supplementary materials
3,5-Dicarboxy-2,6-dimethylpyridinium chloride dihydrate
2,6-Dimethylpyridine-3,5-dicarboxylic acid (1.95 g , 10 mmol) and
concentrated hydrochloric acid (10 mmol) were dissolved in methanol
(25 ml). The solution was filtered and left at room temperature for
5 days. Colourless crystals suitable for X-ray analysis were obtained
by slow evaporation of the solvent.
The pyridinium and water H atoms were located in a difference Fourier
map and refined freely. All other H atoms were calculated geometrically
and allowed to ride on their parent atoms, with C—H = 0.93-0.97 Å,
O—H = 0.82 Å, and with Uiso(H) = 1.5 Ueq(C, O) or
1.2 Ueq(C) for the aromatic H atom.
Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL/PC (Sheldrick, 2008); software used to prepare material for publication: PRPKAPPA (Ferguson, 1999).
3,5-Dicarboxy-2,6-dimethylpyridinium chloride dihydrate
top
Crystal data top
| C9H10NO4+·Cl−·2H2O | F(000) = 560 |
| Mr = 267.66 | Dx = 1.458 Mg m−3 |
| Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -C 2yc | Cell parameters from 1418 reflections |
| a = 8.2301 (10) Å | θ = 3.3–27.1° |
| b = 10.7825 (10) Å | µ = 0.33 mm−1 |
| c = 13.882 (2) Å | T = 293 K |
| β = 98.11 (3)° | Prism, colourless |
| V = 1219.5 (3) Å3 | 0.50 × 0.50 × 0.50 mm |
| Z = 4 | |
Data collection top
Rigaku Mercury2
diffractometer | 1353 independent reflections |
| Radiation source: fine-focus sealed tube | 1204 reflections with I > 2σ(I) |
| graphite | Rint = 0.022 |
| Detector resolution: 13.6612 pixels mm-1 | θmax = 27.1°, θmin = 3.1° |
| CCD_Profile_fitting scans | h = −10→10 |
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005) | k = −13→13 |
| Tmin = 0.938, Tmax = 1.000 | l = −17→17 |
| 5826 measured 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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.120 | H atoms treated by a mixture of independent and constrained refinement |
| S = 1.11 | w = 1/[σ2(Fo2) + (0.0618P)2 + 0.5934P]
where P = (Fo2 + 2Fc2)/3 |
| 1353 reflections | (Δ/σ)max < 0.001 |
| 91 parameters | Δρmax = 0.26 e Å−3 |
| 0 restraints | Δρmin = −0.21 e Å−3 |
Crystal data top
| C9H10NO4+·Cl−·2H2O | V = 1219.5 (3) Å3 |
| Mr = 267.66 | Z = 4 |
| Monoclinic, C2/c | Mo Kα radiation |
| a = 8.2301 (10) Å | µ = 0.33 mm−1 |
| b = 10.7825 (10) Å | T = 293 K |
| c = 13.882 (2) Å | 0.50 × 0.50 × 0.50 mm |
| β = 98.11 (3)° | |
Data collection top
Rigaku Mercury2
diffractometer | 1353 independent reflections |
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005) | 1204 reflections with I > 2σ(I) |
| Tmin = 0.938, Tmax = 1.000 | Rint = 0.022 |
| 5826 measured reflections | θmax = 27.1° |
Refinement top
| R[F2 > 2σ(F2)] = 0.044 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.120 | Δρmax = 0.26 e Å−3 |
| S = 1.11 | Δρmin = −0.21 e Å−3 |
| 1353 reflections | Absolute structure: ? |
| 91 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are
estimated using the full covariance matrix. The cell esds are taken into
account individually in the estimation of esds in distances, angles and
