organic compounds
2-Chlorobenzene-1,4-diaminium bis(dihydrogenphosphate)
aLaboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna, Tunisia, and bDepartment of Chemistry, Youngstown State University, One University Plaza, Youngstown, Ohio 44555-3663, USA
*Correspondence e-mail: cherif_bennasr@yahoo.fr
The 6H9ClN22+·2H2PO4−, contains two dihydrogenphosphate anions and one 2-chlorobenzene-1,4-diaminium dication. The H2PO4− anions are interconnected through strong O—H⋯O hydrogen bonds to form two-dimensional infinite layers parallel to (001). The organic entities are anchored to the inorganic layers through N—H⋯O hydrogen bonds, and through weak C—Cl⋯O halogen bonds [3.159 (2) Å, 140.48 (7)°]. No π–π stacking interactions between neighboring aromatic rings or C—H⋯π interactions towards them are observed. Minor disorder is observed for the Cl atom and one hydroxy group [minor-component occupancy = 3.29 (9)%].
of the title salt, CRelated literature
For common applications of organic phosphate complexes, see: Masse et al. (1993). For network geometries, see: Rayes et al. (2004); Oueslati et al. (2005). For reference structural data, see: Kaabi et al. (2004); Chtioui & Jouini (2006). For halogen bonding, see: Metrangolo & Resnati (2001, 2008); Politzer et al. (2007). For van der Waals radii, see: Bondi (1964).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2011); cell SAINT (Bruker, 2011); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and SHELXLE (Hübschle et al., 2011); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL and publCIF (Westrip, 2010).
Supporting information
10.1107/S1600536812051434/ru2048sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812051434/ru2048Isup2.hkl
Crystals of the title compound were prepared at room temperature by slow addition of a solution of orthophosphoric acid (6 mmol in 20 ml of water) to an alcoholic solution of 2-chlorobenzene-1,4-diamine (3 mmol in 20 ml of ethanol). The acid was added until the alcoholic solution became turbid. After filtration, the solution was allowed to slowly evaporate at room temperature over several days leading to formation of transparent prismatic crystals with suitable dimensions for single-crystal structural analysis (yield 58%). The crystals are stable for months under normal conditions of temperature and humidity.
The chlorine atom is disordered over two chemically equivalent positions with a small but noticable presence of the second moiety (refined value 3.29 (9)%). Associated with this disorder is disorder of one of the phosphate hydroxyl groups, O6. The minor moiety chlorine and oxygen atoms were constrained to have the same ADPs as their major moiety counterparts. Due to the low prevalence of the minor moiety no disorder was modeled for the aromatic ring the Cl atom is bonded to, despite of the obviously unrealistic C—C—Cl angles for the minor Cl atom.
All non hydrogen atoms were refined anisotropically. All H atoms were located in difference density Fourier maps, but were then placed in calculated positions riding on their respective
with C—H distances of 0.95, N—H distances of 0.91 Å, and O—H distances of 0.84 Å. Ammonium and hydroxyl H atoms were allowed to rotate but not to tip to best fit the observed electron density distribution. The position of the hydrogen atom of the minor occupied hydroxyl group was refined with a damping factor (DAMP 2000 in SHELXTL (Sheldrick, 2008)). In the final cycles after removal of the damping factor its position was set to ride on its carrier oxygen atom. Uiso(H) values were constrained to be 1.2 Ueq(C) of the parent atom for C bound H atoms, and 1.5 times Ueq(N/O) for N and O bound H atoms.The compound was refined as a racemic twin. The twin ratio refined to 0.89 (4) to 0.11 (4).
