Bis(2-amino-3-nitro-pyridinium) dichromate(VI).

The title compound, (C(5)H(6)N(3)O(2))(2)[Cr(2)O(7)], consists of 2-amino-3-nitro-pyridinium cations and discrete dichromate anions linked together by N-H⋯O and C-H⋯O hydrogen bonds, forming thick layers parallel to (101). Layer cohesion is ensured by N-H⋯O hydrogen bonding in addition to electrostatic and van der Waals inter-actions, forming a three-dimensional framework. The dichromate anion is located on a twofold axis that passes through its bridging O atom.

Related literature

For related structures, see: Akriche & Rzaigui (2000 ▶); Khadhrani et al. (2006 ▶); Nicoud et al. (1997 ▶); Panunto et al. (1987 ▶); Sieroń (2007 ▶); Le Fur et al. (1998 ▶). For a discussion of hydrogen bonding, see: Desiraju (1989 ▶, 1995 ▶).

Experimental

Crystal data

(C5H6N3O2)2[Cr2O7]

M = 496.26

Monoclinic,

a = 14.799 (2) Å

b = 7.464 (3) Å

c = 17.870 (5) Å

β = 116.71 (4)°

V = 1763.3 (11) Å3

Z = 4

Mo Kα radiation

μ = 1.31 mm−1

T = 298 K

0.25 × 0.23 × 0.19 mm

Data collection

Enraf–Nonius TurboCAD-4 diffractometer

Absorption correction: none

3444 measured reflections

2123 independent reflections

1562 reflections with I > 2σ(I)

R int = 0.021

2 standard reflections frequency: 120 min intensity decay: 3%

Refinement

R[F 2 > 2σ(F 2)] = 0.039

wR(F 2) = 0.106

S = 1.04

2123 reflections

132 parameters

H-atom parameters constrained

Δρmax = 0.44 e Å−3

Δρmin = −0.37 e Å−3

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1996 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-32 for Windows (Farrugia, 1998 ▶); DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808043018/dn2417sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808043018/dn2417Isup2.hkl

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

(C5H6N3O2)2[Cr2O7]	F(000) = 1000
Mr = 496.26	Dx = 1.869 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 14.799 (2) Å	θ = 9–11°
b = 7.464 (3) Å	µ = 1.31 mm−1
c = 17.870 (5) Å	T = 298 K
β = 116.71 (4)°	Diamond-shaped, brown
V = 1763.3 (11) Å3	0.25 × 0.23 × 0.19 mm
Z = 4

Enraf–Nonius TurboCAD-4 diffractometer	Rint = 0.021
Radiation source: fine-focus sealed tube	θmax = 28.0°, θmin = 2.6°
graphite	h = −19→19
non–profiled ω scans	k = 0→9
3444 measured reflections	l = −10→23
2123 independent reflections	2 standard reflections every 120 min
1562 reflections with I > 2σ(I)	intensity decay: 3%

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.106	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.0546P)2 + 0.8978P] where P = (Fo2 + 2Fc2)/3
2123 reflections	(Δ/σ)max = 0.002
132 parameters	Δρmax = 0.44 e Å−3
0 restraints	Δρmin = −0.37 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
Cr1	0.51253 (3)	0.65455 (6)	0.34930 (3)	0.03488 (15)
O1	0.5000	0.5931 (6)	0.2500	0.0760 (11)
O2	0.63121 (14)	0.6372 (3)	0.41598 (13)	0.0434 (5)
O3	0.4736 (2)	0.8522 (3)	0.35084 (18)	0.0672 (7)
O4	0.44934 (17)	0.5121 (3)	0.37400 (14)	0.0544 (6)
O5	0.7372 (2)	−0.1246 (3)	0.67939 (16)	0.0607 (7)
O6	0.6258 (2)	−0.0987 (3)	0.55077 (17)	0.0687 (7)
N1	0.70398 (18)	0.4291 (3)	0.55486 (16)	0.0416 (6)
H1	0.6730	0.5020	0.5139	0.050*
N2	0.58479 (19)	0.2213 (4)	0.47828 (16)	0.0544 (7)
H2A	0.5568	0.3004	0.4397	0.065*
H2B	0.5594	0.1155	0.4719	0.065*
N3	0.69260 (19)	−0.0377 (3)	0.61537 (17)	0.0425 (6)
C1	0.6667 (2)	0.2622 (4)	0.54739 (17)	0.0351 (6)
C2	0.72292 (19)	0.1482 (3)	0.61610 (16)	0.0317 (5)
C3	0.8061 (2)	0.2088 (4)	0.68474 (18)	0.0402 (6)
H3	0.8409	0.1320	0.7296	0.048*
C4	0.8388 (2)	0.3827 (4)	0.6881 (2)	0.0499 (8)
H4	0.8953	0.4252	0.7345	0.060*
C5	0.7856 (2)	0.4899 (4)	0.6213 (2)	0.0494 (8)
H5	0.8063	0.6077	0.6218	0.059*

