N,N-Dimethyl­ethane-1,2-diaminium bis­(3-hy­droxy­benzoate)

Sarkar, A.; Cukrowski, I.

doi:10.1107/S1600536811040578

organic compounds

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ISSN: 2056-9890

Volume 67| Part 11| November 2011| Page o2901

doi:10.1107/S1600536811040578

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N,N-Dimethylethane-1,2-diaminium bis(3-hydroxybenzoate)

Anindita Sarkar ^a and Ignacy Cukrowski ^a ^*

^aDepartment of Chemistry, University of Pretoria, Lynnwood Road, Pretoria 0002, South Africa
^*Correspondence e-mail: ignacy.cukrowski@up.ac.za

(Received 27 May 2011; accepted 3 October 2011; online 8 October 2011)

In the title compound, C₄H₁₄N₂²⁺·2C₇H₅O₃⁻, both the N,N-dimethylethylenediamine N atoms are protonated and two 3-hydroxybenzoate anions act as counter-ions. In the crystal, anions and cations are linked by a network of N—H⋯O and O—H⋯O hydrogen bonds.

Related literature

For bond lengths in fully protonated polyamines, see: Bujak & Angel (2006 ); Bujak & Zaleski (2002 ); Doran et al. (2003 ); Thorn et al. (2005 ); Zhang et al. (2007 ).

Experimental

Crystal data

C₄H₁₄N₂²⁺·2C₇H₅O₃⁻
M_r = 364.39
Monoclinic, C c
a = 14.5439 (3) Å
b = 17.5881 (4) Å
c = 7.7104 (2) Å
β = 114.777 (1)°
V = 1790.76 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.49 × 0.12 × 0.03 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: integration (XPREP; Bruker, 2001 ) T_min = 0.952, T_max = 0.997
14114 measured reflections
4292 independent reflections
3635 reflections with I > 2σ(I)
R_int = 0.048

Refinement

R[F² > 2σ(F²)] = 0.036
wR(F²) = 0.077
S = 0.96
4292 reflections
240 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.20 e Å⁻³
Absolute structure: Flack (1983 ), 2119 Friedel pairs
Flack parameter: 0.00 (7)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N7—H8C⋯O5ⁱ	0.89	1.94	2.7169 (18)	145
N7—H9A⋯O1ⁱⁱ	0.89	2.12	2.8904 (18)	145
N7—H19B⋯O1ⁱⁱⁱ	0.89	1.90	2.7657 (19)	164
N10—H1⋯O4^iv	0.91	1.84	2.7367 (17)	168
O3—H3⋯O4^iv	0.82	1.84	2.6415 (16)	164
O6—H6⋯O2^v	0.82	1.80	2.5897 (16)	161
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[x-{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ ; (iii) $[x-{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (iv) x, y, z-1; (v) x-1, y, z.

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL and SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811040578/fj2425sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811040578/fj2425Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811040578/fj2425Isup3.cml

checkCIF report

Comment top

N,N–Dimethylethane-1,2-diaminium bis 3-hydroxybenzoate [H₂DM-en + 2(3HO-BA)] crystallizes in the centrosymmetric space group Cc. The molecular structure with the atom numbering scheme is shown in Figure 1. The all N–H bonds in H₂DM-en (they are on average close to 0.9 Å) are shorter by about 0.1 Å when compared with those in other fully protonated polyamines (Thorn et al., 2005; Doran et al., 2003) but comparable with (Zhang et al., 2007; Bujak et al., 2002). At the same time, the three N—H bonds on N7 (primary N-atom) are equal in length (0.89 Å) and they are shorter by 0.02 Å than the N—H bond on tertiary N-atom (N10). In this crystal the polyammonium ion adopts an extended, all anti-conformation that minimizes electrostatic repulsions between protonated nitrogen atoms. There is a self-assembly pattern in the crystal through intermolecular noncovalent interactions (the hydrogen bonds of a type N—H···O and O—H···O). The O-atoms are known to participate as donors in intramolecular as well as intermolecular hydrogen-bonding interactions to provide various types of self-assembled networks. As an example, the O4-atom of the carboxylate group forms two intermolecular H-bonds, one with the diamine, N10—H1···O4, and another with hydroxy group of the benzoic acid, O3—H3···O4; both H-bonds are about 1.84 Å. The other O-atom of the carboxylic group is involved in only one intramolecular H-bond, namely N7—H19B···O5 involving terminal N-atom. In general, all O-atoms and H-atoms bonded to the N-atoms are involved in intramolecular interactions.

