organic compounds
A triclinic polymorph of 3-nitroanilinium chloride
aDepartment of Physics, Kalasalingam University, Anand Nagar, Krishnan Koil 626 190, India, and bDepartment of Physics, University College of Engineering Nagercoil, Anna University of Technology Tirunelveli, Nagercoil 629 004, India
*Correspondence e-mail: athi81s@yahoo.co.in
The 6H7N2O2+·Cl−, contains two independent ion pairs. A monoclinic form of the title compound with only one in the has been reported previously [Ploug-Sørensen & Andersen (1986). Acta Cryst. C42, 1813–1815]. In the crystal of the title compound, the components are linked into layers parallel to (001) by intermolecular N—H⋯Cl hydrogen bonds, with alternating hydrophilic and hydrophobic regions.
of the title compound, CRelated literature
For the monoclinic polymorph of the title compound, see: Ploug-Sørensen & Andersen (1986). For the applications of nitroanilines, see: Jain et al. (2005); Teng & Garito (1983). For information on see: Davey (2003); Li et al. (2001); Rodríguez-Spong et al. (2004). For hydrogen-bond motifs, see: Etter et al., (1990).
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: SMART (Bruker, 2001); cell SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL/PC (Sheldrick, 2008).
Supporting information
10.1107/S1600536811029072/lh5286sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811029072/lh5286Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536811029072/lh5286Isup3.cml
The title compound, (I), was crystallized from an aqueous mixture of 3-nitroaniline and hydrochloric acid in the stochiometric ratio of 1:1 at room temperature, by the technique of slow evaporation.
The H atoms, which participate in hydrogen bonds, were located in difference Fourier maps and then refined isotropically [N—H = 0.84 (4) - 0.93 (4)Å]. H atoms bonded to C atoms were treated in a riding-model approximation, with d(C—H) = 0.93 Å and Uiso(H)= 1.2 Ueq(C).
Data collection: SMART (Bruker, 2001); cell
SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL/PC (Sheldrick, 2008).Fig. 1. The molecular structure of the title compound with 50% displacement ellipsoids. H-bonds are shown as dashed lines. | |
Fig. 2. Packing diagram of the title compound viewed down the a-axis. H-bonds are shown as dashed lines. |
C6H7N2O2+·Cl− | Z = 4 |
Mr = 174.59 | F(000) = 360 |
Triclinic, P1 | Dx = 1.514 Mg m−3 Dm = 1.49 (1) Mg m−3 Dm measured by flotation technique using a liquid-mixture of xylene and bromoform |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.9936 (8) Å | Cell parameters from 2545 reflections |
b = 7.8608 (9) Å | θ = 2.7–24.9° |
c = 14.6708 (16) Å | µ = 0.45 mm−1 |
