X-ray diffraction and packing analysis on vintage crystals: Wilhelm Koerner's nitrobenzene derivatives from the School of Agricultural Sciences in Milano

The crystal structures of six nitrotoluene derivatives, synthesized by Wilhelm Koerner about a century ago and retrieved from a depository at the University of Milano, were determined. The correct assignment of molecular structures is verified. The geometry of the nitro groups and factors affecting the orientation of nitro groups with respect to the benzene ring are discussed, also using an auxiliary set of crystal structures retrieved from the Cambridge Structural Database. The crystal packings have been analyzed, and lattice energies have been calculated by atom-atom potential methods and by the newly proposed Pixel method. This method allows a more complete description of intermolecular potentials in terms of the interaction between molecular electron densities and separate Coulombic, polarization, dispersion and overlap repulsion energies. Lattice vibrations and external entropies were calculated by lattice-dynamical procedures. The results of the Pixel energy calculations allow a reliable, quantitative assessment of the relative importance of stacking interactions and hydrogen bonding in the rationalization of the recognition modes of nitrobenzene derivatives, which is impossible to attain using only qualitative atom- atom geometry concepts.

Computing details

For all compounds, program(s) used to solve structure: SIR2000 (Burla et al., 2001); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SCHAKAL (Keller, 1993).

Figures

(K15)

Crystal data

C8H6BrIN2O3	Z = 2
Mr = 384.96	F(000) = 360
Triclinic, P1	Dx = 2.326 Mg m^−3
a = 4.797 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.673 (2) Å	Cell parameters from 3296 reflections
c = 15.654 (4) Å	θ = 2–25°
α = 96.98 (2)°	µ = 6.54 mm^−1
β = 97.03 (2)°	T = 293 K
γ = 103.34 (2)°	Column, yellow
V = 549.7 (3) Å^3	0.3 × 0.25 × 0.15 mm

Data collection

SMART diffractometer	1947 independent reflections
Graphite monochromator	Rint = 0.034
ω–scan	θmax = 25°, θmin = 2°
Absorption correction: SADABS ?	h = −5→5
Tmin = 0.62, Tmax = 1	k = −9→9
4680 measured reflections	l = −18→18

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)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.098	w = 1/[σ^2(Fo^2) + (0.068P)^2] where P = (Fo^2 + 2Fc^2)/3
1947 reflections	(Δ/σ)max = 0.013
136 parameters	Δρmax = 0.59 e Å^−3
0 restraints	Δρmin = −1.48 e Å^−3
Primary atom site location: structure-invariant direct methods

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	0.6105 (9)	0.2304 (6)	0.8716 (3)	0.0373 (9)
C2	0.4599 (9)	0.3601 (6)	0.8553 (3)	0.0397 (9)
H2	0.4385	0.4419	0.9015	0.048*
C3	0.3410 (9)	0.3694 (6)	0.7715 (3)	0.0329 (8)
C4	0.3696 (8)	0.2484 (6)	0.7009 (3)	0.0323 (8)
C5	0.5191 (9)	0.1194 (6)	0.7170 (3)	0.0357 (9)
H5	0.5408	0.0374	0.671	0.043*
C6	0.6372 (9)	0.1110 (6)	0.8013 (3)	0.0349 (9)
Br	0.78062 (14)	0.23819 (8)	0.98720 (3)	0.0599 (2)
I	0.13937 (5)	0.57939 (3)	0.753902 (18)	0.04235 (17)
N1A	0.2506 (7)	0.2556 (5)	0.6152 (2)	0.0373 (8)
H1A	0.0747	0.2653	0.6059	0.045*
C1A	0.3950 (9)	0.2481 (6)	0.5465 (3)	0.0396 (10)
O1A	0.6424 (7)	0.2332 (6)	0.5535 (2)	0.0613 (10)
C2A	0.2284 (11)	0.2573 (9)	0.4603 (3)	0.0563 (14)
H2A1	0.0377	0.2689	0.468	0.084*
H2A2	0.2133	0.1486	0.4207	0.084*
H2A3	0.3276	0.3602	0.4371	0.084*
N1N	0.7909 (8)	−0.0324 (5)	0.8097 (2)	0.0426 (9)
O1N	0.7954 (11)	−0.0982 (6)	0.8770 (3)	0.0794 (13)
O2N	0.8902 (8)	−0.0871 (5)	0.7474 (2)	0.0584 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.042 (2)	0.039 (2)	0.032 (2)	0.0129 (18)	0.0020 (16)	0.0085 (17)
C2	0.044 (2)	0.039 (2)	0.039 (2)	0.0148 (18)	0.0111 (18)	0.0029 (18)
C3	0.034 (2)	0.033 (2)	0.035 (2)	0.0139 (16)	0.0064 (16)	0.0048 (17)
C4	0.0295 (19)	0.035 (2)	0.0343 (19)	0.0140 (16)	0.0015 (15)	0.0050 (16)
C5	0.040 (2)	0.034 (2)	0.036 (2)	0.0187 (18)	0.0044 (17)	−0.0001 (17)
C6	0.034 (2)	0.033 (2)	0.042 (2)	0.0149 (17)	0.0052 (17)	0.0094 (17)
Br	0.0866 (4)	0.0599 (4)	0.0334 (3)	0.0273 (3)	−0.0056 (3)	0.0061 (2)
I	0.0431 (2)	0.0368 (2)	0.0510 (2)	0.02080 (15)	0.00412 (15)	0.00378 (15)
N1A	0.0345 (17)	0.046 (2)	0.0350 (18)	0.0211 (16)	−0.0007 (14)	0.0043 (15)
C1A	0.036 (2)	0.046 (3)	0.038 (2)	0.0132 (19)	0.0047 (18)	0.0053 (19)
O1A	0.0428 (18)	0.104 (3)	0.0493 (19)	0.0368 (19)	0.0120 (15)	0.0182 (19)
C2A	0.053 (3)	0.087 (4)	0.035 (2)	0.027 (3)	0.006 (2)	0.014 (2)
N1N	0.046 (2)	0.040 (2)	0.044 (2)	0.0193 (17)	−0.0031 (17)	0.0089 (17)
O1N	0.124 (4)	0.081 (3)	0.052 (2)	0.065 (3)	0.002 (2)	0.018 (2)
O2N	0.076 (3)	0.059 (3)	0.059 (2)	0.045 (2)	0.022 (2)	0.0152 (19)

