3-Cyano­anilinium hydrogen oxalate hemihydrate

Abstract

In the title hydrated mol­ecular salt, C₇H₇N₂ ⁺·C₂HO₄ ⁻·0.5H₂O, contains a 3-cyano­anilinium cation, a hydrogen oxalate anion and half a water mol­ecule in an asymmetric unit. The dihedral angle between the CO₂(H) and CO₂ planes of the hydrogen oxalate ion is 7.96 (1)°. In the crystal, the components are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming a layer lying parallel to the ac plane.

Related literature  

For the properties of related compounds, see: Chen et al. (2000 ▶); Liu et al. (1999 ▶); Zhao et al. (2003 ▶). For the structures of related compounds, see: Dai & Chen (2011 ▶); Xu et al. (2011 ▶); Zheng (2011 ▶).

Experimental  

Crystal data  

• C₇H₇N₂ ⁺·C₂HO₄ ⁻·0.5H₂O

• M _r = 217.18

• Monoclinic,

• a = 15.1221 (7) Å

• b = 5.6518 (1) Å

• c = 13.6926 (6) Å

• β = 113.22 (4)°

• V = 1075.5 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 173 K

• 0.10 × 0.05 × 0.05 mm

Data collection  

• Rigaku Mercury2 (2 × 2 bin mode) diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.910, T _max = 1.000

• 7209 measured reflections

• 2446 independent reflections

• 1906 reflections with I > 2σ(I)

• R _int = 0.034

Refinement  

• R[F ² > 2σ(F ²)] = 0.054

• wR(F ²) = 0.156

• S = 1.07

• 2446 reflections

• 142 parameters

• 5 restraints

• H-atom parameters constrained

• Δρ_max = 0.28 e Å⁻³

• Δρ_min = −0.24 e Å⁻³

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.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812019824/pv2542Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1WA⋯O1i	0.82	1.96	2.767 (2)	166
N1—H1A⋯O1ii	0.89	1.91	2.797 (2)	172
N1—H1C⋯O2iii	0.89	1.96	2.778 (2)	152
O3—H3⋯O2iii	0.82	1.74	2.559 (2)	178
N1—H1B⋯O1W	0.89	1.91	2.788 (2)	167

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

Comment

Salts of amide attracted more attention as phase transition dielectric materials for its application in micro-electronics, memory storage (Chen et al., 2000; Liu, et al. 1999; Zhao, et al. 2003). With the purpose of obtaining phase transition crystals of 3-aminobenzonitrile salts, its interaction with various acids has been studied and we have elaborated a serie of new materials with this organic molecule (Dai & Chen 2011; Xu, et al. 2011; Zheng 2011). In this paper, we describe the crystal structure of the title compound.

The asymmetric unit is composed of a 3-cyanoanilinium cation, a carboxyformate anion, and a half molecule of water (Fig. 1). The geometric parameters of the title compound agree well with reported similar structure (Dai & Chen 2011). The cation is almost planar (r.m.s. deviation 0.0062 Å, benzene ring as the best plane).

The cations are surrounded by the anions and water molecules via hydrogen bonds which play an important role in stabilizing the crystal structure. In the crystal structure, all the amino H atoms are involved in N—H···O hydrogen bonds with carboxyformate anion and water molecule with the distances of 2.797 (2) Å, 2.778 (2) Å and 2.788 (2) Å, respectively. In addition, the H atoms of water molecule and carboxyformate anion are involved in the O—H···O H-bonding interactions. In the crystal structure, those H-bonds link the ionic units into a two-dimensional sheets parallel to the ac plane (Table 1 and Fig. 2).

Experimental

The commercial 3-aminobenzonitrile (3 mmol, 324 mg) and oxalic acid (3 mmol, 270 mg) were dissolved in 50 ml water/MeOH solution (1:1 v/v). The solvent was slowly evaporated in air affording colourless block-shaped crystals of the title compound suitable for X-ray analysis.

Refinement

The H atoms were included in the refinement at geometrically idealized positions and treated in riding mode with O—H = 0.82 Å, N—H = 0.89 Å and C–H = 0.93 Å, with U_iso(H) = 1.2U_eq(C) or 1.5U_eq(O/N); a rotating-group model was used for the –NH₃ group.