α = 87.079 (19)° | T = 293 K |
β = 81.813 (19)° | Block, colourless |
γ = 73.597 (17)° | 0.21 × 0.18 × 0.13 mm |
V = 765.77 (15) Å3 |
Bruker SMART APEX CCD diffractometer | 2348 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.028 |
Graphite monochromator | θmax = 25.0°, θmin = 2.7° |
ω scans | h = −8→8 |
5204 measured reflections | k = −9→9 |
2640 independent reflections | l = −16→17 |
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)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.139 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.22 | w = 1/[σ2(Fo2) + (0.0689P)2 + 0.295P] where P = (Fo2 + 2Fc2)/3 |
2640 reflections | (Δ/σ)max < 0.001 |
223 parameters | Δρmax = 0.34 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
C6H7N2O2+·Cl− | γ = 73.597 (17)° |
Mr = 174.59 | V = 765.77 (15) Å3 |
Triclinic, P1 | Z = 4 |
a = 6.9936 (8) Å | Mo Kα radiation |
b = 7.8608 (9) Å | µ = 0.45 mm−1 |
c = 14.6708 (16) Å | T = 293 K |
α = 87.079 (19)° | 0.21 × 0.18 × 0.13 mm |
β = 81.813 (19)° |
Bruker SMART APEX CCD diffractometer | 2348 reflections with I > 2σ(I) |
5204 measured reflections | Rint = 0.028 |
2640 independent reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.139 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.22 | Δρmax = 0.34 e Å−3 |
2640 reflections | Δρmin = −0.28 e Å−3 |
223 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. |
Refinement. Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
C11 | 0.1251 (3) | 0.4363 (3) | 0.31823 (15) | 0.0340 (5) | |
C12 | 0.0920 (3) | 0.4668 (3) | 0.22728 (16) | 0.0343 (5) | |
H12 | 0.0690 | 0.3805 | 0.1926 | 0.041* | |
C13 | 0.0947 (3) | 0.6318 (3) | 0.19058 (15) | 0.0329 (5) | |
C14 | 0.1270 (4) | 0.7610 (3) | 0.24223 (17) | 0.0407 (6) | |
H14 | 0.1277 | 0.8712 | 0.2161 | 0.049* | |
C15 | 0.1582 (4) | 0.7248 (3) | 0.33299 (18) | 0.0450 (6) | |
H15 | 0.1794 | 0.8115 | 0.3680 | 0.054* | |
C16 | 0.1582 (4) | 0.5611 (3) | 0.37241 (16) | 0.0402 (6) | |
H16 | 0.1798 | 0.5359 | 0.4333 | 0.048* | |
N11 | 0.1259 (3) | 0.2612 (3) | 0.35946 (15) | 0.0443 (5) | |
N12 | 0.0565 (4) | 0.6733 (4) | 0.09503 (14) | 0.0433 (5) | |
O11 | 0.0976 (3) | 0.1510 (2) | 0.31125 (15) | 0.0622 (6) | |
O12 | 0.1539 (4) | 0.2351 (3) | 0.43994 (14) | 0.0702 (6) | |
H12A | 0.155 (6) | 0.594 (5) | 0.057 (3) | 0.074 (11)* | |
H12B | −0.057 (6) | 0.654 (5) | 0.090 (2) | 0.062 (10)* | |
H12C | 0.041 (5) | 0.780 (6) | 0.078 (2) | 0.066 (10)* | |
C21 | 0.6344 (3) | 0.1548 (3) | 0.33773 (16) | 0.0390 (5) | |
C22 | 0.6145 (3) | 0.2222 (3) | 0.24981 (16) | 0.0359 (5) | |
H22 | 0.6194 | 0.3373 | 0.2343 | 0.043* | |
C23 | 0.5868 (3) | 0.1109 (3) | 0.18579 (15) | 0.0346 (5) | |