	U11	U22	U33	U12	U13	U23
Cr1	0.0320 (2)	0.0429 (3)	0.0274 (2)	0.0004 (2)	0.01125 (17)	0.00519 (19)
O1	0.073 (2)	0.122 (3)	0.0321 (17)	0.000	0.0232 (17)	0.000
O2	0.0357 (9)	0.0461 (11)	0.0406 (11)	−0.0011 (9)	0.0101 (9)	0.0065 (9)
O3	0.0642 (15)	0.0518 (14)	0.0762 (18)	0.0208 (12)	0.0233 (14)	0.0154 (12)
O4	0.0483 (12)	0.0604 (14)	0.0583 (13)	−0.0093 (11)	0.0272 (11)	0.0052 (11)
O5	0.0850 (18)	0.0428 (13)	0.0624 (15)	0.0050 (12)	0.0402 (15)	0.0172 (11)
O6	0.0712 (16)	0.0492 (13)	0.0703 (17)	−0.0253 (12)	0.0182 (14)	−0.0142 (12)
N1	0.0445 (13)	0.0357 (12)	0.0502 (15)	0.0080 (11)	0.0263 (12)	0.0123 (11)
N2	0.0428 (14)	0.0691 (18)	0.0389 (14)	−0.0034 (13)	0.0072 (12)	0.0105 (13)
N3	0.0505 (14)	0.0339 (12)	0.0511 (15)	−0.0035 (11)	0.0298 (12)	−0.0016 (12)
C1	0.0334 (12)	0.0418 (15)	0.0339 (14)	0.0036 (12)	0.0186 (11)	0.0044 (12)
C2	0.0343 (12)	0.0304 (12)	0.0323 (13)	0.0013 (11)	0.0168 (11)	0.0004 (11)
C3	0.0407 (14)	0.0429 (15)	0.0327 (14)	0.0044 (12)	0.0128 (12)	0.0036 (12)
C4	0.0453 (16)	0.0486 (18)	0.0464 (17)	−0.0110 (14)	0.0122 (14)	−0.0121 (14)
C5	0.0550 (18)	0.0321 (15)	0.068 (2)	−0.0080 (13)	0.0342 (17)	−0.0074 (14)

Cr1—O3	1.588 (2)	N2—H2A	0.8600
Cr1—O4	1.603 (2)	N2—H2B	0.8600
Cr1—O2	1.625 (2)	N3—C2	1.457 (3)
Cr1—O1	1.7601 (14)	C1—C2	1.416 (4)
O1—Cr1i	1.7601 (14)	C2—C3	1.366 (4)
O5—N3	1.219 (3)	C3—C4	1.377 (4)
O6—N3	1.221 (4)	C3—H3	0.9300
N1—C5	1.336 (4)	C4—C5	1.356 (5)
N1—C1	1.344 (4)	C4—H4	0.9300
N1—H1	0.8600	C5—H5	0.9300
N2—C1	1.320 (4)
O3—Cr1—O4	110.50 (14)	N2—C1—N1	118.1 (3)
O3—Cr1—O2	110.01 (13)	N2—C1—C2	127.3 (3)
O4—Cr1—O2	108.49 (11)	N1—C1—C2	114.6 (2)
O3—Cr1—O1	112.62 (17)	C3—C2—C1	121.3 (3)
O4—Cr1—O1	107.14 (15)	C3—C2—N3	118.2 (2)
O2—Cr1—O1	107.93 (9)	C1—C2—N3	120.4 (2)
Cr1i—O1—Cr1	149.8 (3)	C2—C3—C4	120.5 (3)
C5—N1—C1	124.7 (3)	C2—C3—H3	119.7
C5—N1—H1	117.7	C4—C3—H3	119.7
C1—N1—H1	117.7	C5—C4—C3	117.7 (3)
C1—N2—H2A	120.0	C5—C4—H4	121.2
C1—N2—H2B	120.0	C3—C4—H4	121.2
H2A—N2—H2B	120.0	N1—C5—C4	121.1 (3)
O5—N3—O6	123.8 (3)	N1—C5—H5	119.4
O5—N3—C2	117.6 (3)	C4—C5—H5	119.4
O6—N3—C2	118.6 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2	0.86	1.87	2.707 (3)	165
N2—H2A···O4	0.86	2.17	2.974 (4)	155
N2—H2B···O6	0.86	2.06	2.654 (4)	125
N2—H2B···O6ii	0.86	2.59	3.061 (4)	116
C3—H3···O4iii	0.93	2.58	3.494 (4)	167
C4—H4···O3iv	0.93	2.50	3.337 (4)	150
C5—H5···O2v	0.93	2.34	3.232 (4)	160

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O2	0.86	1.87	2.707 (3)	165
N2—H2A⋯O4	0.86	2.17	2.974 (4)	155
N2—H2B⋯O6	0.86	2.06	2.654 (4)	125
N2—H2B⋯O6i	0.86	2.59	3.061 (4)	116
C3—H3⋯O4ii	0.93	2.58	3.494 (4)	167
C4—H4⋯O3iii	0.93	2.50	3.337 (4)	150
C5—H5⋯O2iv	0.93	2.34	3.232 (4)	160

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