Data collection: APEX2 (Bruker, 2011); cell
SAINT (Bruker, 2011); data reduction: SAINT (Bruker, 2011); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and SHELXLE (Hübschle et al., 2011); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010).Fig. 1. A view of the title compound, showing 50% probability displacement ellipsoids and arbitrary spheres for the H atoms. | |
Fig. 2. Projection along the c-axis of an inorganic layer in the structure of the title compound. Hydrogen bonds are denoted as red broken lines. | |
Fig. 3. Projection of the structure along the b-axis. Hydrogen bonds are denoted as red broken lines, halogen bonds as black broken lines. For the disordered Cl atom, only the major part is shown. |
C6H9ClN22+·2H2PO4− | F(000) = 696 |
Mr = 338.57 | Dx = 1.752 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 7956 reflections |
a = 7.0084 (8) Å | θ = 2.6–31.8° |
b = 7.9404 (9) Å | µ = 0.58 mm−1 |
c = 23.064 (3) Å | T = 100 K |
V = 1283.5 (3) Å3 | Block, colourless |
Z = 4 | 0.55 × 0.52 × 0.51 mm |
Bruker SMART APEX CCD diffractometer | 4134 independent reflections |
Radiation source: fine-focus sealed tube | 4060 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.021 |
ω scans | θmax = 32.0°, θmin = 2.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2011) | h = −6→10 |
Tmin = 0.689, Tmax = 0.746 | k = −11→11 |
11671 measured reflections | l = −33→33 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.025 | H-atom parameters constrained |
wR(F2) = 0.064 | w = 1/[σ2(Fo2) + (0.0328P)2 + 0.2706P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max = 0.002 |
4134 reflections | Δρmax = 0.44 e Å−3 |
186 parameters | Δρmin = −0.27 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 1694 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.11 (4) |
C6H9ClN22+·2H2PO4− | V = 1283.5 (3) Å3 |
Mr = 338.57 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.0084 (8) Å | µ = 0.58 mm−1 |
b = 7.9404 (9) Å | T = 100 K |
c = 23.064 (3) Å | 0.55 × 0.52 × 0.51 mm |
Bruker SMART APEX CCD diffractometer | 4134 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2011) | 4060 reflections with I > 2σ(I) |
Tmin = 0.689, Tmax = 0.746 | Rint = 0.021 |
11671 measured reflections |
R[F2 > 2σ(F2)] = 0.025 | H-atom parameters constrained |
wR(F2) = 0.064 | Δρmax = 0.44 e Å−3 |
S = 1.11 | Δρmin = −0.27 e Å−3 |
4134 reflections | Absolute structure: Flack (1983), 1694 Friedel pairs |
186 parameters | Absolute structure parameter: 0.11 (4) |
0 restraints |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
C1 | 1.3321 (2) | 0.15359 (17) | 0.76907 (6) | 0.0129 (2) | |
H1 | 1.4496 | 0.1155 | 0.7849 | 0.015* | 0.0329 (9) |
C2 | 1.18845 (19) | 0.20920 (16) | 0.80593 (5) | 0.0109 (2) | |
C3 | 1.0154 (2) | 0.26208 (16) | 0.78290 (5) | 0.0131 (2) | |