C24 | 0.5814 (4) | −0.0610 (3) | 0.20828 (18) | 0.0418 (6) | |
H24 | 0.5615 | −0.1333 | 0.1644 | 0.050* | |
C25 | 0.6059 (4) | −0.1238 (3) | 0.29679 (19) | 0.0483 (6) | |
H25 | 0.6046 | −0.2398 | 0.3119 | 0.058* | |
C26 | 0.6322 (4) | −0.0168 (4) | 0.36326 (18) | 0.0467 (6) | |
H26 | 0.6479 | −0.0586 | 0.4230 | 0.056* | |
N21 | 0.6556 (3) | 0.2741 (4) | 0.40805 (15) | 0.0525 (6) | |
N22 | 0.5575 (4) | 0.1777 (3) | 0.09240 (14) | 0.0415 (5) | |
O21 | 0.6745 (3) | 0.4197 (3) | 0.38419 (14) | 0.0624 (6) | |
O22 | 0.6531 (5) | 0.2192 (4) | 0.48732 (15) | 0.0940 (9) | |
H22A | 0.443 (6) | 0.170 (4) | 0.081 (2) | 0.060 (9)* | |
H22B | 0.565 (5) | 0.282 (6) | 0.082 (2) | 0.066 (10)* | |
H22C | 0.653 (5) | 0.099 (5) | 0.052 (2) | 0.064 (10)* | |
Cl1 | 0.16411 (10) | 0.07512 (8) | 0.06132 (4) | 0.0449 (2) | |
Cl2 | 0.66659 (10) | 0.55025 (8) | 0.07206 (4) | 0.0456 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C11 | 0.0354 (11) | 0.0281 (11) | 0.0384 (12) | −0.0096 (9) | −0.0047 (9) | 0.0038 (9) |
C12 | 0.0376 (11) | 0.0300 (11) | 0.0375 (12) | −0.0115 (9) | −0.0070 (9) | −0.0025 (9) |
C13 | 0.0366 (11) | 0.0342 (12) | 0.0294 (11) | −0.0105 (9) | −0.0082 (9) | 0.0015 (9) |
C14 | 0.0536 (14) | 0.0324 (12) | 0.0421 (13) | −0.0198 (11) | −0.0116 (10) | 0.0032 (10) |
C15 | 0.0637 (16) | 0.0397 (14) | 0.0403 (13) | −0.0232 (12) | −0.0165 (11) | −0.0025 (10) |
C16 | 0.0499 (13) | 0.0425 (14) | 0.0311 (12) | −0.0144 (11) | −0.0124 (10) | 0.0004 (10) |
N11 | 0.0487 (12) | 0.0341 (11) | 0.0473 (12) | −0.0100 (9) | −0.0027 (9) | 0.0072 (9) |
N12 | 0.0573 (15) | 0.0438 (14) | 0.0309 (11) | −0.0155 (11) | −0.0120 (10) | 0.0033 (10) |
O11 | 0.0871 (15) | 0.0324 (10) | 0.0710 (14) | −0.0237 (10) | −0.0098 (11) | 0.0011 (9) |
O12 | 0.1004 (17) | 0.0584 (13) | 0.0515 (13) | −0.0222 (12) | −0.0179 (11) | 0.0240 (10) |
C21 | 0.0371 (12) | 0.0486 (15) | 0.0345 (12) | −0.0157 (10) | −0.0079 (9) | −0.0003 (10) |
C22 | 0.0393 (12) | 0.0351 (12) | 0.0375 (12) | −0.0162 (10) | −0.0070 (9) | −0.0008 (10) |
C23 | 0.0371 (11) | 0.0364 (12) | 0.0327 (12) | −0.0133 (9) | −0.0069 (9) | 0.0005 (9) |
C24 | 0.0460 (13) | 0.0338 (13) | 0.0485 (14) | −0.0153 (10) | −0.0058 (10) | −0.0041 (10) |
C25 | 0.0528 (15) | 0.0341 (13) | 0.0586 (17) | −0.0151 (11) | −0.0074 (12) | 0.0091 (12) |
C26 | 0.0460 (13) | 0.0542 (17) | 0.0400 (13) | −0.0152 (12) | −0.0088 (10) | 0.0128 (12) |
N21 | 0.0545 (13) | 0.0720 (17) | 0.0382 (12) | −0.0250 (12) | −0.0122 (9) | −0.0082 (11) |
N22 | 0.0571 (14) | 0.0388 (13) | 0.0344 (11) | −0.0197 (11) | −0.0118 (10) | −0.0009 (9) |
O21 | 0.0782 (14) | 0.0563 (13) | 0.0612 (13) | −0.0270 (11) | −0.0155 (10) | −0.0136 (10) |