Geometric parameters (Å, º)

C1—C6	1.382 (6)	C5—C6	1.385 (6)
C1—C2	1.387 (6)	C6—N1N	1.469 (5)
C1—Br	1.881 (4)	N1A—C1A	1.352 (6)
C2—C3	1.383 (6)	C1A—O1A	1.211 (5)
C3—C4	1.395 (6)	C1A—C2A	1.499 (6)
C3—I	2.090 (4)	N1N—O2N	1.209 (5)
C4—C5	1.379 (6)	N1N—O1N	1.222 (5)
C4—N1A	1.405 (5)
C6—C1—C2	117.8 (4)	C1—C6—C5	121.6 (4)
C6—C1—Br	124.7 (3)	C1—C6—N1N	123.2 (4)
C2—C1—Br	117.4 (3)	C5—C6—N1N	115.2 (4)
C3—C2—C1	121.0 (4)	C1A—N1A—C4	124.1 (3)
C2—C3—C4	120.8 (4)	O1A—C1A—N1A	122.4 (4)
C2—C3—I	117.6 (3)	O1A—C1A—C2A	121.9 (4)
C4—C3—I	121.5 (3)	N1A—C1A—C2A	115.8 (4)
C5—C4—C3	118.3 (4)	O2N—N1N—O1N	123.4 (4)
C5—C4—N1A	120.0 (4)	O2N—N1N—C6	118.0 (3)
C3—C4—N1A	121.7 (4)	O1N—N1N—C6	118.5 (4)
C4—C5—C6	120.5 (4)

(K19)

Crystal data

C7H5N3O6	F(000) = 464
Mr = 227.14	Dx = 1.548 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.644 (1) Å	Cell parameters from 837 reflections
b = 9.550 (1) Å	θ = 2–22°
c = 8.754 (1) Å	µ = 0.14 mm^−1
β = 121.31 (2)°	T = 293 K
V = 974.53 (17) Å^3	Block, very light yellow
Z = 4	0.36 × 0.3 × 0.26 mm

Data collection

SMART diffractometer	763 independent reflections
Graphite monochromator	Rint = 0.032
ω–scan	θmax = 24°, θmin = 2°
Absorption correction: SADABS ?	h = −15→13
Tmin = 0.79, Tmax = 1	k = −10→10
2636 measured reflections	l = −8→9

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.147	H atoms treated by a mixture of independent and constrained refinement
S = 0.81	w = 1/[σ^2(Fo^2) + (0.1341P)^2 + 0.2249P] where P = (Fo^2 + 2Fc^2)/3
763 reflections	(Δ/σ)max = 0.004
75 parameters	Δρmax = 0.15 e Å^−3
0 restraints	Δρmin = −0.15 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	Occ. (<1)
C1	0.5	0.6741 (3)	0.25	0.0489 (7)
C1M	0.5	0.5173 (3)	0.25	0.0710 (10)
H1M1	0.5689	0.4838	0.2581	0.106*	0.5
H1M2	0.4345	0.4838	0.1414	0.106*	0.5
H1M3	0.4966	0.4838	0.3505	0.106*	0.5
C2	0.59018 (15)	0.7495 (2)	0.2605 (3)	0.0484 (6)
H2	0.6522	0.702	0.2686	0.058*
C3	0.58925 (15)	0.8928 (2)	0.2590 (2)	0.0469 (6)
C4	0.5	0.9686 (3)	0.25	0.0461 (7)
N1	0.68412 (18)	0.9648 (2)	0.2580 (3)	0.0644 (6)
O1	0.77696 (16)	0.9086 (2)	0.3351 (3)	0.1026 (9)
O2	0.66271 (15)	1.07438 (18)	0.1755 (3)	0.0839 (7)
N2	0.5	1.1226 (3)	0.25	0.0628 (7)
O3	0.42778 (17)	1.17968 (16)	0.1136 (2)	0.0843 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0550 (16)	0.0382 (15)	0.0610 (17)	0	0.0354 (14)	0
C1M	0.080 (2)	0.0383 (18)	0.110 (3)	0	0.061 (2)	0
C2	0.0488 (11)	0.0461 (13)	0.0590 (12)	0.0039 (8)	0.0341 (9)	0.0015 (8)
C3	0.0510 (11)	0.0442 (12)	0.0501 (12)	−0.0076 (8)	0.0295 (9)	−0.0004 (8)
C4	0.0634 (17)	0.0316 (14)	0.0447 (15)	0	0.0291 (13)	0
N1	0.0655 (12)	0.0616 (13)	0.0735 (13)	−0.0185 (9)	0.0413 (10)	−0.0014 (9)
O1	0.0558 (11)	0.1121 (19)	0.1362 (19)	−0.0093 (10)	0.0473 (12)	0.0236 (13)
O2	0.0995 (14)	0.0671 (12)	0.0990 (14)	−0.0237 (9)	0.0613 (11)	0.0091 (9)
N2	0.095 (2)	0.0379 (14)	0.0605 (17)	0	0.0436 (16)	0
O3	0.1239 (15)	0.0468 (10)	0.0731 (12)	0.0180 (9)	0.0446 (11)	0.0156 (8)

