organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

2,4,6-Tri­methyl­pyridinium di­hydrogen phosphate

aOrdered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China
*Correspondence e-mail: fudavid88@yahoo.com.cn

(Received 20 November 2010; accepted 3 December 2010; online 18 December 2010)

In the title compound, C8H9N+·H2PO4, both the cation and anion have crystallographically imposed mirror symmetry (all atoms apart from one O atom lie on the mirror plane). In the crystal, anions and cations are linked by O—H⋯O and ππ stacking inter­actions [centroid–centroid distance = 3.4574 (6) Å], forming chains parallel to the b axis. Adjacent chains are further connected by N—H⋯O hydrogen bonds into a two-dimensional network.

Related literature

For background to the properties of pyridine salts as phase-transition dielectric materials, see: Fu et al. (2007[Fu, D.-W., Song, Y.-M., Wang, G.-X., Ye, Q., Xiong, R.-G., Akutagawa, T., Nakamura, T., Chan, P. W. H. & Huang, S.-P.-D. (2007). J. Am. Chem. Soc. 129, 5346-5347.], 2008[Fu, D.-W., Zhang, W. & Xiong, R.-G. (2008). Cryst. Growth Des. 8, 3461-3464.], 2009[Fu, D.-W., Ge, J.-Z., Dai, J., Ye, H.-Y. & Qu, Z.-R. (2009). Inorg. Chem. Commun. 12, 994-997.]); Fu & Xiong (2008[Fu, D.-W. & Xiong, R.-G. (2008). Dalton Trans. pp. 3946-3948.]).

[Scheme 1]

Experimental

Crystal data
  • C8H9N+·H2O4P

  • Mr = 216.15

  • Monoclinic, P 21 /m

  • a = 8.6323 (17) Å

  • b = 6.7133 (13) Å

  • c = 8.6841 (17) Å

  • β = 100.99 (3)°

  • V = 494.02 (17) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.27 mm−1

  • T = 298 K

  • 0.30 × 0.05 × 0.05 mm

Data collection
  • Rigaku Mercury2 diffractometer

  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.910, Tmax = 1.000

  • 5154 measured reflections

  • 1229 independent reflections

  • 1082 reflections with I > 2σ(I)

  • Rint = 0.033

Refinement
  • R[F2 > 2σ(F2)] = 0.047

  • wR(F2) = 0.144

  • S = 1.18

  • 1229 reflections

  • 86 parameters

  • 1 restraint

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.45 e Å−3

  • Δρmin = −0.29 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H2⋯O3i 0.85 (2) 1.76 (2) 2.6054 (19) 169 (2)
N1—H1A⋯O1 0.86 1.75 2.602 (3) 173
Symmetry code: (i) -x, -y, -z+2.

Data collection: CrystalClear (Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Salts of pyridine have attracted attention as phase transition dielectric materials for their applications in memory storage (Fu et al. 2007; Fu & Xiong 2008; Fu et al. 2008; Fu et al. 2009). With the purpose of obtaining new phase transition crystals of 2,4,6-trimethylpyridine salts, their interaction with various acids has been studied and we have elaborated a series of new materials with this organic molecule. In this study, we describe the crystal structure of the title compound, 2,4,6-trimethylpyridinium dihydrogen phosphate.

The asymmetric unit is composed of half an H2PO4- anion and half a C8H9N+ cation (Fig. 1), both anion and cation being located on a mirror plane. The geometric parameters are in the normal range. In the crystal structure, the anions are linked into chains parallel to the b axis by O—H···O hydrogen bonds (Table 1). The cations also are connected into chains along the b axis by ππ stacking interactions with centroid-to-centroid distances of 3.4574 (6) Å. The cationic and anionic chains further interact through N—H···O hydrogen bonds (Fig. 2), forming a two-dimensional network.

Related literature top

For background to the properties of pyridine salts as phase-transition dielectric materials, see: Fu et al. (2007, 2008, 2009); Fu & Xiong (2008).