torsion angles; correlations between esds in cell parameters are only used
when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds 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 | |
| Cl1 | 0.0000 | 0.47434 (6) | 0.2500 | 0.0491 (2) | |
| O1 | 0.80009 (19) | 0.97343 (12) | 0.46240 (10) | 0.0527 (4) | |
| H1 | 0.7609 | 1.0230 | 0.4976 | 0.079* | |
| N1 | 1.0000 | 0.76737 (19) | 0.2500 | 0.0380 (4) | |
| O1W | 0.8401 (3) | 0.38706 (18) | 0.42729 (16) | 0.0882 (8) | |
| C1 | 0.8456 (2) | 1.03196 (17) | 0.38880 (13) | 0.0440 (4) | |
| O2 | 0.8329 (2) | 1.14346 (13) | 0.37602 (13) | 0.0691 (5) | |
| C2 | 0.9224 (2) | 0.95307 (16) | 0.31833 (12) | 0.0388 (4) | |
| C3 | 0.9200 (2) | 0.82364 (16) | 0.31650 (12) | 0.0387 (4) | |
| C4 | 0.8353 (3) | 0.73948 (19) | 0.37910 (16) | 0.0569 (5) | |
| H4A | 0.8362 | 0.6563 | 0.3545 | 0.085* | |
| H4B | 0.7240 | 0.7664 | 0.3784 | 0.085* | |
| H4C | 0.8915 | 0.7417 | 0.4446 | 0.085* | |
| C5 | 1.0000 | 1.0148 (2) | 0.2500 | 0.0395 (5) | |
| H5 | 1.0000 | 1.1011 | 0.2500 | 0.047* | |
| H1A | 1.0000 | 0.679 (4) | 0.2500 | 0.066 (9)* | |
| H2 | 0.844 (4) | 0.315 (4) | 0.422 (2) | 0.097 (11)* | |
| H2A | 0.880 (4) | 0.409 (3) | 0.380 (3) | 0.094 (10)* | |
Atomic displacement parameters (Å2) top| | U11 | U22 | U33 | U12 | U13 | U23 |
| Cl1 | 0.0579 (4) | 0.0409 (4) | 0.0525 (4) | 0.000 | 0.0217 (3) | 0.000 |
| O1 | 0.0749 (9) | 0.0434 (8) | 0.0461 (8) | 0.0062 (6) | 0.0306 (7) | −0.0030 (5) |
| N1 | 0.0476 (11) | 0.0288 (10) | 0.0412 (11) | 0.000 | 0.0183 (8) | 0.000 |
| O1W | 0.152 (2) | 0.0408 (9) | 0.0924 (14) | −0.0033 (10) | 0.0889 (15) | −0.0088 (8) |
| C1 | 0.0525 (10) | 0.0364 (9) | 0.0466 (10) | −0.0028 (7) | 0.0190 (8) | −0.0070 (7) |
| O2 | 0.1067 (13) | 0.0324 (7) | 0.0792 (11) | −0.0005 (7) | 0.0505 (9) | −0.0073 (7) |
| C2 | 0.0440 (9) | 0.0346 (8) | 0.0403 (9) | −0.0001 (6) | 0.0149 (7) | −0.0022 (6) |
| C3 | 0.0455 (9) | 0.0335 (9) | 0.0399 (9) | −0.0003 (6) | 0.0160 (7) | −0.0009 (6) |
| C4 | 0.0809 (14) | 0.0382 (10) | 0.0607 (12) | −0.0052 (9) | 0.0414 (11) | 0.0003 (8) |
| C5 | 0.0453 (12) | 0.0294 (11) | 0.0459 (13) | 0.000 | 0.0137 (10) | 0.000 |
Geometric parameters (Å, °) top
| O1—C1 | 1.300 (2) | C2—C5 | 1.386 (2) |
| O1—H1 | 0.8200 | C2—C3 | 1.396 (3) |
| N1—C3 | 1.3513 (18) | C3—C4 | 1.495 (2) |
| N1—C3i | 1.3513 (18) | C4—H4A | 0.9600 |
| N1—H1A | 0.95 (4) | C4—H4B | 0.9600 |
| O1W—H2 | 0.79 (4) | C4—H4C | 0.9600 |
| O1W—H2A | 0.81 (4) | C5—C2i | 1.386 (2) |
| C1—O2 | 1.218 (2) | C5—H5 | 0.9300 |
| C1—C2 | 1.501 (2) | | |
| | | |
| C1—O1—H1 | 109.5 | N1—C3—C4 | 115.88 (16) |
| C3—N1—C3i | 126.6 (2) | C2—C3—C4 | 127.09 (15) |
| C3—N1—H1A | 116.68 (10) | C3—C4—H4A | 109.5 |
| C3i—N1—H1A | 116.68 (11) | C3—C4—H4B | 109.5 |
| H2—O1W—H2A | 101 (3) | H4A—C4—H4B | 109.5 |
| O2—C1—O1 | 124.43 (16) | C3—C4—H4C | 109.5 |
| O2—C1—C2 | 120.00 (16) | H4A—C4—H4C | 109.5 |
| O1—C1—C2 | 115.55 (16) | H4B—C4—H4C | 109.5 |
| C5—C2—C3 | 118.33 (15) | C2i—C5—C2 | 122.6 (2) |
| C5—C2—C1 | 116.78 (16) | C2i—C5—H5 | 118.7 |
| C3—C2—C1 | 124.89 (15) | C2—C5—H5 | 118.7 |
| N1—C3—C2 | 117.01 (15) | | |
| Symmetry codes: (i) −x+2, y, −z+1/2. |