Figures

Fig. 1.

A view of the title compound with the atomic numbering scheme. Displacement ellipsoids were drawn at the 30% probability level.

Fig. 2.

The crystal packing of the title compound viewing along the b-axis, showing the two-dimensional hydrogen-bonded network.

Crystal data

C7H7N2+·C2HO4−·0.5H2O	F(000) = 452
Mr = 217.18	Dx = 1.341 Mg m−3
Monoclinic, P2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yc	Cell parameters from 2446 reflections
a = 15.1221 (7) Å	θ = 2.9–27.5°
b = 5.6518 (1) Å	µ = 0.11 mm−1
c = 13.6926 (6) Å	T = 173 K
β = 113.22 (4)°	Block, colorless
V = 1075.5 (3) Å3	0.10 × 0.05 × 0.05 mm
Z = 4

Data collection

Rigaku Mercury2 (2x2 bin mode) diffractometer	2446 independent reflections
Radiation source: fine-focus sealed tube	1906 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
Detector resolution: 13.6612 pixels mm-1	θmax = 27.5°, θmin = 2.9°
CCD profile fitting scans	h = −18→19
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −7→7
Tmin = 0.910, Tmax = 1.000	l = −17→17
7209 measured reflections

Refinement

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)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.156	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0872P)2 + 0.1364P] where P = (Fo2 + 2Fc2)/3
2446 reflections	(Δ/σ)max < 0.001
142 parameters	Δρmax = 0.28 e Å−3
5 restraints	Δρmin = −0.24 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.

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

	x	y	z	Uiso*/Ueq
O1W	0.5000	0.3943 (3)	0.7500	0.0237 (4)
H1WA	0.4708	0.3063	0.6999	0.036*
N1	0.63809 (11)	0.7280 (2)	0.75668 (11)	0.0247 (4)
H1A	0.6328	0.8305	0.8034	0.037*
H1B	0.5962	0.6106	0.7469	0.037*
H1C	0.6258	0.8012	0.6952	0.037*
C1	0.73556 (13)	0.6324 (3)	0.79701 (14)	0.0278 (4)
C6	0.75806 (14)	0.4443 (3)	0.86683 (15)	0.0312 (4)
H6A	0.7120	0.3818	0.8888	0.037*
C5	0.85041 (16)	0.3490 (4)	0.90408 (18)	0.0449 (6)
C7	0.87338 (18)	0.1547 (5)	0.9797 (2)	0.0579 (7)
C3	0.8941 (2)	0.6365 (8)	0.8017 (3)	0.0843 (11)
H3A	0.9400	0.7024	0.7805	0.101*
C2	0.80292 (17)	0.7312 (5)	0.7645 (2)	0.0547 (7)
H2A	0.7870	0.8596	0.7183	0.066*
N2	0.89001 (19)	0.0051 (5)	1.0408 (2)	0.0826 (9)
C4	0.9188 (2)	0.4440 (7)	0.8704 (2)	0.0730 (9)
H4A	0.9802	0.3793	0.8937	0.088*
O1	0.60131 (9)	−0.0466 (2)	0.39238 (9)	0.0266 (3)
O2	0.60400 (10)	−0.1979 (2)	0.54425 (9)	0.0294 (3)
O3	0.60355 (10)	0.3895 (2)	0.46709 (9)	0.0302 (3)
H3	0.6034	0.5206	0.4927	0.045*
O4	0.62804 (10)	0.2420 (2)	0.62874 (9)	0.0298 (3)
C9	0.61454 (12)	0.2186 (3)	0.53599 (13)	0.0216 (4)
C8	0.60611 (12)	−0.0294 (3)	0.48550 (13)	0.0210 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1W	0.0349 (10)	0.0193 (8)	0.0149 (8)	0.000	0.0076 (7)	0.000
N1	0.0353 (9)	0.0215 (7)	0.0201 (7)	−0.0007 (6)	0.0140 (6)	−0.0001 (6)
C1	0.0285 (10)	0.0333 (10)	0.0223 (8)	−0.0041 (7)	0.0107 (7)	−0.0045 (7)
C6	0.0315 (10)	0.0308 (10)	0.0305 (10)	−0.0006 (7)	0.0115 (8)	−0.0024 (8)
C5	0.0347 (12)	0.0507 (14)	0.0439 (13)	0.0079 (10)	0.0097 (9)	0.0010 (10)
C7	0.0420 (14)	0.0564 (16)	0.0646 (17)	0.0147 (11)	0.0097 (12)	0.0095 (14)
C3	0.0396 (16)	0.146 (3)	0.076 (2)	0.0062 (17)	0.0328 (15)	0.039 (2)
C2	0.0386 (13)	0.0800 (19)	0.0483 (14)	−0.0052 (11)	0.0200 (11)	0.0215 (13)
N2	0.0643 (16)	0.0727 (18)	0.092 (2)	0.0214 (13)	0.0107 (14)	0.0307 (15)
C4	0.0335 (14)	0.118 (3)	0.0714 (19)	0.0210 (15)	0.0244 (13)	0.0192 (19)
O1	0.0457 (8)	0.0193 (6)	0.0186 (6)	−0.0043 (5)	0.0168 (5)	−0.0029 (5)
O2	0.0541 (9)	0.0158 (6)	0.0209 (6)	−0.0013 (5)	0.0177 (6)	0.0005 (5)
O3	0.0592 (9)	0.0138 (6)	0.0219 (6)	−0.0003 (5)	0.0205 (6)	0.0005 (5)
O4	0.0505 (9)	0.0228 (7)	0.0177 (6)	−0.0020 (5)	0.0154 (5)	−0.0032 (5)
C9	0.0320 (9)	0.0166 (8)	0.0170 (8)	−0.0012 (6)	0.0105 (7)	0.0001 (6)
C8	0.0304 (9)	0.0158 (8)	0.0176 (8)	−0.0006 (6)	0.0104 (6)	0.0000 (6)

