Retracted: Ammonium 2,6-dicarboxy-4-nitrophenolate

The title compound, NH₄⁺·C₈H₄NO₇^- consists of a 2,6-dicarboxy-4-nitrophenolate anion and an ammonium cation, both of which possess crystallographic twofold rotation symmetry. All the O atoms of the anion and the H atoms of the cation contribute to hydrogen bonds, forming a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.059
• wR factor = 0.197
• Data-to-parameter ratio = 11.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    O1     -   C5      ..       9.29 su

Alert level C
CELLV02_ALERT_1_C  The supplied cell volume s.u. differs from that
            calculated from the cell parameter s.u.'s by > 2
            Calculated cell volume su =      10.21
            Cell volume su given      =       8.00
PLAT031_ALERT_4_C Refined Extinction Parameter within Range ......       3.00 Sigma
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O2     -   C5      ..       6.19 su
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors  for         C5
PLAT415_ALERT_2_C Short Inter D-H..H-X       H1     ..  H3      ..       2.10 Ang.
PLAT731_ALERT_1_C Bond    Calc     0.89(3), Rep   0.892(10) ......       3.00 su-Rat
              N1   -H1A     1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.89(3), Rep   0.892(10) ......       3.00 su-Rat
              N1   -H1B     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.89(3), Rep   0.892(10) ......       3.00 su-Rat
              N1   -H1B     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.89(3), Rep   0.892(10) ......       3.00 su-Rat
              N1   -H1A     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.89(3), Rep   0.892(10) ......       3.00 su-Rat
              N1   -H1A     1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     1.97(4), Rep   1.966(16) ......       2.50 su-Rat
              H1A  -O3      1.555   5.555
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.20 Ratio

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
  14 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   9 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

(I)

Crystal data

C8H4NO7·H4N	F(000) = 1008
Mr = 244.16	Dx = 1.713 Mg m^−3
Orthorhombic, Ibca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -I 2b 2c	Cell parameters from 872 reflections
a = 7.128 (3) Å	θ = 2.3–25.7°
b = 13.460 (3) Å	µ = 0.15 mm^−1
c = 19.731 (5) Å	T = 293 K
V = 1893.1 (8) Å^3	Block, colourless
Z = 8	0.35 × 0.28 × 0.25 mm

Data collection

Bruker SMART CCD area-detector diffractometer	1038 independent reflections
Radiation source: fine-focus sealed tube	919 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
ω scans	θmax = 27.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→9
Tmin = 0.948, Tmax = 0.963	k = −16→17
5300 measured reflections	l = −25→20

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.059	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.197	w = 1/[σ^2(Fo^2) + (0.117P)^2 + 2.7596P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max < 0.001
1038 reflections	Δρmax = 0.55 e Å^−3
92 parameters	Δρmin = −0.52 e Å^−3
4 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.006 (2)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.2451 (3)	0.02711 (16)	0.33143 (12)	0.0543 (7)
O2	0.0823 (4)	0.05687 (14)	0.42095 (11)	0.0543 (7)
O3	0.0000	0.2500	0.43544 (12)	0.0404 (7)
O4	0.0599 (4)	0.17740 (19)	0.12496 (10)	0.0672 (8)
N1	0.2500	0.61670 (19)	1.0000	0.0276 (6)
N2	0.0000	0.2500	0.15403 (14)	0.0381 (7)
C1	0.0000	0.2500	0.37246 (15)	0.0301 (7)
C2	0.0606 (3)	0.16682 (16)	0.33094 (12)	0.0302 (6)
C3	0.0631 (3)	0.16685 (16)	0.26145 (12)	0.0318 (6)
H3	0.1080	0.1100	0.2370	0.080*
C4	0.0000	0.2500	0.22755 (16)	0.0314 (7)
C5	0.1344 (3)	0.07804 (14)	0.36361 (11)	0.0264 (5)
H1	0.256 (7)	−0.0345 (11)	0.339 (2)	0.080*
H1A	0.346 (4)	0.652 (3)	0.9845 (17)	0.077 (12)*
H1B	0.224 (5)	0.572 (2)	0.9683 (15)	0.081 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0622 (14)	0.0403 (12)	0.0605 (13)	0.0174 (10)	−0.0020 (10)	0.0009 (9)
O2	0.0784 (16)	0.0394 (11)	0.0451 (12)	0.0127 (10)	0.0032 (10)	0.0123 (8)
O3	0.0644 (17)	0.0298 (12)	0.0271 (11)	−0.0079 (11)	0.000	0.000
O4	0.099 (2)	0.0676 (15)	0.0347 (12)	0.0125 (14)	0.0121 (10)	−0.0110 (10)
N1	0.0373 (14)	0.0247 (13)	0.0209 (11)	0.000	−0.0001 (10)	0.000
N2	0.0389 (16)	0.0459 (17)	0.0296 (15)	−0.0045 (13)	0.000	0.000
C1	0.0359 (16)	0.0240 (14)	0.0303 (16)	−0.0050 (12)	0.000	0.000
C2	0.0321 (12)	0.0243 (11)	0.0342 (12)	−0.0002 (8)	−0.0017 (8)	0.0011 (8)
C3	0.0309 (11)	0.0306 (11)	0.0338 (12)	−0.0023 (9)	−0.0005 (8)	−0.0040 (8)
C4	0.0290 (15)	0.0373 (16)	0.0278 (15)	−0.0025 (12)	0.000	0.000
C5	0.0320 (11)	0.0180 (9)	0.0291 (11)	0.0017 (8)	−0.0048 (8)	−0.0008 (7)