H3 | 0.9161 | 0.2984 | 0.8080 | 0.016* | |
C4 | 0.9869 (2) | 0.26197 (17) | 0.72312 (5) | 0.0133 (2) | |
H4 | 0.8686 | 0.2977 | 0.7072 | 0.016* | |
C5 | 1.13375 (19) | 0.20895 (16) | 0.68709 (5) | 0.0108 (2) | |
C6 | 1.30604 (19) | 0.15298 (17) | 0.70924 (6) | 0.0129 (2) | |
H6 | 1.4044 | 0.1149 | 0.6841 | 0.015* | 0.9671 (9) |
N1 | 1.21619 (16) | 0.20932 (15) | 0.86858 (4) | 0.01139 (19) | |
H1A | 1.2127 | 0.1016 | 0.8820 | 0.017* | |
H1B | 1.1218 | 0.2704 | 0.8857 | 0.017* | |
H1C | 1.3314 | 0.2560 | 0.8771 | 0.017* | |
N2 | 1.10964 (17) | 0.21095 (15) | 0.62440 (4) | 0.01136 (19) | |
H2A | 1.2140 | 0.2587 | 0.6076 | 0.017* | |
H2B | 1.0040 | 0.2719 | 0.6151 | 0.017* | |
H2C | 1.0959 | 0.1036 | 0.6112 | 0.017* | |
O1 | 1.22585 (15) | −0.22787 (14) | 0.49473 (4) | 0.01666 (19) | |
H1D | 1.1180 | −0.2666 | 0.4861 | 0.025* | |
O2 | 1.44777 (14) | −0.15775 (12) | 0.57261 (4) | 0.01261 (17) | |
O3 | 1.20902 (15) | −0.39458 (12) | 0.58809 (4) | 0.01507 (19) | |
H3A | 1.2990 | −0.4584 | 0.5783 | 0.023* | |
O4 | 1.09007 (14) | −0.10621 (12) | 0.58851 (4) | 0.01272 (18) | |
O5 | 1.66727 (16) | 0.25284 (15) | 0.50298 (4) | 0.0190 (2) | |
H5 | 1.7753 | 0.2093 | 0.4981 | 0.029* | |
O6 | 1.64342 (16) | 0.10590 (12) | 0.60055 (5) | 0.01469 (19) | 0.9671 (9) |
H6A | 1.5618 | 0.0408 | 0.5861 | 0.022* | 0.9671 (9) |
O6B | 1.690 (5) | 0.096 (4) | 0.5735 (15) | 0.01469 (19) | 0.0329 (9) |
H6B | 1.5907 | 0.0361 | 0.5728 | 0.022* | 0.0329 (9) |
O7 | 1.78483 (14) | 0.38754 (12) | 0.59744 (4) | 0.01286 (18) | |
O8 | 1.43146 (14) | 0.34988 (12) | 0.57179 (4) | 0.01380 (18) | |
P1 | 1.24379 (5) | −0.21374 (4) | 0.562311 (13) | 0.00959 (7) | |
P2 | 1.63262 (5) | 0.28287 (4) | 0.569303 (13) | 0.00987 (7) | |
Cl1 | 1.54768 (5) | 0.08734 (5) | 0.796787 (14) | 0.01984 (9) | 0.9671 (9) |
Cl1B | 1.5045 (15) | 0.0693 (15) | 0.6861 (4) | 0.01984 (9) | 0.0329 (9) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0096 (5) | 0.0148 (5) | 0.0141 (5) | 0.0021 (5) | −0.0011 (4) | 0.0012 (4) |
C2 | 0.0123 (5) | 0.0106 (5) | 0.0100 (5) | −0.0001 (5) | −0.0002 (4) | 0.0011 (4) |
C3 | 0.0119 (6) | 0.0155 (5) | 0.0119 (5) | 0.0031 (5) | 0.0008 (4) | 0.0000 (4) |
C4 | 0.0108 (6) | 0.0171 (6) | 0.0120 (5) | 0.0040 (5) | 0.0002 (4) | 0.0008 (4) |
C5 | 0.0133 (6) | 0.0101 (5) | 0.0091 (4) | −0.0008 (5) | 0.0002 (4) | 0.0000 (4) |
C6 | 0.0105 (6) | 0.0150 (5) | 0.0132 (5) | 0.0010 (5) | 0.0010 (5) | −0.0011 (4) |
N1 | 0.0123 (5) | 0.0118 (4) | 0.0100 (4) | 0.0000 (4) | −0.0011 (4) | 0.0004 (3) |
N2 | 0.0123 (5) | 0.0127 (4) | 0.0091 (4) | −0.0006 (4) | 0.0006 (4) | −0.0009 (4) |
O1 | 0.0131 (4) | 0.0260 (5) | 0.0109 (4) | −0.0043 (4) | 0.0005 (3) | −0.0040 (4) |
O2 | 0.0092 (4) | 0.0137 (4) | 0.0150 (4) | −0.0019 (4) | −0.0006 (4) | 0.0000 (3) |
O3 | 0.0132 (5) | 0.0101 (4) | 0.0220 (4) | −0.0001 (4) | 0.0028 (4) | 0.0011 (3) |
