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

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ISSN: 2056-9890

2-Amino­anilinium 2-carb­­oxy­acetate

aDepartment of Chemical & Environmental Engineering, Anyang Institute of Technology, Anyang 455000, People's Republic of China
*Correspondence e-mail: ayitzhao@yahoo.com.cn

(Received 22 June 2011; accepted 28 June 2011; online 2 July 2011)

In the crystal structure of the title compound, C6H9N2+·C3H3O4, all the amino H atoms are involved in inter­molecular N—H⋯O hydrogen bonds, which link the ions into double chains parallel to [101]. In the anion, an intra­molecular O—H⋯O hydrogen bond is observed.

Related literature

For background to pharmaceutical applications and growth of co-crystals, see: Almarsson & Zaworotko (2004[Almarsson, O. & Zaworotko, M. J. (2004). Chem. Commun. 17, 1889-1896.]); Blagden et al. (2008[Blagden, N., Berry, D. J., Parkin, A., Javed, H., Ibrahim, A., Gavan, P. T., De Matos, L. L. & Seaton, C. C. (2008). New J. Chem. 32, 1659-1672.]); Vishweshwar et al. (2006[Vishweshwar, P., McMahon, J. A., Bis, J. A. & Zaworotko, M. J. (2006). J. Pharm. Sci. 95, 499-516.]); Kapildev et al. (2011[Kapildev, K. A., Nitin, G. T. & Raj, S. (2011). Mol. Pharm. 8, 982-989.]); Schultheiss & Newman (2009[Schultheiss, N. & Newman, A. (2009). Cryst. Growth Des. 9, 2950-2967.]).

[Scheme 1]

Experimental

Crystal data
  • C6H9N2+·C3H3O4

  • Mr = 212.21

  • Monoclinic, P 21 /n

  • a = 12.735 (3) Å

  • b = 5.7448 (11) Å

  • c = 14.429 (3) Å

  • β = 107.38 (3)°

  • V = 1007.4 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 298 K

  • 0.30 × 0.25 × 0.15 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

  • 10297 measured reflections

  • 2310 independent reflections

  • 2027 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.040

  • wR(F2) = 0.129

  • S = 1.14

  • 2310 reflections

  • 137 parameters

  • H-atom parameters constrained

  • Δρmax = 0.29 e Å−3

  • Δρmin = −0.25 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O3i 0.89 1.90 2.7865 (17) 171
N1—H1B⋯O1ii 0.89 1.86 2.7420 (15) 170
N2—H2A⋯O3iii 0.90 2.21 2.9693 (18) 142
N2—H2B⋯O2iv 0.90 2.21 3.0988 (18) 169
N1—H1C⋯O2 0.89 2.25 2.9019 (15) 130
O4—H4⋯O2 0.82 1.67 2.4616 (15) 161
Symmetry codes: (i) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]; (ii) x, y+1, z; (iii) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]; (iv) -x+1, -y+1, -z+1.

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

Molecular co-crystals are becoming increasingly important within the pharmaceutical industry as an alternative source of new solid crystalline materials with the potential to provide optimal physical properties whilst retaining the chemical properties of the cocrystal components (Almarsson & Zaworotko, 2004; Blagden et al., 2008; Vishweshwar et al., 2006). Physicochemical properties such as the melting point, stability and solubility of an active pharmaceutical ingredient can be tuned through co-crystal formulation (Kapildev et al., 2011; Schultheiss & Newman, 2009). Co-crystal synthesis often relies on the acid-amide H-bonds interactions. Herein, we report the crystal structure of the title compound, 2-aminoanilinium 2-carboxyacetate.

The asymmetric unit of the title compound is composed of one 2-aminoanilinium cation and one 2-carboxyacetate anion (Fig. 1). The amine N1 atom is protonated and one of the carboxyl groups (C7/O1/O2) is deprotonated. The geometric parameters of the title compound are in the normal range. In the crystal structure, all the amino H atoms are involved in intermolecular N—H···O hydrogen bonding interactions with carboxylic O atoms, linking the ions into double chains parallel to the [101] direction (Table 1; Fig. 2). The conformation of the anion is stabilized by an intramolecular O—H···O hydrogen bond (Table 1).