O22 | 0.148 (3) | 0.122 (2) | 0.0384 (12) | −0.071 (2) | −0.0319 (13) | 0.0052 (13) |
Cl1 | 0.0625 (4) | 0.0418 (4) | 0.0377 (4) | −0.0221 (3) | −0.0173 (3) | 0.0055 (3) |
Cl2 | 0.0646 (4) | 0.0358 (4) | 0.0433 (4) | −0.0214 (3) | −0.0147 (3) | 0.0000 (3) |
C11—C16 | 1.381 (4) | C21—C22 | 1.380 (4) |
C11—C12 | 1.384 (4) | C21—C26 | 1.385 (4) |
C11—N11 | 1.473 (3) | C21—N21 | 1.478 (4) |
C12—C13 | 1.383 (3) | C22—C23 | 1.384 (3) |
C12—H12 | 0.9300 | C22—H22 | 0.9300 |
C13—C14 | 1.383 (3) | C23—C24 | 1.384 (4) |
C13—N12 | 1.468 (3) | C23—N22 | 1.463 (3) |
C14—C15 | 1.382 (4) | C24—C25 | 1.382 (4) |
C14—H14 | 0.9300 | C24—H24 | 0.9300 |
C15—C16 | 1.383 (4) | C25—C26 | 1.383 (4) |
C15—H15 | 0.9300 | C25—H25 | 0.9300 |
C16—H16 | 0.9300 | C26—H26 | 0.9300 |
N11—O11 | 1.221 (3) | N21—O21 | 1.217 (3) |
N11—O12 | 1.222 (3) | N21—O22 | 1.219 (3) |
N12—H12A | 0.93 (4) | N22—H22A | 0.86 (4) |
N12—H12B | 0.86 (4) | N22—H22B | 0.84 (4) |
N12—H12C | 0.85 (4) | N22—H22C | 0.93 (4) |
C16—C11—C12 | 123.5 (2) | C22—C21—C26 | 123.4 (2) |
C16—C11—N11 | 118.2 (2) | C22—C21—N21 | 117.8 (2) |
C12—C11—N11 | 118.3 (2) | C26—C21—N21 | 118.9 (2) |
C13—C12—C11 | 116.7 (2) | C21—C22—C23 | 117.0 (2) |
C13—C12—H12 | 121.6 | C21—C22—H22 | 121.5 |
C11—C12—H12 | 121.6 | C23—C22—H22 | 121.5 |
C12—C13—C14 | 121.8 (2) | C24—C23—C22 | 121.8 (2) |
C12—C13—N12 | 119.2 (2) | C24—C23—N22 | 118.9 (2) |
C14—C13—N12 | 118.9 (2) | C22—C23—N22 | 119.2 (2) |
C15—C14—C13 | 119.3 (2) | C25—C24—C23 | 119.2 (2) |
C15—C14—H14 | 120.3 | C25—C24—H24 | 120.4 |
C13—C14—H14 | 120.3 | C23—C24—H24 | 120.4 |
C14—C15—C16 | 120.8 (2) | C24—C25—C26 | 121.1 (2) |
C14—C15—H15 | 119.6 | C24—C25—H25 | 119.5 |
C16—C15—H15 | 119.6 | C26—C25—H25 | 119.5 |
C11—C16—C15 | 117.8 (2) | C25—C26—C21 | 117.6 (2) |
C11—C16—H16 | 121.1 | C25—C26—H26 | 121.2 |
C15—C16—H16 | 121.1 | C21—C26—H26 | 121.2 |
O11—N11—O12 | 123.8 (2) | O21—N21—O22 | 123.9 (2) |
O11—N11—C11 | 118.0 (2) | O21—N21—C21 | 118.9 (2) |
O12—N11—C11 | 118.2 (2) | O22—N21—C21 | 117.2 (3) |
C13—N12—H12A | 108 (2) | C23—N22—H22A | 109 (2) |
C13—N12—H12B | 107 (2) | C23—N22—H22B | 115 (2) |
H12A—N12—H12B | 107 (3) | H22A—N22—H22B | 110 (3) |
C13—N12—H12C | 116 (2) | C23—N22—H22C | 107 (2) |
H12A—N12—H12C | 113 (3) | H22A—N22—H22C | 105 (3) |
H12B—N12—H12C | 104 (3) | H22B—N22—H22C | 110 (3) |
C16—C11—C12—C13 | 0.5 (3) | C26—C21—C22—C23 | 1.4 (4) |
N11—C11—C12—C13 | −179.22 (19) | N21—C21—C22—C23 | −177.5 (2) |
C11—C12—C13—C14 | −0.6 (3) | C21—C22—C23—C24 | −0.7 (3) |
C11—C12—C13—N12 | −178.8 (2) | C21—C22—C23—N22 | 177.8 (2) |
C12—C13—C14—C15 | 0.3 (4) | C22—C23—C24—C25 | −0.5 (4) |
N12—C13—C14—C15 | 178.4 (2) | N22—C23—C24—C25 | −179.0 (2) |