O4 | 0.0125 (4) | 0.0111 (4) | 0.0145 (4) | 0.0010 (4) | 0.0030 (3) | −0.0013 (3) |
O5 | 0.0158 (5) | 0.0301 (6) | 0.0111 (4) | 0.0048 (4) | 0.0007 (4) | −0.0045 (3) |
O6 | 0.0168 (5) | 0.0097 (4) | 0.0176 (5) | −0.0014 (4) | −0.0033 (4) | 0.0011 (3) |
O6B | 0.0168 (5) | 0.0097 (4) | 0.0176 (5) | −0.0014 (4) | −0.0033 (4) | 0.0011 (3) |
O7 | 0.0129 (4) | 0.0110 (4) | 0.0146 (4) | −0.0013 (4) | −0.0023 (3) | −0.0019 (3) |
O8 | 0.0105 (4) | 0.0142 (4) | 0.0167 (4) | 0.0011 (4) | 0.0007 (4) | 0.0000 (3) |
P1 | 0.00924 (14) | 0.00981 (12) | 0.00974 (12) | −0.00071 (12) | 0.00054 (11) | −0.00102 (11) |
P2 | 0.00882 (14) | 0.00994 (12) | 0.01085 (13) | 0.00014 (12) | −0.00035 (11) | −0.00110 (11) |
Cl1 | 0.01175 (15) | 0.03455 (19) | 0.01321 (14) | 0.00876 (14) | −0.00169 (12) | 0.00062 (13) |
Cl1B | 0.01175 (15) | 0.03455 (19) | 0.01321 (14) | 0.00876 (14) | −0.00169 (12) | 0.00062 (13) |
C1—C2 | 1.3898 (18) | N2—H2B | 0.9100 |
C1—C6 | 1.3921 (17) | N2—H2C | 0.9100 |
C1—Cl1 | 1.7228 (14) | O1—P1 | 1.5678 (10) |
C1—H1 | 0.9500 | O1—H1D | 0.8400 |
C2—C3 | 1.3889 (18) | O2—P1 | 1.5159 (10) |
C2—N1 | 1.4578 (14) | O3—P1 | 1.5731 (10) |
C3—C4 | 1.3933 (17) | O3—H3A | 0.8400 |
C3—H3 | 0.9500 | O4—P1 | 1.5016 (10) |
C4—C5 | 1.3879 (18) | O5—P2 | 1.5670 (10) |
C4—H4 | 0.9500 | O5—H5 | 0.8400 |
C5—C6 | 1.3843 (18) | O6—P2 | 1.5811 (11) |
C5—N2 | 1.4558 (14) | O6—H6A | 0.8400 |
C6—Cl1B | 1.631 (10) | O6—H6B | 0.9243 |
C6—H6 | 0.9500 | O6B—P2 | 1.54 (3) |
N1—H1A | 0.9100 | O6B—H6B | 0.8400 |
N1—H1B | 0.9100 | O7—P2 | 1.5000 (10) |
N1—H1C | 0.9100 | O8—P2 | 1.5080 (10) |
N2—H2A | 0.9100 | ||
C2—C1—C6 | 120.83 (12) | C5—N2—H2A | 109.5 |
C2—C1—Cl1 | 120.36 (10) | C5—N2—H2B | 109.5 |
C6—C1—Cl1 | 118.81 (10) | H2A—N2—H2B | 109.5 |
C2—C1—H1 | 119.6 | C5—N2—H2C | 109.5 |
C6—C1—H1 | 119.6 | H2A—N2—H2C | 109.5 |
C3—C2—C1 | 119.64 (11) | H2B—N2—H2C | 109.5 |
C3—C2—N1 | 119.69 (11) | P1—O1—H1D | 109.5 |
C1—C2—N1 | 120.65 (11) | P1—O3—H3A | 109.5 |
C2—C3—C4 | 120.22 (12) | P2—O5—H5 | 109.5 |
C2—C3—H3 | 119.9 | P2—O6—H6A | 109.5 |
C4—C3—H3 | 119.9 | P2—O6—H6B | 101.4 |
C5—C4—C3 | 119.11 (12) | P2—O6B—H6B | 109.2 |
C5—C4—H4 | 120.4 | O4—P1—O2 | 116.53 (6) |
C3—C4—H4 | 120.4 | O4—P1—O1 | 112.54 (6) |
C6—C5—C4 | 121.54 (11) | O2—P1—O1 | 104.62 (6) |
C6—C5—N2 | 118.11 (11) | O4—P1—O3 | 104.82 (5) |
C4—C5—N2 | 120.34 (11) | O2—P1—O3 | 110.77 (6) |
C5—C6—C1 | 118.63 (12) | O1—P1—O3 | 107.34 (6) |
C5—C6—Cl1B | 138.9 (4) | O7—P2—O8 | 116.93 (6) |
C1—C6—Cl1B | 102.3 (4) | O7—P2—O6B | 108.8 (12) |
C5—C6—H6 | 120.7 | O8—P2—O6B | 125.5 (13) |
C1—C6—H6 | 120.7 | O7—P2—O5 | 113.36 (6) |
C2—N1—H1A | 109.5 | O8—P2—O5 | 103.63 (6) |
C2—N1—H1B | 109.5 | O6B—P2—O5 | 82.8 (13) |
H1A—N1—H1B | 109.5 | O7—P2—O6 | 105.14 (6) |
C2—N1—H1C | 109.5 | O8—P2—O6 | 109.93 (6) |