Geometric parameters (Å, º)

C1—C2	1.387 (2)	C4—C3^i	1.383 (2)
C1—C2^i	1.387 (2)	C4—N2	1.471 (4)
C1—C1M	1.497 (4)	N1—O1	1.208 (3)
C2—C3	1.369 (3)	N1—O2	1.218 (2)
C3—C4	1.383 (2)	N2—O3^i	1.213 (2)
C3—N1	1.470 (3)	N2—O3	1.213 (2)
C2—C1—C2^i	117.5 (2)	C3^i—C4—N2	121.55 (12)
C2—C1—C1M	121.27 (12)	C3—C4—N2	121.55 (12)
C2^i—C1—C1M	121.27 (12)	O1—N1—O2	124.86 (18)
C3—C2—C1	121.00 (17)	O1—N1—C3	117.4 (2)
C2—C3—C4	121.82 (17)	O2—N1—C3	117.72 (19)
C2—C3—N1	117.67 (17)	O3^i—N2—O3	126.6 (3)
C4—C3—N1	120.44 (19)	O3^i—N2—C4	116.69 (14)
C3^i—C4—C3	116.9 (2)	O3—N2—C4	116.69 (14)

Symmetry code: (i) −x+1, y, −z+1/2.

(K20)

Crystal data

C7H5N3O6	Z = 2
Mr = 227.14	F(000) = 232
Triclinic, P1	Dx = 1.635 Mg m^−3
a = 7.700 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.329 (2) Å	Cell parameters from 855 reflections
c = 8.694 (2) Å	θ = 2–22°
α = 87.89 (1)°	µ = 0.15 mm^−1
β = 65.10 (1)°	T = 293 K
γ = 67.33 (1)°	Column, light yellow
V = 461.40 (19) Å^3	0.4 × 0.2 × 0.2 mm

Data collection

SMART diffractometer	1165 independent reflections
Graphite monochromator	Rint = 0.024
ω–scan	θmax = 23°, θmin = 2°
Absorption correction: SADABS ?	h = −8→8
Tmin = 0.94, Tmax = 1	k = −8→8
3177 measured reflections	l = −9→9

