trans-2,5-Di-methyl-piperazine-1,4-diium dinitrate.

In the structure of the title salt, C6H16N2 (2+)·2NO3 (-), the cations are connected to the anions through bifurcated N-H⋯(O,O) and weak C-H⋯O hydrogen bonds, generating corrugated layers parallel to the (100) plane. The organic cation is centrosymmetric and the diprotonated piperazine ring adopts a chair conformation, with the methyl groups occupying equatorial positions.

Related literature

For pharmacological properties of piperazine, see: Conrado et al. (2008 ▶). For related structures, see: Gatfaoui et al. (2013 ▶, 2014a ▶,b ▶); Marouani et al. (2012 ▶); Kefi et al. (2013 ▶). For a complex of the title cation, see: Rother et al. (1997 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C6H16N2 2+·2NO3 −

M = 240.23

Monoclinic,

a = 7.0357 (8) Å

b = 10.0277 (10) Å

c = 8.3112 (8) Å

β = 116.149 (8)°

V = 526.36 (9) Å3

Z = 2

Mo Kα radiation

μ = 0.13 mm−1

T = 150 K

0.58 × 0.46 × 0.23 mm

Data collection

Bruker APEXII diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2006 ▶) T min = 0.827, T max = 0.970

4126 measured reflections

1195 independent reflections

1059 reflections with I > 2σ(I)

R int = 0.022

Refinement

R[F 2 > 2σ(F 2)] = 0.034

wR(F 2) = 0.090

S = 1.11

1195 reflections

74 parameters

H-atom parameters constrained

Δρmax = 0.30 e Å−3

Δρmin = −0.23 e Å−3

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: SAINT (Bruker, 2006 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶) and DIAMOND (Brandenburg & Putz 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶) and CRYSCAL (T. Roisnel, local program).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536814012100/bg2529sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814012100/bg2529Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S1600536814012100/bg2529Isup3.cml

CCDC reference: 1005191

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

C6H16N22+·2NO3−	F(000) = 256
Mr = 240.23	Dx = 1.516 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2153 reflections
a = 7.0357 (8) Å	θ = 3.4–27.4°
b = 10.0277 (10) Å	µ = 0.13 mm−1
c = 8.3112 (8) Å	T = 150 K
β = 116.149 (8)°	Prism, colourless
V = 526.36 (9) Å3	0.58 × 0.46 × 0.23 mm
Z = 2

Bruker APEXII diffractometer	1059 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
CCD rotation images, thin slices scans	θmax = 27.5°, θmin = 3.4°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −8→9
Tmin = 0.827, Tmax = 0.970	k = −9→12
4126 measured reflections	l = −10→10
1195 independent reflections

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.090	H-atom parameters constrained
S = 1.11	w = 1/[σ2(Fo2) + (0.0438P)2 + 0.1423P] where P = (Fo2 + 2Fc2)/3
1195 reflections	(Δ/σ)max < 0.001
74 parameters	Δρmax = 0.30 e Å−3
0 restraints	Δρmin = −0.23 e Å−3

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.

	x	y	z	Uiso*/Ueq
N1	0.20352 (15)	−0.09103 (10)	−0.37280 (12)	0.0173 (2)
O1	0.12714 (14)	−0.13760 (9)	−0.27150 (11)	0.0218 (2)
O2	0.24377 (15)	−0.16754 (10)	−0.47090 (11)	0.0255 (2)
O3	0.23709 (16)	0.03059 (9)	−0.36962 (13)	0.0312 (3)
N2	−0.02504 (15)	0.08866 (10)	−0.14298 (12)	0.0169 (2)
H2A	−0.0683	0.1671	−0.2001	0.020*
H2B	0.0282	0.0397	−0.2044	0.020*
C1	0.14685 (18)	0.11399 (12)	0.04232 (15)	0.0165 (3)
H1	0.0915	0.1730	0.1057	0.020*
C2	0.21154 (17)	−0.01747 (12)	0.14274 (15)	0.0176 (3)
H2C	0.2778	−0.0736	0.0869	0.021*
H2D	0.3146	−0.0007	0.2653	0.021*
C3	0.33291 (19)	0.18189 (13)	0.03060 (17)	0.0224 (3)
H3A	0.3930	0.1230	−0.0257	0.034*
H3B	0.4381	0.2036	0.1490	0.034*
H3C	0.2854	0.2621	−0.0389	0.034*

