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Volume 69 
Part 7 
Pages o1114-o1115  
July 2013  

Received 30 May 2013
Accepted 12 June 2013
Online 19 June 2013

Key indicators
Single-crystal X-ray study
T = 298 K
Mean [sigma](C-C) = 0.002 Å
R = 0.062
wR = 0.161
Data-to-parameter ratio = 21.8
Details
Open access

Benzamidinium 2-methoxybenzoate

aChemistry Department, "Sapienza" University of Rome, P.le A. Moro, 5, I-00185 Rome, Italy
Correspondence e-mail: g.portalone@caspur.it

The title molecular salt, C7H9N2+.C8H7O3-, was synthesized by reaction between benzamidine (benzenecarboximidamide) and 2-methoxybenzoic acid. In the cation, the amidinium group has two similar C-N bonds [1.3070 (17) and 1.3145 (16) Å] and is almost coplanar with the benzene ring, making a dihedral angle of 5.34 (12)°. In the anion, the methoxy substituent forces the carboxylate group to be twisted by 69.45 (6)° with respect to the plane of the aromatic fragment. In the crystal, the components are connected by two N+-H...O- (±)CAHB (charge-assisted hydrogen bonds), forming centrosymmetric ionic dimers with graph-set motif R22(8). These ionic dimers are then joined in ribbons running along the b-axis direction by another R42(8) motif involving the remaining N+-H...O- hydrogen bonds. Remarkably, at variance with the well known carboxylic dimer R22(8) motif, the carboxylate-amidinium pair is not planar, the dihedral angle between the planes defined by the CN2+ and CO2- atoms being 18.57 (12)°.

Related literature

For the biological and pharmacological relevance of benzamidine, see: Powers & Harper (1999[Powers, J. C. & Harper, J. W. (1999). Proteinase inhibitors, edited by A. J. Barrett & G. Salvesen, pp. 55-152. Amsterdam: Elsevier.]). For structural analysis of proton-transfer adducts containing molecules of biological interest, see: Portalone (2010[Portalone, G. (2010). Acta Cryst. C66, o295-o301.], 2013[Portalone, G. (2013). Acta Cryst. E69, o14-o15.]). For the supramolecular association in proton-transfer adducts containing benzamidinium cations, see: Portalone (2010[Portalone, G. (2010). Acta Cryst. C66, o295-o301.], 2012[Portalone, G. (2012). Acta Cryst. E68, o268-o269.], 2013[Portalone, G. (2013). Acta Cryst. E69, o14-o15.]); Irrera & Portalone (2012[Irrera, S. & Portalone, G. (2012). Acta Cryst. E68, o3083.], 2013[Irrera, S. & Portalone, G. (2013). Acta Cryst. E69, o56.]); Irrera et al. (2012[Irrera, S., Ortaggi, G. & Portalone, G. (2012). Acta Cryst. C68, o447-o451.]). For 2-methoxybenzoic acid derivatives, see: Portalone (2011[Portalone, G. (2011). Acta Cryst. E67, o3394-o3395.]). For hydrogen-bond 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.]).

[Scheme 1]

Experimental

Crystal data
  • C7H9N2+·C8H7O3-

  • Mr = 272.30

  • Triclinic, [P \overline 1]

  • a = 7.5154 (3) Å

  • b = 9.1393 (4) Å

  • c = 11.6498 (5) Å

  • [alpha] = 69.612 (3)°

  • [beta] = 80.500 (5)°

  • [gamma] = 72.482 (4)°

  • V = 713.63 (6) Å3

  • Z = 2

  • Mo K[alpha] radiation

  • [mu] = 0.09 mm-1

  • T = 298 K

  • 0.12 × 0.09 × 0.05 mm

Data collection
  • Agilent Xcalibur Sapphire3 diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011[Agilent (2011). CrysAlis PRO. Agilent Technologies Ltd, Abingdon, England.]) Tmin = 0.989, Tmax = 0.996

  • 20559 measured reflections

  • 4332 independent reflections

  • 3188 reflections with I > 2[sigma](I)

  • Rint = 0.025

Refinement
  • R[F2 > 2[sigma](F2)] = 0.062

  • wR(F2) = 0.161

  • S = 1.05

  • 4332 reflections

  • 199 parameters

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

  • [Delta][rho]max = 0.38 e Å-3

  • [Delta][rho]min = -0.18 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
N1-H1A...O1 0.913 (19) 1.87 (2) 2.7777 (16) 172.4 (17)
N1-H1B...O1i 0.87 (2) 1.97 (2) 2.7926 (15) 155.7 (17)
N2-H2A...O2 0.959 (19) 1.93 (2) 2.8863 (17) 175.4 (16)
N2-H2B...O2ii 0.86 (2) 2.00 (2) 2.8230 (16) 160.3 (18)
Symmetry codes: (i) -x-1, -y+1, -z+2; (ii) -x, -y, -z+2.

Data collection: CrysAlis PRO (Agilent, 2011[Agilent (2011). CrysAlis PRO. Agilent Technologies Ltd, Abingdon, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR97 (Altomare et al., 1999[Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: NK2209 ).


References

Agilent (2011). CrysAlis PRO. Agilent Technologies Ltd, Abingdon, England.
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.  [CrossRef] [ChemPort] [Web of Science]
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Irrera, S., Ortaggi, G. & Portalone, G. (2012). Acta Cryst. C68, o447-o451.  [CSD] [CrossRef] [ChemPort] [IUCr Journals]
Irrera, S. & Portalone, G. (2012). Acta Cryst. E68, o3083.  [CSD] [CrossRef] [IUCr Journals]
Irrera, S. & Portalone, G. (2013). Acta Cryst. E69, o56.  [CSD] [CrossRef] [IUCr Journals]
Portalone, G. (2010). Acta Cryst. C66, o295-o301.  [CSD] [CrossRef] [ChemPort] [IUCr Journals]
Portalone, G. (2011). Acta Cryst. E67, o3394-o3395.  [CSD] [CrossRef] [ChemPort] [IUCr Journals]
Portalone, G. (2012). Acta Cryst. E68, o268-o269.  [CSD] [CrossRef] [ChemPort] [IUCr Journals]
Portalone, G. (2013). Acta Cryst. E69, o14-o15.  [CSD] [CrossRef] [ChemPort] [IUCr Journals]
Powers, J. C. & Harper, J. W. (1999). Proteinase inhibitors, edited by A. J. Barrett & G. Salvesen, pp. 55-152. Amsterdam: Elsevier.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [ChemPort] [IUCr Journals]


Acta Cryst (2013). E69, o1114-o1115   [ doi:10.1107/S1600536813016395 ]

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