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.111	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.059P)^2 + 0.1766P] where P = (Fo^2 + 2Fc^2)/3
1165 reflections	(Δ/σ)max = 0.017
145 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.21 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	0.5306 (3)	0.2715 (3)	0.7162 (3)	0.0475 (6)
C2	0.4326 (3)	0.2750 (3)	0.6125 (3)	0.0427 (5)
C3	0.5364 (3)	0.2471 (3)	0.4362 (3)	0.0438 (6)
C4	0.7444 (3)	0.2201 (3)	0.3578 (3)	0.0512 (6)
C5	0.8458 (4)	0.2176 (3)	0.4567 (4)	0.0611 (7)
H5	0.9864	0.1991	0.4043	0.073*
C6	0.7398 (4)	0.2422 (3)	0.6318 (3)	0.0574 (7)
H6	0.8113	0.239	0.6962	0.069*
C1M	0.4228 (4)	0.2909 (4)	0.9079 (3)	0.0677 (7)
H111	0.279	0.3105	0.9446	0.102*
H112	0.4286	0.3891	0.9568	0.102*
H113	0.4916	0.1855	0.9452	0.102*
N1	0.2113 (3)	0.3027 (3)	0.6933 (3)	0.0550 (6)
O1	0.0856 (3)	0.4387 (3)	0.7903 (3)	0.0828 (6)
O2	0.1696 (3)	0.1866 (3)	0.6560 (3)	0.0741 (6)
N2	0.4223 (3)	0.2403 (3)	0.3377 (3)	0.0544 (5)
O3	0.2715 (3)	0.3729 (3)	0.3544 (3)	0.0783 (6)
O4	0.4827 (3)	0.1017 (3)	0.2528 (3)	0.0764 (6)
N3	0.8586 (4)	0.2005 (3)	0.1702 (3)	0.0715 (7)
O5	0.7567 (4)	0.2705 (3)	0.0919 (3)	0.0918 (7)
O6	1.0476 (4)	0.1175 (3)	0.1069 (3)	0.1043 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0502 (14)	0.0483 (13)	0.0545 (14)	−0.0224 (10)	−0.0303 (11)	0.0092 (10)
C2	0.0368 (12)	0.0449 (12)	0.0512 (13)	−0.0187 (10)	−0.0221 (10)	0.0093 (10)
C3	0.0478 (13)	0.0412 (12)	0.0519 (14)	−0.0211 (10)	−0.0279 (11)	0.0095 (10)
C4	0.0485 (14)	0.0519 (14)	0.0520 (14)	−0.0257 (11)	−0.0162 (11)	0.0052 (11)
C5	0.0399 (13)	0.0653 (16)	0.0814 (19)	−0.0271 (12)	−0.0244 (13)	0.0079 (13)
C6	0.0536 (15)	0.0654 (15)	0.0707 (18)	−0.0286 (12)	−0.0391 (14)	0.0111 (13)
C1M	0.0759 (18)	0.0845 (19)	0.0556 (15)	−0.0357 (15)	−0.0379 (14)	0.0130 (13)
N1	0.0433 (12)	0.0693 (14)	0.0577 (13)	−0.0248 (11)	−0.0258 (10)	0.0143 (11)
O1	0.0472 (11)	0.0913 (15)	0.0806 (14)	−0.0121 (10)	−0.0152 (10)	−0.0084 (12)
O2	0.0598 (11)	0.0904 (14)	0.0970 (15)	−0.0468 (10)	−0.0426 (10)	0.0226 (11)
N2	0.0663 (14)	0.0574 (13)	0.0568 (12)	−0.0315 (11)	−0.0374 (11)	0.0170 (10)
O3	0.0816 (13)	0.0755 (13)	0.0938 (15)	−0.0213 (11)	−0.0629 (12)	0.0189 (10)
O4	0.1145 (16)	0.0657 (12)	0.0776 (13)	−0.0439 (11)	−0.0610 (12)	0.0097 (10)
N3	0.0675 (17)	0.0764 (16)	0.0629 (15)	−0.0406 (13)	−0.0113 (13)	0.0020 (12)
O5	0.1097 (18)	0.1111 (18)	0.0592 (12)	−0.0575 (14)	−0.0310 (12)	0.0256 (12)
O6	0.0641 (15)	0.125 (2)	0.0867 (16)	−0.0411 (13)	0.0042 (12)	−0.0138 (14)

Geometric parameters (Å, º)

C1—C6	1.381 (3)	C4—N3	1.470 (3)
C1—C2	1.392 (3)	C5—C6	1.369 (4)
C1—C1M	1.498 (3)	N1—O1	1.212 (3)
C2—C3	1.376 (3)	N1—O2	1.221 (3)
C2—N1	1.467 (3)	N2—O4	1.206 (3)
C3—C4	1.377 (3)	N2—O3	1.213 (3)
C3—N2	1.478 (3)	N3—O6	1.215 (3)
C4—C5	1.378 (3)	N3—O5	1.219 (3)
C6—C1—C2	116.0 (2)	C6—C5—C4	120.1 (2)
C6—C1—C1M	120.6 (2)	C5—C6—C1	122.4 (2)
C2—C1—C1M	123.3 (2)	O1—N1—O2	125.6 (2)
C3—C2—C1	122.86 (19)	O1—N1—C2	117.4 (2)
C3—C2—N1	118.08 (18)	O2—N1—C2	117.0 (2)
C1—C2—N1	119.0 (2)	O4—N2—O3	125.8 (2)
C2—C3—C4	119.01 (19)	O4—N2—C3	117.14 (19)
C2—C3—N2	118.64 (19)	O3—N2—C3	117.0 (2)
C4—C3—N2	122.3 (2)	O6—N3—O5	125.6 (3)
C3—C4—C5	119.6 (2)	O6—N3—C4	116.9 (3)
C3—C4—N3	121.1 (2)	O5—N3—C4	117.5 (2)
C5—C4—N3	119.3 (2)

(K6)

Crystal data

C9H9N3O5	F(000) = 496
Mr = 239.19	Dx = 1.463 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.686 (2) Å	Cell parameters from 1024 reflections
b = 11.368 (2) Å	θ = 2–25°
c = 9.976 (2) Å	µ = 0.12 mm^−1
β = 98.74 (2)°	T = 293 K
V = 1085.7 (4) Å^3	Column, bright yellow
Z = 4	0.4 × 0.26 × 0.26 mm

Data collection

SMART diffractometer	1917 independent reflections
Graphite monochromator	Rint = 0.027
ω–scan	θmax = 25°, θmin = 2°
Absorption correction: SADABS ?	h = −11→11
Tmin = 0.79, Tmax = 1	k = −13→13
8680 measured reflections	l = −11→11

