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

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ISSN: 2056-9890

2,6-Di­amino­pyridinium di­hydrogen phosphate

aSchool of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang, 050043, People's Republic of China
*Correspondence e-mail: yugang@stdu.edu.cn

(Received 18 June 2012; accepted 11 August 2012; online 23 August 2012)

In the crystal structure of the title compound, C5H8N3+·H2PO4, N—H⋯O hydrogen bonds, involving the unprotonated amino-group and the NH+ group in the pyridinium ring and dihydrogenphosphate O atoms, link the cations and anions. A long chain-like stacking of dihydrogenphosphate anions along the c-axis direction is constructed by O—H⋯O hydrogen bonds. Also along the c-axis direction, ππ stacking between inversion-related pyridinium rings [centroid–centroid distance = 3.8051 (10) Å] forms columnar stacks of cations.

Related literature

For functional materials with similar crystal structures and their proton-transfer mechanism, see: Lasave et al. (2007[Lasave, J., Koval, S., Dalal, N. S. & Migoni, R. L. (2007). Phys. Rev. Lett. 98, 267601-4.]); Morenzoni et al. (2007[Morenzoni, E., Luetkens, H., Suter, A., Eshchenko, D., Khasanov, R., Amato, A., Prokschaa, T. & Scheuermann, R. (2007). Physica B, 388, 274-277.]); Reiter (2002[Reiter, G. F. (2002). Phys. Rev. Lett. 89, 135505-4.]); Szklarz et al. (2011[Szklarz, P., Chanski, M., Slepokura, K. & Lis, T. (2011). Chem. Mater. 23, 1082-1084.]); Zhang et al. (2010[Zhang, Q., Chen, F., Kioussis, N., Demos, S. G. & Radousky, H. B. (2010). Phys. Rev. B, 65, 024108-10.]). For the design of similar organic–inorganic functional materials, see: Horiuchi & Tokura (2008[Horiuchi, S. & Tokura, Y. (2008). Nat. Mater. 7, 357-366.]); Zhang & Xiong (2012[Zhang, W. & Xiong, R.-G. (2012). Chem. Rev. 112, 1163-1195.]).

[Scheme 1]

Experimental

Crystal data
  • C5H8N3+·H2O4P

  • Mr = 207.13

  • Triclinic, [P \overline 1]

  • a = 7.4821 (4) Å

  • b = 8.1110 (2) Å

  • c = 8.1790 (1) Å

  • α = 70.811 (10)°

  • β = 74.980 (14)°

  • γ = 84.883 (15)°

  • V = 452.77 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.29 mm−1

  • T = 153 K

  • 0.50 × 0.30 × 0.20 mm

Data collection
  • Rigaku Mercury CCD diffractometer

  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.868, Tmax = 0.944

  • 5434 measured reflections

  • 2057 independent reflections

  • 1938 reflections with > σ(I)

  • Rint = 0.013

Refinement
  • R[F2 > 2σ(F2)] = 0.034

  • wR(F2) = 0.090

  • S = 1.17

  • 2057 reflections

  • 133 parameters

  • 4 restraints

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

  • Δρmax = 0.30 e Å−3

  • Δρmin = −0.33 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O2i 0.86 1.90 2.7515 (17) 170
N2—H2N2⋯O2i 0.85 (2) 2.58 (2) 3.241 (2) 136 (2)
N3—H1N3⋯O4i 0.87 (2) 2.05 (2) 2.9078 (19) 167 (2)
N2—H1N2⋯O1ii 0.82 (2) 2.40 (2) 3.0734 (19) 139 (2)
N2—H1N2⋯O4ii 0.82 (2) 2.56 (2) 3.342 (2) 159 (2)
O1—H1A⋯O2iii 0.82 1.76 2.5705 (15) 169
O3—H3⋯O4iv 0.82 1.73 2.5334 (15) 167
N3—H2N3⋯O3 0.85 (2) 2.11 (2) 2.9574 (18) 178 (2)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y+1, z; (iii) -x+1, -y-1, -z+1; (iv) -x+1, -y-1, -z.

