Crystal structure of 2-methyl­piperazine-1,4-diium bis­(hydrogen maleate)

Intissar Wecharine; Arto Valkonen; Mohamed Rzaigui; Wajda Smirani Sta

doi:10.1107/S2056989015003102

. 2015 Feb 21;71(Pt 3):o193–o194. doi: 10.1107/S2056989015003102

Crystal structure of 2-methylpiperazine-1,4-diium bis(hydrogen maleate)

Intissar Wecharine ^a, Arto Valkonen ^b, Mohamed Rzaigui ^a, Wajda Smirani Sta ^a,^*

PMCID: PMC4350694 PMID: 25844244

Abstract

In the title salt, C₅H₁₄N₂ ²⁺·2C₄H₃O₄ ⁻, the asymmetric unit contains two independent 2-methylpiperazinium dications, which comprise a racemic pair, and four hydrogen maleate monoanions. In the roughly planar hydrogen maleate anions, intramolecular O—H⋯O hydrogen bonds generate S(7) rings. In the crystal, the four independent anions are linked to the 2-methylpiperazinium cations through N—H⋯O hydrogen bonds, forming two-dimensional layered structures lying parallel to (001).

Keywords: crystal structure; 2-methylpiperazine-1,4-diium; hydrogen maleate; hydrogen bonding

Related literature

For maleate geometry and its S(7) ring formation, see: Anitha et al. (2012 ▸). For background on 2-methylpiperazine salts, see: Hajlaoui et al. (2011 ▸); Wilkinson & Harrison (2007 ▸). For a similar structure, see: Mathlouthi et al. (2014 ▸). For puckering parameters, see: Cremer & Pople (1975 ▸). graphic file with name e-71-0o193-scheme1.jpg

Experimental

Crystal data

C₅H₁₄N₂ ²⁺·2C₄H₃O₄ ⁻
M _r = 332.31
Triclinic,
a = 11.4678 (9) Å
b = 11.4919 (9) Å
c = 13.3404 (13) Å
α = 71.692 (8)°
β = 75.572 (8)°
γ = 74.303 (7)°
V = 1580.7 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 170 K
0.33 × 0.14 × 0.07 mm

Data collection

Agilent SuperNova (single source at offset, Eos) diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2013 ▸) T _min = 0.970, T _max = 0.990
10102 measured reflections
6990 independent reflections
5127 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.133
S = 1.06
6990 reflections
451 parameters
8 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2013 ▸); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2011 (Burla et al., 2012 ▸); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008 ▸, 2015 ▸) within WinGX (Farrugia, 2012 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸); software used to prepare material for publication: SHELXL2013.

Supplementary Material

Crystal structure: contains datablock(s) I, General. DOI: 10.1107/S2056989015003102/zs2325sup1.cif

e-71-0o193-sup1.cif^{(364.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015003102/zs2325Isup2.hkl

e-71-0o193-Isup2.hkl^{(383KB, hkl)}

Click here for additional data file.^{(6.4KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015003102/zs2325Isup3.cml

Click here for additional data file.^{(1.6MB, tif)}

. DOI: 10.1107/S2056989015003102/zs2325fig1.tif

The two dications and the four anions in the asymmetric unit of the title salt, with atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 30% probability level.

Click here for additional data file.^{(1.7MB, tif)}

c . DOI: 10.1107/S2056989015003102/zs2325fig2.tif

A view of a layerered structure of the title compound along the c axis showing the two-dimensional layers lying parallel to the (001) plane. Hydrogen bonds are denoted by dashed lines.

Click here for additional data file.^{(2MB, tif)}

b . DOI: 10.1107/S2056989015003102/zs2325fig3.tif

The structure of the title compound viewed along the b axis.

CCDC reference: 1049285

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N1H1CO4C ⁱ	0.93(1)	1.91(2)	2.802(2)	162(2)
N1H1DO1	0.93(2)	1.89(2)	2.801(2)	166(2)
N2H2EO1A	0.94(2)	1.80(2)	2.723(2)	168(2)
N2H2FO3B ⁱⁱ	0.95(2)	2.50(2)	3.187(2)	129(2)
N2H2FO4B ⁱⁱ	0.95(2)	1.82(2)	2.760(2)	169(2)
N1AH1EO3	0.96(1)	2.59(2)	3.279(2)	129(2)
N1AH1EO4	0.96(1)	1.86(2)	2.811(2)	169(2)
N1AH1FO1C ⁱⁱⁱ	0.92(2)	1.90(2)	2.787(2)	162(2)
N2AH2GO4A	0.92(2)	1.81(2)	2.710(2)	164(2)
N2AH2HO1B ^iv	0.95(2)	1.82(2)	2.764(2)	168(2)
N2AH2HO2B ^iv	0.95(2)	2.51(2)	3.191(2)	128(2)
O2H2O3	1.15(3)	1.28(3)	2.4258(19)	174(2)
O2AH2IO3A	1.21(2)	1.22(2)	2.4240(19)	175(2)
O3BH2JO2B	1.18(2)	1.24(2)	2.4174(18)	177(2)
O2CH2KO3C	1.20(2)	1.22(2)	2.4192(19)	174(2)

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

supplementary crystallographic information

S1. Comment

Our ongoing studies of novel salts of maleic acid with related substances arises from the fact that hydrogen maleate anions in these systems possess short but highly strained hydrogen bonds in salts with racemic amines (Hajlaoui et al., 2011; Wilkinson & Harrison, 2007). We report herein the synthesis and structure of the title hydrogen maleate salt with 2-methylpiperazine, (C₅ H₁₄ N₂)²⁺ 2(C₄H₃O₄^-).

As shown in Fig. 1, the asymmetric unit of the title salt contains two independent 2-methylpipirazinium dications which form a racemic pair [C1(R) and C1A(S)] and four hydrogen maleate anions. In the planar hydrogen maleate anions, short intramolecular O—H···O hydrogen bonds (Table 1) generate S(7) rings. This is common in many structures of maleic acid as the cis disposition of the alkene places hydrogen-bonding donors and acceptors in close proximity (Mathlouthi et al., 2014).

In the crystal (Fig. 2), the piperazinium groups of the cation are hydrogen-bonded to the carboxylate O atoms of the anion via N—H···O hydrogen bonds, forming a two-dimensional network. The four maleate anions (C6–C9), (C6A–C9A), (C6B–C9B) and (C6C–C9C) are connected to the organic cations, forming two-dimensional layers lying parallel to (001) (Fig. 3).

In the cation, the piperazinium rings adopt distorted chair conformations [puckering parameters Q, θ, and φ = 0.574 (2) Å, 1.11 (1)° and 73.6 (1)° for the first cation and = 0.577 (2) Å, 1.83 (2)° and 73.83 (1) for the second] (Cremer & Pople, 1975).

S2. Experimental

A mixture of maleic acid (1M) and 2-methylpiperazine dissolved in ethanol (molar ratio 1:1:1) was stirred for 2 h and then kept at room temperature. Transparent crystals of the title compound were obtained one week later.