supplementary materials


HTML versionpdf versioncif file3d viewstructure factorssupplementary materialsCIF check reportsimilar papers buy article online

Acta Cryst. (2007). E63, o3759    [ doi:10.1107/S1600536807038068 ]

(2,4,6-Trinitrophenyl)guanidine

G. Smith, U. D. Wermuth and J. M. White

Abstract top

(2,4,6-Trinitrophenyl)guanidine (picrylguanidine), C7H6N6O6, from the reaction of picrylsulfonic acid with guanidine carbonate, forms a three-dimensional framework structure through extensive hydrogen-bonding interactions, extending the centrosymmetric cyclic R22(16) dimer association which includes duplex R22(8) guanidine N-H...Onitro interactions. The guanidine substituent chain has an endo [Ph-N=C(NH2)2] bond sequence rather than the less sterically encumbered exo [Ph-NH-C=NH(NH2)] sequence of the tautomeric form. As a result, there is significant bond-angle distortion about C(-N=) of the aromatic ring.

Comment top

2,4,6-trinitrobenzenesulfonic acid (picrylsulfonic acid) is a very strong acid which is capable of protonating water, such as is found in the crystalline 'tetrahydrate', which has the formula C6H2N3O9S−. H5O2+. 2H2O [Lundgren, 1972 (X-ray); Lundgren & Tellgren, 1974 (neutron)]. It will therefore readily protonate most Lewis bases, e.g. the 1:1 anhydrous salts with guanidine (Russell & Ward, 1997) and quinoline (Smith et al., 2006), and the adduct 2-carboxyquinolinium-picrylsulfonate-quinoline-2-carboxylic acid (1/1/1) (Smith et al., 2007). However, certain Lewis base types are capable of displacing the sulfonic acid substituent group (or chloride in the case of picryl chloride) to give amino addition compounds, such as with the three isomeric aminobenzoic acids (Crocker & Matthews, 1911) and with amino acids and proteins (Goldfarb, 1966). The structure of the 4-aminobenzoic acid compound 4-(2,4,6-trinitrophenylanilino)benzoic acid (Smith et al., 2007) is one of very few of this type which have been determined.

The 1:1 stoichiometric reaction of picrylsulfonic acid with guanidine carbonate in methanol was expected to give the previously reported proton-transfer compound guanidinium 2,4,6-trinitrobenzenesulfonate (Russell & Ward, 1997). However, the title compound, the addition compound (2,4,6-trinitrophenyl)guanidine C7H6N6O6 was formed as the only reaction product and the structure is reported here.

The title compound (Fig. 1) is found to have the endo [Ph–N═C(NH2)2] bond sequence in the guanidine substituent chain rather than the sterically favoured Ph–NH–C═NH(NH2) sequence of the tautomeric form of picrylguanidine (C·A. registry number 134282–41-1), which has the double bond exo. The bond arrangement with the double bond endo results in significant distortion in the aromatic ring angles associated with the C1 guanidine substituent group [C2–C1–N1, 128.4 (2) °; C6–C1–N1, 119.56 (19) °; C2–C1–C6, 111.81 (17) °]. The plane of the guanidine double bond is also twisted [torsion angle C1–N1–C71–N72, 151.3 (2) °]. As expected, the nitro groups of the picryl moiety ortho to the guanidine substituent are rotated out of the plane of the benzene ring [torsion angles C1–C2–N2–O22, 140.4 (2) Å; C1–C6–N6–O61, 136.2 (2) °], while the para-related group is essentially coplanar [C3–C4–N4–O42, −172.1 (2) °].

In the packing of the molecules in the unit cell, all guanidine protons give hydrogen-bonding associations with nitro-O acceptors (Table 1). The basic intermolecular interaction provides a centrosymmetric cyclic R22(16) dimer unit (Fig. 2) which incorporates duplex cyclic R22(8) guanidine N–H···Onitro group associations [N71,N72···O41ii,O42ii: symmetry code; (ii) −x + 1, −y, −z + 1]. The overall result is a three-dimensional framework structure. (Fig. 3).

Related literature top

For related literature, see: Crocker & Matthews (1911); Goldfarb (1966); Lundgren (1972); Lundgren & Tellgren (1974); Russell & Ward (1997); Smith et al. (2006, 2007).

Experimental top

The title compound was synthesized by heating together 1 mmol quantities of 2,4,6-trinitrobenzenesulfonic acid (picrylsulfonic acid) and guanidine carbonate in 50 ml of methanol under reflux for 10 minutes. This reaction is analogous to the reaction of picryl chloride with the isomeric aminobenzoic acids (Crocker & Matthews, 1911) to give the picrylaminobenzoic acids. After concentration to ca 30 ml, partial room temperature evaporation of the hot-filtered solution gave a small quantity of pale yellow short crystal prisms of (I).

Refinement top

The H atoms bonded to N were located by difference methods and its positional and isotropic displacement parameters were refined. The aromatic ring H atoms were included in the refinement in calculated positions (C—H = 0.95 Å) using a riding model approximation, with Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON.

Figures top
[Figure 1] Fig. 1. Molecular configuration and atom naming scheme (I). Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. The cyclic R22(16) hydrogen-bonded dimer incorporating duplex R22(8) N–H···Onitro associations between centrosymmetrically related molecule pairs in the structure of (I), together with other extending interactions shown as dashed lines. For symmetry codes, see Table 1.
[Figure 3] Fig. 3. The three-dimensional framework structure of (I) viewed down the a cell direction.
(2,4,6-Trinitrophenyl)guanidine top
Crystal data top
C7H6N6O6Z = 2
Mr = 270.18F000 = 276
Triclinic, P1Dx = 1.794 Mg m−3
Hall symbol: -P 1Mo Kα radiation
λ = 0.71073 Å
a = 7.6596 (10) ÅCell parameters from 870 reflections
b = 7.7316 (10) Åθ = 2.4–26.8º
c = 9.0411 (12) ŵ = 0.16 mm−1
α = 104.045 (3)ºT = 130 (2) K
β = 95.004 (2)ºBlock, pale yellow
γ = 103.121 (2)º0.15 × 0.10 × 0.10 mm
V = 500.08 (11) Å3
Data collection top
Bruker CCD area-detector
diffractometer		1344 reflections with I > 2σ(I)
Radiation source: sealed tubeRint = 0.055
Monochromator: graphiteθmax = 25.0º
T = 130(2) Kθmin = 2.4º
φ and ω scansh = −9→9
Absorption correction: nonek = −8→9
2614 measured reflectionsl = −9→10
1739 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)] = 0.038H atoms treated by a mixture of
independent and constrained refinement
wR(F2) = 0.083  w = 1/[σ2(Fo2) + (0.0265P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.92(Δ/σ)max < 0.001
1739 reflectionsΔρmax = 0.22 e Å−3
188 parametersΔρmin = −0.21 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
C7H6N6O6γ = 103.121 (2)º
Mr = 270.18V = 500.08 (11) Å3
Triclinic, P1Z = 2
a = 7.6596 (10) ÅMo Kα
b = 7.7316 (10) ŵ = 0.16 mm−1
c = 9.0411 (12) ÅT = 130 (2) K
α = 104.045 (3)º0.15 × 0.10 × 0.10 mm
β = 95.004 (2)º
Data collection top
Bruker CCD area-detector
diffractometer		1739 independent reflections
Absorption correction: none1344 reflections with I > 2σ(I)
2614 measured reflectionsRint = 0.055
Refinement top
R[F2 > 2σ(F2)] = 0.038188 parameters
wR(F2) = 0.083H atoms treated by a mixture of
independent and constrained refinement
S = 0.92Δρmax = 0.22 e Å−3
1739 reflectionsΔρmin = −0.21 e Å−3
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 > 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
O210.55099 (19)0.2258 (2)0.77212 (16)0.0256 (5)
O220.5482 (2)−0.0210 (2)0.84817 (16)0.0266 (5)
O411.0096 (2)0.1267 (2)1.29934 (15)0.0252 (6)
O421.2715 (2)0.3153 (2)1.30851 (16)0.0257 (5)
O611.3738 (2)0.5820 (2)0.86527 (16)0.0238 (5)
O621.2606 (2)0.3618 (2)0.65498 (16)0.0230 (5)
N10.8963 (2)0.3241 (2)0.66327 (19)0.0188 (6)
N20.6276 (2)0.1290 (3)0.83048 (19)0.0195 (6)
N41.1174 (3)0.2305 (2)1.24375 (19)0.0198 (6)
N61.2622 (2)0.4378 (2)0.79090 (19)0.0182 (6)
N710.7296 (3)0.0290 (3)0.5177 (2)0.0202 (7)
N720.6838 (3)0.2908 (3)0.4587 (2)0.0246 (7)
C10.9402 (3)0.2847 (3)0.7955 (2)0.0170 (7)
C20.8224 (3)0.1947 (3)0.8841 (2)0.0167 (7)
C30.8779 (3)0.1727 (3)1.0261 (2)0.0175 (7)
C41.0577 (3)0.2486 (3)1.0925 (2)0.0160 (7)
C51.1831 (3)0.3402 (3)1.0166 (2)0.0176 (7)
C61.1241 (3)0.3516 (3)0.8732 (2)0.0155 (7)
C70.7699 (3)0.2148 (3)0.5494 (2)0.0187 (7)
H30.794400.106701.077400.0210*
H51.305900.393101.063200.0210*
H71A0.810 (3)−0.016 (3)0.553 (2)0.033 (8)*
H71B0.658 (3)−0.040 (3)0.431 (3)0.033 (7)*
H72A0.694 (3)0.414 (4)0.486 (3)0.041 (8)*
H72B0.612 (3)0.231 (3)0.382 (2)0.015 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O210.0228 (9)0.0305 (10)0.0241 (9)0.0108 (8)−0.0001 (7)0.0059 (7)
O220.0240 (9)0.0245 (9)0.0258 (9)−0.0042 (7)0.0026 (7)0.0066 (7)
O410.0292 (10)0.0291 (10)0.0230 (9)0.0093 (8)0.0092 (7)0.0141 (7)
O420.0211 (9)0.0325 (10)0.0204 (9)0.0054 (8)−0.0037 (7)0.0050 (7)
O610.0212 (9)0.0190 (9)0.0266 (9)−0.0002 (7)0.0022 (7)0.0032 (7)
O620.0282 (9)0.0250 (9)0.0171 (8)0.0093 (7)0.0070 (7)0.0047 (7)
N10.0189 (10)0.0173 (10)0.0181 (10)0.0016 (8)−0.0020 (8)0.0056 (8)
N20.0201 (10)0.0221 (11)0.0146 (10)0.0051 (9)0.0025 (8)0.0021 (8)
N40.0243 (11)0.0198 (10)0.0185 (10)0.0113 (9)0.0043 (9)0.0053 (8)
N60.0175 (10)0.0200 (11)0.0194 (10)0.0078 (9)0.0028 (8)0.0070 (8)
N710.0218 (12)0.0192 (11)0.0176 (11)0.0041 (9)−0.0024 (9)0.0040 (9)
N720.0289 (12)0.0200 (12)0.0206 (12)0.0033 (10)−0.0075 (10)0.0042 (10)
C10.0222 (13)0.0123 (11)0.0158 (11)0.0062 (10)0.0027 (9)0.0007 (9)
C20.0170 (12)0.0130 (11)0.0180 (12)0.0036 (9)0.0013 (9)0.0013 (9)
C30.0226 (13)0.0124 (11)0.0195 (12)0.0063 (10)0.0063 (10)0.0050 (9)
C40.0228 (13)0.0148 (11)0.0116 (11)0.0083 (10)0.0025 (9)0.0024 (9)
C50.0166 (12)0.0149 (11)0.0191 (12)0.0049 (9)0.0005 (9)0.0004 (9)
C60.0201 (12)0.0121 (11)0.0152 (11)0.0052 (9)0.0046 (9)0.0037 (9)
C70.0183 (12)0.0217 (13)0.0171 (12)0.0047 (10)0.0041 (9)0.0068 (10)
Geometric parameters (Å, °) top
O21—N21.233 (3)N71—H71B0.89 (3)
O22—N21.236 (3)N71—H71A0.85 (2)
O41—N41.243 (2)N72—H72A0.91 (3)
O42—N41.228 (3)N72—H72B0.812 (19)
O61—N61.237 (2)C1—C21.432 (3)
O62—N61.224 (2)C1—C61.437 (3)
N1—C11.337 (3)C2—C31.379 (3)
N1—C71.321 (3)C3—C41.385 (3)
N2—C21.459 (3)C4—C51.392 (3)
N4—C41.453 (3)C5—C61.365 (3)
N6—C61.475 (3)C3—H30.9500
N71—C71.351 (3)C5—H50.9500
N72—C71.330 (3)
C1—N1—C7124.54 (18)N2—C2—C1120.30 (17)
O21—N2—O22123.64 (17)N2—C2—C3115.16 (19)
O21—N2—C2118.8 (2)C1—C2—C3124.4 (2)
O22—N2—C2117.56 (18)C2—C3—C4118.7 (2)
O41—N4—O42123.57 (17)C3—C4—C5121.37 (18)
O41—N4—C4117.74 (19)N4—C4—C5119.2 (2)
O42—N4—C4118.68 (18)N4—C4—C3119.42 (19)
O61—N6—O62124.34 (16)C4—C5—C6118.0 (2)
O61—N6—C6117.29 (16)N6—C6—C5116.8 (2)
O62—N6—C6118.37 (16)N6—C6—C1117.58 (16)
C7—N71—H71B119.9 (16)C1—C6—C5125.6 (2)
H71A—N71—H71B117 (2)N71—C7—N72118.72 (19)
C7—N71—H71A116.2 (15)N1—C7—N71122.7 (2)
H72A—N72—H72B116 (2)N1—C7—N72118.5 (2)
C7—N72—H72A120.5 (16)C2—C3—H3121.00
C7—N72—H72B123.2 (17)C4—C3—H3121.00
N1—C1—C6119.56 (19)C4—C5—H5121.00
N1—C1—C2128.4 (2)C6—C5—H5121.00
C2—C1—C6111.81 (17)
C7—N1—C1—C2−38.7 (3)N1—C1—C2—N21.5 (3)
C7—N1—C1—C6147.8 (2)C2—C1—C6—N6176.51 (18)
C1—N1—C7—N72151.3 (2)N1—C1—C2—C3−174.5 (2)
C1—N1—C7—N71−31.4 (3)C2—C1—C6—C5−2.6 (3)
O21—N2—C2—C1−40.4 (3)C6—C1—C2—N2175.47 (19)
O22—N2—C2—C1140.4 (2)N1—C1—C6—C5172.0 (2)
O22—N2—C2—C3−43.1 (3)N1—C1—C6—N6−9.0 (3)
O21—N2—C2—C3136.0 (2)C6—C1—C2—C3−0.6 (3)
O41—N4—C4—C39.1 (3)C1—C2—C3—C42.9 (3)
O41—N4—C4—C5−170.2 (2)N2—C2—C3—C4−173.4 (2)
O42—N4—C4—C58.6 (3)C2—C3—C4—C5−2.2 (3)
O42—N4—C4—C3−172.1 (2)C2—C3—C4—N4178.5 (2)
O62—N6—C6—C5134.5 (2)N4—C4—C5—C6178.6 (2)
O61—N6—C6—C5−44.7 (3)C3—C4—C5—C6−0.7 (3)
O61—N6—C6—C1136.2 (2)C4—C5—C6—C13.3 (4)
O62—N6—C6—C1−44.7 (3)C4—C5—C6—N6−175.84 (19)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N71—H71A···O41i0.85 (2)2.28 (2)3.108 (3)165.7 (18)
N71—H71B···O21ii0.89 (3)2.27 (3)3.155 (2)173 (2)
N72—H72A···O42iii0.91 (3)2.38 (3)3.180 (3)147 (2)
N72—H72A···O62iv0.91 (3)2.37 (3)3.058 (3)132 (2)
N72—H72B···O22ii0.812 (19)2.342 (19)3.139 (2)168 (2)
C5—H5···O61v0.952.433.339 (3)159
Symmetry codes: (i) −x+2, −y, −z+2; (ii) −x+1, −y, −z+1; (iii) −x+2, −y+1, −z+2; (iv) −x+2, −y+1, −z+1; (v) −x+3, −y+1, −z+2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N71—H71A···O41i0.85 (2)2.28 (2)3.108 (3)165.7 (18)
N71—H71B···O21ii0.89 (3)2.27 (3)3.155 (2)173 (2)
N72—H72A···O42iii0.91 (3)2.38 (3)3.180 (3)147 (2)
N72—H72A···O62iv0.91 (3)2.37 (3)3.058 (3)132 (2)
N72—H72B···O22ii0.812 (19)2.342 (19)3.139 (2)168 (2)
C5—H5···O61v0.952.433.339 (3)159
Symmetry codes: (i) −x+2, −y, −z+2; (ii) −x+1, −y, −z+1; (iii) −x+2, −y+1, −z+2; (iv) −x+2, −y+1, −z+1; (v) −x+3, −y+1, −z+2.
Acknowledgements top

The authors acknowledge financial support from the School of Physical and Chemical Sciences, Queensland University of Technology, the School of Biomolecular and Physical Sciences, Griffith University and the School of Chemistry, University of Melbourne.

references
References top

Bruker (1999). SAINT. Version 6.02. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2000). SMART. Version 5.55. Bruker AXS Inc., Madison, Wisconsin, USA.

Crocker, J. C. & Matthews, F. (1911). J. Chem. Soc. 99, 301–313.

Goldfarb, A. R. (1966). Biochem. 5, 2570–2574.

Lundgren, J.-O. (1972). Acta Cryst. B28, 1684–1691.

Lundgren, J.-O. & Tellgren, R. (1974). Acta Cryst. B30, 1937–1947.

Russell, V. A. & Ward, M. D. (1997). J. Mater. Chem. 7, 1123–1133.

Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of Göttingen, Germany.

Smith, G., Wermuth, U. D. & Healy, P. C. (2006). Acta Cryst. E62, o5510–o5512.

Smith, G., Wermuth, U. D. & White, J. M. (2007). Unpublished results.

Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13.