Related literature top

For background to pharmaceutical applications and growth of co-crystals, see: Almarsson & Zaworotko (2004); Blagden et al. (2008); Vishweshwar et al. (2006); Kapildev et al. (2011); Schultheiss & Newman (2009).

Experimental top

A mixture of benzene-1,2-diamine (2.0 mmol), malonic acid (2.0 mmol) in distilled water (20 ml) was added into a 50 ml flask and refluxed for 5 hours, then cooled and filtrated. The solution was evaporated slowly in the air. Colourless block crystals suitable for X-ray analysis were obtained after one week.

Refinement top

All H atoms attached to C atoms were fixed geometrically and treated as riding with C-H = 0.93–0.97 Å and with Uiso(H) = 1.2 Ueq(C). The amine and carboxylic H atoms were located in a difference Fourier map and refined freely. In the last stage of the refinement, they were restrained with the H—N1 = 0.90 (2) Å, H—N2 = 0.89 (2) Å and H—O4 = 0.82 (2) Å, and with Uiso(H) = 1.5 Ueq(N1, O4) or 1.2 Ueq(N2).

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. The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level.
[Figure 2] Fig. 2. The crystal packing of the title compound viewed along the b axis, showing a double chain formed by intermolecular hydrogen bonds (dashed line). Hydrogen atoms not involved in hydrogen bonding are omitted for clarity.
2-Aminoanilinium 2-carboxyacetate top
Crystal data top
C6H9N2+·C3H3O4F(000) = 448
Mr = 212.21Dx = 1.399 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2310 reflections
a = 12.735 (3) Åθ = 1.9–27.5°
b = 5.7448 (11) ŵ = 0.11 mm1
c = 14.429 (3) ÅT = 298 K
β = 107.38 (3)°Block, colourless
V = 1007.4 (3) Å30.30 × 0.25 × 0.15 mm
Z = 4
Data collection top
Rigaku Mercury2
diffractometer
2310 independent reflections
Radiation source: fine-focus sealed tube2027 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
Detector resolution: 13.6612 pixels mm-1θmax = 27.5°, θmin = 1.9°
CCD profile fitting scansh = 1616
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
k = 77
Tmin = 0.910, Tmax = 1.000l = 1818
10297 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)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.129H-atom parameters constrained
S = 1.14 w = 1/[σ2(Fo2) + (0.0733P)2 + 0.1065P]
where P = (Fo2 + 2Fc2)/3
2310 reflections(Δ/σ)max < 0.001
137 parametersΔρmax = 0.29 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C6H9N2+·C3H3O4V = 1007.4 (3) Å3
Mr = 212.21Z = 4
Monoclinic, P21/nMo Kα radiation
a = 12.735 (3) ŵ = 0.11 mm1
b = 5.7448 (11) ÅT = 298 K
c = 14.429 (3) Å0.30 × 0.25 × 0.15 mm
β = 107.38 (3)°
Data collection top
Rigaku Mercury2
diffractometer
2310 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
2027 reflections with I > 2σ(I)
Tmin = 0.910, Tmax = 1.000Rint = 0.026
10297 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.129H-atom parameters constrained
S = 1.14Δρmax = 0.29 e Å3
2310 reflectionsΔρmin = 0.25 e Å3
137 parameters
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
O20.61965 (7)0.52957 (17)0.59590 (7)0.0380 (3)
N10.58132 (8)0.80154 (19)0.41942 (8)0.0318 (3)
H1A0.53360.83760.36230.048*
H1B0.59970.92970.45520.048*
H1C0.55060.69980.45000.048*
O40.78587 (8)0.72834 (17)0.69666 (7)0.0407 (3)
H40.72310.68620.66700.061*
O30.94464 (8)0.5435 (2)0.74114 (7)0.0458 (3)
O10.62897 (9)0.1692 (2)0.54632 (9)0.0538 (3)
C10.67983 (9)0.6987 (2)0.40414 (8)0.0286 (3)
C90.84796 (9)0.5516 (2)0.69323 (8)0.0303 (3)
C70.67270 (10)0.3478 (2)0.58610 (8)0.0320 (3)
C80.79755 (9)0.3559 (2)0.62487 (9)0.0307 (3)
H8A0.82260.21010.65800.037*
H8B0.82630.36410.56980.037*
C60.77981 (11)0.8061 (3)0.44260 (10)0.0390 (3)
H6A0.78450.94350.47770.047*
N20.56773 (12)0.3929 (3)0.31118 (11)0.0569 (4)
H2A0.56010.25180.28280.068*
H2B0.50780.42220.33030.068*
C20.66864 (11)0.4931 (2)0.35095 (9)0.0342 (3)
C30.76464 (13)0.3975 (3)0.33892 (10)0.0436 (4)
H3A0.76070.25960.30430.052*
C40.86492 (13)0.5041 (3)0.37757 (12)0.0515 (4)
H4A0.92770.43690.36880.062*
C50.87378 (12)0.7085 (3)0.42893 (12)0.0513 (4)
H5A0.94180.78040.45420.062*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O20.0268 (4)0.0449 (5)0.0408 (5)0.0064 (4)0.0079 (4)0.0038 (4)
N10.0269 (5)0.0348 (6)0.0329 (5)0.0024 (4)0.0074 (4)0.0021 (4)
O40.0355 (5)0.0373 (5)0.0450 (5)0.0022 (4)0.0055 (4)0.0112 (4)
O30.0282 (5)0.0568 (6)0.0444 (6)0.0005 (4)0.0012 (4)0.0073 (5)
O10.0412 (6)0.0616 (7)0.0592 (7)0.0177 (5)0.0160 (5)0.0293 (6)
C10.0259 (6)0.0320 (6)0.0282 (6)0.0026 (4)0.0085 (4)0.0031 (4)
C90.0265 (6)0.0365 (6)0.0275 (6)0.0006 (5)0.0075 (4)0.0004 (5)
C70.0277 (6)0.0421 (7)0.0262 (5)0.0027 (5)0.0082 (4)0.0023 (5)
C80.0274 (6)0.0325 (6)0.0324 (6)0.0012 (5)0.0092 (5)0.0031 (5)
C60.0319 (6)0.0423 (7)0.0414 (7)0.0037 (5)0.0088 (5)0.0007 (6)
N20.0508 (8)0.0546 (8)0.0686 (9)0.0159 (6)0.0229 (7)0.0303 (7)
C20.0384 (7)0.0349 (7)0.0314 (6)0.0004 (5)0.0134 (5)0.0004 (5)
C30.0542 (9)0.0426 (8)0.0409 (7)0.0124 (7)0.0246 (6)0.0031 (6)
C40.0425 (8)0.0685 (11)0.0513 (9)0.0203 (7)0.0259 (7)0.0154 (8)
C50.0279 (7)0.0690 (11)0.0571 (9)0.0014 (7)0.0128 (6)0.0069 (8)
Geometric parameters (Å, º) top
O2—C71.2742 (16)C8—H8A0.9700
N1—C11.4618 (15)C8—H8B0.9700
N1—H1A0.8900C6—C51.388 (2)
N1—H1B0.8900C6—H6A0.9300
N1—H1C0.8900N2—C21.3679 (19)
O4—C91.2969 (16)N2—H2A0.9003
O4—H40.8221N2—H2B0.9008
O3—C91.2195 (15)C2—C31.3978 (19)
O1—C71.2253 (17)C3—C41.375 (2)
C1—C61.3737 (18)C3—H3A0.9300
C1—C21.3924 (18)C4—C51.375 (3)
C9—C81.5069 (17)C4—H4A0.9300
C7—C81.5205 (17)C5—H5A0.9300
C1—N1—H1A109.5C7—C8—H8B108.0
C1—N1—H1B109.5H8A—C8—H8B107.2
H1A—N1—H1B109.5C1—C6—C5119.72 (14)
C1—N1—H1C109.5C1—C6—H6A120.1
H1A—N1—H1C109.5C5—C6—H6A120.1
H1B—N1—H1C109.5C2—N2—H2A122.0
C9—O4—H4105.0C2—N2—H2B124.6
C6—C1—C2122.23 (12)H2A—N2—H2B108.7
C6—C1—N1119.42 (12)N2—C2—C1121.12 (12)
C2—C1—N1118.34 (11)N2—C2—C3121.96 (13)
O3—C9—O4122.15 (12)C1—C2—C3116.91 (13)
O3—C9—C8120.19 (12)C4—C3—C2121.01 (14)
O4—C9—C8117.62 (10)C4—C3—H3A119.5
O1—C7—O2123.81 (12)C2—C3—H3A119.5
O1—C7—C8118.48 (12)C5—C4—C3121.04 (13)
O2—C7—C8117.71 (11)C5—C4—H4A119.5
C9—C8—C7117.25 (10)C3—C4—H4A119.5
C9—C8—H8A108.0C4—C5—C6119.08 (14)
C7—C8—H8A108.0C4—C5—H5A120.5
C9—C8—H8B108.0C6—C5—H5A120.5
O3—C9—C8—C7165.75 (12)C6—C1—C2—C30.67 (19)
O4—C9—C8—C716.10 (16)N1—C1—C2—C3179.06 (11)
O1—C7—C8—C9165.98 (12)N2—C2—C3—C4178.41 (14)
O2—C7—C8—C914.93 (16)C1—C2—C3—C40.5 (2)
C2—C1—C6—C50.2 (2)C2—C3—C4—C50.2 (2)
N1—C1—C6—C5179.56 (12)C3—C4—C5—C60.8 (2)
C6—C1—C2—N2178.23 (14)C1—C6—C5—C40.6 (2)
N1—C1—C2—N22.05 (19)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O3i0.891.902.7865 (17)171
N1—H1B···O1ii0.891.862.7420 (15)170
N2—H2A···O3iii0.902.212.9693 (18)142
N2—H2B···O2iv0.902.213.0988 (18)169
N1—H1C···O20.892.252.9019 (15)130
O4—H4···O20.821.672.4616 (15)161
Symmetry codes: (i) x1/2, y+3/2, z1/2; (ii) x, y+1, z; (iii) x1/2, y+1/2, z1/2; (iv) x+1, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC6H9N2+·C3H3O4
Mr212.21
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)12.735 (3), 5.7448 (11), 14.429 (3)
β (°) 107.38 (3)
V3)1007.4 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.30 × 0.25 × 0.15
Data collection
DiffractometerRigaku Mercury2
diffractometer
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.910, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
10297, 2310, 2027
Rint0.026
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.129, 1.14
No. of reflections2310
No. of parameters137
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.29, 0.25

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

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O3i0.891.902.7865 (17)171
N1—H1B···O1ii0.891.862.7420 (15)170
N2—H2A···O3iii0.902.212.9693 (18)142
N2—H2B···O2iv0.902.213.0988 (18)169
N1—H1C···O20.892.252.9019 (15)130
O4—H4···O20.821.672.4616 (15)161
Symmetry codes: (i) x1/2, y+3/2, z1/2; (ii) x, y+1, z; (iii) x1/2, y+1/2, z1/2; (iv) x+1, y+1, z+1.
 

Acknowledgements

This work was supported by the start-up fund of Anyang Institute of Technology, China.

References

First citationAlmarsson, O. & Zaworotko, M. J. (2004). Chem. Commun. 17, 1889–1896.  Web of Science CrossRef Google Scholar
First citationBlagden, N., Berry, D. J., Parkin, A., Javed, H., Ibrahim, A., Gavan, P. T., De Matos, L. L. & Seaton, C. C. (2008). New J. Chem. 32, 1659–1672.  Web of Science CSD CrossRef CAS Google Scholar
First citationKapildev, K. A., Nitin, G. T. & Raj, S. (2011). Mol. Pharm. 8, 982–989.  Web of Science PubMed Google Scholar
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationSchultheiss, N. & Newman, A. (2009). Cryst. Growth Des. 9, 2950–2967.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationVishweshwar, P., McMahon, J. A., Bis, J. A. & Zaworotko, M. J. (2006). J. Pharm. Sci. 95, 499–516.  Web of Science CrossRef PubMed CAS Google Scholar

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