Related literature top

For bond lengths in fully protonated polyamines, see: Bujak & Angel (2006); Bujak & Zaleski (2002); Doran et al. (2003); Thorn et al. (2005); Zhang et al. (2007).

Experimental top

DM-en (0.83 ml, 8.97M) was mixed with 3-Hydroxy Benzoic acid (1 g m, 7.24 mmol) in water (1 ml). Colourless crystals obtained after 15 days of slow evaporation.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008) and SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. Molecular structure of N,N–dimethylethane-1,2-diaminium bis 3-hydroxybenzoate with atom labels and 50% probabilty ellipsoids.
	Fig. 2. The H– bonded packing of N,N–dimethylethane-1,2-diaminium bis 3-hydroxybenzoate.

N,N-Dimethylethane-1,2-diaminium bis(3-hydroxybenzoate) top

Crystal data top

C₄H₁₄N₂²⁺·2C₇H₅O₃⁻	F(000) = 776
M_r = 364.39	D_x = 1.352 Mg m⁻³ D_m = 1.352 Mg m⁻³ D_m measured by not measured
Monoclinic, Cc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C -2yc	Cell parameters from 4375 reflections
a = 14.5439 (3) Å	θ = 2.3–27.2°
b = 17.5881 (4) Å	µ = 0.10 mm⁻¹
c = 7.7104 (2) Å	T = 293 K
β = 114.777 (1)°	Needle, colourless
V = 1790.76 (7) Å³	0.49 × 0.12 × 0.03 mm
Z = 4

Data collection top

Bruker APEXII CCD diffractometer	4292 independent reflections
Radiation source: fine-focus sealed tube	3635 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.048
ϕ and ω scans	θ_max = 28.0°, θ_min = 1.9°
Absorption correction: integration (XPREP; Bruker, 2005)	h = −19→19
T_min = 0.952, T_max = 0.997	k = −23→23
14114 measured reflections	l = −9→10

Refinement top

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)] = 0.036	H-atom parameters constrained
wR(F²) = 0.077	w = 1/[σ²(F_o²) + (0.037P)²] where P = (F_o² + 2F_c²)/3
S = 0.96	(Δ/σ)_max < 0.001
4292 reflections	Δρ_max = 0.18 e Å⁻³
240 parameters	Δρ_min = −0.20 e Å⁻³
2 restraints	Absolute structure: Flack (1983), 2119 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.00 (7)

Crystal data top

C₄H₁₄N₂²⁺·2C₇H₅O₃⁻	V = 1790.76 (7) Å³
M_r = 364.39	Z = 4
Monoclinic, Cc	Mo Kα radiation
a = 14.5439 (3) Å	µ = 0.10 mm⁻¹
b = 17.5881 (4) Å	T = 293 K
c = 7.7104 (2) Å	0.49 × 0.12 × 0.03 mm
β = 114.777 (1)°

Data collection top

Bruker APEXII CCD diffractometer	4292 independent reflections
Absorption correction: integration (XPREP; Bruker, 2005)	3635 reflections with I > 2σ(I)
T_min = 0.952, T_max = 0.997	R_int = 0.048
14114 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.036	H-atom parameters constrained
wR(F²) = 0.077	Δρ_max = 0.18 e Å⁻³
S = 0.96	Δρ_min = −0.20 e Å⁻³
4292 reflections	Absolute structure: Flack (1983), 2119 Friedel pairs
240 parameters	Absolute structure parameter: 0.00 (7)
2 restraints

