Piperazinediium dioxamate.

The title compound, C(4)H(12)N(2) (2+)·2C(2)H(2)NO(3) (-), contains a network of doubly protanated piperazinium cations (lying about centres of inversion) and dioxamate anions. The piperazinium dication adopts a typical chair conformation. The crystal structure is stabilized by cation-to-anion N-H⋯O and anion-to-anion N-H⋯O hydrogen bonds.

Related literature

For related structures, see: Büyükgüngör & Odabaşoğlu (2008 ▶); Wilkinson & Harrison (2007 ▶). For biological applications of piperazines, see: Berkheij et al. (2005 ▶); Humle & Cherrier (1999 ▶). For the synthesis of a ligand with two piperazine arms, see: Bharathi et al. (2006 ▶). For the use of piperazine derivatives as buffers, see: Good et al. (1966 ▶). For the piperazine nucleus and its ability to bind to multiple receptors, see: Dinsmore & Beshore (2002 ▶).

Experimental

Crystal data

C4H12N2 2+·2C2H2NO3 −

M = 264.25

Monoclinic,

a = 6.4323 (4) Å

b = 6.7681 (4) Å

c = 13.0032 (7) Å

β = 94.488 (2)°

V = 564.35 (6) Å3

Z = 2

Mo Kα radiation

μ = 0.13 mm−1

T = 293 K

0.24 × 0.22 × 0.16 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.969, T max = 0.979

9313 measured reflections

2606 independent reflections

2197 reflections with I > 2σ(I)

R int = 0.021

Refinement

R[F 2 > 2σ(F 2)] = 0.041

wR(F 2) = 0.119

S = 1.09

2606 reflections

82 parameters

3 restraints

H-atom parameters constrained

Δρmax = 0.36 e Å−3

Δρmin = −0.34 e Å−3

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia (1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97 and PLATON.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809012513/lx2097sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809012513/lx2097Isup2.hkl

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

C4H12N22+·2C2H2NO3−	F(000) = 280
Mr = 264.25	Dx = 1.555 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2743 reflections
a = 6.4323 (4) Å	θ = 3.1–36.3°
b = 6.7681 (4) Å	µ = 0.13 mm−1
c = 13.0032 (7) Å	T = 293 K
β = 94.488 (2)°	Block, colourless
V = 564.35 (6) Å3	0.24 × 0.22 × 0.16 mm
Z = 2

Bruker APEXII CCD diffractometer	2606 independent reflections
Radiation source: fine-focus sealed tube	2197 reflections with I > 2σ(I)
graphite	Rint = 0.021
Detector resolution: 10.0 pixels mm-1	θmax = 36.3°, θmin = 3.1°
ω scans	h = −10→10
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −11→10
Tmin = 0.969, Tmax = 0.979	l = −20→9
9313 measured 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)] = 0.041	Hydrogen site location: difference Fourier map
wR(F2) = 0.119	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0667P)2 + 0.0606P] where P = (Fo2 + 2Fc2)/3
2606 reflections	(Δ/σ)max < 0.001
82 parameters	Δρmax = 0.36 e Å−3
3 restraints	Δρmin = −0.34 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
N2	0.08666 (10)	0.95960 (10)	0.40409 (4)	0.02372 (13)
H2A	0.1752	0.9900	0.3562	0.028*
H2B	0.0161	0.8502	0.3830	0.028*
C3	−0.06294 (12)	1.12524 (12)	0.41301 (5)	0.02590 (15)
H3A	−0.1436	1.1441	0.3475	0.031*
H3B	0.0132	1.2462	0.4297	0.031*
C4	0.20790 (11)	0.91851 (12)	0.50401 (6)	0.02572 (15)
H4A	0.2938	1.0320	0.5240	0.031*
H4B	0.2992	0.8064	0.4962	0.031*
O1	0.13426 (8)	0.15896 (9)	0.19612 (4)	0.02683 (13)
O2	0.44704 (10)	−0.03929 (12)	0.30376 (4)	0.03431 (16)
O3	0.28309 (12)	0.09059 (12)	0.05073 (4)	0.03678 (17)
N1	0.61883 (11)	−0.06196 (13)	0.15969 (5)	0.03142 (17)
H1A	0.7247	−0.1186	0.1917	0.038*
H1B	0.6182	−0.0387	0.0946	0.038*
C1	0.27471 (10)	0.08954 (10)	0.14582 (4)	0.02114 (13)
C2	0.45721 (11)	−0.01070 (11)	0.21043 (5)	0.02200 (14)