	U11	U22	U33	U12	U13	U23
N1	0.0184 (5)	0.0158 (5)	0.0155 (5)	0.0005 (4)	0.0054 (4)	0.0005 (4)
O1	0.0288 (5)	0.0212 (5)	0.0202 (4)	−0.0019 (3)	0.0153 (4)	−0.0007 (3)
O2	0.0331 (5)	0.0274 (5)	0.0203 (4)	0.0033 (4)	0.0158 (4)	−0.0025 (4)
O3	0.0356 (5)	0.0134 (5)	0.0400 (6)	−0.0040 (4)	0.0125 (4)	0.0023 (4)
N2	0.0199 (5)	0.0162 (5)	0.0150 (5)	0.0030 (4)	0.0081 (4)	0.0023 (4)
C1	0.0185 (5)	0.0144 (6)	0.0161 (5)	0.0018 (4)	0.0071 (4)	−0.0010 (4)
C2	0.0166 (5)	0.0168 (6)	0.0178 (5)	0.0020 (4)	0.0062 (4)	0.0016 (4)
C3	0.0207 (6)	0.0178 (6)	0.0287 (6)	0.0003 (5)	0.0112 (5)	0.0009 (5)

N1—O2	1.2398 (13)	C1—C2	1.5188 (17)
N1—O3	1.2403 (14)	C1—H1	0.9800
N1—O1	1.2706 (13)	C2—N2i	1.4945 (15)
N2—C2i	1.4945 (15)	C2—H2C	0.9700
N2—C1	1.5024 (14)	C2—H2D	0.9700
N2—H2A	0.9000	C3—H3A	0.9600
N2—H2B	0.9000	C3—H3B	0.9600
C1—C3	1.5163 (17)	C3—H3C	0.9600
O2—N1—O3	121.73 (10)	C2—C1—H1	108.8
O2—N1—O1	119.62 (10)	N2i—C2—C1	111.39 (9)
O3—N1—O1	118.65 (10)	N2i—C2—H2C	109.4
C2i—N2—C1	112.95 (9)	C1—C2—H2C	109.4
C2i—N2—H2A	109.0	N2i—C2—H2D	109.4
C1—N2—H2A	109.0	C1—C2—H2D	109.4
C2i—N2—H2B	109.0	H2C—C2—H2D	108.0
C1—N2—H2B	109.0	C1—C3—H3A	109.5
H2A—N2—H2B	107.8	C1—C3—H3B	109.5
N2—C1—C3	109.74 (9)	H3A—C3—H3B	109.5
N2—C1—C2	109.11 (9)	C1—C3—H3C	109.5
C3—C1—C2	111.53 (10)	H3A—C3—H3C	109.5
N2—C1—H1	108.8	H3B—C3—H3C	109.5
C3—C1—H1	108.8

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O1ii	0.90	1.99	2.8471 (14)	158
N2—H2A···O2iii	0.90	2.45	2.9899 (13)	119
N2—H2B···O1	0.90	2.07	2.9057 (13)	153
N2—H2B···O3	0.90	2.42	3.2172 (14)	149
C1—H1···O1i	0.98	2.50	3.2614 (14)	134

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯O1i	0.90	1.99	2.8471 (14)	158
N2—H2A⋯O2ii	0.90	2.45	2.9899 (13)	119
N2—H2B⋯O1	0.90	2.07	2.9057 (13)	153
N2—H2B⋯O3	0.90	2.42	3.2172 (14)	149
C1—H1⋯O1iii	0.98	2.50	3.2614 (14)	134

Symmetry codes: (i) ; (ii) ; (iii) .