Geometric parameters (Å, º)

O1W—H1WA	0.8207	C3—C2	1.376 (4)
N1—C1	1.459 (2)	C3—C4	1.389 (5)
N1—H1A	0.8900	C3—H3A	0.9300
N1—H1B	0.8900	C2—H2A	0.9300
N1—H1C	0.8900	C4—H4A	0.9300
C1—C6	1.380 (3)	O1—C8	1.2521 (19)
C1—C2	1.380 (3)	O2—C8	1.255 (2)
C6—C5	1.392 (3)	O3—C9	1.314 (2)
C6—H6A	0.9300	O3—H3	0.8205
C5—C4	1.395 (4)	O4—C9	1.211 (2)
C5—C7	1.454 (4)	C9—C8	1.546 (2)
C7—N2	1.146 (4)
C1—N1—H1A	109.5	C2—C3—C4	121.2 (3)
C1—N1—H1B	109.5	C2—C3—H3A	119.4
H1A—N1—H1B	109.5	C4—C3—H3A	119.4
C1—N1—H1C	109.5	C3—C2—C1	118.8 (2)
H1A—N1—H1C	109.5	C3—C2—H2A	120.6
H1B—N1—H1C	109.5	C1—C2—H2A	120.6
C6—C1—C2	121.57 (19)	C3—C4—C5	119.3 (2)
C6—C1—N1	118.97 (16)	C3—C4—H4A	120.3
C2—C1—N1	119.46 (18)	C5—C4—H4A	120.3
C1—C6—C5	119.32 (19)	C9—O3—H3	112.2
C1—C6—H6A	120.3	O4—C9—O3	126.41 (15)
C5—C6—H6A	120.3	O4—C9—C8	121.21 (15)
C6—C5—C4	119.8 (2)	O3—C9—C8	112.36 (13)
C6—C5—C7	118.5 (2)	O1—C8—O2	125.99 (15)
C4—C5—C7	121.7 (2)	O1—C8—C9	119.18 (14)
N2—C7—C5	177.9 (3)	O2—C8—C9	114.83 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O1i	0.82	1.96	2.767 (2)	166
N1—H1A···O1ii	0.89	1.91	2.797 (2)	172
N1—H1C···O2iii	0.89	1.96	2.778 (2)	152
O3—H3···O2iii	0.82	1.74	2.559 (2)	178
N1—H1B···O1W	0.89	1.91	2.788 (2)	167

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