	U11	U22	U33	U12	U13	U23
N2	0.0244 (3)	0.0285 (3)	0.0190 (2)	−0.0053 (2)	0.00670 (19)	−0.0034 (2)
C3	0.0285 (3)	0.0280 (3)	0.0214 (3)	−0.0015 (3)	0.0027 (2)	0.0021 (2)
C4	0.0208 (3)	0.0312 (4)	0.0254 (3)	0.0001 (2)	0.0034 (2)	−0.0022 (2)
O1	0.0230 (2)	0.0337 (3)	0.0242 (2)	0.0066 (2)	0.00426 (18)	0.00091 (19)
O2	0.0304 (3)	0.0553 (4)	0.0179 (2)	0.0129 (3)	0.0059 (2)	0.0084 (2)
O3	0.0432 (4)	0.0502 (4)	0.0168 (2)	0.0188 (3)	0.0017 (2)	0.0017 (2)
N1	0.0291 (3)	0.0460 (4)	0.0200 (2)	0.0156 (3)	0.0067 (2)	0.0051 (2)
C1	0.0232 (3)	0.0222 (3)	0.0181 (2)	0.0024 (2)	0.0014 (2)	0.0006 (2)
C2	0.0225 (3)	0.0261 (3)	0.0178 (3)	0.0038 (2)	0.0039 (2)	0.0019 (2)

N2—C3	1.4879 (11)	C4—H4B	0.9700
N2—C4	1.4883 (10)	O1—C1	1.2478 (5)
N2—H2A	0.9000	O2—C2	1.2357 (8)
N2—H2B	0.9000	O3—C1	1.2419 (5)
C3—C4i	1.5095 (10)	N1—C2	1.3205 (9)
C3—H3A	0.9700	N1—H1A	0.8600
C3—H3B	0.9700	N1—H1B	0.8600
C4—C3i	1.5095 (10)	C1—O3	1.2419 (5)
C4—H4A	0.9700	C1—C2	1.5459 (10)
C3—N2—C4	111.75 (6)	N2—C4—H4B	109.6
C3—N2—H2A	109.3	C3i—C4—H4B	109.6
C4—N2—H2A	109.3	H4A—C4—H4B	108.1
C3—N2—H2B	109.3	C2—N1—H1A	120.0
C4—N2—H2B	109.3	C2—N1—H1B	120.0
H2A—N2—H2B	107.9	H1A—N1—H1B	120.0
N2—C3—C4i	110.33 (6)	O3—C1—O1	127.54 (7)
N2—C3—H3A	109.6	O3—C1—O1	127.54 (7)
C4i—C3—H3A	109.6	O3—C1—C2	116.96 (6)
N2—C3—H3B	109.6	O3—C1—C2	116.96 (6)
C4i—C3—H3B	109.6	O1—C1—C2	115.50 (5)
H3A—C3—H3B	108.1	O2—C2—N1	123.63 (7)
N2—C4—C3i	110.48 (6)	O2—C2—C1	120.41 (6)
N2—C4—H4A	109.6	N1—C2—C1	115.96 (5)
C3i—C4—H4A	109.6
C4—N2—C3—C4i	−56.67 (9)	O3—C1—C2—O2	−170.89 (8)
C3—N2—C4—C3i	56.75 (9)	O1—C1—C2—O2	8.52 (11)
O3—O3—C1—O1	0.00 (4)	O3—C1—C2—N1	8.95 (11)
O3—O3—C1—C2	0.00 (4)	O3—C1—C2—N1	8.95 (11)
O3—C1—C2—O2	−170.89 (8)	O1—C1—C2—N1	−171.64 (7)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1ii	0.86	2.24	3.0232 (9)	152
N1—H1B···O3iii	0.86	2.07	2.8622 (8)	153
N2—H2A···O1iv	0.90	2.37	3.0589 (8)	133
N2—H2A···O2iv	0.90	1.94	2.7475 (9)	149
N2—H2B···O1v	0.90	1.87	2.7509 (9)	164

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O1i	0.86	2.24	3.0232 (9)	152
N1—H1B⋯O3ii	0.86	2.07	2.8622 (8)	153
N2—H2A⋯O1iii	0.90	2.37	3.0589 (8)	133
N2—H2A⋯O2iii	0.90	1.94	2.7475 (9)	149
N2—H2B⋯O1iv	0.90	1.87	2.7509 (9)	164

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