3-Amino-2-chloro­pyridinium dihydrogen­phosphate

The crystal structure of the title compound, C₅H₆ClN₂⁺·H₂PO₄⁻, can be described as a stacking of 3-amino-2-chloro­pyridinium cations and dihydrogenphosphate anions. As well as electrostatic van der Waals inter­actions, the component species inter­act by means of multiple hydrogen bonds. The H₂PO₄⁻ units are linked into polymeric chains propagating along the c axis by way of O—H...O hydrogen bonds. The organic cations are anchored between planes parallel to ac, linking the chains into a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.030
• wR factor = 0.085
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

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Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   0 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Chemistry of organic-inorganic hybrid materials continue to be a focus area in material science. In the last few years, a considerable stategy employed in crystal engineering, is to take advantage of hydrogen bond interactions. Indeed, hydrogen bonds are of value not only because they are recognized as the most powerful force to generate interesting supramolecular networks (Desiraju, 1989; Desiraju, 1995)) but also because of their widespread biological occurrence (Adams, (1977); Nelmes & Choudhary (1978); Blessing, (1986)). As part of our continuing interest in this field, we have synthesized a new compound, 3-amino-2-chloropiridinium dihydrogenmonophosphate (I),

The Crystal structure of (I), consists of dihydrogenmonophosphate anions, and 3-amino-2-chloropiridinium cations. The asymmetric unit contains one crystallographically independent cation and an anion (Fig. 1). The H₂PO₄^- anion shows its normal tetrahedral geometry with the protonated P1—O1 and P1—O2 vertices showing their expected lengthening relative to the unprotonated P—O bonds (Table 1). The 3-amino-2-cloropyridinium cation shows no unusual geometrical features. The anions are linked into polymeric chains of single tetrahedra propagating along [001] by way of the O1—H1···O4 and O2—H2···O3 hydrogen bonds. Similar chains have been seen in amphetamine dihydrogenmonophosphate (Hebert,1978) and in L,b-methyl alaninium dihydrogenmonophosphate (Masse & Durif, 1990). These polymeric chains are interconnected by means of N—H···O hydrogen bonds originating from the NH₂ groups of organic cation, to form infinite layers parallel to the ac plane and centred at y = 0 and y =1/2, as shown in Fig. 2. Charge compensation of these layers is achieved by the incorporation of the protonated pyridinium cation in the inetrlayer spaces. The cationic units interact with the anionic framework through different interactions (electrostatic, H-bonds and Van Der Waals) to make up into three dimensional infinite network. The organic and the inorganic species interact by way of three types of hydrogen bonds. The first one O—H···.O, involving short contacts H···.O of lengths 1.81 Å and 1.83 Å, connects the H₂PO₄^- anions to develop the corrugated chains along the c direction. The second type N—H···.O, with N···O distances ranging from 2.577 (3) Å to 3.052 (3) Å, interconnects two successive chains, while the pertinent angles fall in the interval 149° to 173°. A PLATON (Spek, 2003) analysis of (I) indicated the presence of a third type of weak C—H···O contacts that ensure the cohesion of the ionic groups, giving rise to three-dimensional complex network of hydrogen bonds. It is worth noticing, the presence of a weak intramolecular bonding identified by PLATON (Spek, 2003) analysis (N2—H21···Cl = 2.66 (3) Å), occurring between NH₂ group adjacent to Cl group to reinforce the pyridinium cation.

Related literature

For related literature, see: Adams (1977); Blessing (1986); Desiraju (1989, 1995); Nelmes & Choudhary (1978); Spek (2003).

For related literature, see: Hebert (1978); Masse & Durif (1990).

S2. Experimental

Single crystals of C₅H₆N₂ClH₂PO₄ were prepared by adding drop by drop 0.25 mmol of orthophosphoric acid in 50 ml of water, to a solution of 3-amino-2chloro pyridine (m = 0.5 g, 3.88 mmol) in ethanol. The solution thus obtained was slowly evaporated at room temperature, until the formation of crystals of (I) of good quality.

