4-Nitro­phenyl­piperazinium chloride monohydrate

In the title compound, C₁₀H₁₄N₃O₂⁺·Cl⁻·H₂O, the cation acts with a water mol­ecule as a chloride-ion receptor. The water mol­ecule forms three strong hydrogen bonds. The H atoms of the piperazinium cation form hydrogen bonds to the chloride ion and to a water mol­ecule, giving a three-dimensional hydrogen-bond network. Weak inter­molecular C—H...O hydrogen bonds and π–π stacking inter­actions between pairs of anti­parallel benzene rings, with a mean inter­planar separation of 3.66 Å, also stabilize the structure.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.042
• wR factor = 0.120
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        400 Deg.
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O1     -   N3      ..       5.08 su
PLAT410_ALERT_2_C Short Intra H...H Contact  H2B    ..  H6A     ..       1.97 Ang.
PLAT410_ALERT_2_C Short Intra H...H Contact  H4A    ..  H10A    ..       1.98 Ang.

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

4-Nitrophenylpiperazinium chloride monohydrate (I) has been used as an intermediate in the synthesis of anticancer durgs, transcriptase inhibitors and antifungal reagents (Saczewski et al., 2006; Chen et al., 2000; Hepperle et al., 1999). It is also an important reagent for potassium channel openers, which show considerable biomolecular current-voltage rectification characteristics (Wu et al., 2005; Lan et al., 2005, 2006).

The basic structural unit of (I) consists of a 4-nitrophenylpiperazinium cation, a chloride ion and a water molecule. The molecular structure and atom-labeling scheme are shown in Fig. 1. The bonds N3—O1, N3—O2 [1.224 (2), 1.218 (2) Å, respectively] have partial double-bond character. The shorter intramolecular distance of H2b···H6a and H4a···H10a [1.97 and 1.98 Å] demonstrates the existence of H···H contacts.

The chloride anion forms one N—H···Cl and two O—H···Cl hydrogen bonds, namely one to piperazinium atom N1H1c, and two to the H atom of the water molecule (O3H3D, O3H3c) (Table 1). The H···Cl1 interaction lengths of the hydrogen bonds range from 2.21 to 2.317 (18) Å (Sopo & Sillanpää, 2007).

The H atoms of the piperazinium cation form hydrogen bonds to the chloride ion and to water atom O3 in an adjacent unit, forming a three-dimensional hydrogen-bond network (Fig. 2). Thus, the piperazinium cation plays an important role by acting as a bridge between the water O atom and the chloride ion.

The NO₂ groups also help to stabilize the crystal structure. The hydrogen bonds C3—H3b···O1^iv [symmetry code: (iv) -x + 1, -y + 2, -z + 1] are responsible for two-membered aggregates (Fig. 3), and C1—H1b···O2^v [symmetry code: (v) x, y - 1, z - 1] for zigzag molecular chains (Fig. 4) (Zou et al., 2005).

π···π Stacking interactions between pairs of antiparallel benzene rings are observed [mean separation of 3.66 Å] (Fig. 5) (How et al., 2007).

Related literature

For related literature, see: Chen et al. (2000); Hepperle et al. (1999); How et al. (2007); Lan et al. (2005, 2006); Saczewski et al. (2006); Sopo & Sillanpää (2007); Wu et al. (2005); Zou et al. (2005).

S2. Experimental

Crystals suitable for single-crystal X-ray analysis were obtained at room temperature by slow evaporation of an aqueous solution of 4-nitrophenylpiperazine and hydrochloric acid (1:1).

S3. Refinement

H atoms were included using a riding model with C—H = 0.97 or 0.93 Å, O—H = 0.85 or 0.87 Å, N—H = 0.90 Å, and U_iso = 1.2U_eq of the parent atom.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radius.
	Fig. 2. The crystal structure of (I), viewed along the a axis. Dashed lines indicate hydrogen bonds.
	Fig. 3. Two-membered aggregates. Dashed lines indicate hydrogen bonds.
	Fig. 4. Zigzag molecular chains. Dashed lines indicate hydrogen bonds.
	Fig. 5. π···π Stacking interactions. Dashed lines indicate the pairs of antiparallel benzene rings.

