | 1.98 | 2.650 (2) | 138 |
O6—H6A···O2 | 0.85 (3) | 1.85 (3) | 2.691 (2) | 167 (3) |
O6—H6B···O3v | 0.83 (3) | 2.31 (3) | 2.829 (2) | 121 (2) |
O6—H6B···O4v | 0.83 (3) | 2.23 (3) | 3.054 (2) | 169 (3) |
N—H1B···O2 | 0.92 (2) | 1.90 (2) | 2.787 (2) | 161 (2) |
N—H1A···O6ii | 0.89 (2) | 1.99 (2) | 2.848 (2) | 160.0 (17) |
Symmetry codes: (ii) x+1/2, −y+1/2, z+1/2; (iii) x+1/2, −y+3/2, z+1/2; (iv) −x+3/2, y+1/2, −z+3/2; (v) −x+1, −y+1, −z+2. |
Experimental details
Crystal data |
Chemical formula | C4H12N22+·2C7H5O5−·2H2O |
Mr | 462.41 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 294 |
a, b, c (Å) | 8.197 (2), 9.449 (2), 12.655 (2) |
β (°) | 106.516 (3) |
V (Å3) | 939.7 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.14 |
Crystal size (mm) | 0.20 × 0.16 × 0.12 |
|
Data collection |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5263, 1922, 1591 |
Rint | 0.028 |
(sin θ/λ)max (Å−1) | 0.625 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.107, 1.10 |
No. of reflections | 1922 |
No. of parameters | 161 |
No. of restraints | 4 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.23, −0.42 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O6i | 0.82 | 1.92 | 2.664 (2) | 151.2 |
O4—H4···O1ii | 0.82 | 2.08 | 2.703 (2) | 132.6 |
O5—H5···O1iii | 0.82 | 1.98 | 2.650 (2) | 137.8 |
O6—H6A···O2 | 0.85 (3) | 1.85 (3) | 2.691 (2) | 167 (3) |
O6—H6B···O3iv | 0.83 (3) | 2.31 (3) | 2.829 (2) | 121 (2) |
O6—H6B···O4iv | 0.83 (3) | 2.23 (3) | 3.054 (2) | 169 (3) |
N—H1B···O2 | 0.92 (2) | 1.90 (2) | 2.787 (2) | 161 (2) |
N—H1A···O6i | 0.89 (2) | 1.99 (2) | 2.848 (2) | 160.0 (17) |
Symmetry codes: (i) x+1/2, −y+1/2, z+1/2; (ii) x+1/2, −y+3/2, z+1/2; (iii) −x+3/2, y+1/2, −z+3/2; (iv) −x+1, −y+1, −z+2. |
Gallic acid (3, 4, 5-trihydroxybenzoic acid) is one of the main endogenous phenolic acids found in plants as a free or esterified form, and a large amount of them is present in tea, being present at about 5% of the dry weight (Harbowy & Ballentine 1997). Significantly, it has been found that gallic acid and its derivatives are pharmacologically active, and possess antioxidative (Fukumoto & Mazza, 2000), antimutagenic, anticarcinogenic (Akao et al., 2001; Saeki et al., 2000; Stich & Rosin, 1984), antiinflammatory (Kawada et al., 1992), and hepatoprotective activities (Anand et al., 1997). In the earlier work, acetic anhydride had been used to protect hydroxyl group (Li & Guo, 2007). Herein we report the molecular and crystal structure of the title compound (Fig. 1)
The title compound (Fig. 1) was obtained from the solution of 3,4,5-trihydroxybenzoic acid monohydrate and piperazine. The bond distances and angles in the title compound are normal. The molecular packing (Fig. 2) is stabilized by hydrogen bonds of all H atoms in the O and N atoms (Table 1). The molecular packing (Fig. 2) is further stabilized by π—π stacking interactions between the benzene rings of adjacent molecules. The Cg···Cgv distance is 3.348 (2) Å (Cg is the centroid of the C2—C7 ring; symmetry code as in Fig.2).