2,4,6-Trimethyl­pyridinium dihydrogen phosphate

Cai, H.-L.; Dai, J.

doi:10.1107/S1600536810050646

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 1| January 2011| Page o72

https://doi.org/10.1107/S1600536810050646

Open

access

2,4,6-Trimethylpyridinium dihydrogen phosphate

Hong-Ling Cai ^a ^* and Jing Dai ^a

^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 π–π 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 , 2008 , 2009 ); Fu & Xiong (2008 ).

Experimental

Crystal data

C₈H₉N⁺·H₂O₄P⁻
M_r = 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 ) T_min = 0.910, T_max = 1.000
5154 measured reflections
1229 independent reflections
1082 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810050646/rz2528sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810050646/rz2528Isup2.hkl

checkCIF report

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 π–π 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).

Structure description top

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

	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.
	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⁺·H₂O₄P⁻	F(000) = 226
M_r = 216.15	D_x = 1.453 Mg m⁻³
Monoclinic, P2₁/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yb	Cell parameters from 1229 reflections
a = 8.6323 (17) Å	θ = 3.1–27.5°
b = 6.7133 (13) Å	µ = 0.27 mm⁻¹
c = 8.6841 (17) Å	T = 298 K
β = 100.99 (3)°	Block, colorless
V = 494.02 (17) Å³	0.30 × 0.05 × 0.05 mm
Z = 2

Data collection top

Rigaku Mercury2 diffractometer	1229 independent reflections
Radiation source: fine-focus sealed tube	1082 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
Detector resolution: 13.6612 pixels mm^-1	θ_max = 27.5°, θ_min = 3.1°
CCD profile fitting scans	h = −11→11
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −8→8
T_min = 0.910, T_max = 1.000	l = −11→11
5154 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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.144	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	w = 1/[σ²(F_o²) + (0.0788P)² + 0.1875P] where P = (F_o² + 2F_c²)/3
1229 reflections	(Δ/σ)_max < 0.001
86 parameters	Δρ_max = 0.45 e Å⁻³
1 restraint	Δρ_min = −0.29 e Å⁻³

Crystal data top

C₈H₉N⁺·H₂O₄P⁻	V = 494.02 (17) Å³
M_r = 216.15	Z = 2
Monoclinic, P2₁/m	Mo Kα radiation
a = 8.6323 (17) Å	µ = 0.27 mm⁻¹
b = 6.7133 (13) Å	T = 298 K
c = 8.6841 (17) Å	0.30 × 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)
T_min = 0.910, T_max = 1.000	R_int = 0.033
5154 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	1 restraint
wR(F²) = 0.144	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	Δρ_max = 0.45 e Å⁻³
1229 reflections	Δρ_min = −0.29 e Å⁻³
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

	x	y	z	U_iso*/U_eq	Occ. (<1)
N1	0.3386 (3)	0.2500	0.5841 (3)	0.0298 (5)
H1A	0.2650	0.2500	0.6385	0.036*
C3	0.5712 (4)	0.2500	0.4112 (4)	0.0382 (7)
C2	0.4135 (4)	0.2500	0.3392 (4)	0.0378 (7)
H2A	0.3862	0.2500	0.2303	0.045*
C1	0.2974 (3)	0.2500	0.4270 (3)	0.0333 (6)
C5	0.4890 (3)	0.2500	0.6600 (4)	0.0338 (6)
C4	0.6066 (3)	0.2500	0.5731 (4)	0.0383 (7)
H4A	0.7115	0.2500	0.6242	0.046*
C7	0.6980 (5)	0.2500	0.3145 (5)	0.0548 (10)
H7A	0.7986	0.2500	0.3845	0.082*
H7B	0.6891	0.1332	0.2496	0.082*	0.50
C8	0.5179 (4)	0.2500	0.8351 (4)	0.0456 (8)
H8A	0.6296	0.2500	0.8750	0.068*
H8B	0.4717	0.3668	0.8715	0.068*	0.50
C6	0.1257 (4)	0.2500	0.3578 (4)	0.0505 (9)
H6A	0.0675	0.2500	0.4417	0.076*
H6B	0.0992	0.3668	0.2945	0.076*	0.50
P1	0.09606 (8)	0.2500	0.89656 (8)	0.0280 (3)
O1	0.0994 (3)	0.2500	0.7269 (3)	0.0515 (7)
O2	0.19545 (18)	0.0720 (3)	0.9782 (2)	0.0494 (5)
O3	−0.0654 (2)	0.2500	0.9371 (2)	0.0343 (5)
H2	0.145 (3)	−0.024 (3)	1.010 (3)	0.066 (9)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0261 (11)	0.0273 (11)	0.0368 (12)	0.000	0.0079 (9)	0.000
C3	0.0383 (16)	0.0230 (13)	0.0587 (19)	0.000	0.0226 (14)	0.000
C2	0.0431 (17)	0.0325 (15)	0.0408 (16)	0.000	0.0156 (13)	0.000
C1	0.0325 (14)	0.0303 (14)	0.0375 (15)	0.000	0.0078 (12)	0.000
C5	0.0289 (14)	0.0270 (13)	0.0446 (16)	0.000	0.0044 (12)	0.000
C4	0.0256 (13)	0.0288 (14)	0.0609 (19)	0.000	0.0091 (13)	0.000
C7	0.0469 (19)	0.0458 (19)	0.082 (3)	0.000	0.0385 (19)	0.000
C8	0.0344 (16)	0.056 (2)	0.0419 (17)	0.000	−0.0032 (13)	0.000
C6	0.0344 (16)	0.080 (3)	0.0366 (16)	0.000	0.0040 (13)	0.000
P1	0.0243 (4)	0.0276 (4)	0.0340 (4)	0.000	0.0102 (3)	0.000
O1	0.0383 (12)	0.0835 (19)	0.0353 (12)	0.000	0.0131 (9)	0.000
O2	0.0297 (8)	0.0390 (9)	0.0826 (13)	0.0050 (7)	0.0181 (8)	0.0211 (8)
O3	0.0267 (10)	0.0300 (10)	0.0493 (12)	0.000	0.0152 (9)	0.000

