Methyl 3,5-di­nitro­salicyl­ate

The title compound, C₈H₆N₂O₇, crystallizes with an intramolecular hydrogen bond between the hydroxyl group and the O atom of the carbonyl group. A weak intermolecular hydrogen bond between the hydroxyl group and a nitro O atom forms planes parallel to the b axis.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.051
• wR factor = 0.133
• Data-to-parameter ratio = 12.0

checkCIF/PLATON results

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.

Methyl 3,5-dinitrosalicylate

Crystal data

C8H6N2O7	F(000) = 496
Mr = 242.16	Dx = 1.692 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.459 (2) Å	Cell parameters from 1976 reflections
b = 16.942 (5) Å	θ = 2.4–28.2°
c = 6.6832 (18) Å	µ = 0.15 mm^−1
β = 96.929 (4)°	T = 293 K
V = 950.8 (4) Å^3	Column, colorless
Z = 4	0.38 × 0.22 × 0.10 mm

Data collection

Bruker SMART CCD area-detector diffractometer	1520 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
Graphite monochromator	θmax = 26.0°, θmin = 2.4°
φ and ω scans	h = −10→7
4905 measured reflections	k = −20→19
1869 independent reflections	l = −7→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.133	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0628P)^2 + 0.421P] where P = (Fo^2 + 2Fc^2)/3
1869 reflections	(Δ/σ)max = 0.018
156 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.30 e Å^−3

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
C1	0.6300 (2)	0.56515 (12)	0.2291 (3)	0.0335 (5)
C2	0.4663 (2)	0.57121 (12)	0.2540 (3)	0.0342 (5)
C3	0.4019 (2)	0.64721 (12)	0.2561 (3)	0.0350 (5)
C4	0.4883 (3)	0.71403 (12)	0.2309 (3)	0.0348 (5)
H4	0.4428	0.7639	0.2355	0.042*
C5	0.6457 (2)	0.70485 (11)	0.1984 (3)	0.0337 (5)
C6	0.7172 (2)	0.63215 (12)	0.1990 (3)	0.0339 (5)
H6	0.8238	0.6280	0.1793	0.041*
C7	0.7065 (3)	0.48605 (12)	0.2435 (3)	0.0387 (5)
C8	0.9540 (3)	0.41851 (15)	0.2634 (5)	0.0600 (7)
H8A	0.9533	0.3991	0.3982	0.090*
H8B	1.0615	0.4292	0.2396	0.090*
H8C	0.9086	0.3796	0.1691	0.090*
N1	0.2350 (2)	0.65921 (12)	0.2927 (3)	0.0441 (5)
N2	0.7398 (2)	0.77534 (10)	0.1682 (3)	0.0386 (5)
O1	0.86066 (18)	0.49074 (9)	0.2382 (3)	0.0523 (5)
O2	0.6342 (2)	0.42520 (9)	0.2604 (3)	0.0532 (5)
O3	0.37768 (18)	0.50811 (9)	0.2800 (3)	0.0486 (5)
H3	0.4314	0.4681	0.2735	0.073*
O4	0.13718 (19)	0.61036 (11)	0.2276 (3)	0.0669 (6)
O5	0.2055 (2)	0.71811 (11)	0.3858 (3)	0.0620 (5)
O6	0.6845 (2)	0.83945 (9)	0.2036 (3)	0.0556 (5)
O7	0.86876 (19)	0.76610 (10)	0.1071 (3)	0.0522 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0306 (11)	0.0318 (11)	0.0381 (11)	0.0013 (8)	0.0036 (8)	−0.0009 (9)
C2	0.0315 (11)	0.0322 (11)	0.0385 (11)	−0.0041 (9)	0.0019 (9)	−0.0005 (9)
C3	0.0245 (10)	0.0405 (12)	0.0399 (12)	0.0006 (8)	0.0030 (8)	0.0017 (9)
C4	0.0320 (11)	0.0312 (10)	0.0408 (12)	0.0035 (8)	0.0025 (9)	0.0014 (9)
C5	0.0314 (11)	0.0313 (11)	0.0384 (12)	−0.0031 (8)	0.0038 (9)	0.0035 (8)
C6	0.0266 (10)	0.0381 (11)	0.0374 (11)	−0.0012 (9)	0.0055 (8)	0.0001 (9)
C7	0.0366 (12)	0.0339 (11)	0.0453 (13)	0.0010 (9)	0.0045 (10)	−0.0013 (9)
C8	0.0490 (15)	0.0469 (14)	0.085 (2)	0.0199 (12)	0.0111 (14)	0.0031 (13)
N1	0.0277 (9)	0.0438 (10)	0.0611 (13)	0.0015 (9)	0.0061 (9)	0.0058 (10)
N2	0.0345 (10)	0.0345 (10)	0.0462 (11)	−0.0042 (8)	0.0026 (8)	0.0052 (8)
O1	0.0349 (9)	0.0365 (9)	0.0869 (14)	0.0074 (7)	0.0122 (8)	0.0035 (8)
O2	0.0454 (10)	0.0295 (8)	0.0853 (13)	−0.0011 (7)	0.0104 (9)	0.0012 (8)
O3	0.0363 (9)	0.0335 (8)	0.0768 (12)	−0.0068 (7)	0.0108 (8)	0.0013 (8)
O4	0.0288 (9)	0.0618 (12)	0.1093 (17)	−0.0087 (8)	0.0049 (9)	−0.0077 (11)
O5	0.0428 (10)	0.0572 (11)	0.0889 (15)	0.0094 (8)	0.0207 (10)	−0.0111 (10)
O6	0.0519 (11)	0.0284 (8)	0.0882 (14)	0.0000 (8)	0.0155 (9)	0.0011 (8)
O7	0.0366 (9)	0.0460 (9)	0.0765 (13)	−0.0072 (7)	0.0175 (8)	0.0071 (8)