4-Nitrophenylpiperazinium chloride monohydrate

Crystal data

C10H14N3O2^+·Cl^−·H2O	Z = 2
Mr = 261.71	F(000) = 276
Triclinic, P1	Dx = 1.401 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.404 (2) Å	Cell parameters from 899 reflections
b = 9.212 (3) Å	θ = 3.5–27.1°
c = 9.757 (3) Å	µ = 0.31 mm^−1
α = 110.111 (4)°	T = 293 K
β = 90.209 (4)°	Prism, brown
γ = 96.484 (4)°	0.15 × 0.10 × 0.10 mm
V = 620.3 (3) Å^3

Data collection

Bruker APEX CCD area-detector diffractometer	2390 independent reflections
Radiation source: fine-focus sealed tube	2078 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
φ and ω scans	θmax = 26.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997b)	h = −8→9
Tmin = 0.955, Tmax = 0.970	k = −9→11
2866 measured reflections	l = −10→12

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.042	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.120	w = 1/[σ^2(Fo^2) + (0.0696P)^2 + 0.1053P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
2390 reflections	Δρmax = 0.27 e Å^−3
163 parameters	Δρmin = −0.30 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997a), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.085 (9)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.21896 (6)	0.24305 (5)	0.06332 (5)	0.0512 (2)
N1	0.6240 (2)	0.36182 (16)	0.15956 (17)	0.0453 (4)
H1C	0.5109	0.3277	0.1189	0.054*
H1D	0.6921	0.2830	0.1256	0.054*
N2	0.8687 (2)	0.61144 (16)	0.35096 (15)	0.0406 (4)
N3	0.6741 (2)	1.20158 (19)	0.66763 (19)	0.0527 (4)
O1	0.6553 (2)	1.29264 (17)	0.60370 (19)	0.0710 (5)
O2	0.6467 (3)	1.2324 (2)	0.79697 (18)	0.0825 (6)
O3	0.1758 (2)	0.88143 (18)	0.8816 (2)	0.0721 (5)
C1	0.7023 (3)	0.4943 (2)	0.11475 (19)	0.0460 (4)
H1A	0.6205	0.5738	0.1384	0.055*
H1B	0.7165	0.4581	0.0100	0.055*
C2	0.8841 (3)	0.5617 (2)	0.19315 (19)	0.0450 (4)
H2A	0.9681	0.4841	0.1632	0.054*
H2B	0.9327	0.6501	0.1665	0.054*
C3	0.6164 (3)	0.4062 (2)	0.3206 (2)	0.0456 (4)
H3A	0.5761	0.3147	0.3454	0.055*
H3B	0.5295	0.4805	0.3564	0.055*
C4	0.8020 (3)	0.4773 (2)	0.3922 (2)	0.0458 (4)
H4A	0.7947	0.5100	0.4975	0.055*
H4B	0.8864	0.4001	0.3625	0.055*
C5	0.8183 (2)	0.75675 (18)	0.42769 (17)	0.0354 (4)
C6	0.8009 (2)	0.86723 (19)	0.36100 (18)	0.0403 (4)
H6A	0.8202	0.8418	0.2618	0.048*
C7	0.7560 (2)	1.0121 (2)	0.4393 (2)	0.0416 (4)
H7A	0.7459	1.0846	0.3937	0.050*
C8	0.7259 (2)	1.04990 (19)	0.58589 (19)	0.0402 (4)
C9	0.7443 (2)	0.9451 (2)	0.65606 (19)	0.0436 (4)
H9A	0.7259	0.9725	0.7556	0.052*
C10	0.7898 (2)	0.8006 (2)	0.57808 (19)	0.0412 (4)
H10A	0.8022	0.7301	0.6255	0.049*
H3C	0.070 (4)	0.851 (4)	0.908 (4)	0.161 (17)*
H3D	0.192 (4)	0.978 (2)	0.932 (4)	0.119 (12)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0505 (3)	0.0478 (3)	0.0549 (3)	−0.0029 (2)	−0.0015 (2)	0.0202 (2)
N1	0.0411 (8)	0.0349 (7)	0.0528 (9)	0.0034 (6)	−0.0028 (7)	0.0068 (6)
N2	0.0429 (8)	0.0333 (7)	0.0426 (8)	0.0026 (6)	0.0010 (6)	0.0099 (6)
N3	0.0486 (9)	0.0427 (9)	0.0552 (10)	0.0057 (7)	−0.0011 (7)	0.0021 (7)
O1	0.0838 (12)	0.0447 (8)	0.0861 (11)	0.0203 (8)	0.0102 (9)	0.0208 (8)
O2	0.1138 (15)	0.0672 (10)	0.0509 (9)	0.0295 (10)	0.0062 (9)	−0.0054 (8)
O3	0.0616 (10)	0.0425 (8)	0.1024 (13)	0.0119 (7)	0.0190 (9)	0.0109 (8)
C1	0.0560 (11)	0.0383 (9)	0.0385 (9)	0.0058 (8)	0.0029 (8)	0.0068 (7)
C2	0.0470 (10)	0.0372 (9)	0.0463 (10)	0.0077 (7)	0.0134 (8)	0.0078 (7)
C3	0.0466 (10)	0.0373 (9)	0.0548 (11)	0.0042 (7)	0.0057 (8)	0.0186 (8)
C4	0.0515 (11)	0.0353 (8)	0.0520 (10)	0.0068 (7)	−0.0044 (8)	0.0165 (8)
C5	0.0315 (8)	0.0347 (8)	0.0372 (8)	−0.0006 (6)	−0.0005 (6)	0.0104 (7)
C6	0.0455 (10)	0.0403 (9)	0.0340 (8)	0.0025 (7)	0.0034 (7)	0.0125 (7)
C7	0.0435 (9)	0.0368 (8)	0.0459 (10)	0.0021 (7)	0.0009 (7)	0.0170 (7)
C8	0.0369 (9)	0.0352 (8)	0.0426 (9)	0.0024 (7)	−0.0002 (7)	0.0068 (7)
C9	0.0462 (10)	0.0460 (9)	0.0341 (8)	0.0008 (7)	0.0021 (7)	0.0097 (7)
C10	0.0449 (10)	0.0410 (9)	0.0386 (9)	0.0017 (7)	0.0001 (7)	0.0159 (7)