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) = 0.165	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.092P)^2 + 0.5057P] where P = (Fo^2 + 2Fc^2)/3
1917 reflections	(Δ/σ)max = 0.001
154 parameters	Δρmax = 0.30 e Å^−3
0 restraints	Δρmin = −0.27 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	0.7689 (2)	0.12669 (19)	0.0674 (2)	0.0467 (5)
C2	0.7933 (2)	0.00603 (19)	0.06609 (19)	0.0418 (5)
C3	0.7191 (2)	−0.07198 (19)	−0.02665 (19)	0.0416 (5)
C4	0.6158 (2)	−0.0250 (2)	−0.1244 (2)	0.0511 (6)
H4	0.5654	−0.0745	−0.1881	0.061*
C5	0.5877 (2)	0.0930 (2)	−0.1278 (2)	0.0527 (6)
H5	0.5195	0.124	−0.1942	0.063*
C6	0.6614 (2)	0.16557 (19)	−0.0318 (2)	0.0484 (5)
C1M	0.8600 (3)	0.2112 (2)	0.1574 (3)	0.0689 (7)
H1M1	0.8243	0.2896	0.1422	0.103*
H1M2	0.9536	0.2077	0.1369	0.103*
H1M3	0.8602	0.1901	0.2507	0.103*
N1N	0.91218 (19)	−0.04037 (18)	0.16319 (19)	0.0528 (5)
O11N	0.9153 (2)	−0.0159 (2)	0.28279 (18)	0.0773 (6)
O12N	0.99971 (17)	−0.09790 (18)	0.1172 (2)	0.0695 (6)
N2N	0.6201 (2)	0.29050 (19)	−0.0361 (2)	0.0636 (6)
O21N	0.6114 (3)	0.3423 (2)	−0.1422 (2)	0.0975 (8)
O22N	0.5892 (3)	0.3343 (2)	0.0650 (3)	0.1137 (10)
N1A	0.7439 (2)	−0.19381 (16)	−0.02853 (17)	0.0494 (5)
H1A	0.7564	−0.2247	−0.1045	0.059*
C1A	0.7499 (2)	−0.26651 (19)	0.0804 (2)	0.0484 (5)
O1A	0.73809 (18)	−0.22804 (14)	0.19282 (15)	0.0570 (5)
C2A	0.7702 (3)	−0.3941 (2)	0.0523 (3)	0.0703 (7)
H2A1	0.7772	−0.4045	−0.0419	0.106*
H2A2	0.6921	−0.4383	0.0742	0.106*
H2A3	0.8544	−0.4215	0.1067	0.106*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0435 (11)	0.0536 (13)	0.0432 (11)	−0.0071 (9)	0.0072 (9)	−0.0016 (9)
C2	0.0370 (10)	0.0525 (12)	0.0348 (10)	−0.0014 (8)	0.0023 (8)	0.0045 (8)
C3	0.0434 (10)	0.0505 (12)	0.0314 (10)	−0.0027 (8)	0.0069 (8)	0.0005 (8)
C4	0.0518 (12)	0.0625 (14)	0.0363 (11)	−0.0045 (10)	−0.0024 (9)	−0.0015 (9)
C5	0.0481 (12)	0.0650 (14)	0.0426 (12)	0.0043 (10)	−0.0010 (9)	0.0093 (10)
C6	0.0473 (11)	0.0506 (12)	0.0483 (12)	0.0031 (9)	0.0103 (9)	0.0060 (9)
C1M	0.0700 (16)	0.0615 (15)	0.0714 (17)	−0.0159 (12)	−0.0011 (13)	−0.0103 (12)
N1N	0.0440 (10)	0.0649 (12)	0.0462 (11)	−0.0072 (9)	−0.0033 (8)	0.0109 (9)
O11N	0.0779 (13)	0.1006 (15)	0.0452 (10)	−0.0102 (10)	−0.0167 (8)	0.0018 (9)
O12N	0.0478 (9)	0.0823 (13)	0.0785 (12)	0.0145 (9)	0.0096 (9)	0.0246 (10)
N2N	0.0668 (13)	0.0568 (12)	0.0670 (14)	0.0056 (10)	0.0096 (10)	0.0079 (10)
O21N	0.1194 (19)	0.0785 (14)	0.0916 (16)	0.0231 (13)	0.0066 (14)	0.0291 (12)
O22N	0.170 (3)	0.0785 (15)	0.1025 (18)	0.0360 (16)	0.0511 (18)	−0.0035 (13)
N1A	0.0630 (11)	0.0499 (11)	0.0359 (9)	−0.0015 (8)	0.0089 (8)	−0.0030 (7)
C1A	0.0492 (12)	0.0506 (12)	0.0452 (12)	−0.0001 (9)	0.0061 (9)	0.0026 (9)
O1A	0.0762 (11)	0.0573 (10)	0.0385 (8)	−0.0001 (8)	0.0120 (7)	0.0052 (7)
C2A	0.0875 (19)	0.0526 (15)	0.0708 (17)	0.0067 (13)	0.0116 (14)	0.0007 (12)

Geometric parameters (Å, º)