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: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

Recently, explorations for new ferroelectrics of organic-inorganic complexes have attracted extensive attention (Zhang & Xiong, 2012). Among the well known functional materials, KH2PO4 (KDP) and its analogue crystals have been widely studied from the viewpoint of both their crystal structures and basic physical properties (Lasave et al., 2007; Morenzoni et al., 2007). The O—H···O hydrogen bonds not only support their structural frameworks, but also play critical roles in their properties. The simultaneous displacive deformation of H2PO4- moieties contributes mainly to spontaneous polarization, together with the protonic order-disorder phenomena. For KDP crystals in an electric field, the collective site-to-site transfer of protons in the O—H···O bonds switches the spontaneous polarization, which is known as the proton-transfer mechanism (Reiter, 2002; Zhang et al., 2010; Horiuchi & Tokura, 2008). As a potential promising strategy, one can imagine that the movements of protons within the hydrogen bonds would be generally advantageous in designing novel ferroelectrics (Horiuchi & Tokura, 2008). Investigation of this type of functional material continues, however, only a few novel crystals have been discovered in recent years. In the present work, a novel complex of the KDP family, 2,6-diaminopyridine phosphate, has been synthesized. Crystal structure analysis (Fig. 1) reveals that O—H···O hydrogen bonds of the H2PO4- anionic moieties in 2,6-diaminopyridine phosphate assemble into a long chain-like architecture along the c axis direction, which is similar to the hydrogen bonds in KDP crystals.

Related literature top

For functional materials with similar crystal structures and their proton-transfer mechanism, see: Lasave et al. (2007); Morenzoni et al. (2007); Reiter (2002); Szklarz et al. (2011); Zhang et al. (2010). For the design of similar organic–inorganic functional materials, see: Horiuchi & Tokura (2008); Zhang & Xiong (2012).

Experimental top

The title complex was synthesized from a mixture of 2,6-pyridinediamine and phosphoric acid with the chemical ratio of 1:1 in aqueous solution. The reaction mixture was stirred for several hours and slowly heated to 45°C yielding a clear solution. After solvent evaporation at controlled temperature for several days, yellow block-shaped crystals were obtained in 96% yield.

Refinement top

H atoms were found in difference Fourier maps. Carbon and oxygen-bound H atoms were subsequently placed in idealized positions with constrained distances of 0.95 Å (C—H) and 0.82 Å (O—H). Nitrogen-bound H atoms were refined subject to distance restraints. Uiso(H) values were set to either 1.2Ueq or 1.5Ueq (O—H only) of the attached atom.

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: publCIF (Westrip, 2010).