Experimental top

The commercial 2,4,6-trimethylpyridine (3 mmol) was dissolved in water/H3PO4 (50:1 v/v) solution. The solvent was slowly evaporated in air affording colourless block-shaped crystals of the title compound suitable for X-ray analysis.

The dielectric constant of title compound as a function of temperature indicates that the permittivity is basically temperature-independent, suggesting that this compound should be not a real ferroelectrics or there may be no distinct phase transition occurred within the measured temperature range. Similarly, below the melting point (413 K) of the compound, the dielectric constant as a function of temperature also goes smoothly, and there is no dielectric anomaly observed (dielectric constant equaling to 6.6 to 8.9).

Refinement top

All H atoms attached to C and N atoms were fixed geometrically and treated as riding with C–H = 0.93–0.96 Å, N–H = 0.86 Å, and with Uiso(H) = 1.2 Ueq(C, N) or 1.5 Ueq(C) for methyl H atoms. The H atom of the H2PO4- anion was located in difference Fourier maps and freely refined, with the O—H distance constrained to 0.86 Å..

Structure description top

Salts of pyridine have attracted attention as phase transition dielectric materials for their applications in memory storage (Fu et al. 2007; Fu & Xiong 2008; Fu et al. 2008; Fu et al. 2009). With the purpose of obtaining new phase transition crystals of 2,4,6-trimethylpyridine salts, their interaction with various acids has been studied and we have elaborated a series of new materials with this organic molecule. In this study, we describe the crystal structure of the title compound, 2,4,6-trimethylpyridinium dihydrogen phosphate.

The asymmetric unit is composed of half an H2PO4- anion and half a C8H9N+ cation (Fig. 1), both anion and cation being located on a mirror plane. The geometric parameters are in the normal range. In the crystal structure, the anions are linked into chains parallel to the b axis by O—H···O hydrogen bonds (Table 1). The cations also are connected into chains along the b axis by ππ stacking interactions with centroid-to-centroid distances of 3.4574 (6) Å. The cationic and anionic chains further interact through N—H···O hydrogen bonds (Fig. 2), forming a two-dimensional network.

For background to the properties of pyridine salts as phase-transition dielectric materials, see: Fu et al. (2007, 2008, 2009); Fu & Xiong (2008).

