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In the title compound, C7H5N3O2S, the mol­ecules are linked into a three-dimensional framework by a combination of a three-centre N—H...(O)2 hydrogen bond, and two-centre N—H...N and C—H...O hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101012574/gg1076sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101012574/gg1076Isup2.hkl
Contains datablock I

CCDC reference: 174843

Comment top

In nitroanilines where the amino and nitro substituents are remote from one another such that intramolecular hydrogen-bond formation is precluded, the molecules generally act as double donors and double acceptors of hydrogen bonds; the resulting supramolecular structures can be either two-dimensional (Ploug-Sørensen & Andersen, 1986; Tonogaki et al., 1993; Ellena et al., 1999; Cannon et al., 2001) or three-dimensional (Ferguson et al., 2001). The effect of introducing an excess of hydrogen-bond acceptors, as in 3,5-dinitroaniline (Glidewell et al., 2001), can be unexpected; in this compound, not all of the N—H bonds are engaged in the hydrogen bonding, despite the excess of acceptors over donors. Pursuing this theme, we have now investigated the molecular and supramolecular structure of 2-amino-6-nitrobenzothiazole, (I), where the ring N atom provides an additional hydrogen-bond acceptor site, so giving an excess of acceptors over donors.

Molecules of (I) (Fig. 1) are linked by N—H···O, N—H···N and C—H···O hydrogen bonds (Table 2) into a three-dimensional framework, which is reinforced by aromatic ππ-stacking interactions; the framework structure can readily be analysed in terms of the low-dimensional motifs generated by the individual hydrogen bonds in turn.

The amino N2 atom acts as hydrogen-bond donor, via H22, in a nearly planar three-centre system where the two acceptors are O71 atoms in two different molecules (Table 2). Atom N2 at (x, y, z) acts as donor to O71 at (1/2 - x, 1/2 + y, 3/2 - z), so producing a C(9) chain running parallel to the [010] direction and generated by the 21 axis along (1/4, y, 3/4); at the same time, N2 at (x, y, z) also acts as donor to O71 at (-1/2 - x, 1/2 + y, 3/2 - z), producing a similar C(9) spiral chain around the 21 axis along (-0.25, y, 3/4). The combination of these two one-dimensional motifs generates a sheet parallel to (001) in the form of a (4,4)-net (Batten & Robson, 1998) built from a single type of R33(20) ring (Fig. 2). This sheet is reinforced by aromatic ππ-stacking interactions; in molecules related by translation along the [100] direction, the interplanar spacing is ca 3.38 Å and there is ππ overlap between the carbocyclic ring of the molecule at (x, y, z) with the heterocyclic ring of the molecule at (-1 + x, y, z), with a centroid offset of ca 1.24 Å (Fig. 2); propagation of this interaction by translation gives a sheared-stack motif.

There are two (001) sheets passing through each unit cell, one in the domain -0.02 < z < 0.52 and the other in the domain 0.48 < z < 1.02, and these sheets are linked into a three-dimensional framework by almost linear N—H···N hydrogen bonds, whose effect is reinforced by C—H···O hydrogen bonds (Table 2). The amino N2 atom at (x, y, z) lies in the domain 0.48 < z < 1.02 and acts as hydrogen-bond donor, via H21, to the thiazole N3 atom in the molecule at (1 - x, 1 - y, 1 - z), which lies in the domain -0.02 < z < 0.48; N2 at (1 - x, 1 - y, 1 - z), in turn, acts as donor to N3 at (x, y, z), so generating a centrosymmetric R22(8) motif (Fig. 3). Similarly, N2 at (1/2 - x, 1/2 + y, 3/2 - z), which also lies in the domain 0.48 < z < 1.02, acts as donor to N3 at (-1/2 + x, 3/2 - y, 1/2 + z), which lies in the domain 0.98 < z < 1.52. In this manner, each (001) sheet is linked to its two immediate neighbours, so generating a continuous three-dimensional array.