Figures top
The molecular structure of the title compound drawn with 30% probability displacement ellipsoids for non-H atoms.
2,6-Diaminopyridinium dihydrogen phosphate top
Crystal data top
C5H8N3+·H2O4PZ = 2
Mr = 207.13F(000) = 216
Triclinic, P1Dx = 1.519 Mg m3
Hall symbol: -P 1Melting point: 396 K
a = 7.4821 (4) ÅMo Kα radiation, λ = 0.71073 Å
b = 8.1110 (2) ÅCell parameters from 1340 reflections
c = 8.1790 (1) Åθ = 2.7–27.5°
α = 70.811 (10)°µ = 0.29 mm1
β = 74.980 (14)°T = 153 K
γ = 84.883 (15)°Block, yellow
V = 452.77 (3) Å30.50 × 0.30 × 0.20 mm
Data collection top
Rigaku Mercury CCD
diffractometer
2057 independent reflections
Radiation source: fine-focus sealed tube1938 reflections with > σ(I)
Graphite monochromatorRint = 0.013
ω and ϕ scansθmax = 27.5°, θmin = 2.7°
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
h = 98
Tmin = 0.868, Tmax = 0.944k = 1010
5434 measured reflectionsl = 1010
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)] = 0.034Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.090H atoms treated by a mixture of independent and constrained refinement
S = 1.17 w = 1/[σ2(Fo2) + (0.0388P)2 + 0.1286P]
where P = (Fo2 + 2Fc2)/3
2057 reflections(Δ/σ)max < 0.001
133 parametersΔρmax = 0.30 e Å3
4 restraintsΔρmin = 0.33 e Å3
Crystal data top
C5H8N3+·H2O4Pγ = 84.883 (15)°
Mr = 207.13V = 452.77 (3) Å3
Triclinic, P1Z = 2
a = 7.4821 (4) ÅMo Kα radiation
b = 8.1110 (2) ŵ = 0.29 mm1
c = 8.1790 (1) ÅT = 153 K
α = 70.811 (10)°0.50 × 0.30 × 0.20 mm
β = 74.980 (14)°
Data collection top
Rigaku Mercury CCD
diffractometer
2057 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
1938 reflections with > σ(I)
Tmin = 0.868, Tmax = 0.944Rint = 0.013
5434 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0344 restraints
wR(F2) = 0.090H atoms treated by a mixture of independent and constrained refinement
S = 1.17Δρmax = 0.30 e Å3
2057 reflectionsΔρmin = 0.33 e Å3
133 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*/Ueq
N11.09610 (18)0.12682 (15)0.27998 (16)0.0371 (3)
H11.17890.20470.30650.044*
N21.2828 (3)0.0630 (2)0.3140 (3)0.0656 (5)
H1N21.294 (3)0.166 (3)0.304 (3)0.079*
H2N21.350 (3)0.023 (3)0.354 (3)0.079*
N30.9398 (2)0.34142 (19)0.2483 (2)0.0494 (4)
H1N31.044 (3)0.400 (3)0.241 (3)0.059*
H2N30.852 (3)0.368 (3)0.213 (3)0.059*
C11.1233 (2)0.0373 (2)0.2779 (2)0.0457 (4)
C20.9892 (3)0.1617 (2)0.2384 (3)0.0615 (5)
H3C1.00280.27530.23610.074*
C30.8346 (3)0.1145 (2)0.2023 (3)0.0626 (5)
H4A0.74400.19840.17630.075*
C40.8092 (2)0.0517 (2)0.2035 (2)0.0502 (4)
H5A0.70370.08040.17880.060*
C50.9458 (2)0.17538 (19)0.2426 (2)0.0376 (3)
P10.44212 (5)0.47555 (5)0.25676 (5)0.03232 (13)
O10.46973 (19)0.65793 (14)0.39139 (15)0.0485 (3)
H1A0.51930.64560.46500.073*
O20.39135 (16)0.34140 (14)0.35200 (15)0.0439 (3)
O30.63300 (16)0.4229 (2)0.12119 (16)0.0564 (4)
H30.63900.45520.03480.085*
O40.30132 (14)0.50108 (16)0.16548 (15)0.0451 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0417 (7)0.0296 (6)0.0424 (6)0.0011 (5)0.0130 (5)0.0124 (5)
N20.0784 (12)0.0459 (9)0.0813 (12)0.0211 (8)0.0222 (10)0.0242 (9)
N30.0382 (7)0.0458 (8)0.0771 (10)0.0003 (6)0.0228 (7)0.0301 (7)
C10.0575 (10)0.0331 (7)0.0434 (8)0.0106 (6)0.0015 (7)0.0140 (6)
C20.0734 (13)0.0313 (8)0.0683 (12)0.0015 (8)0.0017 (10)0.0158 (8)
C30.0571 (11)0.0464 (9)0.0668 (12)0.0172 (8)0.0012 (9)0.0102 (8)
C40.0384 (8)0.0548 (10)0.0524 (9)0.0092 (7)0.0097 (7)0.0140 (8)
C50.0348 (7)0.0401 (7)0.0380 (7)0.0006 (6)0.0072 (6)0.0138 (6)
P10.0338 (2)0.0371 (2)0.0335 (2)0.00135 (14)0.01388 (14)0.01632 (15)
O10.0767 (8)0.0343 (5)0.0468 (6)0.0030 (5)0.0286 (6)0.0196 (5)
O20.0588 (7)0.0381 (5)0.0482 (6)0.0114 (5)0.0289 (5)0.0223 (5)
O30.0419 (6)0.0955 (10)0.0429 (6)0.0273 (6)0.0061 (5)0.0329 (7)
O40.0328 (5)0.0688 (7)0.0477 (6)0.0014 (5)0.0154 (5)0.0322 (6)
Geometric parameters (Å, º) top
N1—C11.3586 (18)C2—H3C0.9300
N1—C51.3601 (19)C3—C41.375 (3)
N1—H10.8600C3—H4A0.9300
N2—C11.350 (3)C4—C51.389 (2)
N2—H1N20.822 (18)C4—H5A0.9300
N2—H2N20.848 (19)P1—O41.5028 (10)
N3—C51.336 (2)P1—O21.5050 (10)
N3—H1N30.874 (17)P1—O31.5584 (12)
N3—H2N30.852 (17)P1—O11.5608 (12)
C1—C21.379 (3)O1—H1A0.8200
C2—C31.378 (3)O3—H30.8200
C1—N1—C5123.93 (14)C4—C3—H4A118.7
C1—N1—H1118.0C2—C3—H4A118.7
C5—N1—H1118.0C3—C4—C5118.03 (17)
C1—N2—H1N2110.8 (18)C3—C4—H5A121.0
C1—N2—H2N2120.4 (18)C5—C4—H5A121.0
H1N2—N2—H2N2128 (3)N3—C5—N1116.91 (13)
C5—N3—H1N3117.6 (14)N3—C5—C4124.57 (15)
C5—N3—H2N3116.4 (15)N1—C5—C4118.52 (14)
H1N3—N3—H2N3120 (2)O4—P1—O2115.15 (6)
N2—C1—N1115.83 (16)O4—P1—O3110.88 (6)
N2—C1—C2126.02 (16)O2—P1—O3107.55 (7)
N1—C1—C2118.14 (17)O4—P1—O1106.11 (7)
C3—C2—C1118.83 (16)O2—P1—O1110.22 (6)
C3—C2—H3C120.6O3—P1—O1106.64 (8)
C1—C2—H3C120.6P1—O1—H1A109.5
C4—C3—C2122.54 (17)P1—O3—H3109.5
C5—N1—C1—N2178.37 (15)C2—C3—C4—C50.0 (3)
C5—N1—C1—C21.1 (2)C1—N1—C5—N3179.29 (15)
N2—C1—C2—C3179.19 (19)C1—N1—C5—C41.4 (2)
N1—C1—C2—C30.2 (3)C3—C4—C5—N3179.93 (17)
C1—C2—C3—C40.3 (3)C3—C4—C5—N10.8 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O2i0.861.902.7515 (17)170
N2—H2N2···O2i0.85 (2)2.58 (2)3.241 (2)136 (2)
N3—H1N3···O4i0.87 (2)2.05 (2)2.9078 (19)167 (2)
N2—H1N2···O1ii0.82 (2)2.40 (2)3.0734 (19)139 (2)
N2—H1N2···O4ii0.82 (2)2.56 (2)3.342 (2)159 (2)
O1—H1A···O2iii0.821.762.5705 (15)169
O3—H3···O4iv0.821.732.5334 (15)167
N3—H2N3···O30.85 (2)2.11 (2)2.9574 (18)178 (2)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y+1, z; (iii) x+1, y1, z+1; (iv) x+1, y1, z.

