Bis(2,3-dimethyl-anilinium) dihydrogen-diphosphate.

In the title compound, 2C(8)H(12)N(+)·H(2)P(2)O(7) (2-), the complete dihydrogendiphosphate anion is generated by crystallographic twofold symmetry, with the bridging O atom lying on the rotation axis [P-O-P = 135.50 (9)°]. In the crystal, the 2,3-xylidinium cations are anchored between ribbons formed by the H(2)P(2)O(7) entities. Crystal cohesion and stability are supported by electrostatic inter-actions which, together with N-H⋯O and O-H⋯O hydrogen bonds, build up a three-dimensional network.

Related literature

For related structures, see: Akriche & Rzaigui (2000 ▶, 2001 ▶); Rayes et al. (2004 ▶); Aloui et al. (2006 ▶); Souissi et al. (2007 ▶). For a discussion on hydrogen bonding, see: Brown (1976 ▶); Blessing (1986 ▶). For tetra­hedral distortions, see: Baur (1974 ▶). For π–π inter­actions, see: Janiak (2000 ▶).

Experimental

Crystal data

2C8H12N+·H2P2O7 2−

M = 420.33

Monoclinic,

a = 32.9401 (10) Å

b = 4.5348 (10) Å

c = 15.560 (8) Å

β = 113.06 (4)°

V = 2138.6 (12) Å3

Z = 4

Ag Kα radiation

λ = 0.56087 Å

μ = 0.13 mm−1

T = 293 K

0.50 × 0.45 × 0.25 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

3944 measured reflections

3815 independent reflections

2891 reflections with I > 2σ(I)

R int = 0.011

2 standard reflections every 120 min intensity decay: 1%

Refinement

R[F 2 > 2σ(F 2)] = 0.040

wR(F 2) = 0.138

S = 1.11

3815 reflections

127 parameters

H-atom parameters constrained

Δρmax = 0.44 e Å−3

Δρmin = −0.22 e Å−3

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); 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, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810004149/hb5321sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810004149/hb5321Isup2.hkl

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

2C8H12N+·H2P2O72−	F(000) = 888
Mr = 420.33	Dx = 1.305 Mg m−3
Monoclinic, C2/c	Ag Kα radiation, λ = 0.56087 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 32.9401 (10) Å	θ = 8–10°
b = 4.5348 (10) Å	µ = 0.13 mm−1
c = 15.560 (8) Å	T = 293 K
β = 113.06 (4)°	Prism, pink
V = 2138.6 (12) Å3	0.50 × 0.45 × 0.25 mm
Z = 4

Enraf–Nonius CAD-4 diffractometer	Rint = 0.011
Radiation source: Enraf Nonius FR590	θmax = 25.0°, θmin = 2.1°
graphite	h = −49→45
non–profiled ω scans	k = 0→6
3944 measured reflections	l = 0→23
3815 independent reflections	2 standard reflections every 120 min
2891 reflections with I > 2σ(I)	intensity decay: 1%

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.138	H-atom parameters constrained
S = 1.11	w = 1/[σ2(Fo2) + (0.0801P)2 + 0.3731P] where P = (Fo2 + 2Fc2)/3
3815 reflections	(Δ/σ)max = 0.001
127 parameters	Δρmax = 0.44 e Å−3
0 restraints	Δρmin = −0.22 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 > 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
P1	0.510805 (12)	0.68375 (7)	0.35144 (2)	0.03189 (11)
O1	0.53139 (4)	0.9396 (2)	0.41487 (7)	0.0424 (3)
O2	0.5000	0.8169 (3)	0.2500	0.0384 (3)
O3	0.54560 (4)	0.4412 (2)	0.36452 (9)	0.0470 (3)
H3	0.5369	0.2852	0.3779	0.071*
O4	0.46936 (4)	0.5703 (2)	0.35653 (8)	0.0424 (2)
N1	0.43242 (4)	0.0895 (3)	0.39453 (8)	0.0350 (2)
H1A	0.4485	0.2236	0.3802	0.052*
H1B	0.4353	−0.0845	0.3711	0.052*
H1C	0.4417	0.0755	0.4563	0.052*
C1	0.38624 (5)	0.1778 (4)	0.35532 (12)	0.0445 (3)
C2	0.36165 (6)	0.1438 (4)	0.26065 (13)	0.0540 (4)
C3	0.31819 (7)	0.2505 (7)	0.22611 (18)	0.0764 (7)
C4	0.30194 (8)	0.3801 (8)	0.2858 (3)	0.1040 (11)
H4	0.2730	0.4483	0.2622	0.125*
C5	0.32707 (9)	0.4116 (9)	0.3788 (3)	0.1165 (13)
H5	0.3154	0.5022	0.4177	0.140*
C6	0.36968 (7)	0.3087 (6)	0.41443 (18)	0.0796 (7)
H6	0.3871	0.3273	0.4778	0.095*
C7	0.38165 (8)	0.0022 (7)	0.19904 (14)	0.0804 (7)
H7A	0.4052	0.1237	0.1972	0.121*
H7B	0.3595	−0.0192	0.1370	0.121*
H7C	0.3931	−0.1885	0.2235	0.121*
C8	0.28886 (9)	0.2238 (11)	0.1235 (2)	0.1297 (14)
H8A	0.2637	0.3508	0.1092	0.195*
H8B	0.2791	0.0234	0.1096	0.195*
H8C	0.3051	0.2803	0.0867	0.195*