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O6	−0.04233 (9)	0.58513 (7)	0.31587 (16)	0.0236 (3)
H6	−0.0877	0.6024	0.3410	0.035*
O4	0.24002 (8)	0.70635 (7)	1.07125 (16)	0.0235 (3)
N7	0.41688 (11)	0.92211 (8)	0.40647 (19)	0.0192 (3)
H9A	0.4078	0.9518	0.4914	0.029*
H19B	0.3910	0.9446	0.2926	0.029*
H8C	0.4828	0.9142	0.4427	0.029*
N10	0.19982 (10)	0.78889 (8)	0.3324 (2)	0.0202 (3)
H1	0.2057	0.7653	0.2325	0.024*
C7	0.05796 (12)	0.62591 (9)	0.6407 (2)	0.0174 (3)
H005	0.0023	0.6493	0.6479	0.021*
C1	0.25729 (12)	0.86195 (9)	0.3681 (2)	0.0189 (3)
H3A	0.2578	0.8860	0.4817	0.023*
H2B	0.2238	0.8961	0.2611	0.023*
O5	0.08907 (9)	0.66203 (7)	1.02369 (18)	0.0284 (3)
C6	0.04672 (12)	0.58805 (9)	0.4740 (2)	0.0177 (3)
C8	0.15193 (12)	0.62880 (8)	0.7962 (2)	0.0170 (3)
C4	0.36527 (12)	0.84847 (9)	0.3943 (3)	0.0225 (4)
H6A	0.4014	0.8195	0.5102	0.027*
H5B	0.3652	0.8193	0.2875	0.027*
C19	0.16091 (12)	0.66816 (9)	0.9766 (2)	0.0186 (3)
C9	0.23557 (12)	0.59331 (9)	0.7864 (2)	0.0190 (3)
H012	0.2989	0.5961	0.8888	0.023*
C10	0.22300 (13)	0.55372 (9)	0.6214 (2)	0.0215 (4)
H013	0.2780	0.5287	0.6155	0.026*
C5	0.12971 (12)	0.55123 (9)	0.4663 (2)	0.0206 (4)
H014	0.1224	0.5249	0.3566	0.025*
C15	0.09028 (13)	0.80408 (11)	0.2764 (3)	0.0297 (4)
H18C	0.0823	0.8318	0.3766	0.044*
H16D	0.0544	0.7567	0.2557	0.044*
H17E	0.0636	0.8336	0.1610	0.044*
C11	0.24122 (15)	0.73670 (10)	0.4997 (3)	0.0305 (4)
H13F	0.2456	0.7630	0.6119	0.046*
H14G	0.3075	0.7199	0.5180	0.046*
H12H	0.1973	0.6935	0.4770	0.046*
O1	0.80917 (9)	0.53105 (7)	0.53286 (16)	0.0231 (3)
O2	0.78810 (9)	0.62504 (7)	0.32384 (18)	0.0267 (3)
O3	0.43039 (9)	0.70905 (7)	0.11670 (19)	0.0272 (3)
H3	0.3697	0.7025	0.0857	0.041*
C23	0.60027 (13)	0.52862 (10)	0.4403 (2)	0.0229 (4)
H020	0.6388	0.4881	0.5111	0.027*
C26	0.75606 (12)	0.57987 (9)	0.4128 (2)	0.0192 (3)
C25	0.58608 (13)	0.64466 (10)	0.2662 (2)	0.0199 (4)
H022	0.6158	0.6824	0.2222	0.024*
C24	0.64459 (12)	0.58440 (9)	0.3717 (2)	0.0184 (3)
C22	0.49872 (13)	0.53375 (10)	0.4027 (3)	0.0256 (4)
H024	0.4694	0.4966	0.4493	0.031*