Experimental details

Crystal data
Chemical formulaC5H8N3+·H2O4P
Mr207.13
Crystal system, space groupTriclinic, P1
Temperature (K)153
a, b, c (Å)7.4821 (4), 8.1110 (2), 8.1790 (1)
α, β, γ (°)70.811 (10), 74.980 (14), 84.883 (15)
V3)452.77 (3)
Z2
Radiation typeMo Kα
µ (mm1)0.29
Crystal size (mm)0.50 × 0.30 × 0.20
Data collection
DiffractometerRigaku Mercury CCD
diffractometer
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.868, 0.944
No. of measured, independent and
observed [ > σ(I)] reflections
5434, 2057, 1938
Rint0.013
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.090, 1.17
No. of reflections2057
No. of parameters133
No. of restraints4
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.30, 0.33

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O2i0.861.902.7515 (17)169.5
N2—H2N2···O2i0.848 (19)2.58 (2)3.241 (2)136 (2)
N3—H1N3···O4i0.874 (17)2.049 (17)2.9078 (19)167.2 (19)
N2—H1N2···O1ii0.822 (18)2.40 (2)3.0734 (19)139 (2)
N2—H1N2···O4ii0.822 (18)2.56 (2)3.342 (2)159 (2)
O1—H1A···O2iii0.821.762.5705 (15)169.1
O3—H3···O4iv0.821.732.5334 (15)167.1
N3—H2N3···O30.852 (17)2.106 (17)2.9574 (18)178 (2)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y+1, z; (iii) x+1, y1, z+1; (iv) x+1, y1, z.
 

Acknowledgements

The author expresses his thanks to Dr Zhihua Sun (Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences) for his help with the crystal structure determination.

References

First citationHoriuchi, S. & Tokura, Y. (2008). Nat. Mater. 7, 357–366.  Web of Science CrossRef PubMed CAS
First citationLasave, J., Koval, S., Dalal, N. S. & Migoni, R. L. (2007). Phys. Rev. Lett. 98, 267601–4.  Web of Science CrossRef PubMed CAS
First citationMorenzoni, E., Luetkens, H., Suter, A., Eshchenko, D., Khasanov, R., Amato, A., Prokschaa, T. & Scheuermann, R. (2007). Physica B, 388, 274–277.  Web of Science CrossRef CAS
First citationReiter, G. F. (2002). Phys. Rev. Lett. 89, 135505–4.  Web of Science CrossRef PubMed CAS
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSzklarz, P., Chanski, M., Slepokura, K. & Lis, T. (2011). Chem. Mater. 23, 1082–1084.  Web of Science CrossRef CAS
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals
First citationZhang, Q., Chen, F., Kioussis, N., Demos, S. G. & Radousky, H. B. (2010). Phys. Rev. B, 65, 024108–10.  Web of Science CrossRef
First citationZhang, W. & Xiong, R.-G. (2012). Chem. Rev. 112, 1163–1195.  Web of Science CrossRef CAS PubMed

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