Computing details top

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 (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the title compound with the atomic numbering scheme. Displacement ellipsoids were drawn at the 30% probability level. Symmetry code: (A) x, 0.5-y, z.
[Figure 2] Fig. 2. The crystal packing of the title compound, showing the two-dimensional network. H atoms not involved in hydrogen bonding (dashed line) have been omitted for clarity.
2,4,6-Trimethylpyridinium dihydrogen phosphate top
Crystal data top
C8H9N+·H2O4PF(000) = 226
Mr = 216.15Dx = 1.453 Mg m3
Monoclinic, P21/mMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybCell parameters from 1229 reflections
a = 8.6323 (17) Åθ = 3.1–27.5°
b = 6.7133 (13) ŵ = 0.27 mm1
c = 8.6841 (17) ÅT = 298 K
β = 100.99 (3)°Block, colorless
V = 494.02 (17) Å30.30 × 0.05 × 0.05 mm
Z = 2
Data collection top
Rigaku Mercury2
diffractometer
1229 independent reflections
Radiation source: fine-focus sealed tube1082 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.033
Detector resolution: 13.6612 pixels mm-1θmax = 27.5°, θmin = 3.1°
CCD profile fitting scansh = 1111
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
k = 88
Tmin = 0.910, Tmax = 1.000l = 1111
5154 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.144H atoms treated by a mixture of independent and constrained refinement
S = 1.18 w = 1/[σ2(Fo2) + (0.0788P)2 + 0.1875P]
where P = (Fo2 + 2Fc2)/3
1229 reflections(Δ/σ)max < 0.001
86 parametersΔρmax = 0.45 e Å3
1 restraintΔρmin = 0.29 e Å3
Crystal data top
C8H9N+·H2O4PV = 494.02 (17) Å3
Mr = 216.15Z = 2
Monoclinic, P21/mMo Kα radiation
a = 8.6323 (17) ŵ = 0.27 mm1
b = 6.7133 (13) ÅT = 298 K
c = 8.6841 (17) Å0.30 × 0.05 × 0.05 mm
β = 100.99 (3)°
Data collection top
Rigaku Mercury2
diffractometer
1229 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
1082 reflections with I > 2σ(I)
Tmin = 0.910, Tmax = 1.000Rint = 0.033
5154 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0471 restraint
wR(F2) = 0.144H atoms treated by a mixture of independent and constrained refinement
S = 1.18Δρmax = 0.45 e Å3
1229 reflectionsΔρmin = 0.29 e Å3
86 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
xyzUiso*/UeqOcc. (<1)
N10.3386 (3)0.25000.5841 (3)0.0298 (5)
H1A0.26500.25000.63850.036*
C30.5712 (4)0.25000.4112 (4)0.0382 (7)
C20.4135 (4)0.25000.3392 (4)0.0378 (7)
H2A0.38620.25000.23030.045*
C10.2974 (3)0.25000.4270 (3)0.0333 (6)
C50.4890 (3)0.25000.6600 (4)0.0338 (6)
C40.6066 (3)0.25000.5731 (4)0.0383 (7)
H4A0.71150.25000.62420.046*
C70.6980 (5)0.25000.3145 (5)0.0548 (10)
H7A0.79860.25000.38450.082*
H7B0.68910.13320.24960.082*0.50
C80.5179 (4)0.25000.8351 (4)0.0456 (8)
H8A0.62960.25000.87500.068*
H8B0.47170.36680.87150.068*0.50
C60.1257 (4)0.25000.3578 (4)0.0505 (9)
H6A0.06750.25000.44170.076*
H6B0.09920.36680.29450.076*0.50
P10.09606 (8)0.25000.89656 (8)0.0280 (3)
O10.0994 (3)0.25000.7269 (3)0.0515 (7)
O20.19545 (18)0.0720 (3)0.9782 (2)0.0494 (5)
O30.0654 (2)0.25000.9371 (2)0.0343 (5)
H20.145 (3)0.024 (3)1.010 (3)0.066 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0261 (11)0.0273 (11)0.0368 (12)0.0000.0079 (9)0.000
C30.0383 (16)0.0230 (13)0.0587 (19)0.0000.0226 (14)0.000
C20.0431 (17)0.0325 (15)0.0408 (16)0.0000.0156 (13)0.000
C10.0325 (14)0.0303 (14)0.0375 (15)0.0000.0078 (12)0.000
C50.0289 (14)0.0270 (13)0.0446 (16)0.0000.0044 (12)0.000
C40.0256 (13)0.0288 (14)0.0609 (19)0.0000.0091 (13)0.000
C70.0469 (19)0.0458 (19)0.082 (3)0.0000.0385 (19)0.000
C80.0344 (16)0.056 (2)0.0419 (17)0.0000.0032 (13)0.000
C60.0344 (16)0.080 (3)0.0366 (16)0.0000.0040 (13)0.000
P10.0243 (4)0.0276 (4)0.0340 (4)0.0000.0102 (3)0.000
O10.0383 (12)0.0835 (19)0.0353 (12)0.0000.0131 (9)0.000
O20.0297 (8)0.0390 (9)0.0826 (13)0.0050 (7)0.0181 (8)0.0211 (8)
O30.0267 (10)0.0300 (10)0.0493 (12)0.0000.0152 (9)0.000
Geometric parameters (Å, º) top
N1—C51.339 (4)C7—H7A0.9601
N1—C11.343 (4)C7—H7B0.9600
N1—H1A0.8600C8—H8A0.9600
C3—C41.381 (5)C8—H8B0.9600
C3—C21.385 (5)C6—H6A0.9600
C3—C71.501 (4)C6—H6B0.9600
C2—C11.371 (4)P1—O11.479 (2)
C2—H2A0.9300P1—O31.502 (2)
C1—C61.489 (4)P1—O2i1.5603 (17)
C5—C41.376 (4)P1—O21.5603 (16)
C5—C81.493 (4)O2—H20.85 (2)
C4—H4A0.9300
C5—N1—C1123.0 (3)C3—C4—H4A119.5
C5—N1—H1A118.5C3—C7—H7A108.3
C1—N1—H1A118.5C3—C7—H7B110.1
C4—C3—C2117.9 (3)H7A—C7—H7B109.5
C4—C3—C7121.7 (3)C5—C8—H8A109.2
C2—C3—C7120.4 (3)C5—C8—H8B109.6
C1—C2—C3120.6 (3)H8A—C8—H8B109.5
C1—C2—H2A119.7C1—C6—H6A108.5
C3—C2—H2A119.7C1—C6—H6B109.9
N1—C1—C2119.0 (3)H6A—C6—H6B109.5
N1—C1—C6117.4 (3)O1—P1—O3115.41 (13)
C2—C1—C6123.5 (3)O1—P1—O2i109.81 (9)
N1—C5—C4118.5 (3)O3—P1—O2i110.37 (8)
N1—C5—C8117.4 (3)O1—P1—O2109.81 (9)
C4—C5—C8124.1 (3)O3—P1—O2110.37 (8)
C5—C4—C3121.1 (3)O2i—P1—O299.97 (14)
C5—C4—H4A119.5P1—O2—H2117 (2)
Symmetry code: (i) x, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O3ii0.85 (2)1.76 (2)2.6054 (19)169 (2)
N1—H1A···O10.861.752.602 (3)173
Symmetry code: (ii) x, y, z+2.