C20	0.48344 (12)	0.64932 (9)	0.2253 (2)	0.0204 (4)
C21	0.43992 (13)	0.59385 (10)	0.2960 (2)	0.0235 (4)
H026	0.3718	0.5969	0.2719	0.028*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O6	0.0184 (6)	0.0337 (7)	0.0185 (6)	−0.0004 (5)	0.0076 (5)	−0.0060 (5)
O4	0.0171 (6)	0.0275 (7)	0.0248 (7)	−0.0043 (5)	0.0078 (5)	−0.0107 (5)
N7	0.0191 (7)	0.0217 (7)	0.0169 (7)	−0.0024 (6)	0.0077 (6)	−0.0010 (5)
N10	0.0213 (7)	0.0201 (7)	0.0199 (7)	−0.0032 (6)	0.0094 (6)	−0.0044 (6)
C7	0.0177 (8)	0.0160 (8)	0.0207 (8)	0.0001 (6)	0.0103 (7)	−0.0004 (7)
C1	0.0221 (8)	0.0167 (8)	0.0165 (8)	−0.0013 (7)	0.0068 (7)	−0.0007 (7)
O5	0.0234 (6)	0.0402 (8)	0.0262 (7)	−0.0092 (6)	0.0149 (6)	−0.0120 (6)
C6	0.0193 (8)	0.0163 (8)	0.0177 (8)	−0.0025 (6)	0.0081 (7)	0.0016 (6)
C8	0.0204 (8)	0.0130 (8)	0.0193 (8)	−0.0026 (6)	0.0099 (7)	0.0002 (6)
C4	0.0220 (9)	0.0171 (9)	0.0286 (10)	−0.0005 (7)	0.0107 (8)	−0.0008 (7)
C19	0.0180 (8)	0.0188 (8)	0.0168 (8)	0.0033 (7)	0.0051 (7)	0.0010 (7)
C9	0.0161 (8)	0.0180 (8)	0.0199 (8)	−0.0001 (6)	0.0047 (7)	0.0008 (7)
C10	0.0202 (8)	0.0196 (8)	0.0262 (10)	0.0041 (7)	0.0112 (7)	0.0001 (7)
C5	0.0248 (9)	0.0166 (8)	0.0224 (9)	−0.0012 (7)	0.0118 (8)	−0.0039 (7)
C15	0.0216 (9)	0.0359 (11)	0.0332 (11)	−0.0053 (8)	0.0132 (9)	−0.0075 (9)
C11	0.0375 (11)	0.0220 (9)	0.0344 (11)	−0.0023 (8)	0.0173 (10)	0.0045 (8)
O1	0.0219 (6)	0.0241 (6)	0.0191 (6)	0.0058 (5)	0.0046 (5)	0.0003 (5)
O2	0.0213 (6)	0.0294 (7)	0.0322 (7)	0.0044 (5)	0.0139 (6)	0.0091 (6)
O3	0.0149 (6)	0.0242 (6)	0.0393 (8)	0.0024 (5)	0.0081 (6)	0.0063 (6)
C23	0.0261 (9)	0.0210 (9)	0.0197 (9)	0.0017 (7)	0.0078 (7)	0.0026 (7)
C26	0.0190 (8)	0.0213 (9)	0.0151 (8)	0.0007 (7)	0.0050 (7)	−0.0051 (7)
C25	0.0202 (8)	0.0216 (8)	0.0198 (9)	−0.0031 (7)	0.0103 (7)	−0.0013 (7)
C24	0.0197 (8)	0.0196 (8)	0.0143 (8)	−0.0009 (6)	0.0057 (7)	−0.0034 (6)
C22	0.0271 (9)	0.0246 (9)	0.0271 (10)	−0.0066 (8)	0.0134 (8)	0.0003 (8)
C20	0.0194 (8)	0.0203 (9)	0.0187 (9)	0.0000 (7)	0.0053 (7)	−0.0034 (7)
C21	0.0174 (8)	0.0286 (9)	0.0240 (10)	−0.0042 (7)	0.0083 (7)	−0.0043 (7)