Computing details

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. ORTEP-3 (Farrugia,1999) view of (I) with atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 30% probability level
	Fig. 2. Projection of (I) along c axis.

3-Amino-2-chloropyridinium dihydrogenphosphate

Crystal data

C5H6ClN2^+·H2PO4^−	F(000) = 464
Mr = 226.55	Dx = 1.687 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 7.391 (2) Å	θ = 8–10°
b = 16.230 (3) Å	µ = 0.59 mm^−1
c = 7.504 (4) Å	T = 293 K
β = 97.73 (3)°	Prism, colorless
V = 891.9 (6) Å^3	0.21 × 0.19 × 0.17 mm
Z = 4

Data collection

Enraf–Nonius Turbo-CAD-4 diffractometer	Rint = 0.022
Radiation source: fine-focus sealed tube	θmax = 25°, θmin = 2°
Graphite monochromator	h = −8→8
non–profiled ω scans	k = 0→19
3120 measured reflections	l = −8→8
1568 independent reflections	2 standard reflections every 120 min
1467 reflections with I > 2σ(I)	intensity decay: 1%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.085	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0403P)^2 + 0.5528P] where P = (Fo^2 + 2Fc^2)/3
1568 reflections	(Δ/σ)max = 0.0001
126 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.39 e Å^−3

Special details

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.

H atoms bonded to N2 were allowed to refine while the rest of the H-atoms were treated as riding, with C—H = 0.93 A °, N—H =0.86 A ° and O—H = 0.82 A °, and with U_iso(H) = 1.2Ueq(C,N) and 1.5Ueq(O).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
P	0.40091 (7)	0.51420 (3)	0.23747 (7)	0.03013 (17)
Cl	0.32834 (7)	0.72253 (4)	0.51245 (8)	0.04714 (19)
O1	0.5783 (2)	0.55975 (10)	0.3199 (2)	0.0455 (4)
H1	0.6305	0.5327	0.4038	0.068*
O2	0.4582 (2)	0.42619 (8)	0.1812 (2)	0.0424 (4)
H2	0.5285	0.4302	0.1059	0.064*
O3	0.3260 (2)	0.56276 (9)	0.0720 (2)	0.0439 (4)
O4	0.27281 (19)	0.50273 (9)	0.3745 (2)	0.0374 (3)
N1	0.0778 (2)	0.82641 (10)	0.5819 (2)	0.0357 (4)
H11	0.1582	0.8624	0.5625	0.043*
N2	0.0393 (3)	0.60423 (12)	0.5991 (3)	0.0482 (5)
H22	−0.050 (4)	0.5675 (16)	0.606 (3)	0.046 (7)*
H21	0.138 (4)	0.5870 (17)	0.561 (4)	0.056 (8)*
C1	0.1183 (3)	0.74668 (12)	0.5701 (3)	0.0322 (4)
C2	−0.0037 (3)	0.68483 (12)	0.6048 (3)	0.0325 (4)
C3	−0.1721 (3)	0.71241 (12)	0.6491 (3)	0.0370 (5)
H3	−0.2588	0.6740	0.6737	0.044*
C4	−0.2113 (3)	0.79467 (13)	0.6568 (3)	0.0418 (5)
H4	−0.3243	0.8118	0.6847	0.050*
C5	−0.0826 (3)	0.85219 (13)	0.6228 (3)	0.0415 (5)
H5	−0.1077	0.9082	0.6284	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P	0.0342 (3)	0.0262 (3)	0.0324 (3)	0.00296 (18)	0.0132 (2)	0.00355 (18)
Cl	0.0324 (3)	0.0520 (3)	0.0595 (4)	−0.0018 (2)	0.0151 (2)	−0.0031 (3)
O1	0.0473 (9)	0.0466 (9)	0.0440 (9)	−0.0149 (7)	0.0113 (7)	0.0093 (7)
O2	0.0565 (9)	0.0285 (7)	0.0471 (9)	0.0075 (6)	0.0247 (7)	0.0042 (6)
O3	0.0531 (9)	0.0438 (8)	0.0375 (8)	0.0213 (7)	0.0161 (7)	0.0093 (6)
O4	0.0366 (7)	0.0408 (8)	0.0383 (8)	−0.0012 (6)	0.0174 (6)	0.0004 (6)
N1	0.0394 (9)	0.0308 (9)	0.0369 (9)	−0.0086 (7)	0.0050 (7)	−0.0011 (7)
N2	0.0422 (11)	0.0303 (9)	0.0761 (15)	0.0001 (8)	0.0229 (10)	−0.0013 (9)
C1	0.0307 (9)	0.0344 (10)	0.0318 (10)	−0.0019 (8)	0.0051 (7)	−0.0018 (8)
C2	0.0329 (10)	0.0320 (10)	0.0330 (10)	−0.0021 (8)	0.0058 (8)	−0.0013 (8)
C3	0.0345 (10)	0.0362 (11)	0.0418 (11)	−0.0050 (8)	0.0110 (9)	−0.0043 (9)
C4	0.0347 (11)	0.0404 (11)	0.0519 (13)	0.0007 (9)	0.0116 (9)	−0.0089 (10)
C5	0.0433 (12)	0.0321 (10)	0.0496 (12)	0.0008 (9)	0.0079 (9)	−0.0061 (9)