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| O1—H1···O1Wii | 0.82 | 1.72 | 2.537 (2) | 173 |
| N1—H1A···Cl1iii | 0.95 (4) | 2.21 (4) | 3.160 (2) | 180 (1) |
| O1W—H2···O2iv | 0.79 (4) | 1.95 (4) | 2.720 (2) | 166 (3) |
| O1W—H2A···Cl1iii | 0.81 (4) | 2.29 (4) | 3.096 (2) | 177 (3) |
| Symmetry codes: (ii) −x+3/2, −y+3/2, −z+1; (iii) x+1, y, z; (iv) x, y−1, z. |
Table 1
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| O1—H1···O1Wi | 0.82 | 1.72 | 2.537 (2) | 173 |
| N1—H1A···Cl1ii | 0.95 (4) | 2.21 (4) | 3.160 (2) | 180 (1) |
| O1W—H2···O2iii | 0.79 (4) | 1.95 (4) | 2.720 (2) | 166 (3) |
| O1W—H2A···Cl1ii | 0.81 (4) | 2.29 (4) | 3.096 (2) | 177 (3) |
| Symmetry codes: (i) −x+3/2, −y+3/2, −z+1; (ii) x+1, y, z; (iii) x, y−1, z. |
The author is grateful to the starter fund of Southeast University for financial
support topurchase a single-crystal X-ray diffractometer.
Allen, F. H. (2002). Acta Cryst. B58, 380–388.
Ferguson, G. (1999). PRPKAPPA. University of Guelph, Canada.
Hang, T., Fu, D. W., Ye, Q. & Xiong, R. G. (2009). Cryst. Growth Des. 5, 2026–2029.
Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.
Rowan, K. R. & Holt, E. M. (1997). Acta Cryst. C53, 106–108.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Ye, Q., Hang, T., Fu, D. W., Xu, G. H. & Xiong, R. G. (2008). Cryst. Growth Des. 8, 3501–3503.
O, O-H![[Figure 1]](./rz2448fig1thm.gif)
![[Figure 2]](./rz2448fig2thm.gif)
Organic and inorganic complexes or salts can develop supramolecular structures via multiple hydrogen-bonding systems by self-assembly of components which contain abundant hydrogen-bonding sites (Rowan & Holt, 1997). The present study is a part of systematic investigation of ferroelectric materials (Ye et al., 2008; Hang et al., 2009) that include metal-organic coordination compounds with organic ligands or compounds whose structures consist both of organic and inorganic building fragments.
The asymmetric unit of the title compound is composed of a half of a 3,5-dicarboxy-2,6-dimethylpyridinium cation, a half of a chloride anion and a water molecule. Both cation and anion have crystallographically imposed twofold rotation symmetry (Fig. 1). In the cation, the C—O bond lengths in the carboxylic group (C1—O1 = 1.300 (2) Å; C1—O2 = 1.218 (2) Å) conform to the expected values (Allen, 2002). The C3—N1—C3 angle of 126.6 (2) ° corresponds closely to the average value found in protonated pyridinium ions (122.0 (2) °). In the crystal structure (Fig. 2), the 3,5-dicarboxy-2,6-dimethylpyridinium cations, the chloride anions and the water molecules are linked via O—H···O, O—H···Cl and N—H···Cl hydrogen bonds (Table 1) to form two-dimensional layers parallel to the (101) plane. Dielectric studies (capacitance and dielectric loss measurements) were performed on powder samples of the title compound pressed into tablets on the surfaces of which a conducting carbon glue was deposited. The automatic impedance TongHui 2828 Analyzer has been used. In the measured temperature ranges (80 to 480 K, m.p. > 480 K), the structure showed no dielectric anomaly.