Geometric parameters (Å, º) top

O6—C6	1.358 (2)	C10—C5	1.383 (2)
O6—H6	0.8200	C10—H013	0.9300
O4—C19	1.2664 (19)	C5—H014	0.9300
N7—C4	1.480 (2)	C15—H18C	0.9600
N7—H9A	0.8900	C15—H16D	0.9600
N7—H19B	0.8900	C15—H17E	0.9600
N7—H8C	0.8900	C11—H13F	0.9600
N10—C11	1.489 (2)	C11—H14G	0.9600
N10—C15	1.490 (2)	C11—H12H	0.9600
N10—C1	1.494 (2)	O1—C26	1.262 (2)
N10—H1	0.9100	O2—C26	1.260 (2)
C7—C8	1.391 (2)	O3—C20	1.363 (2)
C7—C6	1.395 (2)	O3—H3	0.8200
C7—H005	0.9300	C23—C22	1.384 (2)
C1—C4	1.516 (2)	C23—C24	1.394 (2)
C1—H3A	0.9700	C23—H020	0.9300
C1—H2B	0.9700	C26—C24	1.518 (2)
O5—C19	1.246 (2)	C25—C24	1.389 (2)
C6—C5	1.393 (2)	C25—C20	1.393 (2)
C8—C9	1.397 (2)	C25—H022	0.9300
C8—C19	1.510 (2)	C22—C21	1.391 (2)
C4—H6A	0.9700	C22—H024	0.9300
C4—H5B	0.9700	C20—C21	1.392 (2)
C9—C10	1.393 (2)	C21—H026	0.9300
C9—H012	0.9300

C6—O6—H6	109.5	C5—C10—C9	120.73 (15)
C4—N7—H9A	109.5	C5—C10—H013	119.6
C4—N7—H19B	109.5	C9—C10—H013	119.6
H9A—N7—H19B	109.5	C10—C5—C6	120.13 (15)
C4—N7—H8C	109.5	C10—C5—H014	119.9
H9A—N7—H8C	109.5	C6—C5—H014	119.9
H19B—N7—H8C	109.5	N10—C15—H18C	109.5
C11—N10—C15	110.88 (14)	N10—C15—H16D	109.5
C11—N10—C1	112.24 (13)	H18C—C15—H16D	109.5
C15—N10—C1	110.30 (13)	N10—C15—H17E	109.5
C11—N10—H1	107.7	H18C—C15—H17E	109.5
C15—N10—H1	107.7	H16D—C15—H17E	109.5
C1—N10—H1	107.7	N10—C11—H13F	109.5
C8—C7—C6	120.34 (15)	N10—C11—H14G	109.5
C8—C7—H005	119.8	H13F—C11—H14G	109.5
C6—C7—H005	119.8	N10—C11—H12H	109.5
N10—C1—C4	111.00 (13)	H13F—C11—H12H	109.5
N10—C1—H3A	109.4	H14G—C11—H12H	109.5
C4—C1—H3A	109.4	C20—O3—H3	109.5
N10—C1—H2B	109.4	C22—C23—C24	119.82 (17)
C4—C1—H2B	109.4	C22—C23—H020	120.1
H3A—C1—H2B	108.0	C24—C23—H020	120.1
O6—C6—C5	117.48 (15)	O2—C26—O1	125.20 (15)
O6—C6—C7	123.03 (14)	O2—C26—C24	117.38 (15)
C5—C6—C7	119.49 (15)	O1—C26—C24	117.43 (15)
C7—C8—C9	120.00 (15)	C24—C25—C20	120.85 (16)
C7—C8—C19	119.04 (14)	C24—C25—H022	119.6
C9—C8—C19	120.92 (15)	C20—C25—H022	119.6
N7—C4—C1	109.95 (13)	C25—C24—C23	119.48 (15)
N7—C4—H6A	109.7	C25—C24—C26	120.04 (15)
C1—C4—H6A	109.7	C23—C24—C26	120.47 (15)
N7—C4—H5B	109.7	C23—C22—C21	120.72 (16)
C1—C4—H5B	109.7	C23—C22—H024	119.6
H6A—C4—H5B	108.2	C21—C22—H024	119.6
O5—C19—O4	123.25 (15)	O3—C20—C21	123.19 (15)
O5—C19—C8	118.00 (14)	O3—C20—C25	117.46 (15)
O4—C19—C8	118.74 (14)	C21—C20—C25	119.35 (16)
C10—C9—C8	119.26 (16)	C22—C21—C20	119.76 (16)
C10—C9—H012	120.4	C22—C21—H026	120.1
C8—C9—H012	120.4	C20—C21—H026	120.1