C13—C14—C15—C16 | 0.2 (4) | C23—C24—C25—C26 | 1.1 (4) |
C12—C11—C16—C15 | −0.1 (4) | C24—C25—C26—C21 | −0.4 (4) |
N11—C11—C16—C15 | 179.7 (2) | C22—C21—C26—C25 | −0.9 (4) |
C14—C15—C16—C11 | −0.3 (4) | N21—C21—C26—C25 | 178.0 (2) |
C16—C11—N11—O11 | −179.6 (2) | C22—C21—N21—O21 | −7.2 (3) |
C12—C11—N11—O11 | 0.1 (3) | C26—C21—N21—O21 | 173.9 (2) |
C16—C11—N11—O12 | 0.7 (3) | C22—C21—N21—O22 | 172.9 (3) |
C12—C11—N11—O12 | −179.5 (2) | C26—C21—N21—O22 | −6.0 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
N12—H12A···Cl2i | 0.93 (4) | 2.28 (4) | 3.164 (4) | 161 (3) |
N12—H12B···Cl2ii | 0.86 (4) | 2.35 (4) | 3.204 (4) | 170 (3) |
N12—H12C···Cl1iii | 0.85 (4) | 2.68 (4) | 3.445 (5) | 151 (3) |
N12—H12C···Cl1iv | 0.85 (4) | 2.69 (4) | 3.221 (3) | 123 (3) |
N22—H22A···Cl1 | 0.86 (4) | 2.33 (4) | 3.174 (4) | 166 (3) |
N22—H22B···Cl2 | 0.84 (4) | 2.40 (4) | 3.218 (4) | 165 (3) |
N22—H22C···Cl1v | 0.93 (4) | 2.21 (4) | 3.138 (3) | 170 (3) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x−1, y, z; (iii) x, y+1, z; (iv) −x, −y+1, −z; (v) −x+1, −y, −z. |
Experimental details
Crystal data | |
Chemical formula | C6H7N2O2+·Cl− |
Mr | 174.59 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 6.9936 (8), 7.8608 (9), 14.6708 (16) |
α, β, γ (°) | 87.079 (19), 81.813 (19), 73.597 (17) |
V (Å3) | 765.77 (15) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.45 |
Crystal size (mm) | 0.21 × 0.18 × 0.13 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5204, 2640, 2348 |
Rint | 0.028 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.139, 1.22 |
No. of reflections | 2640 |
No. of parameters | 223 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.34, −0.28 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009), SHELXTL/PC (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N12—H12A···Cl2i | 0.93 (4) | 2.28 (4) | 3.164 (4) | 161 (3) |
N12—H12B···Cl2ii | 0.86 (4) | 2.35 (4) | 3.204 (4) | 170 (3) |
N12—H12C···Cl1iii | 0.85 (4) | 2.68 (4) | 3.445 (5) | 151 (3) |
N12—H12C···Cl1iv | 0.85 (4) | 2.69 (4) | 3.221 (3) | 123 (3) |
N22—H22A···Cl1 | 0.86 (4) | 2.33 (4) | 3.174 (4) | 166 (3) |
N22—H22B···Cl2 | 0.84 (4) | 2.40 (4) | 3.218 (4) | 165 (3) |
N22—H22C···Cl1v | 0.93 (4) | 2.21 (4) | 3.138 (3) | 170 (3) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) x−1, y, z; (iii) x, y+1, z; (iv) −x, −y+1, −z; (v) −x+1, −y, −z. |
Acknowledgements
ST and SAB sincerely thank the Vice-Chancellor and the Management of Kalasalingam University, Anand Nagar, Krishnan Koil for their support and encouragement. SA thanks the Vice Chancellor of Anna University of Technology, Tirunelveli, for his support and encouragement.