H1A—N1—H1C | 109.5 | O5—P2—O6 | 107.60 (6) |
H1B—N1—H1C | 109.5 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O7i | 0.91 | 1.76 | 2.6726 (15) | 175 |
N1—H1B···O4ii | 0.91 | 1.88 | 2.7807 (15) | 172 |
N1—H1C···O2iii | 0.91 | 2.05 | 2.9155 (15) | 158 |
N2—H2A···O8 | 0.91 | 1.88 | 2.7886 (15) | 178 |
N2—H2B···O7iv | 0.91 | 1.84 | 2.7450 (15) | 178 |
N2—H2C···O4 | 0.91 | 1.75 | 2.6545 (15) | 175 |
O1—H1D···O2v | 0.84 | 1.90 | 2.6525 (14) | 148 |
O3—H3A···O8vi | 0.84 | 1.79 | 2.5863 (14) | 158 |
O5—H5···O8vii | 0.84 | 2.00 | 2.6585 (14) | 134 |
O6—H6A···O2 | 0.84 | 1.79 | 2.5841 (14) | 156 |
O6B—H6B···O2 | 0.84 | 1.84 | 2.63 (3) | 157 |
Symmetry codes: (i) −x+3, y−1/2, −z+3/2; (ii) −x+2, y+1/2, −z+3/2; (iii) −x+3, y+1/2, −z+3/2; (iv) x−1, y, z; (v) x−1/2, −y−1/2, −z+1; (vi) x, y−1, z; (vii) x+1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C6H9ClN22+·2H2PO4− |
Mr | 338.57 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 100 |
a, b, c (Å) | 7.0084 (8), 7.9404 (9), 23.064 (3) |
V (Å3) | 1283.5 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.58 |
Crystal size (mm) | 0.55 × 0.52 × 0.51 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2011) |
Tmin, Tmax | 0.689, 0.746 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11671, 4134, 4060 |
Rint | 0.021 |
(sin θ/λ)max (Å−1) | 0.745 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.025, 0.064, 1.11 |
No. of reflections | 4134 |
No. of parameters | 186 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.44, −0.27 |
Absolute structure | Flack (1983), 1694 Friedel pairs |
Absolute structure parameter | 0.11 (4) |
Computer programs: APEX2 (Bruker, 2011), SAINT (Bruker, 2011), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and SHELXLE (Hübschle et al., 2011), SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O7i | 0.91 | 1.76 | 2.6726 (15) | 175.2 |
N1—H1B···O4ii | 0.91 | 1.88 | 2.7807 (15) | 172.3 |
N1—H1C···O2iii | 0.91 | 2.05 | 2.9155 (15) | 158.1 |
N2—H2A···O8 | 0.91 | 1.88 | 2.7886 (15) | 178.0 |
N2—H2B···O7iv | 0.91 | 1.84 | 2.7450 (15) | 177.7 |
N2—H2C···O4 | 0.91 | 1.75 | 2.6545 (15) | 174.8 |
O1—H1D···O2v | 0.84 | 1.90 | 2.6525 (14) | 148.0 |
O3—H3A···O8vi | 0.84 | 1.79 | 2.5863 (14) | 157.8 |
O5—H5···O8vii | 0.84 | 2.00 | 2.6585 (14) | 134.2 |
O6—H6A···O2 | 0.84 | 1.79 | 2.5841 (14) | 155.9 |
O6B—H6B···O2 | 0.84 | 1.84 | 2.63 (3) | 157.4 |
Symmetry codes: (i) −x+3, y−1/2, −z+3/2; (ii) −x+2, y+1/2, −z+3/2; (iii) −x+3, y+1/2, −z+3/2; (iv) x−1, y, z; (v) x−1/2, −y−1/2, −z+1; (vi) x, y−1, z; (vii) x+1/2, −y+1/2, −z+1. |
Acknowledgements
The authors acknowledge the support provided by the Secretary of State for Scientific Research and Technology of Tunisia. The diffractometer was funded by NSF grant No. 0087210, by Ohio Board of Regents grant CAP-491 and by YSU.