C11—N10—C1—C4	64.80 (17)	C7—C6—C5—C10	−1.4 (2)
C15—N10—C1—C4	−171.02 (14)	C20—C25—C24—C23	−1.1 (2)
C8—C7—C6—O6	−178.08 (14)	C20—C25—C24—C26	179.29 (15)
C8—C7—C6—C5	1.8 (2)	C22—C23—C24—C25	0.0 (3)
C6—C7—C8—C9	−0.4 (2)	C22—C23—C24—C26	179.60 (15)
C6—C7—C8—C19	−178.15 (13)	O2—C26—C24—C25	−10.9 (2)
N10—C1—C4—N7	173.31 (13)	O1—C26—C24—C25	169.32 (15)
C7—C8—C19—O5	36.5 (2)	O2—C26—C24—C23	169.52 (15)
C9—C8—C19—O5	−141.30 (16)	O1—C26—C24—C23	−10.3 (2)
C7—C8—C19—O4	−142.72 (15)	C24—C23—C22—C21	0.4 (3)
C9—C8—C19—O4	39.5 (2)	C24—C25—C20—O3	−178.29 (15)
C7—C8—C9—C10	−1.5 (2)	C24—C25—C20—C21	1.8 (2)
C19—C8—C9—C10	176.23 (14)	C23—C22—C21—C20	0.3 (3)
C8—C9—C10—C5	1.9 (2)	O3—C20—C21—C22	178.71 (16)
C9—C10—C5—C6	−0.4 (3)	C25—C20—C21—C22	−1.3 (3)
O6—C6—C5—C10	178.49 (15)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N7—H8C···O5ⁱ	0.89	1.94	2.7169 (18)	145
N7—H9A···O1ⁱⁱ	0.89	2.12	2.8904 (18)	145
N7—H19B···O1ⁱⁱⁱ	0.89	1.90	2.7657 (19)	164
N10—H1···O4^iv	0.91	1.84	2.7367 (17)	168
O3—H3···O4^iv	0.82	1.84	2.6415 (16)	164
O6—H6···O2^v	0.82	1.80	2.5897 (16)	161

Symmetry codes: (i) x+1/2, −y+3/2, z−1/2; (ii) x−1/2, y+1/2, z; (iii) x−1/2, −y+3/2, z−1/2; (iv) x, y, z−1; (v) x−1, y, z.

Experimental details

Crystal data
Chemical formula	C₄H₁₄N₂²⁺·2C₇H₅O₃⁻
M_r	364.39
Crystal system, space group	Monoclinic, Cc
Temperature (K)	293
a, b, c (Å)	14.5439 (3), 17.5881 (4), 7.7104 (2)
β (°)	114.777 (1)
V (Å³)	1790.76 (7)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.49 × 0.12 × 0.03

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Integration (XPREP; Bruker, 2005)
T_min, T_max	0.952, 0.997
No. of measured, independent and observed [I > 2σ(I)] reflections	14114, 4292, 3635
R_int	0.048
(sin θ/λ)_max (Å⁻¹)	0.661

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.036, 0.077, 0.96
No. of reflections	4292
No. of parameters	240
No. of restraints	2
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.20
Absolute structure	Flack (1983), 2119 Friedel pairs
Absolute structure parameter	0.00 (7)

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N7—H8C···O5ⁱ	0.89	1.94	2.7169 (18)	145
N7—H9A···O1ⁱⁱ	0.89	2.12	2.8904 (18)	145
N7—H19B···O1ⁱⁱⁱ	0.89	1.90	2.7657 (19)	164
N10—H1···O4^iv	0.91	1.84	2.7367 (17)	168
O3—H3···O4^iv	0.82	1.84	2.6415 (16)	164.0
O6—H6···O2^v	0.82	1.80	2.5897 (16)	161.0

Symmetry codes: (i) x+1/2, −y+3/2, z−1/2; (ii) x−1/2, y+1/2, z; (iii) x−1/2, −y+3/2, z−1/2; (iv) x, y, z−1; (v) x−1, y, z.

Acknowledgements

The authors thank the University of Pretoria for financial support and research facilities. The XRD facilities of the University of Witwatersrand, South Africa are gratefully acknowledged.

References

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