	U11	U22	U33	U12	U13	U23
P1	0.04612 (19)	0.02030 (15)	0.03291 (17)	0.00149 (12)	0.01944 (14)	0.00289 (11)
O1	0.0698 (7)	0.0241 (4)	0.0301 (5)	−0.0029 (4)	0.0160 (4)	0.0017 (4)
O2	0.0632 (9)	0.0255 (6)	0.0304 (6)	0.000	0.0226 (6)	0.000
O3	0.0532 (6)	0.0243 (4)	0.0715 (8)	0.0059 (4)	0.0330 (6)	0.0104 (5)
O4	0.0523 (6)	0.0313 (5)	0.0537 (6)	0.0016 (4)	0.0316 (5)	0.0055 (4)
N1	0.0379 (5)	0.0330 (5)	0.0349 (5)	−0.0003 (4)	0.0152 (4)	0.0025 (4)
C1	0.0365 (6)	0.0454 (8)	0.0512 (8)	−0.0012 (6)	0.0169 (6)	0.0025 (7)
C2	0.0410 (7)	0.0636 (11)	0.0511 (9)	−0.0091 (7)	0.0113 (7)	0.0096 (8)
C3	0.0417 (9)	0.0942 (16)	0.0760 (14)	−0.0044 (11)	0.0043 (9)	0.0159 (14)
C4	0.0411 (10)	0.124 (2)	0.135 (3)	0.0155 (13)	0.0218 (14)	−0.008 (2)
C5	0.0570 (13)	0.169 (3)	0.123 (3)	0.0279 (18)	0.0343 (16)	−0.037 (2)
C6	0.0507 (10)	0.112 (2)	0.0743 (14)	0.0127 (12)	0.0227 (10)	−0.0250 (14)
C7	0.0648 (12)	0.129 (2)	0.0413 (9)	−0.0042 (14)	0.0146 (8)	−0.0027 (12)
C8	0.0561 (13)	0.213 (4)	0.084 (2)	−0.003 (2)	−0.0123 (13)	0.030 (3)

P1—O4	1.4900 (11)	C3—C4	1.372 (4)
P1—O1	1.5020 (11)	C3—C8	1.513 (3)
P1—O3	1.5433 (11)	C4—C5	1.364 (5)
P1—O2	1.5945 (10)	C4—H4	0.9300
O2—P1i	1.5944 (10)	C5—C6	1.373 (3)
O3—H3	0.8200	C5—H5	0.9300
N1—C1	1.4559 (19)	C6—H6	0.9300
N1—H1A	0.8900	C7—H7A	0.9600
N1—H1B	0.8900	C7—H7B	0.9600
N1—H1C	0.8900	C7—H7C	0.9600
C1—C6	1.374 (3)	C8—H8A	0.9600
C1—C2	1.384 (2)	C8—H8B	0.9600
C2—C3	1.404 (3)	C8—H8C	0.9600
C2—C7	1.503 (3)
O4—P1—O1	114.78 (7)	C2—C3—C8	120.7 (3)
O4—P1—O3	113.29 (6)	C5—C4—C3	121.8 (2)
O1—P1—O3	110.06 (7)	C5—C4—H4	119.1
O4—P1—O2	109.24 (6)	C3—C4—H4	119.1
O1—P1—O2	103.08 (6)	C4—C5—C6	119.5 (3)
O3—P1—O2	105.47 (6)	C4—C5—H5	120.2
P1i—O2—P1	135.50 (9)	C6—C5—H5	120.2
P1—O3—H3	109.5	C5—C6—C1	119.2 (3)
C1—N1—H1A	109.5	C5—C6—H6	120.4
C1—N1—H1B	109.5	C1—C6—H6	120.4
H1A—N1—H1B	109.5	C2—C7—H7A	109.5
C1—N1—H1C	109.5	C2—C7—H7B	109.5
H1A—N1—H1C	109.5	H7A—C7—H7B	109.5
H1B—N1—H1C	109.5	C2—C7—H7C	109.5
C6—C1—C2	122.71 (18)	H7A—C7—H7C	109.5
C6—C1—N1	117.50 (17)	H7B—C7—H7C	109.5
C2—C1—N1	119.68 (16)	C3—C8—H8A	109.5
C1—C2—C3	116.9 (2)	C3—C8—H8B	109.5
C1—C2—C7	120.43 (17)	H8A—C8—H8B	109.5
C3—C2—C7	122.6 (2)	C3—C8—H8C	109.5
C4—C3—C2	119.9 (2)	H8A—C8—H8C	109.5
C4—C3—C8	119.4 (3)	H8B—C8—H8C	109.5

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1ii	0.82	1.70	2.5088 (15)	167
N1—H1A···O4	0.89	1.81	2.6733 (15)	163
N1—H1B···O4ii	0.89	1.99	2.8175 (16)	154
N1—H1C···O1iii	0.89	1.85	2.732 (2)	172

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O1i	0.82	1.70	2.5088 (15)	167
N1—H1A⋯O4	0.89	1.81	2.6733 (15)	163
N1—H1B⋯O4i	0.89	1.99	2.8175 (16)	154
N1—H1C⋯O1ii	0.89	1.85	2.732 (2)	172

Symmetry codes: (i) ; (ii) .