Atom C8 at (x, y, z), in the domain 0.48 < z < 1.02, acts as hydrogen-bond donor to the nitro O72 atom at (-1 - x, 1 - y, 2 - z), which is in the domain -0.02 < z < 0.52. In so doing, it generates a centrosymmetric R22(10) motif, and the propagation of this motif of paired C—H···O hydrogen bonds again serves to link each (001) sheet to each of its neighbours. The combination of these two cyclic motifs generates a C22(14)[R22(8)][R22(10)] chain of rings running parallel to the [201] direction (Fig. 3)

In the isomeric 2-amino-4-nitrobenzothiazole, (II) [Cambridge Structural Database (CSD; Allen & Kennard, 1993) refcode ZUHVUT (Lokaj et al., 1996)], the hydrogen bonding links the molecules into (101) sheets (Fig. 4) rather than into a three-dimensional array. A combination of N—H···O and N—H···N hydrogen bonds generates a checkerboard array of R22(8) and R66(32) rings; the resulting net is of (4,4)-type (Batten & Robson, 1998) if the dimeric units produced by the R22(8) motif are regarded as the nodes of this net.

Within the molecule of (I), the C2—N2 and C2—N3 distances are very similar (Table 1); both the exocyclic C—N bonds are short for their types (Allen et al., 1987) and there is evidence for quinonoid-type bond fixation within the aryl ring, indicating that forms (Ia) and (Ib) both contribute to the overall structure.

Experimental top

A sample of (I) was obtained from Aldrich. Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation of a solution in ethanol.

Refinement top

Compound (I) crystallized in the monoclinic system; space group P21/n was assumed from the systematic absences. H atoms were treated as riding atoms with a C—H distance of 0.95 Å and an N—H distance of 0.88 Å.

Computing details top

Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2001); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997) and PRPKAPPA (Ferguson, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. Part of the crystal structure of (I) showing the formation of an R33(20) ring in the (001) sheet by a three-centre N—H···(O)2 hydrogen bond. H atoms bonded to C atoms have been omitted for clarity. Atoms marked with an asterisk (*), hash (#) or dollar sign ($) are at the symmetry positions (0.5 - x, 0.5 + y, 1.5 - z), (-0.5 - x, 0.5 + y, 1.5 - z) and (x, 1 + y, z), respectively.
[Figure 3] Fig. 3. Part of the crystal structure of (I) showing a [201] chain of alternating R22(8) and R22(10) rings which link adjacent (001) sheets. Atoms marked with an asterisk (*), hash (#) or dollar sign ($) are at the symmetry positions (1 - x, 1 - y, 1 - z), (-1 - x, 1 - y, 2 - z) and (2 + x, y, -1 + z), respectively.
[Figure 4] Fig. 4. Part of the crystal structure of ZUHVUT (Lokaj et al., 1996) showing the formation of a (101) sheet built from R22(8) and R66(32) rings. H atoms bonded to C atoms have been omitted for clarity.
2-Amino-6-nitrobenzothiazole top
Crystal data top
C7H5N3O2SF(000) = 400
Mr = 195.20Dx = 1.649 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 3.7715 (2) ÅCell parameters from 1785 reflections
b = 15.6399 (8) Åθ = 3.0–27.5°
c = 13.3484 (9) ŵ = 0.38 mm1
β = 93.252 (2)°T = 150 K
V = 786.10 (8) Å3Needle, yellow
Z = 40.48 × 0.10 × 0.02 mm
Data collection top
Nonius KappaCCD
diffractometer
1785 independent reflections
Radiation source: fine-focus sealed X-ray tube1252 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.061
ϕ scans, and ω scans with κ offsetsθmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan
(DENZO-SMN; Otwinowski & Minor, 1997)
h = 44
Tmin = 0.837, Tmax = 0.990k = 2020
8740 measured reflectionsl = 1717
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)] = 0.045Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.108H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.0528P)2]
where P = (Fo2 + 2Fc2)/3
1785 reflections(Δ/σ)max < 0.001
118 parametersΔρmax = 0.32 e Å3
0 restraintsΔρmin = 0.38 e Å3
Crystal data top
C7H5N3O2SV = 786.10 (8) Å3
Mr = 195.20Z = 4
Monoclinic, P21/nMo Kα radiation
a = 3.7715 (2) ŵ = 0.38 mm1
b = 15.6399 (8) ÅT = 150 K
c = 13.3484 (9) Å0.48 × 0.10 × 0.02 mm
β = 93.252 (2)°
Data collection top
Nonius KappaCCD
diffractometer
1785 independent reflections
Absorption correction: multi-scan
(DENZO-SMN; Otwinowski & Minor, 1997)
1252 reflections with I > 2σ(I)
Tmin = 0.837, Tmax = 0.990Rint = 0.061
8740 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0450 restraints
wR(F2) = 0.108H-atom parameters constrained
S = 1.01Δρmax = 0.32 e Å3
1785 reflectionsΔρmin = 0.38 e Å3
118 parameters
Special details top

Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm [Fox, G·C. & Holmes, K·C. (1966). Acta Cryst. 20, 886–891] which effectively corrects for absorption effects. High redundancy data were used in the scaling program hence the 'multi-scan' code word was used. No transmission coefficients are available from the program (only scale factors for each frame). The scale factors in the experimental table are calculated from the 'size' command in the SHELXL97 input file.

Geometry. Mean-plane data from the final SHELXL97 refinement run:-

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
S10.13369 (14)0.59656 (4)0.73695 (4)0.0212 (2)
C20.2747 (5)0.55738 (15)0.62235 (16)0.0194 (5)
N20.4038 (4)0.60932 (12)0.55432 (13)0.0222 (4)
N30.2508 (5)0.47380 (11)0.60927 (13)0.0191 (4)
C40.1075 (5)0.43604 (14)0.69082 (15)0.0168 (5)
C50.0369 (5)0.34875 (14)0.69966 (16)0.0200 (5)
C60.1067 (5)0.31891 (14)0.78566 (16)0.0204 (5)
C70.1796 (5)0.37582 (15)0.86222 (15)0.0181 (5)
N70.3315 (5)0.34311 (13)0.95236 (13)0.0238 (5)
O710.3864 (4)0.26500 (11)0.95848 (12)0.0351 (5)
O720.4024 (4)0.39324 (11)1.01911 (12)0.0324 (4)
C80.1189 (5)0.46298 (14)0.85607 (15)0.0173 (5)
C90.0242 (5)0.49212 (14)0.76966 (16)0.0173 (5)
H210.47740.58830.49800.027*
H220.41550.66470.56570.027*
H50.08720.31050.64710.024*
H60.15580.25970.79280.025*
H80.17310.50080.90880.021*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0260 (3)0.0155 (3)0.0226 (3)0.0001 (2)0.0053 (2)0.0009 (2)
C20.0147 (11)0.0208 (14)0.0224 (12)0.0009 (9)0.0011 (9)0.0011 (10)
N20.0311 (11)0.0167 (11)0.0196 (10)0.0021 (8)0.0084 (8)0.0023 (8)
N30.0205 (10)0.0184 (11)0.0187 (10)0.0008 (7)0.0027 (7)0.0005 (8)
C40.0145 (11)0.0167 (13)0.0193 (12)0.0007 (8)0.0005 (8)0.0005 (9)
C50.0216 (12)0.0175 (13)0.0208 (12)0.0019 (9)0.0009 (9)0.0025 (9)
C60.0213 (13)0.0155 (13)0.0246 (13)0.0020 (9)0.0015 (9)0.0009 (10)
C70.0154 (11)0.0198 (13)0.0194 (11)0.0009 (9)0.0028 (8)0.0021 (9)
N70.0236 (11)0.0231 (12)0.0249 (11)0.0010 (8)0.0033 (8)0.0028 (9)
O710.0518 (11)0.0170 (10)0.0382 (11)0.0036 (8)0.0164 (8)0.0056 (8)
O720.0478 (11)0.0251 (10)0.0256 (9)0.0002 (8)0.0136 (8)0.0038 (8)
C80.0169 (11)0.0192 (13)0.0159 (11)0.0023 (9)0.0011 (8)0.0021 (9)
C90.0155 (11)0.0142 (12)0.0218 (12)0.0008 (8)0.0016 (9)0.0008 (9)
Geometric parameters (Å, º) top
S1—C21.758 (2)C2—N21.331 (3)
C2—N31.321 (3)C7—N71.455 (3)
N3—C41.376 (3)N7—O711.243 (2)
C4—C51.397 (3)N7—O721.228 (2)
C5—C61.378 (3)N2—H210.8800
C6—C71.394 (3)N2—H220.8800
C7—C81.386 (3)C5—H50.9500
C8—C91.378 (3)C6—H60.9500
C9—S11.746 (2)C8—H80.9500
C4—C91.419 (3)
C9—S1—C288.80 (10)C5—C6—H6120.1
N3—C2—N2122.58 (19)C7—C6—H6120.1
N3—C2—S1115.99 (16)C8—C7—C6123.0 (2)
N2—C2—S1121.42 (17)C8—C7—N7117.99 (19)
C2—N2—H21120.0C6—C7—N7119.0 (2)
C2—N2—H22120.0O72—N7—O71122.43 (18)
H21—N2—H22120.0O72—N7—C7119.21 (19)
C2—N3—C4110.30 (18)O71—N7—C7118.36 (19)
N3—C4—C5124.86 (19)C9—C8—C7116.7 (2)
N3—C4—C9115.8 (2)C9—C8—H8121.7
C5—C4—C9119.34 (19)C7—C8—H8121.7
C6—C5—C4119.1 (2)C8—C9—C4122.0 (2)
C6—C5—H5120.4C8—C9—S1128.90 (17)
C4—C5—H5120.4C4—C9—S1109.10 (16)
C5—C6—C7119.8 (2)
C6—C7—N7—O711.0 (3)C8—C7—N7—O71179.93 (17)
C6—C7—N7—O72178.61 (18)C8—C7—N7—O720.4 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H21···N3i0.882.052.912 (2)165
N2—H22···O71ii0.882.543.119 (2)124
N2—H22···O71iii0.882.413.051 (2)130
C8—H8···O72iv0.952.533.381 (3)149
Symmetry codes: (i) x+1, y+1, z+1; (ii) x1/2, y+1/2, z+3/2; (iii) x+1/2, y+1/2, z+3/2; (iv) x1, y+1, z+2.