C1—C2	1.392 (3)	C6—N2N	1.474 (3)
C1—C6	1.395 (3)	N1N—O12N	1.215 (3)
C1—C1M	1.506 (3)	N1N—O11N	1.221 (3)
C2—C3	1.399 (3)	N2N—O22N	1.202 (3)
C2—N1N	1.484 (3)	N2N—O21N	1.204 (3)
C3—C4	1.392 (3)	N1A—C1A	1.360 (3)
C3—N1A	1.406 (3)	C1A—O1A	1.225 (3)
C4—C5	1.369 (3)	C1A—C2A	1.496 (3)
C5—C6	1.378 (3)
C2—C1—C6	114.52 (18)	C5—C6—N2N	116.6 (2)
C2—C1—C1M	123.3 (2)	C1—C6—N2N	119.7 (2)
C6—C1—C1M	121.8 (2)	O12N—N1N—O11N	125.2 (2)
C1—C2—C3	124.02 (18)	O12N—N1N—C2	117.48 (18)
C1—C2—N1N	117.40 (18)	O11N—N1N—C2	117.3 (2)
C3—C2—N1N	118.43 (19)	O22N—N2N—O21N	122.8 (2)
C4—C3—C2	117.5 (2)	O22N—N2N—C6	118.4 (2)
C4—C3—N1A	118.32 (18)	O21N—N2N—C6	118.6 (2)
C2—C3—N1A	124.13 (18)	C1A—N1A—C3	125.05 (17)
C5—C4—C3	120.8 (2)	O1A—C1A—N1A	121.1 (2)
C4—C5—C6	119.3 (2)	O1A—C1A—C2A	123.4 (2)
C5—C6—C1	123.8 (2)	N1A—C1A—C2A	115.5 (2)

(K12)

Crystal data

C9H10N2O3	F(000) = 408
Mr = 194.19	Dx = 1.311 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.430 (2) Å	Cell parameters from 912 reflections
b = 9.991 (2) Å	θ = 2–23°
c = 9.574 (2) Å	µ = 0.1 mm^−1
β = 99.51 (1)°	T = 293 K
V = 984.0 (3) Å^3	Needle, light yellow
Z = 4	0.4 × 0.12 × 0.12 mm

Data collection

SMART diffractometer	1735 independent reflections
Graphite monochromator	Rint = 0.039
ω–scan	θmax = 25°, θmin = 2°
Absorption correction: SADABS ?	h = −12→12
Tmin = 0.92, Tmax = 1	k = −11→11
8196 measured reflections	l = −11→11

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.157	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0705P)^2 + 0.4277P] where P = (Fo^2 + 2Fc^2)/3
1735 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.21 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
N1N	0.7859 (2)	−0.0103 (2)	0.7697 (2)	0.0613 (6)
O1N	0.8043 (2)	−0.0202 (2)	0.8991 (2)	0.0813 (7)
O2N	0.6959 (2)	−0.0632 (2)	0.6920 (2)	0.0878 (8)
N1A	0.7129 (2)	0.1885 (2)	0.54083 (19)	0.0546 (6)
H1A	0.6861	0.1855	0.451	0.066*
C1A	0.6281 (3)	0.2297 (3)	0.6237 (2)	0.0533 (7)
O1A	0.65474 (19)	0.2237 (2)	0.75322 (16)	0.0677 (6)
C2A	0.5021 (3)	0.2819 (4)	0.5476 (3)	0.0809 (10)
H2A1	0.5015	0.2774	0.4473	0.121*
H2A2	0.4914	0.3731	0.5747	0.121*
H2A3	0.4322	0.2287	0.5715	0.121*
C1M	1.2487 (3)	0.0695 (4)	0.7495 (4)	0.0833 (10)
H1M1	1.3016	0.1154	0.6917	0.125*
H1M2	1.2657	−0.0249	0.7477	0.125*
H1M3	1.2691	0.1016	0.8452	0.125*
C1	0.8807 (2)	0.0646 (2)	0.7041 (2)	0.0470 (6)
C2	0.8422 (3)	0.1500 (2)	0.5905 (2)	0.0471 (6)
C3	0.9415 (3)	0.2032 (3)	0.5261 (3)	0.0573 (7)
H3	0.9202	0.2593	0.4482	0.069*
C4	1.0694 (3)	0.1750 (3)	0.5749 (3)	0.0605 (7)
H4	1.1326	0.2103	0.5275	0.073*
C5	1.1075 (3)	0.0952 (3)	0.6933 (3)	0.0566 (7)
C6	1.0103 (3)	0.0406 (3)	0.7566 (3)	0.0545 (7)
H6	1.0322	−0.0133	0.8362	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1N	0.0792 (17)	0.0519 (14)	0.0531 (14)	−0.0075 (12)	0.0115 (12)	0.0074 (11)
O1N	0.1033 (17)	0.0910 (16)	0.0517 (12)	−0.0046 (13)	0.0192 (11)	0.0255 (11)
O2N	0.0965 (17)	0.0813 (16)	0.0834 (15)	−0.0362 (13)	0.0087 (13)	0.0008 (12)
N1A	0.0639 (14)	0.0724 (15)	0.0260 (9)	0.0041 (11)	0.0028 (9)	0.0005 (9)
C1A	0.0620 (17)	0.0624 (17)	0.0351 (12)	−0.0010 (13)	0.0073 (12)	−0.0040 (11)
O1A	0.0810 (14)	0.0915 (15)	0.0305 (9)	0.0082 (11)	0.0086 (9)	−0.0069 (9)
C2A	0.066 (2)	0.117 (3)	0.0570 (17)	0.0120 (19)	0.0039 (15)	0.0038 (18)
C1M	0.069 (2)	0.085 (2)	0.094 (2)	0.0088 (17)	0.0064 (18)	−0.0072 (19)
C1	0.0657 (17)	0.0398 (13)	0.0352 (12)	−0.0032 (12)	0.0073 (11)	−0.0024 (10)
C2	0.0640 (17)	0.0477 (14)	0.0292 (11)	−0.0005 (12)	0.0068 (11)	−0.0029 (10)
C3	0.075 (2)	0.0554 (17)	0.0434 (13)	0.0042 (14)	0.0147 (13)	0.0083 (12)
C4	0.0687 (19)	0.0565 (17)	0.0606 (16)	−0.0048 (14)	0.0232 (14)	−0.0017 (13)
C5	0.0667 (18)	0.0489 (16)	0.0537 (15)	0.0022 (13)	0.0083 (13)	−0.0087 (13)
C6	0.0731 (19)	0.0447 (14)	0.0439 (13)	0.0056 (13)	0.0040 (13)	0.0030 (11)