Geometric parameters (Å, º)

P—O4	1.5001 (15)	C1—C2	1.397 (3)
P—O3	1.5116 (16)	C2—C3	1.404 (3)
P—O1	1.5591 (16)	C3—C4	1.369 (3)
P—O2	1.5641 (14)	C4—C5	1.381 (3)
O1—H1	0.8200	N2—H22	0.90 (3)
O2—H2	0.8200	N2—H21	0.87 (3)
Cl—C1	1.712 (2)	C3—H3	0.9300
N1—H11	0.8600	C4—C5	1.381 (3)
N1—C5	1.332 (3)	C4—H4	0.9300
N1—C1	1.334 (3)	C5—H5	0.9300
N2—C2	1.348 (3)
O4—P—O3	115.62 (9)	N1—C5—C4	119.14 (19)
O4—P—O1	111.20 (9)	P—O1—H1	109.5
O3—P—O1	105.94 (9)	P—O2—H2	109.5
O4—P—O2	106.88 (8)	C5—N1—H11	118.8
O3—P—O2	109.68 (9)	C1—N1—H11	118.8
O1—P—O2	107.25 (9)	C2—N2—H22	117.7 (16)
C5—N1—C1	122.31 (17)	C2—N2—H21	122.5 (18)
N1—C1—C2	121.94 (18)	H22—N2—H21	118 (2)
N1—C1—Cl	117.24 (15)	C4—C3—H3	119.3
C2—C1—Cl	120.82 (15)	C2—C3—H3	119.3
N2—C2—C1	122.07 (19)	C3—C4—H4	120.1
N2—C2—C3	122.47 (19)	C5—C4—H4	120.1
C1—C2—C3	115.45 (18)	N1—C5—H5	120.4
C4—C3—C2	121.34 (19)	C4—C5—H5	120.4
C3—C4—C5	119.8 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4^i	0.82	1.81	2.611 (3)	164
O2—H2···O3^ii	0.82	1.83	2.646 (3)	177
N1—H11···O3^iii	0.86	1.73	2.577 (3)	168
N2—H21···Cl	0.87 (3)	2.66 (3)	3.008 (3)	105 (2)
N2—H21···O4	0.87 (3)	2.28 (3)	3.052 (3)	149 (3)
N2—H22···O4^iv	0.90 (3)	2.02 (3)	2.915 (3)	173 (3)
C3—H3···O2^iv	0.93	2.54	3.446 (3)	166
C4—H4···O1^v	0.93	2.47	3.164 (3)	132

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z; (iii) x, −y+3/2, z+1/2; (iv) −x, −y+1, −z+1; (v) x−1, −y+3/2, z+1/2.