Bis[1-(2,3-di­methyl­phen­yl)piperazine-1,4-diium] bis­(oxonium) cyclo­hexa­phosphate dihydrate

Iness Ameur; Sonia Abid; Salem S Al-Deyab; Mohamed Rzaigui

doi:10.1107/S1600536813016759

. 2013 Jun 22;69(Pt 7):o1145–o1146. doi: 10.1107/S1600536813016759

Bis[1-(2,3-dimethylphenyl)piperazine-1,4-diium] bis(oxonium) cyclohexaphosphate dihydrate

Iness Ameur ^a, Sonia Abid ^a,^*, Salem S Al-Deyab ^b, Mohamed Rzaigui ^a

PMCID: PMC3770409 PMID: 24046694

Abstract

In the title compound, 2C₁₂H₂₀N₂ ²⁺·2H₃O⁺·P₆O₁₈ ⁶⁻·2H₂O, a protonated water molecule bridges the centrosymmetrical anionic P₆O₁₈ ring via O—H⋯O hydrogen bonds. The centrosymmetric hydrogen-bonded rings formed by four oxonium cations and four phosphate anions can be described by an R ₄ ⁸(36) graph-set motif. The ring motifs are connected by hydrogen bonds into inorganic layers perpendicular to [100]. The 1-(2,3-dimethylphenyl)piperazine-1,4-diium cations are located between the layers, compensating their negative charge and establishing N—H⋯O hydrogen bonds with the O atoms of the anionic framework.

Related literature

For background to the chemistry of cyclohexaphosphate, see: Durif (1995 ▶); Amri et al. (2008 ▶); Marouani et al. (2010 ▶). For applications of piperazine derivatives, see: Kaur et al. (2010 ▶); Eswaran et al. (2010 ▶); Chou et al. (2010 ▶); Chen et al. (2004 ▶); Shingalapur et al. (2009 ▶). For related structures with cyclohexaphosphate rings, see: Abid et al. (2011 ▶); Ameur et al. (2013 ▶); Amri et al. (2009 ▶). For related structures with 1-phenylpiperazine-1,4-diium salts, see: Marouani et al. (2010 ▶); Ben Gharbia et al. (2005 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶). For graph-set descriptions of hydrogen-bond ring motifs, see: Bernstein et al. (1995 ▶). For the synthesis of the precursor, see: Schülke & Kayser (1985 ▶). graphic file with name e-69-o1145-scheme1.jpg

Experimental

Crystal data

2C₁₂H₂₀N₂ ²⁺·2H₃O⁺·P₆O₁₈ ⁶⁻·2H₂O
M _r = 932.50
Monoclinic,
a = 8.630 (6) Å
b = 14.495 (4) Å
c = 17.072 (3) Å
β = 114.93 (4)°
V = 1936.6 (15) Å³
Z = 2
Ag Kα radiation
λ = 0.56085 Å
μ = 0.20 mm⁻¹
T = 293 K
0.60 × 0.40 × 0.10 mm

Data collection

Nonius MACH-3 diffractometer
Absorption correction: refined from ΔF (Walker & Stuart, 1983 ▶) T _min = 0.892, T _max = 0.981
12060 measured reflections
9442 independent reflections
5475 reflections with I > 2σ(I)
R _int = 0.031
2 standard reflections every 120 min intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.152
S = 0.99
9442 reflections
253 parameters
H-atom parameters constrained
Δρ_max = 0.87 e Å⁻³
Δρ_min = −0.67 e Å⁻³

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1996 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813016759/jj2168sup1.cif

e-69-o1145-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813016759/jj2168Isup2.hkl

e-69-o1145-Isup2.hkl^{(452.5KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
OW1—H1W1⋯O9	0.79	1.84	2.614 (3)	166
OW1—H2W1⋯O2ⁱ	0.86	1.97	2.781 (3)	159
OW2—H1W2⋯O8	0.82	1.69	2.487 (2)	167
OW2—H2W2⋯OW1ⁱⁱ	0.80	1.77	2.503 (3)	152
OW2—H3W2⋯O6ⁱⁱⁱ	0.85	1.64	2.481 (2)	178
N1—H1⋯O1	0.91	1.82	2.690 (2)	160
N2—H2A⋯O5^iv	0.90	1.87	2.714 (2)	156
N2—H2B⋯O2^v	0.90	2.10	2.858 (3)	142
N2—H2B⋯O5^v	0.90	2.28	2.916 (3)	127