Geometric parameters (Å, º)

N1N—O2N	1.217 (3)	C1M—C5	1.505 (4)
N1N—O1N	1.225 (3)	C1—C6	1.383 (4)
N1N—C1	1.462 (3)	C1—C2	1.389 (3)
N1A—C1A	1.347 (3)	C2—C3	1.395 (4)
N1A—C2	1.407 (3)	C3—C4	1.368 (4)
C1A—O1A	1.226 (3)	C4—C5	1.389 (4)
C1A—C2A	1.488 (4)	C5—C6	1.377 (4)
O2N—N1N—O1N	124.0 (2)	C1—C2—C3	116.1 (2)
O2N—N1N—C1	117.9 (2)	C1—C2—N1A	124.7 (2)
O1N—N1N—C1	118.1 (2)	C3—C2—N1A	119.1 (2)
C1A—N1A—C2	124.77 (19)	C4—C3—C2	121.6 (2)
O1A—C1A—N1A	121.3 (2)	C3—C4—C5	121.9 (3)
O1A—C1A—C2A	123.1 (3)	C6—C5—C4	117.0 (3)
N1A—C1A—C2A	115.5 (2)	C6—C5—C1M	121.6 (3)
C6—C1—C2	122.0 (2)	C4—C5—C1M	121.4 (3)
C6—C1—N1N	116.4 (2)	C5—C6—C1	121.2 (2)
C2—C1—N1N	121.5 (2)

(K14)

Crystal data

C14H14N6O8	Dx = 1.489 Mg m^−3
Mr = 394.31	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Cmc21	Cell parameters from 790 reflections
a = 12.239 (2) Å	θ = 2–24°
b = 10.582 (2) Å	µ = 0.12 mm^−1
c = 13.582 (3) Å	T = 293 K
V = 1759.0 (6) Å^3	Orange, needle
Z = 4	0.32 × 0.14 × 0.12 mm
F(000) = 816

Data collection

SMART diffractometer	1416 independent reflections
Graphite monochromator	Rint = 0.026
ω–scan	θmax = 25°, θmin = 2°
Absorption correction: SADABS ?	h = −14→14
Tmin = 0.89, Tmax = 1	k = −12→8
4779 measured reflections	l = −15→15