Geometric parameters (Å, º)

O1—C5	1.223 (3)	N2—C4	1.451 (4)
O1—H1	0.846 (10)	C1—C2	1.453 (3)
O2—C5	1.224 (3)	C1—C2^i	1.453 (3)
O3—C1	1.243 (4)	C2—C3	1.371 (3)
O4—N2	1.211 (3)	C2—C5	1.456 (3)
N1—H1A	0.892 (10)	C3—C4	1.379 (3)
N1—H1B	0.892 (10)	C3—H3	0.9599
N2—O4^i	1.211 (3)	C4—C3^i	1.379 (3)
C5—O1—H1	121 (3)	C1—C2—C5	119.4 (2)
H1A—N1—H1B	106.7 (16)	C2—C3—C4	118.7 (2)
O4—N2—O4^i	123.5 (3)	C2—C3—H3	120.4
O4—N2—C4	118.27 (15)	C4—C3—H3	120.8
O4^i—N2—C4	118.27 (15)	C3^i—C4—C3	122.0 (3)
O3—C1—C2	124.32 (13)	C3^i—C4—N2	119.00 (15)
O3—C1—C2^i	124.32 (13)	C3—C4—N2	119.00 (15)
C2—C1—C2^i	111.4 (3)	O1—C5—O2	123.0 (2)
C3—C2—C1	124.6 (2)	O1—C5—C2	117.6 (2)
C3—C2—C5	115.99 (19)	O2—C5—C2	119.4 (2)
O3—C1—C2—C3	−179.16 (16)	O4—N2—C4—C3^i	178.29 (19)
C2^i—C1—C2—C3	0.84 (16)	O4^i—N2—C4—C3^i	−1.71 (19)
O3—C1—C2—C5	−2.7 (2)	O4—N2—C4—C3	−1.71 (19)
C2^i—C1—C2—C5	177.3 (2)	O4^i—N2—C4—C3	178.29 (19)
C1—C2—C3—C4	−1.6 (3)	C3—C2—C5—O1	23.6 (3)
C5—C2—C3—C4	−178.20 (17)	C1—C2—C5—O1	−153.2 (2)
C2—C3—C4—C3^i	0.78 (15)	C3—C2—C5—O2	−155.5 (2)
C2—C3—C4—N2	−179.22 (15)	C1—C2—C5—O2	27.7 (3)

Symmetry code: (i) −x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4^ii	0.85 (1)	2.48 (3)	3.172 (4)	139 (4)
N1—H1B···O2^iii	0.89 (1)	2.21 (2)	3.053 (3)	158 (3)
N1—H1A···O2^iv	0.89 (1)	2.46 (4)	2.948 (3)	115 (3)
N1—H1A···O3^iv	0.89 (1)	1.97 (2)	2.832 (2)	163 (4)

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