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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 8| August 2010| Page o1947
https://doi.org/10.1107/S1600536810025821

Guanidinium 2-phenyl­acetate

Graham Smitha* and Urs D. Wermuthb

aFaculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia, and bSchool of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland 4111, Australia
*Correspondence e-mail: g.smith@qut.edu.au

(Received 25 May 2010; accepted 1 July 2010; online 7 July 2010)

In the structure of the title salt, CH6N3+·C8H7O2−, the guanidinium cation gives three cyclic hydrogen-bonding inter­actions with O-atom acceptors of three independent phenyl­acetate anions, one R22(8) and two R21(6), giving one-dimensional columnar structures which extend down the 42 axis in the tetra­gonal cell. Within these structures, there are solvent-accessible voids of volume 86.5 Å3.

Related literature

For the structures of simple monocyclic aromatic guanidinium carboxyl­ates, see: Pereira Silva et al. (2007[Pereira Silva, P. S., Ramos Silva, M., Paixão, J. A. & Matos Beja, A. (2007). Acta Cryst. E63, o2783.], 2010[Pereira Silva, P. S., Ramos Silva, M., Paixão, J. A. & Matos Beja, A. (2010). Acta Cryst. E66, o524.]); Kleb et al. (1998[Kleb, D.-C., Schürmann, M., Preut, H. & Bleckmann, P. (1998). Z. Kristallogr. New Cryst. Struct. pp. 581-582.]); Smith & Wermuth (2010[Smith, G. & Wermuth, U. D. (2010). Acta Cryst. E66, o1946.]). For graph-set analysis, see: Etter et al. (1990[Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.]).

[Scheme 1]

Experimental

Crystal data

  • CH6N3+·C8H7O2−

  • Mr = 195.22

  • Tetragonal, P 42 /n

  • a = 16.8418 (10) Å

  • c = 7.8372 (6) Å

  • V = 2223.0 (3) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 200 K

  • 0.30 × 0.25 × 0.20 mm
Data collection

  • Oxford Diffraction Gemini-S CCD-detector diffractometer

  • 7477 measured reflections

  • 2191 independent reflections

  • 1430 reflections with I > 2σ(I)

  • Rint = 0.027
Refinement

  • R[F2 > 2σ(F2)] = 0.040

  • wR(F2) = 0.101

  • S = 0.93

  • 2191 reflections

  • 151 parameters

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

  • Δρmax = 0.14 e Å−3

  • Δρmin = −0.14 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1G—H11G⋯O22i 0.86 (2) 2.02 (2) 2.876 (2) 173.9 (15)
N1G—H12G⋯O21 0.866 (16) 2.123 (17) 2.900 (2) 149.0 (15)
N2G—H21G⋯O22ii 0.834 (16) 2.219 (17) 2.9625 (19) 148.5 (15)
N2G—H22G⋯O21i 0.86 (2) 1.97 (2) 2.827 (2) 172.6 (15)
N3G—H31G⋯O21 0.897 (16) 2.068 (16) 2.8634 (17) 147.2 (13)
N3G—H32G⋯O22ii 0.859 (16) 2.073 (16) 2.8520 (17) 150.5 (15)
Symmetry codes: (i) [y+{\script{1\over 2}}, -x+1, z+{\script{1\over 2}}]; (ii) x, y, z+1.

Data collection: CrysAlis PRO (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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.]); software used to prepare material for publication: PLATON.

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536810025821/bv2147sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810025821/bv2147Isup2.hkl

checkCIF report


Comment top

The known structures of the guanidinium salts of simple monocyclic aromatic carboxylic acids comsist of those with benzoic acid (Pereira Silva et al., 2007), 4-aminobenzoic acid (Pereira Silva et al., 2010), 4-nitrobenzoic acid (Kleb et al., 1998) and 3-nitrobenzoic acid (Smith & Wermuth, 2010). In these anhydrous structures the guanidinium cation is usually involved in cyclic hydrogen-bonding associations through N–H···Ocarboxyl links [graph sets R22(8) or R21(6) (Etter et al., 1990)] giving most commonly three-dimensional structures. The structure of the guanidinium salt of phenylacetic acid had not been previously reported so we carried out the 2:1 stoichiometric reaction of phenylacetic acid with guanidinium carbonate in aqueous ethanol solution, providing colourless crystals of the title compound, CH6N3+ C8H7O2- (I) when recrystallized from water.

In the structure of (I) (Figs. 1, 2), each guanidinium cation is involved in three cyclic hydrogen-bonding interactions with the carboxyl O-acceptors of three independent phenylacetate anions, one R22(8) and two R21(6). These result in un-associated one-dimensional columnar structures which extend down the 42 (c) axis in the tetragonal cell (Fig. 3). Within these columnar structures there are 86.5 Å3 solvent accessible voids which are large enough to accommodate water molecules but surprisingly do not, despite the sample having been obtained by recrystallization from water.

With the anion, the acetate substituent is close to normal to the plane of the benzene ring [torsion angle C2–C1–C11–C21, 86.98 (18)°]. Present in the benzene ring are unexplained high unidirectional displacement parameters for three atoms [C3, C4, C5: U11, 0.1009 (18), 0.185 (3), 0.1019 (18) Å2 respectively, cf. a typical value 0.0427 (9) Å2 for C2].

Related literature top

For the structures of simple monocyclic aromatic guanidinium carboxylates, see: Pereira Silva et al. (2007, 2010); Kleb et al. (1998); Smith & Wermuth (2010). For graph-set analysis, see: Etter et al. (1990). For related literature, see: Farrugia (1999).

Experimental top

The title compound was synthesized by heating together under reflux for 10 minutes 1 mmol of phenylacetic acid and 0.5 mmol of guanidinium carbonate in 50 ml of 50% ethanol-water. After concentration to ca 30 ml, room temperature evaporation of the hot-filtered solution gave a colourless powder which was recrystallized from a minimum volume of water, giving on total evaporation, crystal plates of (I) (m.p. 443 K), from which a specimen suitable for X-ray analysis was cleaved.

Refinement top

Hydrogen atoms involved in hydrogen-bonding interactions were located by difference methods and their positional and isotropic displacement parameters were refined. The H atoms were included in the refinement in calculated positions (C–Haromatic = 0.93 Å and C–Haliphatc = 0.97 Å) and treated as riding, with Uiso(H) = 1.2Ueq(C).

Structure description top

The known structures of the guanidinium salts of simple monocyclic aromatic carboxylic acids comsist of those with benzoic acid (Pereira Silva et al., 2007), 4-aminobenzoic acid (Pereira Silva et al., 2010), 4-nitrobenzoic acid (Kleb et al., 1998) and 3-nitrobenzoic acid (Smith & Wermuth, 2010). In these anhydrous structures the guanidinium cation is usually involved in cyclic hydrogen-bonding associations through N–H···Ocarboxyl links [graph sets R22(8) or R21(6) (Etter et al., 1990)] giving most commonly three-dimensional structures. The structure of the guanidinium salt of phenylacetic acid had not been previously reported so we carried out the 2:1 stoichiometric reaction of phenylacetic acid with guanidinium carbonate in aqueous ethanol solution, providing colourless crystals of the title compound, CH6N3+ C8H7O2- (I) when recrystallized from water.

In the structure of (I) (Figs. 1, 2), each guanidinium cation is involved in three cyclic hydrogen-bonding interactions with the carboxyl O-acceptors of three independent phenylacetate anions, one R22(8) and two R21(6). These result in un-associated one-dimensional columnar structures which extend down the 42 (c) axis in the tetragonal cell (Fig. 3). Within these columnar structures there are 86.5 Å3 solvent accessible voids which are large enough to accommodate water molecules but surprisingly do not, despite the sample having been obtained by recrystallization from water.

With the anion, the acetate substituent is close to normal to the plane of the benzene ring [torsion angle C2–C1–C11–C21, 86.98 (18)°]. Present in the benzene ring are unexplained high unidirectional displacement parameters for three atoms [C3, C4, C5: U11, 0.1009 (18), 0.185 (3), 0.1019 (18) Å2 respectively, cf. a typical value 0.0427 (9) Å2 for C2].

For the structures of simple monocyclic aromatic guanidinium carboxylates, see: Pereira Silva et al. (2007, 2010); Kleb et al. (1998); Smith & Wermuth (2010). For graph-set analysis, see: Etter et al. (1990). For related literature, see: Farrugia (1999).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. Molecular configuration and atom naming scheme for the guanidinium cation and the phenylacetate anion in (I). Inter-species hydrogen bonds are shown as dashed lines. Displacement ellipsoids are drawn at the 40% probability level.
[Figure 2] Fig. 2. The hydrogen-bonding extensions of the basic asymmetric unit in the structure of (I), showing the three cyclic cation–anion hydrogen-bonding associations as dashed lines. Non-associative hydrogen atoms are deleted. For symmetry codes, see Table 1.
[Figure 3] Fig. 3. The hydrogen-bonded columnar structures of (I) viewed down the c axial direction of the tetragonal unit cell. Non-associative hydrogen atoms are deleted.
Guanidinium 2-phenylacetate top
Crystal data top
CH6N3+·C8H7O2−Dx = 1.167 Mg m−3
Mr = 195.22Melting point: 443 K
Tetragonal, P42/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 4bcCell parameters from 2510 reflections
a = 16.8418 (10) Åθ = 3.1–28.6°
c = 7.8372 (6) ŵ = 0.09 mm−1
V = 2223.0 (3) Å3T = 200 K
Z = 8Block, colourless
F(000) = 8320.30 × 0.25 × 0.20 mm
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer		1430 reflections with I > 2σ(I)
Radiation source: Enhance (Mo) X-ray sourceRint = 0.027
Graphite monochromatorθmax = 26.0°, θmin = 3.1°
ω scansh = −20→18
7477 measured reflectionsk = −10→20
2191 independent reflectionsl = −9→8
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) = 0.101H atoms treated by a mixture of independent and constrained refinement
S = 0.93 w = 1/[σ2(Fo2) + (0.0592P)2]
where P = (Fo2 + 2Fc2)/3
2191 reflections(Δ/σ)max = 0.001
151 parametersΔρmax = 0.14 e Å−3
0 restraintsΔρmin = −0.14 e Å−3
Crystal data top
CH6N3+·C8H7O2−Z = 8
Mr = 195.22Mo Kα radiation
Tetragonal, P42/nµ = 0.09 mm−1
a = 16.8418 (10) ÅT = 200 K
c = 7.8372 (6) Å0.30 × 0.25 × 0.20 mm
V = 2223.0 (3) Å3
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer		1430 reflections with I > 2σ(I)
7477 measured reflectionsRint = 0.027
2191 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.101H atoms treated by a mixture of independent and constrained refinement
S = 0.93Δρmax = 0.14 e Å−3
2191 reflectionsΔρmin = −0.14 e Å−3
151 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O210.64098 (7)0.43351 (6)0.19316 (12)0.0534 (4)
O220.62981 (7)0.44279 (6)−0.08684 (12)0.0518 (4)
C10.61757 (8)0.59370 (8)0.25158 (18)0.0364 (5)
C20.68820 (9)0.61788 (9)0.3219 (2)0.0510 (6)
C30.69086 (15)0.64720 (11)0.4853 (3)0.0775 (9)
C40.6222 (2)0.65222 (12)0.5811 (2)0.0918 (11)
C50.55179 (15)0.62730 (13)0.5105 (3)0.0817 (9)
C60.54971 (10)0.59874 (10)0.3487 (2)0.0554 (6)
C110.61473 (11)0.56093 (9)0.07399 (18)0.0550 (6)
C210.62985 (8)0.47232 (9)0.05979 (17)0.0378 (5)
N1G0.77589 (11)0.40624 (9)0.41545 (18)0.0537 (5)
N2G0.77186 (10)0.40368 (9)0.70667 (17)0.0517 (5)
N3G0.66128 (8)0.43990 (8)0.55565 (18)0.0445 (5)
C1G0.73652 (9)0.41692 (8)0.55946 (17)0.0381 (5)
H20.734700.614400.258300.0610*
H30.739000.663700.531500.0930*
H40.623600.672100.691800.1100*
H50.505200.630000.574000.0980*
H60.501600.582300.302600.0670*
H110.653900.588600.005300.0660*
H120.562900.572300.025900.0660*
H11G0.8248 (12)0.3924 (10)0.4193 (18)0.054 (5)*
H12G0.7504 (10)0.4141 (10)0.321 (2)0.063 (5)*
H21G0.7451 (10)0.4104 (9)0.795 (2)0.049 (5)*
H22G0.8201 (12)0.3872 (10)0.710 (2)0.061 (6)*
H31G0.6432 (9)0.4549 (9)0.453 (2)0.049 (5)*
H32G0.6410 (10)0.4547 (10)0.651 (2)0.055 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O210.0885 (9)0.0400 (6)0.0317 (6)0.0054 (6)−0.0136 (5)−0.0003 (5)
O220.0728 (8)0.0548 (7)0.0279 (6)−0.0017 (6)0.0036 (5)−0.0026 (5)
C10.0399 (8)0.0297 (8)0.0397 (8)0.0033 (7)−0.0008 (7)0.0028 (6)
C20.0427 (9)0.0458 (10)0.0646 (11)−0.0026 (8)−0.0051 (8)0.0073 (8)
C30.1009 (18)0.0509 (12)0.0807 (15)−0.0161 (12)−0.0466 (13)0.0084 (11)
C40.185 (3)0.0493 (12)0.0411 (11)0.0059 (15)−0.0096 (14)−0.0145 (9)
C50.1019 (18)0.0733 (14)0.0699 (14)0.0135 (13)0.0366 (13)−0.0137 (12)
C60.0406 (10)0.0558 (11)0.0698 (12)0.0006 (8)0.0068 (8)−0.0051 (9)
C110.0797 (13)0.0446 (9)0.0406 (9)0.0064 (9)−0.0023 (8)0.0044 (7)
C210.0400 (8)0.0445 (9)0.0288 (8)0.0002 (7)0.0003 (6)0.0004 (7)
N1G0.0462 (9)0.0832 (11)0.0318 (8)0.0094 (8)0.0017 (7)0.0011 (7)
N2G0.0433 (9)0.0805 (11)0.0312 (8)0.0052 (8)−0.0022 (7)−0.0033 (7)
N3G0.0449 (8)0.0599 (9)0.0288 (8)0.0051 (6)0.0005 (6)0.0030 (6)
C1G0.0415 (9)0.0413 (8)0.0314 (8)−0.0044 (7)−0.0011 (7)−0.0003 (6)
Geometric parameters (Å, º) top
O21—C211.2470 (17)C1—C21.373 (2)
O22—C211.2522 (17)C2—C31.373 (3)
N1G—C1G1.321 (2)C3—C41.381 (4)
N2G—C1G1.317 (2)C4—C51.374 (4)
N3G—C1G1.325 (2)C5—C61.357 (3)
N1G—H11G0.86 (2)C11—C211.518 (2)
N1G—H12G0.866 (16)C2—H20.9300
N2G—H21G0.834 (16)C3—H30.9300
N2G—H22G0.86 (2)C4—H40.9300
N3G—H31G0.897 (16)C5—H50.9300
N3G—H32G0.859 (16)C6—H60.9300
C1—C61.376 (2)C11—H120.9700
C1—C111.498 (2)C11—H110.9700
C1G—N1G—H12G117.4 (11)O21—C21—O22124.14 (14)
H11G—N1G—H12G123.3 (15)C1—C2—H2120.00
C1G—N1G—H11G119.3 (10)C3—C2—H2120.00
C1G—N2G—H22G120.6 (11)C2—C3—H3120.00
H21G—N2G—H22G122.0 (15)C4—C3—H3120.00
C1G—N2G—H21G117.4 (11)C5—C4—H4120.00
C1G—N3G—H32G116.5 (11)C3—C4—H4121.00
H31G—N3G—H32G124.3 (15)C4—C5—H5120.00
C1G—N3G—H31G115.3 (10)C6—C5—H5120.00
C2—C1—C6118.65 (14)C1—C6—H6119.00
C2—C1—C11120.66 (13)C5—C6—H6119.00
C6—C1—C11120.68 (14)C21—C11—H11109.00
C1—C2—C3120.62 (16)C21—C11—H12108.00
C2—C3—C4120.1 (2)H11—C11—H12108.00
C3—C4—C5119.00 (18)C1—C11—H11108.00
C4—C5—C6120.5 (2)C1—C11—H12108.00
C1—C6—C5121.17 (17)N2G—C1G—N3G120.08 (14)
C1—C11—C21115.15 (12)N1G—C1G—N2G119.89 (15)
O21—C21—C11118.63 (12)N1G—C1G—N3G120.02 (14)
O22—C21—C11117.24 (12)
C6—C1—C2—C3−0.6 (2)C1—C2—C3—C40.4 (3)
C11—C1—C2—C3−179.37 (15)C2—C3—C4—C50.2 (3)
C2—C1—C6—C50.3 (2)C3—C4—C5—C6−0.5 (3)
C11—C1—C6—C5179.08 (16)C4—C5—C6—C10.2 (3)
C2—C1—C11—C2186.98 (18)C1—C11—C21—O212.0 (2)
C6—C1—C11—C21−91.75 (18)C1—C11—C21—O22−178.42 (13)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1G—H11G···O22i0.86 (2)2.02 (2)2.876 (2)173.9 (15)
N1G—H12G···O210.866 (16)2.123 (17)2.900 (2)149.0 (15)
N2G—H21G···O22ii0.834 (16)2.219 (17)2.9625 (19)148.5 (15)
N2G—H22G···O21i0.86 (2)1.97 (2)2.827 (2)172.6 (15)
N3G—H31G···O210.897 (16)2.068 (16)2.8634 (17)147.2 (13)
N3G—H32G···O22ii0.859 (16)2.073 (16)2.8520 (17)150.5 (15)
Symmetry codes: (i) y+1/2, −x+1, z+1/2; (ii) x, y, z+1.

Experimental details

Crystal data
Chemical formulaCH6N3+·C8H7O2−
Mr195.22
Crystal system, space groupTetragonal, P42/n
Temperature (K)200
a, c (Å)16.8418 (10), 7.8372 (6)
V (Å3)2223.0 (3)
Z8
Radiation typeMo Kα
µ (mm−1)0.09
Crystal size (mm)0.30 × 0.25 × 0.20
Data collection
DiffractometerOxford Diffraction Gemini-S CCD-detector
diffractometer
Absorption correction–
No. of measured, independent and
observed [I > 2σ(I)] reflections		7477, 2191, 1430
Rint0.027
(sin θ/λ)max (Å−1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.101, 0.93
No. of reflections2191
No. of parameters151
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.14, −0.14

Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1G—H11G···O22i0.86 (2)2.02 (2)2.876 (2)173.9 (15)
N1G—H12G···O210.866 (16)2.123 (17)2.900 (2)149.0 (15)
N2G—H21G···O22ii0.834 (16)2.219 (17)2.9625 (19)148.5 (15)
N2G—H22G···O21i0.86 (2)1.97 (2)2.827 (2)172.6 (15)
N3G—H31G···O210.897 (16)2.068 (16)2.8634 (17)147.2 (13)
N3G—H32G···O22ii0.859 (16)2.073 (16)2.8520 (17)150.5 (15)
Symmetry codes: (i) y+1/2, −x+1, z+1/2; (ii) x, y, z+1.
 

Acknowledgements

The authors acknowledge financial support from the Australian Research Council, the Faculty of Science and Technology, Queensland University of Technology and the School of Biomolecular and Physical Sciences, Griffith University.

References

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 8| August 2010| Page o1947
https://doi.org/10.1107/S1600536810025821
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