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.119	H atoms treated by a mixture of independent and constrained refinement
S = 1.15	w = 1/[σ^2(Fo^2) + (0.0757P)^2 + 0.3587P] where P = (Fo^2 + 2Fc^2)/3
765 reflections	(Δ/σ)max = 0.717
140 parameters	Δρmax = 0.19 e Å^−3
1 restraint	Δρmin = −0.17 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	Occ. (<1)
C1A	0.5	0.9173 (4)	0.1429 (4)	0.0578 (12)
C2A	0.4055 (2)	0.9918 (4)	0.1400 (3)	0.0540 (7)
C3A	0.4034 (3)	1.1216 (3)	0.1352 (3)	0.0559 (8)
H3A	0.3368	1.1639	0.1342	0.067*
C4A	0.5	1.1897 (5)	0.1318 (4)	0.0549 (11)
C5A	0.5	0.7766 (5)	0.1590 (5)	0.0820 (19)
H5A1	0.4262	0.7458	0.1579	0.123*	0.5
H5A2	0.5324	0.7578	0.2217	0.123*	0.5
H5A3	0.5413	0.7363	0.1078	0.123*	0.5
N1A	0.5	1.3184 (4)	0.1245 (4)	0.0774 (15)
H1A1	0.4391	1.3589	0.122	0.093*	0.5
H1A2	0.5609	1.359	0.1225	0.093*	0.5
N2A	0.2969 (3)	0.9313 (3)	0.1404 (3)	0.0710 (9)
O1A	0.2840 (3)	0.8365 (3)	0.0926 (4)	0.0964 (11)
O2A	0.2243 (2)	0.9814 (3)	0.1878 (4)	0.0997 (11)
C1B	0.5	1.3390 (4)	0.3885 (4)	0.0559 (11)
C2B	0.5945 (2)	1.2647 (3)	0.3879 (3)	0.0548 (8)
C3B	0.5969 (2)	1.1352 (3)	0.3861 (3)	0.0541 (8)
H3B	0.6636	1.0932	0.3846	0.065*
C4B	0.5	1.0662 (4)	0.3867 (4)	0.0480 (10)
C5B	0.5	1.4824 (5)	0.3776 (6)	0.0803 (17)
H5B1	0.5738	1.513	0.3798	0.12*	0.5
H5B2	0.4588	1.5194	0.4304	0.12*	0.5
H5B3	0.4674	1.505	0.3158	0.12*	0.5
N1B	0.5	0.9370 (4)	0.3858 (4)	0.0631 (10)
H1B1	0.5608	0.8964	0.3849	0.076*	0.5
H1B2	0.4392	0.8964	0.3862	0.076*	0.5
N2B	0.7023 (3)	1.3252 (3)	0.3949 (3)	0.0767 (9)
O1B	0.7108 (3)	1.4184 (3)	0.4477 (4)	0.1015 (11)
O2B	0.7784 (3)	1.2782 (3)	0.3501 (5)	0.1116 (14)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1A	0.070 (3)	0.059 (3)	0.045 (2)	0	0	−0.002 (2)
C2A	0.0463 (15)	0.0628 (16)	0.0527 (15)	−0.0061 (15)	0.0049 (17)	0.0017 (16)
C3A	0.0468 (18)	0.0641 (18)	0.0569 (17)	0.0024 (13)	0.0021 (16)	0.0016 (16)
C4A	0.048 (2)	0.058 (3)	0.058 (3)	0	0	0.004 (2)
C5A	0.119 (5)	0.051 (3)	0.076 (4)	0	0	−0.002 (3)
N1A	0.060 (2)	0.055 (2)	0.116 (5)	0	0	0.011 (3)
N2A	0.0599 (18)	0.0795 (19)	0.0737 (19)	−0.0190 (16)	0.0087 (17)	0.0021 (17)
O1A	0.091 (2)	0.095 (2)	0.103 (2)	−0.0444 (18)	0.014 (2)	−0.0178 (19)
O2A	0.0592 (15)	0.113 (2)	0.127 (3)	−0.0136 (17)	0.026 (2)	−0.007 (2)
C1B	0.057 (3)	0.057 (2)	0.053 (2)	0	0	0.001 (2)
C2B	0.0469 (17)	0.0623 (16)	0.0552 (17)	−0.0094 (13)	−0.0022 (16)	0.0015 (18)
C3B	0.0408 (17)	0.0660 (18)	0.0554 (16)	0.0054 (13)	−0.0002 (15)	−0.0009 (16)
C4B	0.045 (2)	0.053 (2)	0.046 (2)	0	0	−0.002 (2)
C5B	0.091 (3)	0.054 (3)	0.096 (5)	0	0	0.004 (3)
N1B	0.055 (2)	0.058 (2)	0.077 (3)	0	0	−0.003 (2)
N2B	0.060 (2)	0.082 (2)	0.088 (2)	−0.0209 (16)	−0.0092 (18)	0.0150 (19)
O1B	0.095 (2)	0.0926 (18)	0.117 (3)	−0.0395 (19)	−0.023 (2)	−0.001 (2)
O2B	0.0542 (17)	0.124 (3)	0.157 (4)	−0.0172 (15)	0.024 (2)	0.005 (3)

Geometric parameters (Å, º)

C1A—C2A^i	1.400 (4)	C1B—C2B^i	1.399 (4)
C1A—C2A	1.400 (4)	C1B—C2B	1.399 (4)
C1A—C5A	1.505 (6)	C1B—C5B	1.524 (5)
C2A—C3A	1.375 (5)	C2B—C3B	1.371 (4)
C2A—N2A	1.476 (4)	C2B—N2B	1.469 (4)
C3A—C4A	1.385 (4)	C3B—C4B	1.393 (4)
C4A—N1A	1.366 (6)	C4B—N1B	1.367 (5)
C4A—C3A^i	1.385 (4)	C4B—C3B^i	1.393 (4)
N2A—O1A	1.205 (5)	N2B—O2B	1.219 (5)
N2A—O2A	1.219 (5)	N2B—O1B	1.224 (5)
C2A^i—C1A—C2A	111.3 (4)	C2B^i—C1B—C2B	111.6 (4)
C2A^i—C1A—C5A	124.2 (2)	C2B^i—C1B—C5B	123.99 (19)
C2A—C1A—C5A	124.2 (2)	C2B—C1B—C5B	123.99 (19)
C3A—C2A—C1A	125.4 (3)	C3B—C2B—C1B	125.4 (3)
C3A—C2A—N2A	114.6 (3)	C3B—C2B—N2B	114.7 (3)
C1A—C2A—N2A	119.9 (3)	C1B—C2B—N2B	119.8 (3)
C2A—C3A—C4A	120.3 (3)	C2B—C3B—C4B	120.4 (3)
N1A—C4A—C3A	121.4 (2)	N1B—C4B—C3B	121.63 (19)
N1A—C4A—C3A^i	121.4 (2)	N1B—C4B—C3B^i	121.63 (19)
C3A—C4A—C3A^i	117.2 (4)	C3B—C4B—C3B^i	116.7 (4)
O1A—N2A—O2A	123.5 (3)	O2B—N2B—O1B	123.8 (3)
O1A—N2A—C2A	118.5 (3)	O2B—N2B—C2B	118.4 (4)
O2A—N2A—C2A	118.0 (3)	O1B—N2B—C2B	117.8 (4)

Symmetry code: (i) −x+1, y, z.