References
Bruker (2001). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Davey, R. J. (2003). Chem. Commun. pp. 1463–1467. Web of Science CrossRef 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
Jain, A. K., Mehta, S. C. & Shrivastava, N. M. (2005). Ind. J. Pharmacol. 37, 395–396. CrossRef CAS Google Scholar
Li, N., Shanks, R. A. & Murphy, D. M. (2001). J. Cryst. Growth, 224, 128–133. Web of Science CrossRef CAS Google Scholar
Ploug-Sørensen, G. & Andersen, E. K. (1986). Acta Cryst. C42, 1813–1815. CSD CrossRef Web of Science IUCr Journals Google Scholar
Rodríguez-Spong, B., Price, C. P., Jayasankar, A., Matzger, A. J. & Rodríguez-Hornedo, N. (2004). Adv. Drug Del. Rev. 56, 241–274. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Teng, C. C. & Garito, A. F. (1983). Phys. Rev. B28, 6766–6773. CrossRef Google Scholar
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Nitroanilines belong to the so-called push–pull molecules due to the intramolecular charge transfer (ICT) from the –NH2 electron-donor group, through the phenyl ring, to the electron-acceptor –NO2 group. 4-Nitroaniline and 3-nitroaniline serve as the reference compounds in both, experimental and computational studies on optical nonlinearity (Teng & Garito, 1983). Also 3-Nitroaniline and its derivatives are biologically important compounds owing to the production of significant hypoglycemic as well as antihyperglycemic effects in normal and alloxan-induced diabetic rabbits (Jain et al., 2005). Organic molecules including most of pharmaceutical compounds are prone to polymorphic formation in the solid state. Variations in crystallization environment (e.g., solvent, temperature, using as additives and concentration), can cause the same molecules to pack differently and form different crystal lattices or polymorphs (Davey, 2003). As a result, the physical, chemical and mechanical properties of crystals can be dramatically affected (Li et al., 2001). It is now widely appreciated that the occurrence of polymorphism in molecular crystalline solids impacts on the production of fine chemical products such as pharmaceuticals, pigments and photographic couplers (Rodríguez-Spong et al., 2004).
The title compound, (I), crystallizes with two crystallographically independent 3-nitroanilinium cations and two chloride anions in the asymmetric unit of the triclic unit cell, with the spacegroup P1. A monoclinic form with space group P21/c has been previously reported by Ploug-Sørensen & Andersen (1986). In the title compound the nitro groups of the cations are twisted from the plane of the aromatic rings by 0.32 (3) and 7.1 (3)°. The protonation on the N atom of the cations are confirmed from the elongated C—N bond distances.
The crystal packing, is stabilized through intermolecular N—H···Cl interactions, as shown in Fig. 2 and hydrogen bond parameters are listed in Table 1. All ammonium H atoms of the cations are involved in the hydrogen bonds with the chloride anions. The cations and anions are connected to form R42(8) ring motifs (Etter et al., 1990). Overall, the components are linked into two-dimensional layers parallel to (001) by the intermolecular N—H···Cl hydrogen bonds. This type of aggregation forms alternating hydrophilic and hydrophobic regions.