Geometric parameters (Å, º) top

N1—C5	1.339 (4)	C7—H7A	0.9601
N1—C1	1.343 (4)	C7—H7B	0.9600
N1—H1A	0.8600	C8—H8A	0.9600
C3—C4	1.381 (5)	C8—H8B	0.9600
C3—C2	1.385 (5)	C6—H6A	0.9600
C3—C7	1.501 (4)	C6—H6B	0.9600
C2—C1	1.371 (4)	P1—O1	1.479 (2)
C2—H2A	0.9300	P1—O3	1.502 (2)
C1—C6	1.489 (4)	P1—O2ⁱ	1.5603 (17)
C5—C4	1.376 (4)	P1—O2	1.5603 (16)
C5—C8	1.493 (4)	O2—H2	0.85 (2)
C4—H4A	0.9300

C5—N1—C1	123.0 (3)	C3—C4—H4A	119.5
C5—N1—H1A	118.5	C3—C7—H7A	108.3
C1—N1—H1A	118.5	C3—C7—H7B	110.1
C4—C3—C2	117.9 (3)	H7A—C7—H7B	109.5
C4—C3—C7	121.7 (3)	C5—C8—H8A	109.2
C2—C3—C7	120.4 (3)	C5—C8—H8B	109.6
C1—C2—C3	120.6 (3)	H8A—C8—H8B	109.5
C1—C2—H2A	119.7	C1—C6—H6A	108.5
C3—C2—H2A	119.7	C1—C6—H6B	109.9
N1—C1—C2	119.0 (3)	H6A—C6—H6B	109.5
N1—C1—C6	117.4 (3)	O1—P1—O3	115.41 (13)
C2—C1—C6	123.5 (3)	O1—P1—O2ⁱ	109.81 (9)
N1—C5—C4	118.5 (3)	O3—P1—O2ⁱ	110.37 (8)
N1—C5—C8	117.4 (3)	O1—P1—O2	109.81 (9)
C4—C5—C8	124.1 (3)	O3—P1—O2	110.37 (8)
C5—C4—C3	121.1 (3)	O2ⁱ—P1—O2	99.97 (14)
C5—C4—H4A	119.5	P1—O2—H2	117 (2)

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3ⁱⁱ	0.85 (2)	1.76 (2)	2.6054 (19)	169 (2)
N1—H1A···O1	0.86	1.75	2.602 (3)	173

Symmetry code: (ii) −x, −y, −z+2.

Experimental details

Crystal data
Chemical formula	C₈H₉N⁺·H₂O₄P⁻
M_r	216.15
Crystal system, space group	Monoclinic, P2₁/m
Temperature (K)	298
a, b, c (Å)	8.6323 (17), 6.7133 (13), 8.6841 (17)
β (°)	100.99 (3)
V (Å³)	494.02 (17)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.27
Crystal size (mm)	0.30 × 0.05 × 0.05

Data collection
Diffractometer	Rigaku Mercury2
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.910, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	5154, 1229, 1082
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.144, 1.18
No. of reflections	1229
No. of parameters	86
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	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)	173.0

Symmetry code: (i) −x, −y, −z+2.

Acknowledgements

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

References

Fu, 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
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. Web of Science CSD CrossRef PubMed CAS Google Scholar
Fu, D.-W. & Xiong, R.-G. (2008). Dalton Trans. pp. 3946–3948. Web of Science CSD CrossRef Google Scholar
Fu, D.-W., Zhang, W. & Xiong, R.-G. (2008). Cryst. Growth Des. 8, 3461–3464. Web of Science CSD CrossRef CAS Google Scholar
Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar