organic compounds
2-(1,3-Benzoxazol-2-yl)guanidinium chloride
aChemistry and Environmental Division, Manchester Metropolitan University, Manchester M15 6BH, England, bSchool of Chemistry, University of Southampton, Southampton SO17 1BJ, England, cDepartment of Chemistry, Faculty of Science, Sohag University, Egypt, dDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and eChemistry Department, King Abdulaziz University, PO Box 80203 Jeddah, Saudi Arabia
*Correspondence e-mail: seikweng@um.edu.my
The non-H atoms of the cation of the title salt, C8H9N4O+·Cl−, are approximately co-planar (r.m.s. deviation = 0.024 Å) with one amino group forming an intramolecular hydrogen bond to the tertiary N atom of the benzoxazole fused-ring system. The cations and anions are linked by cyclic R21(6) N—H⋯Cl hydrogen-bonding associations, generating linear chains running along the a-axis direction.
Related literature
For the synthesis, see: Takahashi & Niino (1943). For the structure of a of 2-(1,3-benzoxazol-2-yl)guanidine, see: Bishop et al. (2005) and for the structure of 2-(1,3-benzothiazol-2-yl)guanidine, see: Mohamed et al. (2011). For graph-set analysis, see: Etter et al. (1990).
Experimental
Crystal data
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Refinement
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Data collection: COLLECT (Hooft, 1998); cell DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
10.1107/S1600536811044655/zs2158sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811044655/zs2158Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536811044655/zs2158Isup3.cml
2-(1,3-Benzoxazol-2-yl)guanidine was synthesized by using a literature procedure similar to that used for synthesizing 2-(1,3-benzothioazol-2-yl)guanidine (Takahashi & Niino, 1943). The guanidine (0.05 mol) was heated in ethanol (50 ml) in the presence of a few drops of hydrochloric acid for 3 h. The mixture was cooled and the product was recrystallized from ethanol to give the title compound (m.p. 538 K)in 95% yield.
Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 Å) and were included in the
in the riding model approximation, with Uiso(H) set to 1.2Ueq(C). The amino H-atoms were located in a difference Fourier map, and were refined with a distance restraint of N–H = 0.88±0.01 Å, with their isotropic displacement parameters freely refining.Data collection: COLLECT (Hooft, 1998); cell
DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C8H9N4O+ Cl- at the 70% probability level. Hydrogen atoms are drawn as spheres of arbitrary radius. |
C8H9N4O+·Cl− | Z = 2 |
Mr = 212.64 | F(000) = 220 |
Triclinic, P1 | Dx = 1.551 Mg m−3 |
Hall symbol: -P 1 | Melting point: 538 K |
a = 6.669 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.152 (4) Å | Cell parameters from 1979 reflections |
c = 9.630 (3) Å | θ = 2.9–27.5° |
α = 65.062 (2)° | µ = 0.39 mm−1 |
β = 85.020 (2)° | T = 120 K |
γ = 73.710 (2)° | Prism, colorless |
V = 455.4 (3) Å3 | 0.20 × 0.05 × 0.04 mm |
Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer | 2088 independent reflections |
Radiation source: Bruker-Nonius FR591 rotating anode | 1895 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
Detector resolution: 9.091 pixels mm-1 | θmax = 27.5°, θmin = 3.2° |
ϕ and ω scans | h = −8→8 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | k = −10→10 |
Tmin = 0.926, Tmax = 0.985 | l = −12→12 |
8184 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.036 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.089 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0256P)2 + 0.4591P] where P = (Fo2 + 2Fc2)/3 |
2088 reflections | (Δ/σ)max = 0.001 |
147 parameters | Δρmax = 0.31 e Å−3 |
5 restraints | Δρmin = −0.26 e Å−3 |
C8H9N4O+·Cl− | γ = 73.710 (2)° |
Mr = 212.64 | V = 455.4 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.669 (2) Å | Mo Kα radiation |
b = 8.152 (4) Å | µ = 0.39 mm−1 |
c = 9.630 (3) Å | T = 120 K |
α = 65.062 (2)° | 0.20 × 0.05 × 0.04 mm |
β = 85.020 (2)° |
Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer | 2088 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1895 reflections with I > 2σ(I) |
Tmin = 0.926, Tmax = 0.985 | Rint = 0.044 |
8184 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 5 restraints |
wR(F2) = 0.089 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.03 | Δρmax = 0.31 e Å−3 |
2088 reflections | Δρmin = −0.26 e Å−3 |
147 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cl1 | 0.25918 (6) | 0.37898 (6) | 0.41313 (5) | 0.01998 (13) | |
O1 | 0.50373 (17) | −0.01606 (16) | 0.27313 (13) | 0.0176 (3) | |
N1 | 0.8440 (2) | −0.0414 (2) | 0.21101 (16) | 0.0179 (3) | |
N2 | 0.6679 (2) | 0.1505 (2) | 0.34140 (17) | 0.0186 (3) | |
N3 | 0.7839 (2) | 0.3256 (2) | 0.43342 (18) | 0.0215 (3) | |
N4 | 1.0159 (2) | 0.1588 (2) | 0.31608 (18) | 0.0212 (3) | |
C1 | 0.5575 (3) | −0.1365 (2) | 0.19970 (19) | 0.0171 (3) | |
C2 | 0.4318 (3) | −0.2237 (2) | 0.1669 (2) | 0.0197 (3) | |
H2A | 0.2904 | −0.2110 | 0.1960 | 0.024* | |
C3 | 0.5268 (3) | −0.3327 (2) | 0.0875 (2) | 0.0224 (4) | |
H3A | 0.4482 | −0.3975 | 0.0619 | 0.027* | |
C4 | 0.7347 (3) | −0.3490 (2) | 0.0448 (2) | 0.0221 (4) | |
H4A | 0.7930 | −0.4229 | −0.0106 | 0.027* | |
C5 | 0.8592 (3) | −0.2595 (2) | 0.0815 (2) | 0.0210 (4) | |
H5A | 1.0010 | −0.2719 | 0.0533 | 0.025* | |
C6 | 0.7658 (3) | −0.1517 (2) | 0.16100 (19) | 0.0178 (3) | |
C7 | 0.6845 (2) | 0.0303 (2) | 0.27334 (19) | 0.0171 (3) | |
C8 | 0.8270 (2) | 0.2129 (2) | 0.36229 (19) | 0.0169 (3) | |
H1 | 0.544 (2) | 0.201 (3) | 0.367 (3) | 0.035 (6)* | |
H2 | 0.654 (2) | 0.367 (4) | 0.454 (3) | 0.046 (7)* | |
H3 | 0.881 (3) | 0.372 (3) | 0.446 (3) | 0.039 (7)* | |
H4 | 1.110 (3) | 0.205 (3) | 0.334 (2) | 0.025 (5)* | |
H5 | 1.035 (4) | 0.085 (3) | 0.268 (2) | 0.035 (6)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0149 (2) | 0.0214 (2) | 0.0280 (2) | −0.00545 (15) | 0.00285 (15) | −0.01445 (17) |
O1 | 0.0145 (5) | 0.0191 (6) | 0.0231 (6) | −0.0051 (4) | 0.0008 (4) | −0.0122 (5) |
N1 | 0.0169 (7) | 0.0190 (7) | 0.0208 (7) | −0.0048 (5) | 0.0015 (5) | −0.0111 (6) |
N2 | 0.0133 (7) | 0.0216 (7) | 0.0259 (8) | −0.0041 (5) | 0.0015 (5) | −0.0151 (6) |
N3 | 0.0182 (7) | 0.0238 (8) | 0.0295 (8) | −0.0066 (6) | 0.0011 (6) | −0.0170 (7) |
N4 | 0.0162 (7) | 0.0250 (8) | 0.0288 (8) | −0.0068 (6) | 0.0028 (6) | −0.0169 (7) |
C1 | 0.0188 (8) | 0.0156 (8) | 0.0171 (8) | −0.0032 (6) | −0.0001 (6) | −0.0076 (6) |
C2 | 0.0180 (8) | 0.0196 (8) | 0.0215 (8) | −0.0062 (6) | 0.0008 (6) | −0.0079 (7) |
C3 | 0.0241 (9) | 0.0211 (9) | 0.0249 (9) | −0.0074 (7) | −0.0021 (7) | −0.0110 (7) |
C4 | 0.0247 (9) | 0.0208 (9) | 0.0232 (9) | −0.0040 (7) | 0.0007 (7) | −0.0127 (7) |
C5 | 0.0195 (8) | 0.0221 (9) | 0.0225 (9) | −0.0039 (7) | 0.0025 (7) | −0.0118 (7) |
C6 | 0.0173 (8) | 0.0176 (8) | 0.0194 (8) | −0.0049 (6) | −0.0002 (6) | −0.0081 (7) |
C7 | 0.0147 (7) | 0.0175 (8) | 0.0199 (8) | −0.0046 (6) | −0.0009 (6) | −0.0079 (7) |
C8 | 0.0153 (7) | 0.0170 (8) | 0.0176 (8) | −0.0037 (6) | −0.0005 (6) | −0.0067 (7) |
O1—C7 | 1.361 (2) | N4—H5 | 0.879 (10) |
O1—C1 | 1.391 (2) | C1—C2 | 1.371 (2) |
N1—C7 | 1.292 (2) | C1—C6 | 1.391 (2) |
N1—C6 | 1.409 (2) | C2—C3 | 1.395 (3) |
N2—C8 | 1.361 (2) | C2—H2A | 0.9500 |
N2—C7 | 1.368 (2) | C3—C4 | 1.397 (3) |
N2—H1 | 0.879 (10) | C3—H3A | 0.9500 |
N3—C8 | 1.321 (2) | C4—C5 | 1.398 (2) |
N3—H2 | 0.875 (10) | C4—H4A | 0.9500 |
N3—H3 | 0.874 (10) | C5—C6 | 1.387 (2) |
N4—C8 | 1.318 (2) | C5—H5A | 0.9500 |
N4—H4 | 0.876 (9) | ||
C7—O1—C1 | 102.84 (12) | C2—C3—H3A | 119.2 |
C7—N1—C6 | 102.87 (14) | C4—C3—H3A | 119.2 |
C8—N2—C7 | 125.13 (14) | C3—C4—C5 | 121.75 (16) |
C8—N2—H1 | 115.8 (16) | C3—C4—H4A | 119.1 |
C7—N2—H1 | 118.9 (16) | C5—C4—H4A | 119.1 |
C8—N3—H2 | 119.2 (18) | C6—C5—C4 | 116.77 (16) |
C8—N3—H3 | 119.4 (16) | C6—C5—H5A | 121.6 |
H2—N3—H3 | 121 (2) | C4—C5—H5A | 121.6 |
C8—N4—H4 | 115.4 (14) | C5—C6—C1 | 119.91 (16) |
C8—N4—H5 | 118.0 (16) | C5—C6—N1 | 131.01 (16) |
H4—N4—H5 | 127 (2) | C1—C6—N1 | 109.06 (14) |
C2—C1—O1 | 127.63 (15) | N1—C7—O1 | 117.68 (15) |
C2—C1—C6 | 124.81 (16) | N1—C7—N2 | 129.18 (15) |
O1—C1—C6 | 107.55 (14) | O1—C7—N2 | 113.14 (14) |
C1—C2—C3 | 115.05 (16) | N4—C8—N3 | 122.14 (16) |
C1—C2—H2A | 122.5 | N4—C8—N2 | 120.88 (15) |
C3—C2—H2A | 122.5 | N3—C8—N2 | 116.97 (15) |
C2—C3—C4 | 121.70 (16) | ||
C7—O1—C1—C2 | −179.20 (17) | O1—C1—C6—N1 | 0.35 (18) |
C7—O1—C1—C6 | −0.35 (17) | C7—N1—C6—C5 | 177.86 (18) |
O1—C1—C2—C3 | 178.07 (15) | C7—N1—C6—C1 | −0.19 (18) |
C6—C1—C2—C3 | −0.6 (3) | C6—N1—C7—O1 | 0.0 (2) |
C1—C2—C3—C4 | −0.4 (3) | C6—N1—C7—N2 | −179.71 (17) |
C2—C3—C4—C5 | 1.1 (3) | C1—O1—C7—N1 | 0.26 (19) |
C3—C4—C5—C6 | −0.7 (3) | C1—O1—C7—N2 | 179.97 (14) |
C4—C5—C6—C1 | −0.2 (3) | C8—N2—C7—N1 | −3.1 (3) |
C4—C5—C6—N1 | −178.12 (17) | C8—N2—C7—O1 | 177.25 (15) |
C2—C1—C6—C5 | 0.9 (3) | C7—N2—C8—N4 | 0.0 (3) |
O1—C1—C6—C5 | −177.95 (15) | C7—N2—C8—N3 | −178.54 (16) |
C2—C1—C6—N1 | 179.24 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H1···Cl1 | 0.88 (1) | 2.18 (1) | 3.047 (2) | 168 (2) |
N3—H2···Cl1 | 0.88 (1) | 2.67 (2) | 3.415 (2) | 144 (2) |
N3—H3···Cl1i | 0.87 (1) | 2.53 (2) | 3.297 (2) | 147 (2) |
N4—H4···Cl1i | 0.88 (1) | 2.33 (1) | 3.168 (2) | 160 (2) |
N4—H5···N1 | 0.88 (1) | 2.08 (2) | 2.765 (2) | 134 (2) |
Symmetry code: (i) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C8H9N4O+·Cl− |
Mr | 212.64 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 120 |
a, b, c (Å) | 6.669 (2), 8.152 (4), 9.630 (3) |
α, β, γ (°) | 65.062 (2), 85.020 (2), 73.710 (2) |
V (Å3) | 455.4 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.39 |
Crystal size (mm) | 0.20 × 0.05 × 0.04 |
Data collection | |
Diffractometer | Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.926, 0.985 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8184, 2088, 1895 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.089, 1.03 |
No. of reflections | 2088 |
No. of parameters | 147 |
No. of restraints | 5 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.31, −0.26 |
Computer programs: , DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998), DENZO (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H1···Cl1 | 0.88 (1) | 2.18 (1) | 3.047 (2) | 168 (2) |
N3—H2···Cl1 | 0.88 (1) | 2.67 (2) | 3.415 (2) | 144 (2) |
N3—H3···Cl1i | 0.87 (1) | 2.53 (2) | 3.297 (2) | 147 (2) |
N4—H4···Cl1i | 0.88 (1) | 2.33 (1) | 3.168 (2) | 160 (2) |
N4—H5···N1 | 0.88 (1) | 2.08 (2) | 2.765 (2) | 134 (2) |
Symmetry code: (i) x+1, y, z. |
Acknowledgements
The use of the EPSRC X-ray crystallographic facilities at the University of Southampton, England, is gratefully acknowledged. We thank Manchester Metropolitan University, Sohag University and the University of Malaya for supporting this study.
References
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bishop, M. M., Coles, S. J., Lee, A. H. W., Lindoy, L. F., Parkin, A., Thorn-Seshold, O. T. & Turner, P. (2005). Supramol. Chem. 17, 567–578. Web of Science CrossRef CAS Google Scholar
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. CrossRef CAS Web of Science IUCr Journals Google Scholar
Hooft, R. (1998). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Mohamed, S. K., Horton, P. N., El-Remaily, M. A. A. & Ng, S. W. (2011). Acta Cryst. E67, o3132. Web of Science CSD CrossRef IUCr Journals Google Scholar
Otwinowski, O. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Takahashi, T. & Niino, A. (1943). Yakugaku Zasshi, 63, 249–252. CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
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The preceding study reports 2-(1,3-benzothiazol-2-yl)guanidinium chloride (Mohamed et al., 2011). Replacing the sulfur in the fused-ring by oxygen leads to the analogous compound, 2-(1,3-benzoxazol-2-yl)guandinium chloride (Scheme I). However, this salt and 2-(1,3-benzothiazol-2-yl)guanidinium chloride are are not isostructural as they belong to different crystal systems. The non-H atoms of the cation of the title salt, C8H9N4O+ Cl- (Fig. 1), lie on a plane with one amino group forming an intramolecular hydrogen bond to the tertiary N atom of the benzoxazole fused-ring. The cations and anions are linked by cyclic R12(6) N—H···Cl hydrogen-bonding associations [Etter et al., 1990)], to generate linear chains running along the a-axis of the tricinic unit cell (Table 1). This salt was first reported in 1943 (Takahashi & Niino, 1943). The structure of a co-crystal of 2-(1,3-benzoxazol-2-yl)guanidine has been reported (Bishop et al., 2005).