supplementary materials


zq2139 scheme

Acta Cryst. (2012). E68, o18-o19    [ doi:10.1107/S1600536811051105 ]

1,1-Dimethylbiguanidium(2+) dinitrate

M. Fridrichová, I. Císarová and I. Nemec

Abstract top

In the crystal structure of the title compound, C4H13N52+·2NO3-, the main intermolecular interactions are the N-H...O hydrogen bonds between the cationic amino groups and the O atoms of the nitrate ions. All amino H atoms and nitrate O atoms are involved in the three-dimensional hydrogen-bond network. There are two graph-set motifs R22(8), which include the amino groups connected to the N atoms in the biguanide 3-, 4- and 5-positions, and the O atoms of a nitrate ion. They are extended along the a axis. An O atom of the second nitrate ion is involved in a graph-set motif C(4) that is a part of a helix-like N-H...O...H-N-H...O... chain oriented along the b axis. There are also two weak C-H...O interactions in the crystal structure.

Comment top

Among derivatives of biguanide widely used in medicine (Watkins et al., 1987), 1,1-dimethylbiguanide, known also under common name metformin, is an important component of drugs for diabetes treatment (Hopker, 1961; Wiernsperger, 2000). An overview of the investigation and use of 1,1-dimethylbiguanide has been published by Bell & Hadden (1997).

Complexes of 1,1-dimethylbiguanide, namely Cu(II) (Viossat et al., 1995; Zhu et al., 2002), Rh(III) (Spacu & Gheorghiu, 1968), Ir(III) (Gheorghiu, 1969), Os(II) and Os(III) (Spacu & Gheorghiu, 1969), Tc(V) and Re(V) complexes (Marchi et al., 1999) have been studied.

Surprisingly only eight structures concerning 1,1-dimethylbiguanide are available in the current version of the Cambridge Structure Database (Allen, 2002). Five of them contain a monocation: chloride (Hariharan et al., 1989), bromide (Lu et al., 2004a), nitrate (Zhu et al., 2003), [TlBr4]3- salt (He et al., 2002) and perchlorate, with the cation enclosed in a large complex (Huang et al., 2008). Other three salts contain dications: oxalate (Lu et al., 2004b), sulfate (Lu et al., 2004b) and a [CuCl4]2- complex (Lemoine et al., 1994).

In the crystal structure of the title compound, 1,1-Dimethylbiguanidium(2+) dinitrate, the main intermolecular interactions are the N—H···O hydrogen bonds between the amino groups of the cations and the O atoms of the nitrate anions with distances ranging from 2.848 (2) to 3.315 (2) Å, forming a three dimensional network (Fig. 2). Along the a axis there are extended two graph set motifs R22(8) (Etter et al., 1990; Fig. 3). The atoms involved in these two graph set motifs are N7—O5···H11—N1—C1—N2—H21···O4-(N7) and C1—N3—H3···O5(i)-N7(i)-O6(i)···H22—N22-(C1) with the symmetry code (i) = 1 - x, y, z. Along the b axis there is a chain O3(i)···H42—N4—H41···O3(ii)··· (Fig. 4; symmetry codes (i) = x, y - 1, z; (ii) = 1 - x, -1/2 + y, 1/2 - z) containing the graph set motif C(4). This chain forms a helix with the axis parallel to b. Two consecutive graph set motifs C(4) correspond to the pitch of this helix which equals to the unit-cell length b. O1 and O2 are involved in N1—H12···O1 and N1—H12···O2, respectively. In comparison to the monocation nitrate (Zhu et al., 2003), there are no important hydrogen bonds between the cations.

The title compound was prepared during the primary research oriented on salt materials with delocalized π electrons for applications in non-linear optics. For comparison, see similar salt materials (Fridrichová et al., 2010; Matulková et al., 2011).

Related literature top

For uses of biguanide derivatives in medicine, see: Watkins et al. (1987). For applications of 1,1-dimethylbiguanide, see: Bell & Hadden (1997); Hopker (1961); Wiernsperger (2000). For 1,1-dimethylbiguanide in metal complexes, see: Gheorghiu (1969); Marchi et al. (1999); Spacu & Gheorghiu (1968, 1969); Viossat et al. (1995); Zhu et al. (2002). For related structures of monocation salts, see: Hariharan et al. (1989); He et al. (2002); Huang et al. (2008); Lu et al. (2004a); Zhu et al. (2003). For related structures of dication salts, see: Lemoine et al. (1994); Lu et al. (2004b). For related salt materials, see: Fridrichová et al. (2010); Matulková et al. (2011). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990). For details of the Cambridge Structural Database, see: Allen (2002).

Experimental top

A solution of the title compound was prepared by neutralization of stoichiometric amounts of dimethylbiguanidium hydroxide and nitric acid. The hydroxide was prepared from dimethylbiguanide hydrochloride (97%, Sigma-Aldrich) by the exchange reaction on an anex. Small transparent colourless crystals were obtained from water solution first after two years of crystallization. They were stable on air and non-hygroscopic.

Refinement top

The primary amino H atoms were located in a difference Fourier map and refined with a N—H distance restraint equal to 0.88 Å and with Uiso(H) = 1.2Ueq(N). All other H positions were calculated after each cycle of refinement using a riding model, with C—H = 0.98 Å for methyl H atoms and Uiso(H) = 1.5Ueq(C).

Computing details top

Data collection: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); cell refinement: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); data reduction: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Atom-labelling scheme of the title compound. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Packing scheme of the title compound along the monoclinic axis (blue: N; red: O; large grey spheres: C; small grey spheres: H). The dashed lines indicate the hydrogen bonds.
[Figure 3] Fig. 3. Section of the structure showing the graph-set motifs R22(8) extended along the a axis. The hydrogen bonds involved in these graph-set motifs are enhanced (blue: N; red: O; large grey spheres: C; small grey spheres: H; symmetry code (i) = 1 - x, y, z).
[Figure 4] Fig. 4. View of the graph set motif C(4). The atoms involved are H42—N4—H41···O3(ii)···H42—N4(iii) etc. The hydrogen bonds pertinent to the C(4) motif are enhanced (blue: N; red: O; large grey spheres: C; small grey spheres: H; symmetry codes (i) = x, y - 1, z; (ii) = 1 - x, -1/2 + y, 1/2 - z; (iii) = 1 - x, 1/2 + y, 1/2 - z; (iv) = x, y + 1, z).
1,1-Dimethylbiguanidium(2+) dinitrate top
Crystal data top
C4H13N52+·2NO3F(000) = 536
Mr = 255.21Dx = 1.462 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2377 reflections
a = 7.7850 (2) Åθ = 1–26.0°
b = 5.7313 (2) ŵ = 0.13 mm1
c = 26.5321 (7) ÅT = 150 K
β = 101.6020 (15)°Plate, colourless
V = 1159.63 (6) Å30.4 × 0.3 × 0.18 mm
Z = 4
Data collection top
Nonius KappaCCD area-detector
diffractometer
1913 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.050
graphiteθmax = 26.0°, θmin = 2.7°
Detector resolution: 9.091 pixels mm-1h = 99
φ and ω scans to fill the Ewald spherek = 77
13222 measured reflectionsl = 3232
2228 independent 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)] = 0.041Hydrogen site location: difference Fourier map
wR(F2) = 0.113H atoms treated by a mixture of independent and constrained refinement
S = 1.08 w = 1/[σ2(Fo2) + (0.0581P)2 + 0.3152P]
where P = (Fo2 + 2Fc2)/3
2228 reflections(Δ/σ)max < 0.001
178 parametersΔρmax = 0.19 e Å3
7 restraintsΔρmin = 0.24 e Å3
Crystal data top
C4H13N52+·2NO3V = 1159.63 (6) Å3
Mr = 255.21Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.7850 (2) ŵ = 0.13 mm1
b = 5.7313 (2) ÅT = 150 K
c = 26.5321 (7) Å0.4 × 0.3 × 0.18 mm
β = 101.6020 (15)°
Data collection top
Nonius KappaCCD area-detector
diffractometer
1913 reflections with I > 2σ(I)
13222 measured reflectionsRint = 0.050
2228 independent reflectionsθmax = 26.0°
Refinement top
R[F2 > 2σ(F2)] = 0.041H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.113Δρmax = 0.19 e Å3
S = 1.08Δρmin = 0.24 e Å3
2228 reflectionsAbsolute structure: ?
178 parametersFlack parameter: ?
7 restraintsRogers parameter: ?
Special details top

Experimental. Vibrational spectra were recorded on a Nicolet Magna 760 FTIR spectrometer: IR spectra using DRIFTS technique in the 100 - 4000 cm-1 region, with 2 cm-1 resolution and Happ-Genzel apodization, Raman spectra using Nicolet Nexus FT Raman module (1064 nm N d:YVO4 laser excitation, 200 mW power at the sample) in the 100–3700 cm-1 region, with 2 cm-1 resolution and Happ-Genzel apodization. For further characterization of the studied compound vibrational spectra are given as a peaklist: IR spectra: 464 m, 505 m, 583 m, 602 m, 722 m, 824 m, 848 w, 937 m, 981 m,1043 m, 1052 m, 1111 m, 1145 m, 1184 m, 1283 m, 1312 m, 1385 m, 1406 s, 1416 s, 1459 m,1486 s, 1574 s, 1600 s, 1630 s, 1659 s, 1748 w, 2080 w, 2134 w, 2340 w, 2445 w, 2471 w, 2619 w, 2737 w, 2797 w, 2879 m, 2953 m, 2981 m, 3177 s, 3327 s. Raman spectra: 158 s, 197 m, 258 w, 332 w, 409 w, 441 w, 476 w, 490 w, 602 m, 709 w, 736 m, 844 m, 939 s, 1042 versus, 1061 m, 1100 m, 1144 w, 1186 w, 1262 w, 1286 w, 1413 m, 1430 w, 1457 m, 1475 m, 1500 m, 1597 w, 1662 w, 1674 w, 2813 w, 2880 m, 2935 s, 2956 m, 3012 w, 3114 w,3220 w, 3294 w, 3340 w.

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 (Å2) top
xyzUiso*/Ueq
C10.31918 (18)0.4058 (2)0.08102 (5)0.0302 (3)
C20.18235 (17)0.5649 (2)0.14924 (5)0.0292 (3)
C30.0566 (2)0.8084 (3)0.20625 (6)0.0413 (4)
H3A0.07270.67570.23000.062*
H3B0.05870.87890.20530.062*
H3C0.14840.92450.21790.062*
C40.0215 (2)0.8737 (3)0.11244 (6)0.0390 (4)
H4A0.02520.84020.08150.059*
H4B0.00201.03860.12170.059*
H4C0.14750.84030.10560.059*
N10.47682 (16)0.4787 (2)0.10136 (5)0.0346 (3)
H110.567 (2)0.428 (3)0.0891 (7)0.042*
H120.497 (2)0.586 (3)0.1260 (6)0.042*
N20.28755 (18)0.2669 (2)0.04101 (5)0.0356 (3)
H210.372 (2)0.217 (3)0.0291 (7)0.043*
H220.184 (2)0.210 (3)0.0295 (7)0.043*
N30.17655 (15)0.4775 (2)0.10035 (4)0.0312 (3)
H30.0744 (19)0.459 (3)0.0822 (6)0.037*
N40.29198 (17)0.4743 (2)0.18829 (5)0.0349 (3)
H410.319 (2)0.542 (3)0.2192 (6)0.042*
H420.354 (2)0.357 (3)0.1842 (7)0.042*
N50.06775 (15)0.7280 (2)0.15485 (4)0.0315 (3)
N60.53721 (16)0.9772 (2)0.18120 (4)0.0338 (3)
O10.39367 (14)0.9879 (2)0.15067 (4)0.0453 (3)
O20.62993 (15)0.7999 (2)0.18337 (5)0.0505 (4)
O30.58703 (17)1.1475 (2)0.21013 (4)0.0495 (3)
N70.78091 (15)0.2624 (2)0.02958 (5)0.0327 (3)
O40.63326 (15)0.1814 (2)0.01442 (5)0.0581 (4)
O50.81006 (13)0.3970 (2)0.06767 (4)0.0412 (3)
O60.90260 (14)0.2106 (2)0.00741 (4)0.0446 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0339 (7)0.0290 (7)0.0289 (7)0.0024 (6)0.0091 (5)0.0016 (5)
C20.0290 (7)0.0307 (7)0.0303 (7)0.0027 (6)0.0119 (5)0.0016 (5)
C30.0397 (8)0.0511 (10)0.0367 (8)0.0086 (7)0.0164 (6)0.0039 (7)
C40.0417 (8)0.0349 (8)0.0411 (8)0.0073 (7)0.0099 (6)0.0040 (6)
N10.0315 (7)0.0381 (7)0.0371 (7)0.0009 (5)0.0137 (5)0.0086 (5)
N20.0357 (7)0.0412 (7)0.0308 (6)0.0008 (6)0.0087 (5)0.0071 (5)
N30.0273 (6)0.0373 (7)0.0298 (6)0.0026 (5)0.0074 (5)0.0018 (5)
N40.0381 (7)0.0377 (7)0.0302 (6)0.0078 (6)0.0095 (5)0.0022 (5)
N50.0306 (6)0.0344 (6)0.0318 (6)0.0033 (5)0.0116 (5)0.0007 (5)
N60.0361 (7)0.0345 (7)0.0321 (6)0.0019 (5)0.0098 (5)0.0009 (5)
O10.0395 (6)0.0408 (7)0.0513 (7)0.0015 (5)0.0010 (5)0.0057 (5)
O20.0410 (7)0.0419 (7)0.0667 (8)0.0099 (5)0.0062 (5)0.0108 (6)
O30.0708 (8)0.0346 (6)0.0387 (6)0.0015 (6)0.0004 (5)0.0067 (5)
N70.0311 (6)0.0348 (7)0.0337 (6)0.0022 (5)0.0100 (5)0.0032 (5)
O40.0355 (6)0.0671 (8)0.0749 (9)0.0132 (6)0.0188 (6)0.0362 (7)
O50.0373 (6)0.0458 (7)0.0400 (6)0.0018 (5)0.0069 (4)0.0150 (5)
O60.0345 (6)0.0628 (8)0.0403 (6)0.0094 (5)0.0163 (5)0.0049 (5)
Geometric parameters (Å, °) top
C1—N11.3060 (19)N1—H110.878 (14)
C1—N21.3100 (19)N1—H120.891 (14)
C1—N31.3763 (17)N2—H210.837 (14)
C2—N41.3098 (18)N2—H220.867 (14)
C2—N51.3212 (18)N3—H30.849 (14)
C2—N31.3827 (17)N4—H410.893 (14)
C3—N51.4584 (19)N4—H420.846 (14)
C3—H3A0.9800N6—O21.2411 (17)
C3—H3B0.9800N6—O11.2428 (16)
C3—H3C0.9800N6—O31.2538 (16)
C4—N51.4601 (19)N7—O41.2301 (16)
C4—H4A0.9800N7—O61.2474 (15)
C4—H4B0.9800N7—O51.2551 (16)
C4—H4C0.9800
N1—C1—N2122.49 (13)H11—N1—H12117.7 (16)
N1—C1—N3120.79 (13)C1—N2—H21118.6 (12)
N2—C1—N3116.70 (13)C1—N2—H22121.5 (12)
N4—C2—N5122.59 (13)H21—N2—H22119.3 (18)
N4—C2—N3119.46 (13)C1—N3—C2125.54 (12)
N5—C2—N3117.80 (12)C1—N3—H3119.0 (12)
N5—C3—H3A109.5C2—N3—H3115.3 (12)
N5—C3—H3B109.5C2—N4—H41123.6 (12)
H3A—C3—H3B109.5C2—N4—H42120.7 (12)
N5—C3—H3C109.5H41—N4—H42115.1 (16)
H3A—C3—H3C109.5C2—N5—C3119.81 (12)
H3B—C3—H3C109.5C2—N5—C4123.05 (12)
N5—C4—H4A109.5C3—N5—C4115.56 (12)
N5—C4—H4B109.5O2—N6—O1120.59 (12)
H4A—C4—H4B109.5O2—N6—O3120.23 (12)
N5—C4—H4C109.5O1—N6—O3119.18 (13)
H4A—C4—H4C109.5O4—N7—O6120.27 (12)
H4B—C4—H4C109.5O4—N7—O5120.08 (11)
C1—N1—H11119.7 (11)O6—N7—O5119.65 (12)
C1—N1—H12122.4 (11)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H12···O20.89 (1)2.06 (2)2.9158 (17)160.(2)
N1—H12···O10.89 (1)2.57 (2)3.3151 (17)142.(1)
N1—H11···O50.88 (1)2.09 (2)2.9463 (16)164.(2)
N1—H11···O40.88 (1)2.57 (2)3.2920 (17)140.(1)
N2—H21···O40.84 (1)2.15 (2)2.9571 (18)161.(2)
N2—H21···O4i0.84 (1)2.56 (2)3.0833 (17)122.(2)
N2—H22···O6ii0.87 (1)2.15 (2)2.9674 (18)157.(2)
N2—H22···O6i0.87 (1)2.64 (2)3.2503 (18)128.(2)
N3—H3···O5ii0.85 (1)2.05 (2)2.8479 (16)157.(2)
N3—H3···O6ii0.85 (1)2.59 (2)3.2947 (17)142.(2)
N4—H42···O3iii0.85 (1)2.17 (2)2.9300 (18)149.(2)
N4—H42···O1iii0.85 (1)2.34 (2)3.1164 (18)153.(2)
N4—H41···O3iv0.89 (1)1.97 (2)2.8487 (17)170.(2)
C3—H3B···O2ii0.982.423.255 (2)143
C4—H4A···O6v0.982.553.519 (2)170
Symmetry codes: (i) −x+1, −y, −z; (ii) x−1, y, z; (iii) x, y−1, z; (iv) −x+1, y−1/2, −z+1/2; (v) −x+1, −y+1, −z.
Table 1
Hydrogen-bond geometry (Å, °)
top
D—H···AD—HH···AD···AD—H···A
N1—H12···O20.89 (1)2.06 (2)2.9158 (17)160.(2)
N1—H12···O10.89 (1)2.57 (2)3.3151 (17)142.(1)
N1—H11···O50.88 (1)2.09 (2)2.9463 (16)164.(2)
N1—H11···O40.88 (1)2.57 (2)3.2920 (17)140.(1)
N2—H21···O40.84 (1)2.15 (2)2.9571 (18)161.(2)
N2—H21···O4i0.84 (1)2.56 (2)3.0833 (17)122.(2)
N2—H22···O6ii0.87 (1)2.15 (2)2.9674 (18)157.(2)
N2—H22···O6i0.87 (1)2.64 (2)3.2503 (18)128.(2)
N3—H3···O5ii0.85 (1)2.05 (2)2.8479 (16)157.(2)
N3—H3···O6ii0.85 (1)2.59 (2)3.2947 (17)142.(2)
N4—H42···O3iii0.85 (1)2.17 (2)2.9300 (18)149.(2)
N4—H42···O1iii0.85 (1)2.34 (2)3.1164 (18)153.(2)
N4—H41···O3iv0.89 (1)1.97 (2)2.8487 (17)170.(2)
C3—H3B···O2ii0.982.423.255 (2)143
C4—H4A···O6v0.982.553.519 (2)170
Symmetry codes: (i) −x+1, −y, −z; (ii) x−1, y, z; (iii) x, y−1, z; (iv) −x+1, y−1/2, −z+1/2; (v) −x+1, −y+1, −z.
Acknowledgements top

This work was supported by the Grant Agency of Charles University in Prague (grant No. 58608), the Czech Science Foundation (grant No. 203/09/0878) and it is a part of the long term Research Plan of the Ministry of Education of the Czech Republic (No. MSM0021620857). We would like to thank Dr Jan Fábry for his careful supervision and inspiring critique.

references
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