Geometric parameters (Å, º)

C1—C6	1.381 (3)	C7—O2	1.211 (3)
C1—C2	1.419 (3)	C7—O1	1.312 (3)
C1—C7	1.486 (3)	C8—O1	1.455 (3)
C2—O3	1.329 (2)	C8—H8A	0.9600
C2—C3	1.399 (3)	C8—H8B	0.9600
C3—C4	1.369 (3)	C8—H8C	0.9600
C3—N1	1.475 (3)	N1—O4	1.214 (3)
C4—C5	1.384 (3)	N1—O5	1.218 (2)
C4—H4	0.9300	N2—O6	1.217 (2)
C5—C6	1.372 (3)	N2—O7	1.220 (2)
C5—N2	1.463 (3)	O3—H3	0.8200
C6—H6	0.9300
C6—C1—C2	120.22 (18)	O2—C7—O1	124.7 (2)
C6—C1—C7	120.98 (18)	O2—C7—C1	123.6 (2)
C2—C1—C7	118.76 (18)	O1—C7—C1	111.72 (18)
O3—C2—C3	120.83 (18)	O1—C8—H8A	109.5
O3—C2—C1	122.08 (18)	O1—C8—H8B	109.5
C3—C2—C1	117.06 (18)	H8A—C8—H8B	109.5
C4—C3—C2	123.04 (19)	O1—C8—H8C	109.5
C4—C3—N1	116.25 (18)	H8A—C8—H8C	109.5
C2—C3—N1	120.68 (18)	H8B—C8—H8C	109.5
C3—C4—C5	117.70 (19)	O4—N1—O5	124.68 (19)
C3—C4—H4	121.1	O4—N1—C3	118.13 (19)
C5—C4—H4	121.1	O5—N1—C3	117.20 (18)
C6—C5—C4	122.17 (18)	O6—N2—O7	124.03 (18)
C6—C5—N2	119.13 (18)	O6—N2—C5	118.27 (18)
C4—C5—N2	118.68 (18)	O7—N2—C5	117.70 (17)
C5—C6—C1	119.71 (19)	C7—O1—C8	118.25 (18)
C5—C6—H6	120.1	C2—O3—H3	109.5
C1—C6—H6	120.1
C6—C1—C2—O3	178.9 (2)	C7—C1—C6—C5	−176.1 (2)
C7—C1—C2—O3	−3.4 (3)	C6—C1—C7—O2	−176.5 (2)
C6—C1—C2—C3	−2.9 (3)	C2—C1—C7—O2	5.8 (3)
C7—C1—C2—C3	174.82 (19)	C6—C1—C7—O1	4.3 (3)
O3—C2—C3—C4	179.7 (2)	C2—C1—C7—O1	−173.42 (19)
C1—C2—C3—C4	1.5 (3)	C4—C3—N1—O4	146.9 (2)
O3—C2—C3—N1	1.6 (3)	C2—C3—N1—O4	−34.9 (3)
C1—C2—C3—N1	−176.57 (18)	C4—C3—N1—O5	−32.7 (3)
C2—C3—C4—C5	1.2 (3)	C2—C3—N1—O5	145.5 (2)
N1—C3—C4—C5	179.35 (18)	C6—C5—N2—O6	−167.0 (2)
C3—C4—C5—C6	−2.6 (3)	C4—C5—N2—O6	11.2 (3)
C3—C4—C5—N2	179.14 (19)	C6—C5—N2—O7	13.6 (3)
C4—C5—C6—C1	1.3 (3)	C4—C5—N2—O7	−168.1 (2)
N2—C5—C6—C1	179.48 (19)	O2—C7—O1—C8	−3.0 (4)
C2—C1—C6—C5	1.6 (3)	C1—C7—O1—C8	176.2 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O6^i	0.82	2.40	2.910 (2)	121
O3—H3···O2	0.82	1.88	2.602 (2)	147

Symmetry code: (i) −x+1, y−1/2, −z+1/2.