Experimental details

Crystal data
Chemical formulaC8H9N+·H2O4P
Mr216.15
Crystal system, space groupMonoclinic, P21/m
Temperature (K)298
a, b, c (Å)8.6323 (17), 6.7133 (13), 8.6841 (17)
β (°) 100.99 (3)
V3)494.02 (17)
Z2
Radiation typeMo Kα
µ (mm1)0.27
Crystal size (mm)0.30 × 0.05 × 0.05
Data collection
DiffractometerRigaku Mercury2
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.910, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
5154, 1229, 1082
Rint0.033
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.144, 1.18
No. of reflections1229
No. of parameters86
No. of restraints1
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.45, 0.29

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O3i0.85 (2)1.76 (2)2.6054 (19)169 (2)
N1—H1A···O10.861.752.602 (3)173.0
Symmetry code: (i) x, y, z+2.
 

Acknowledgements

This work was supported by a start-up grant from Southeast University, China.

References

First citationFu, D.-W., Ge, J.-Z., Dai, J., Ye, H.-Y. & Qu, Z.-R. (2009). Inorg. Chem. Commun. 12, 994–997.  Web of Science CSD CrossRef CAS Google Scholar
First citationFu, D.-W., Song, Y.-M., Wang, G.-X., Ye, Q., Xiong, R.-G., Akutagawa, T., Nakamura, T., Chan, P. W. H. & Huang, S.-P.-D. (2007). J. Am. Chem. Soc. 129, 5346–5347.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationFu, D.-W. & Xiong, R.-G. (2008). Dalton Trans. pp. 3946–3948.  Web of Science CSD CrossRef Google Scholar
First citationFu, D.-W., Zhang, W. & Xiong, R.-G. (2008). Cryst. Growth Des. 8, 3461–3464.  Web of Science CSD CrossRef CAS Google Scholar
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds