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

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ISSN: 2056-9890

Glycine–phthalic acid (1/1)

aSchool of Physics, Bharathidasan University, Tiruchirappalli 620 024, India, bDepartment of Physics and Nanotechnology, SRM University, Kattankulathur 603 203, India, and cDepartment of Bioinformatics, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, India
*Correspondence e-mail: thamu@scbt.sastra.edu

(Received 6 November 2012; accepted 4 December 2012; online 8 December 2012)

In the title compound, C2H5NO2·C8H6O4, the glycine mol­ecule exists as a zwitterion (2-aza­niumyl­ethano­ate) with a positively charged amino group and a negatively charged carboxyl­ate group. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the components into layers parallel to the ab plane. The central part of each layer is composed of hydrogen-bonded glycine zwitterions, while phthalic acid mol­ecules inter­act with the zwitterions in such a way that benzene rings protrude up and down from the layer.

Related literature

For related structures, see: Losev et al. (2011[Losev, E. A., Zakharov, B. A., Drebushchak, T. N. & Boldyreva, E. V. (2011). Acta Cryst. C67, o297-o300.]); Herbstein et al. (1981[Herbstein, F. H., Kapon, M., Maor, I. & Reisner, G. M. (1981). Acta Cryst. B37, 136-140.]). For graph-set motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For head-to-tail hydrogen bonds, see: Sharma et al. (2006[Sharma, A., Thamotharan, S., Roy, S. & Vijayan, M. (2006). Acta Cryst. C62, o148-o152.]); Selvaraj et al. (2007[Selvaraj, M., Thamotharan, S., Roy, S. & Vijayan, M. (2007). Acta Cryst. B63, 459-468.]).

[Scheme 1]

Experimental

Crystal data
  • C2H5NO2·C8H6O4

  • Mr = 241.20

  • Orthorhombic, P b c a

  • a = 7.9657 (5) Å

  • b = 11.3470 (7) Å

  • c = 23.513 (2) Å

  • V = 2125.3 (3) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.13 mm−1

  • T = 173 K

  • 0.53 × 0.46 × 0.30 mm

Data collection
  • Stoe IPDS diffractometer

  • 15716 measured reflections

  • 2077 independent reflections

  • 1597 reflections with I > 2σ(I)

  • Rint = 0.041

Refinement
  • R[F2 > 2σ(F2)] = 0.034

  • wR(F2) = 0.090

  • S = 1.01

  • 2077 reflections

  • 175 parameters

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

  • Δρmax = 0.22 e Å−3

  • Δρmin = −0.19 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O5i 0.917 (19) 1.992 (19) 2.8398 (16) 153.0 (16)
N1—H1B⋯O3ii 0.91 (2) 2.13 (2) 3.0219 (16) 164.6 (17)
N1—H1C⋯O2iii 0.88 (2) 2.181 (19) 2.8934 (16) 137.4 (15)
N1—H1C⋯O3iv 0.88 (2) 2.416 (19) 3.0681 (16) 130.9 (15)
O4—H4O⋯O2i 0.96 (3) 1.58 (3) 2.5383 (14) 175 (2)
O6—H6O⋯O1v 0.98 (2) 1.56 (2) 2.5337 (13) 171 (2)
Symmetry codes: (i) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]; (ii) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z]; (iii) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, z]; (iv) x+1, y, z; (v) -x+1, -y, -z.

Data collection: EXPOSE in IPDS-I Software (Stoe & Cie, 2000[Stoe & Cie (2000). IPDS-I Software. Stoe & Cie GmbH, Darmstadt, Germany.]); cell refinement: CELL in IPDS-I Software; data reduction: INTEGRATE in IPDS-I Software; 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: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

As part of our studies on amino acids and carboxylic acids interactions (Sharma et al. 2006; Selvaraj et al., 2007), we report here the crystal structure of the title cocrystal of glycine and phthalic acid, (I).

The asymmetric unit of (I) contains one glycine molecule and one phthalic acid molecule (Fig. 1). The glycine molecule exists as a zwitterion with a positively charged amino group and a negatively charged carboxylate group as found in glycine-trimesic acid complex (Herbstein et al., 1981) and glycine-glutaric acid cocrystal (Losev et al., 2011), where glutaric acid exists as a neutral molecule. The phthalic acid exists as a neutral molecule with both carboxylic acid groups being unionized. The stoichiometry between the glycine and phthalic acid is 1:1.

The crystal packing is stabilized by a network of N—H···O and O—H···O hydrogen bonds (Table 1). As illustrated in Fig. 2, the basic aggregation pattern observed in the complex is a layered architecture of zwitterionic glycine and neutral phthalic acid molecules. An antiparallel linear array of zwitterionic glycines are sandwiched between phthalic acid layers.

In (I), the zwitterionic glycine has one donor atom capable of forming three hydrogen bonds, and one of them forms bifurcated hydrogen bonds, while neutral phthalic acid can also forms three hydrogen bonds through two acceptors (Table 1). In the crystal structure, the zwitterionic glycines are arranged in linear arrays along [010] direction. In each array, adjacent glycines are connected by a N1···O2 hydrogen bond which can be described as a head-to-tail sequence having a graph-set motif of C5 (Bernstein et al., 1995) (Fig. 3). In contrast to (I), no head-to-tail sequence was observed in glycine-glutaric acid cocrystal (Losev et al., 2011). As observed in many binary complexes of amino acids complexed with carboxylic acids, the neutral molecules in the complex do not interact among themselves. However, here, phthalic acid molecule is interconnected by zwitterionic glycines via two intermolecular N1···O3 hydrogen bonds. The glycine amino group acts as donor for 1-substituted carboxylic O3 atoms of the phthalic acid molecules emanating from different phthalic acids layers. Another carboxylic O5 atom acts as acceptor for an intermolecular hydrogen bond with the amino group of a glycine. The 2-substituted carboxylic group of the phthalic acid molecules in two different layers are interconnected by glycines. One carboxylic group in one layer interacts with the glycine in one layer, while its symmetry-related equivalents in the adjacent layers interacts with the glycine in the neighbouring layer [C12(4) graph-set motif]. The donor atoms (O4 and O6) of the phthalic acid molecule participate in intermolecular short and linear O—H···O hydrogen bonds with the carboxylate group of glycine. These hydrogen bonds produce C22(11) chains that run parallel to the a axis.

Related literature top

For related structures, see: Losev et al. (2011); Herbstein et al. (1981). For graph-set motifs, see: Bernstein et al. (1995). For head-to-tail hydrogen bonds, see: Sharma et al. (2006); Selvaraj et al. (2007).

Experimental top

The title complex was prepared by dissolving glycine and phthalic acid in a stoichiometric ratio in double distilled water. The resulting solution was heated to ca 50° C and the title cocrystal was obtained by a slow cooling method from an aqueous solution.

Refinement top

The H-atoms bound to nitrogen and oxygen were located from difference electron density maps and isotropically refined. All the remaining H atoms were placed in geometrically idealized positions (C—H = 0.95-0.99 Å) and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: EXPOSE in IPDS-I Software (Stoe & Cie, 2000); cell refinement: CELL in IPDS-I Software (Stoe & Cie, 2000); data reduction: INTEGRATE in IPDS-I Software (Stoe & Cie, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and ORTEP-3 (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A content of asymmetric unit of (I) showing the atomic-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Basic aggregation pattern in (I) viewed in [100]. Dashed lines denote hydrogen bonds. H atoms have been omitted for clarity.
[Figure 3] Fig. 3. Head-to-tail sequences of zwitterionic glycine molecules in (I) viewed in [001]. Dashed lines denote hydrogen bonds. H atoms not involved in H-bonding were omitted for clarity.
2-Azaniumylethanoate–phthalic acid (1/1) top
Crystal data top
C2H5NO2·C8H6O4F(000) = 1008
Mr = 241.20Dx = 1.508 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 8000 reflections
a = 7.9657 (5) Åθ = 2.6–26.1°
b = 11.3470 (7) ŵ = 0.13 mm1
c = 23.513 (2) ÅT = 173 K
V = 2125.3 (3) Å3Block, colourless
Z = 80.53 × 0.46 × 0.30 mm
Data collection top
Stoe IPDS
diffractometer
1597 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.041
Graphite monochromatorθmax = 26.0°, θmin = 3.1°
Detector resolution: 0.81Å pixels mm-1h = 99
phi rotation scansk = 1313
15716 measured reflectionsl = 2928
2077 independent reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.090 w = 1/[σ2(Fo2) + (0.064P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
2077 reflectionsΔρmax = 0.22 e Å3
175 parametersΔρmin = 0.19 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0086 (15)
Crystal data top
C2H5NO2·C8H6O4V = 2125.3 (3) Å3
Mr = 241.20Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 7.9657 (5) ŵ = 0.13 mm1
b = 11.3470 (7) ÅT = 173 K
c = 23.513 (2) Å0.53 × 0.46 × 0.30 mm
Data collection top
Stoe IPDS
diffractometer
1597 reflections with I > 2σ(I)
15716 measured reflectionsRint = 0.041
2077 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0340 restraints
wR(F2) = 0.090H atoms treated by a mixture of independent and constrained refinement
S = 1.01Δρmax = 0.22 e Å3
2077 reflectionsΔρmin = 0.19 e Å3
175 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
O30.06389 (12)0.23293 (9)0.08480 (4)0.0293 (3)
O40.00401 (15)0.40181 (9)0.12875 (4)0.0374 (3)
H4O0.058 (3)0.435 (2)0.0959 (11)0.075 (7)*
O50.00354 (13)0.05643 (9)0.12213 (4)0.0365 (3)
O60.19779 (12)0.05907 (9)0.08314 (4)0.0311 (3)
H6O0.205 (3)0.008 (2)0.0572 (10)0.072 (6)*
C30.06342 (15)0.22668 (12)0.17621 (5)0.0238 (3)
C40.10175 (15)0.10660 (12)0.17542 (5)0.0242 (3)
C50.15369 (17)0.05214 (13)0.22514 (6)0.0294 (3)
H50.17950.02960.22470.035*
C60.16855 (19)0.11483 (14)0.27541 (6)0.0347 (3)
H60.20540.07640.30910.042*
C70.12967 (18)0.23317 (14)0.27639 (6)0.0336 (3)
H70.13870.27650.31080.040*
C80.07751 (17)0.28854 (13)0.22713 (6)0.0278 (3)
H80.05080.37010.22800.033*
C90.00603 (16)0.28671 (12)0.12521 (5)0.0249 (3)
C100.09312 (16)0.03014 (11)0.12370 (5)0.0247 (3)
O10.75187 (11)0.11587 (8)0.01838 (4)0.0269 (2)
O20.65409 (12)0.01881 (8)0.04157 (4)0.0317 (3)
N10.59761 (16)0.29647 (10)0.03063 (5)0.0258 (3)
H1A0.543 (2)0.3538 (16)0.0511 (8)0.042 (5)*
H1B0.560 (2)0.2998 (17)0.0061 (9)0.051 (5)*
H1C0.704 (3)0.3178 (16)0.0329 (8)0.043 (5)*
C10.66689 (15)0.08474 (11)0.02398 (5)0.0226 (3)
C20.57097 (16)0.17890 (11)0.05551 (6)0.0249 (3)
H2A0.44970.15990.05460.030*
H2B0.60720.17980.09580.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O30.0348 (5)0.0245 (5)0.0286 (5)0.0013 (4)0.0052 (4)0.0042 (4)
O40.0615 (7)0.0201 (6)0.0307 (6)0.0003 (5)0.0090 (5)0.0012 (4)
O50.0476 (6)0.0296 (6)0.0322 (6)0.0152 (5)0.0070 (4)0.0067 (4)
O60.0368 (5)0.0226 (5)0.0338 (5)0.0036 (4)0.0124 (4)0.0055 (4)
C30.0231 (6)0.0230 (7)0.0251 (7)0.0023 (5)0.0022 (5)0.0020 (5)
C40.0215 (6)0.0229 (7)0.0280 (7)0.0032 (5)0.0035 (5)0.0018 (5)
C50.0318 (7)0.0250 (7)0.0315 (7)0.0004 (6)0.0006 (5)0.0024 (6)
C60.0398 (8)0.0363 (9)0.0279 (7)0.0013 (6)0.0036 (6)0.0047 (6)
C70.0408 (8)0.0355 (9)0.0245 (7)0.0047 (7)0.0017 (6)0.0044 (6)
C80.0313 (7)0.0239 (7)0.0283 (7)0.0016 (5)0.0009 (5)0.0055 (5)
C90.0269 (6)0.0213 (7)0.0266 (7)0.0011 (5)0.0014 (5)0.0026 (5)
C100.0278 (6)0.0186 (7)0.0277 (7)0.0001 (5)0.0021 (5)0.0004 (5)
O10.0323 (5)0.0227 (5)0.0256 (5)0.0013 (4)0.0069 (4)0.0038 (4)
O20.0415 (6)0.0204 (5)0.0332 (5)0.0037 (4)0.0057 (4)0.0041 (4)
N10.0293 (6)0.0192 (6)0.0288 (6)0.0010 (5)0.0024 (5)0.0043 (5)
C10.0244 (6)0.0211 (7)0.0223 (6)0.0002 (5)0.0017 (5)0.0016 (5)
C20.0283 (7)0.0216 (7)0.0247 (6)0.0002 (5)0.0040 (5)0.0012 (5)
Geometric parameters (Å, º) top
O3—C91.2197 (15)C6—H60.9500
O4—C91.3088 (18)C7—C81.382 (2)
O4—H4O0.96 (3)C7—H70.9500
O5—C101.2147 (16)C8—H80.9500
O6—C101.3086 (16)O1—C11.2550 (15)
O6—H6O0.98 (2)O2—C11.2498 (16)
C3—C81.3925 (18)N1—C21.4720 (17)
C3—C41.396 (2)N1—H1A0.917 (19)
C3—C91.4859 (18)N1—H1B0.91 (2)
C4—C51.3855 (19)N1—H1C0.88 (2)
C4—C101.4955 (18)C1—C21.5083 (18)
C5—C61.385 (2)C2—H2A0.9900
C5—H50.9500C2—H2B0.9900
C6—C71.378 (2)
C9—O4—H4O109.8 (14)O3—C9—C3122.68 (13)
C10—O6—H6O107.5 (13)O4—C9—C3113.67 (11)
C8—C3—C4119.06 (12)O5—C10—O6123.72 (12)
C8—C3—C9119.52 (12)O5—C10—C4121.39 (11)
C4—C3—C9121.20 (11)O6—C10—C4114.70 (11)
C5—C4—C3119.29 (12)C2—N1—H1A111.5 (11)
C5—C4—C10116.18 (12)C2—N1—H1B111.5 (12)
C3—C4—C10124.53 (12)H1A—N1—H1B108.2 (16)
C6—C5—C4121.11 (13)C2—N1—H1C111.3 (12)
C6—C5—H5119.4H1A—N1—H1C103.1 (16)
C4—C5—H5119.4H1B—N1—H1C110.9 (17)
C7—C6—C5119.71 (13)O2—C1—O1124.83 (12)
C7—C6—H6120.1O2—C1—C2117.52 (11)
C5—C6—H6120.1O1—C1—C2117.64 (11)
C6—C7—C8119.78 (13)N1—C2—C1111.94 (11)
C6—C7—H7120.1N1—C2—H2A109.2
C8—C7—H7120.1C1—C2—H2A109.2
C7—C8—C3121.05 (13)N1—C2—H2B109.2
C7—C8—H8119.5C1—C2—H2B109.2
C3—C8—H8119.5H2A—C2—H2B107.9
O3—C9—O4123.61 (13)
C8—C3—C4—C50.36 (18)C8—C3—C9—O3159.60 (13)
C9—C3—C4—C5174.93 (12)C4—C3—C9—O314.95 (19)
C8—C3—C4—C10179.55 (12)C8—C3—C9—O418.29 (17)
C9—C3—C4—C105.88 (19)C4—C3—C9—O4167.16 (12)
C3—C4—C5—C60.2 (2)C5—C4—C10—O559.45 (18)
C10—C4—C5—C6179.09 (12)C3—C4—C10—O5121.34 (15)
C4—C5—C6—C70.6 (2)C5—C4—C10—O6115.59 (13)
C5—C6—C7—C80.5 (2)C3—C4—C10—O663.62 (17)
C6—C7—C8—C30.0 (2)O2—C1—C2—N1179.74 (11)
C4—C3—C8—C70.46 (19)O1—C1—C2—N11.15 (17)
C9—C3—C8—C7175.12 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O5i0.917 (19)1.992 (19)2.8398 (16)153.0 (16)
N1—H1B···O3ii0.91 (2)2.13 (2)3.0219 (16)164.6 (17)
N1—H1C···O2iii0.88 (2)2.181 (19)2.8934 (16)137.4 (15)
N1—H1C···O3iv0.88 (2)2.416 (19)3.0681 (16)130.9 (15)
O4—H4O···O2i0.96 (3)1.58 (3)2.5383 (14)175 (2)
O6—H6O···O1v0.98 (2)1.56 (2)2.5337 (13)171 (2)
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x+1/2, y+1/2, z; (iii) x+3/2, y+1/2, z; (iv) x+1, y, z; (v) x+1, y, z.

Experimental details

Crystal data
Chemical formulaC2H5NO2·C8H6O4
Mr241.20
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)173
a, b, c (Å)7.9657 (5), 11.3470 (7), 23.513 (2)
V3)2125.3 (3)
Z8
Radiation typeMo Kα
µ (mm1)0.13
Crystal size (mm)0.53 × 0.46 × 0.30
Data collection
DiffractometerStoe IPDS
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
15716, 2077, 1597
Rint0.041
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.090, 1.01
No. of reflections2077
No. of parameters175
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.22, 0.19

Computer programs: EXPOSE in IPDS-I Software (Stoe & Cie, 2000), CELL in IPDS-I Software (Stoe & Cie, 2000), INTEGRATE in IPDS-I Software (Stoe & Cie, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and ORTEP-3 (Farrugia, 2012).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O5i0.917 (19)1.992 (19)2.8398 (16)153.0 (16)
N1—H1B···O3ii0.91 (2)2.13 (2)3.0219 (16)164.6 (17)
N1—H1C···O2iii0.88 (2)2.181 (19)2.8934 (16)137.4 (15)
N1—H1C···O3iv0.88 (2)2.416 (19)3.0681 (16)130.9 (15)
O4—H4O···O2i0.96 (3)1.58 (3)2.5383 (14)175 (2)
O6—H6O···O1v0.98 (2)1.56 (2)2.5337 (13)171 (2)
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x+1/2, y+1/2, z; (iii) x+3/2, y+1/2, z; (iv) x+1, y, z; (v) x+1, y, z.
 

Acknowledgements

TB thanks the University Grants Commission (UGC) for the award of a Research Fellowship under the Faculty Improvement Programme (FIP). We are grateful to Professor Helen Stoeckli-Evans, University of Neuchâtel, Switzerland, for measuring the X-ray diffraction data. ST thanks the management of SASTRA University for their encouragement.

References

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