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In organic-cation monophosphates, the phosphate anions generally observed are the partially protonated acidic ones H2PO4- or HPO42-. In the solid state such anions are generally interconnected through strong hydrogen bonds so as to build infinite networks with various geometries (Rayes et al., 2004; Oueslati et al., 2005). If these organic-cation monophosphates hybrid materials crystallize in a noncentrosymmetric setting they are of particular interest as nonlinear optical (NLO) materials (Masse et al., 1993). The present work is devoted to the structure of an organic-cation hydrogenphosphate, C6H9ClN2(H2PO4)2, formed by the reaction of 2-chlorobenzene-1,4-diamine with orthophosphoric acid, which crystallized in a non-centrosymmetric setting.
The title organic-inorganic hybrid material, while made from achiral components, crystallizes in the chiral space group P212121. The crystal investigated is partially racemically twinned, with a twinning ratio of 0.89 (4) to 0.11 (4). Its structure consists of one 2-chlorobenzene-1,4-diaminium dication and two crystallographically distinct H2PO4- anions (Fig. 1). The chlorine atom is disordered over two chemically equivalent positions with a small but noticable presence of the second moiety (refined value 3.29 (9)%). Associated with this disorder is disorder of one phosphate hydroxyl group of one of the H2P(2)O4- anions, O6. Where not mentioned otherwise, this disorder is ignored in the following more detailed discussion of the structure.
The HPO42- anions show two types of P—O distances depending on whether the oxygen atoms are hydrogen donors or acceptors. As expected, the P—OH distances, varying between 1.54 (3) and 1.581 (1) Å, are significantly longer than the other P—O distances ranging from 1.500 (1) to 1.516 (1) Å. This is in agreement with the literature data (Chtioui & Jouini, 2006; Kaabi et al., 2004). Figure 2 shows that the H2PO4- anions are interconnected through O—H···O hydrogen bonds to form a two dimensional layer spreading parallel to the (0 0 1) plane at z = 0, 1/2 and 1 (Fig. 3). The organic cations, assembled in layers parallel to the H2PO4- anions at z = 1/4 and 3/4, are anchored to the inorganic layers through N—H···O hydrogen bonds whose geometrical characteristics are given in Table 1. The projection of the whole arrangement along the c-axis (Fig. 3) shows the alternating cationic and anionic layers. The structure also features a weak C—Cl···O halogen bond between the chlorine atom and one of the H2PO4- phosphate ions, a type of interaction that has recently attracted high levels of interest due to the observation of such interactions between halogenated compounds and the phosphate moieties in DNA (see e.g. Metrangolo & Resnati, 2008). In the title compound the Cl···O distance between Cl1 and O3i is 3.159 (2) Å, the C—Cl···O angle 140.48 (7)° (symmetry operator (i) -x + 3, y + 1/2, -z + 3/2), the equivalent values for the interaction of the minor occupied Cl atom Cl1B with O6B are 2.91 (5) Å and 130 (1)°. While the Cl···O distances are shorter than the sum of the van der Waals radii of chlorine and oxygen (ca 3.3 Å, Bondi, 1964), the angles observed are on the small side for C—Cl···O halogen bonds (160–180°, see e.g. Politzer et al., 2007; Metrangolo & Resnati, 2001), indicating that the interactions observed are quite weak and more likely a result of the stronger hydrogen bonding interactions rather than one of the major driving forces determining the outcome of the assembly of the structural components of the title compound. No π-π stacking interactions between neighboring aromatic rings or significant C—H···π interactions towards them are observed.