Experimental details

Crystal data
Chemical formulaC7H5N3O2S
Mr195.20
Crystal system, space groupMonoclinic, P21/n
Temperature (K)150
a, b, c (Å)3.7715 (2), 15.6399 (8), 13.3484 (9)
β (°) 93.252 (2)
V3)786.10 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.38
Crystal size (mm)0.48 × 0.10 × 0.02
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(DENZO-SMN; Otwinowski & Minor, 1997)
Tmin, Tmax0.837, 0.990
No. of measured, independent and
observed [I > 2σ(I)] reflections
8740, 1785, 1252
Rint0.061
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.045, 0.108, 1.01
No. of reflections1785
No. of parameters118
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.32, 0.38

Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO-SMN (Otwinowski & Minor, 1997), DENZO-SMN, SHELXS97 (Sheldrick, 1997), PLATON (Spek, 2001), SHELXL97 (Sheldrick, 1997) and PRPKAPPA (Ferguson, 1999).

Selected geometric parameters (Å, º) top
S1—C21.758 (2)C8—C91.378 (3)
C2—N31.321 (3)C9—S11.746 (2)
N3—C41.376 (3)C4—C91.419 (3)
C4—C51.397 (3)C2—N21.331 (3)
C5—C61.378 (3)C7—N71.455 (3)
C6—C71.394 (3)N7—O711.243 (2)
C7—C81.386 (3)N7—O721.228 (2)
C6—C7—N7—O711.0 (3)C6—C7—N7—O72178.61 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H21···N3i0.882.052.912 (2)165
N2—H22···O71ii0.882.543.119 (2)124
N2—H22···O71iii0.882.413.051 (2)130
C8—H8···O72iv0.952.533.381 (3)149
Symmetry codes: (i) x+1, y+1, z+1; (ii) x1/2, y+1/2, z+3/2; (iii) x+1/2, y+1/2, z+3/2; (iv) x1, y+1, z+2.
 

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