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

This work was supported by the Tunisian Ministry of H. E. Sc. R. and the Deanship of Scientific Research at King Saud University (research group project No. RGP-VPP-089).

supplementary crystallographic information

Comment

The literature reports several cyclohexaphosphates of organic cations and/or inorganic cations (Durif,1995). However, cyclohexaphosphates of mixed cations associating the oxoniumion are still relatively very limited. Up to now, only two examples have been known and structurally characterized (Amri et al., 2008, Marouani et al.,2010). In this work, we report the preparation and the structural investigation of a new organic oxonium cyclohexaphospohate, 2(C₁₂H₂₀N₂)²⁺.2H₃O⁺.P₆O₁₈^6-. 2H₂O, (I), where the organic species is the piperazinium group. Piperazine derivatives have wide range of applications in pharmaceuticals as antimalarial (Kaur et al., 2010), anti-tuberculosis (Eswaran et al., 2010), antitumor (Chou et al., 2010), anticancer (Chen et al., 2004) and antiviral (Shingalapur et al., 2009) agents.

The asymmetric unit of (I) includes one-half of the P₆O₁₈ ring lying on an inversion center (1/2, 1/2, 0), one 1-(2,3-dimethylphenyl) piperazine-1,4-diium cation, one hydronium cation and one water molecule (Fig.1). As shown in Fig.2, the hydronium cations (OW2) bridge the anionic ring to form 2-D corrugated layers, located at x = 1/2 and parallel to the bc-plane. The result of these interactions is the formation of a 36-membered ring with an R₄⁸(36) graph-set motif (Bernstein et al., 1995). The centre of 36-membered ring is situated on a crystallographic centre of symmetry. Inside these layers, the phosphoric rings display a chair conformation with geometrical characteristics that show no significant difference in deviation from those observed in other cyclohexaphosphates having the same internal symmetry -1 (Amri et al., 2009; Abid et al., 2011; Ameur et al., 2013). The anchorage of the water molecule OW1 and the organic cations is made by short and long H-bonds, ensuring the interconnection between layers, and thus giving rise to a three-dimensional network. The benzyl ring (C5—C10) is essentially planar with an r.m.s. deviation of 0.0047 Å and is orientated at an angle of 54.09 (5)° with respect to the piperazine ring (Fig.3). The piperazine (N1–N2/C1–C4) ring adopts a chair conformation [puckering parameters: Q_T = 0.577 (2) Å, θ = 0.7 (2)° and φ = 326 (12) (Cremer & Pople, 1975)] with atoms N1 and N2 deviating by -0.683 (2) and 0.657 (2) Å from the least-squares plane defined by the remaining atoms in the ring. The interatomic bond lengths (C—C,N—C) and angles in (C—C—C,C—N—C) do not show significant deviation from those reported in a related 1-phenylpiperazine-1,4-diium salt (Ben Gharbia et al., 2005). An extensive network of N—H···O and O—H···O hydrogen-bonding interactions link the components of the structure into a three-dimensional network (Fig. 3).

Experimental

Crystals of the title compound were prepared by adding dropwise an ethanolic solution (5 ml) of 1-(2,3)dimethlphenylpiperazine (4 mmol) to an aqueous solution (10 ml) of cyclohexaphosphoric acid (2 mmol). The reaction mixture was stirred at room temperature for few minutes. X-ray quality crystals of the title compound appeared after a few days. The cyclohexaphosphoric acid H₆P₆O₁₈, was produced from Li₆P₆O₁₈.6H₂O, prepared according to the procedure of Schülke and Kayser (Schülke & Kayser, 1985), through an ion-exchange resin in H-state (Amberlite IR 120).