Geometric parameters (Å, º)

N1—C3	1.484 (2)	C2—H2B	0.970
N1—C1	1.491 (2)	C3—C4	1.510 (3)
N1—H1C	0.900	C3—H3A	0.970
N1—H1D	0.900	C3—H3B	0.970
N2—C5	1.385 (2)	C4—H4A	0.970
N2—C2	1.457 (2)	C4—H4B	0.970
N2—C4	1.462 (2)	C5—C6	1.400 (2)
N3—O2	1.218 (2)	C5—C10	1.405 (2)
N3—O1	1.224 (2)	C6—C7	1.370 (2)
N3—C8	1.446 (2)	C6—H6A	0.930
O3—H3C	0.871 (18)	C7—C8	1.376 (2)
O3—H3D	0.853 (18)	C7—H7A	0.930
C1—C2	1.503 (3)	C8—C9	1.379 (3)
C1—H1A	0.970	C9—C10	1.368 (2)
C1—H1B	0.970	C9—H9A	0.930
C2—H2A	0.970	C10—H10A	0.930
C3—N1—C1	112.33 (13)	N1—C3—H3B	109.6
C3—N1—H1C	109.1	C4—C3—H3B	109.6
C1—N1—H1C	109.1	H3A—C3—H3B	108.2
C3—N1—H1D	109.1	N2—C4—C3	110.52 (14)
C1—N1—H1D	109.1	N2—C4—H4A	109.5
H1C—N1—H1D	107.9	C3—C4—H4A	109.5
C5—N2—C2	120.40 (14)	N2—C4—H4B	109.5
C5—N2—C4	119.96 (14)	C3—C4—H4B	109.5
C2—N2—C4	109.57 (13)	H4A—C4—H4B	108.1
O2—N3—O1	122.48 (17)	N2—C5—C6	121.83 (15)
O2—N3—C8	118.60 (17)	N2—C5—C10	120.60 (14)
O1—N3—C8	118.90 (17)	C6—C5—C10	117.52 (15)
H3C—O3—H3D	103 (2)	C7—C6—C5	121.15 (15)
N1—C1—C2	109.55 (15)	C7—C6—H6A	119.4
N1—C1—H1A	109.8	C5—C6—H6A	119.4
C2—C1—H1A	109.8	C6—C7—C8	119.67 (16)
N1—C1—H1B	109.8	C6—C7—H7A	120.2
C2—C1—H1B	109.8	C8—C7—H7A	120.2
H1A—C1—H1B	108.2	C7—C8—C9	120.92 (16)
N2—C2—C1	111.17 (15)	C7—C8—N3	119.60 (16)
N2—C2—H2A	109.4	C9—C8—N3	119.48 (16)
C1—C2—H2A	109.4	C10—C9—C8	119.44 (16)
N2—C2—H2B	109.4	C10—C9—H9A	120.3
C1—C2—H2B	109.4	C8—C9—H9A	120.3
H2A—C2—H2B	108.0	C9—C10—C5	121.27 (15)
N1—C3—C4	110.06 (15)	C9—C10—H10A	119.4
N1—C3—H3A	109.6	C5—C10—H10A	119.4
C4—C3—H3A	109.6

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3D···Cl1^i	0.85 (2)	2.32 (2)	3.1681 (18)	176 (3)
O3—H3C···Cl1^ii	0.87 (2)	2.27 (2)	3.135 (2)	170 (4)
N1—H1D···O3^iii	0.90	1.88	2.741 (2)	161
N1—H1C···Cl1	0.90	2.21	3.0994 (17)	168

Symmetry codes: (i) x, y+1, z+1; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+1, −z+1.