Extensive hydrogen and halogen bonding, and absence of intra­molecular hydrogen bonding between alcohol and nitro groups in a series of endo-nitro­norbornanol compounds

The influence of the substituent at the C2 position on the hydrogen-bonding patterns is compared for a series of five related compounds, namely (±)-3-exo,6-exo-dibromo-5-endo-hy­droxy-3-endo-nitro­bicyclo­[2.2.1]heptane-2-exo-carbonitrile, C₈H₈Br₂N₂O₃, (II), (±)-3-exo,6-exo-dibromo-6-endo-nitro-5-exo-phenyl­bicyclo­[2.2.1]heptan-2-endo-ol, C₁₃H₁₃Br₂NO₃, (III), (±)-methyl 3-exo,6-exo-dibromo-5-endo-hy­droxy-3-endo-nitro­bicyclo­[2.2.1]heptane-2-exo-carboxyl­ate, C₉H₁₁Br₂NO₅, (IV), (±)-methyl 3-exo,6-exo-dibromo-7-diphenyl­methyl­idene-5-endo-hy­droxy-3-endo-nitro­bicyclo­[2.2.1]heptane-2-exo-car­box­yl­ate, C₂₂H₁₉Br₂NO₅, (V), and (±)-methyl 3-exo,6-exo-dibromo-5-endo-hy­droxy-3-endo-nitro-7-oxabicyclo­[2.2.1]hep­tane-2-exo-carboxyl­ate, C₈H₉Br₂NO₆, (VI). The hydrogen-bonding motif in all five compounds is a chain, formed by O—H...O hydrogen bonds in (III), (IV), (V) and (VI), and by O—H...N hydrogen bonds in (II). All compounds except (III) contain a number of Br...Br and Br...O halogen bonds that connect the chains to each other to form two-dimensional sheets or three-dimensional networks. None of the compounds features intra­molecular hydrogen bonding between the alcohol and nitro functional groups, as was found in the related com­pound (±)-methyl 3-exo,6-exo-dichloro-5-endo-hy­droxy-3-endo-nitro­bicyclo­[2.2.1]heptane-2-exo-carboxyl­ate, (I) [Boeyens, Denner & Michael (1984b). J. Chem. Soc. Perkin Trans. 2, pp. 767–770]. The crystal structure of (V) exhibits whole-mol­ecule disorder.

S1. Comment

Although hydrogen bonding between hydroxy and nitro groups is not uncommon (Desiraju, 2002), intramolecular hydrogen bonding between these groups is largely confined to systems in which they find themselves in enforced proximity, as in 2-nitrophenols (Baitinger et al., 1964; Heintz et al., 2007; Litwinienko et al., 2009). We have been interested in hydrogen bonding in nitronorbornanol systems for several years (Boeyens et al., 1984a; Michael et al., 1994). In particular, when both groups are constrained to occupy the endo cavity of the norbornane skeleton, the likelihood of intramolecular hydrogen bonding is high, as we have found, for example, in 3-exo,6-exo-dichloro-5-endo-hydroxy-3-endo-nitrobicyclo[2.2.1]heptane-2-exo-carbonitrile, (I) (Boeyens et al., 1984b). We previously determined the room-temperature crystal structure of the corresponding dibromo compound 3-exo,6-exo-dibromo-5-endo-hydroxy-3-endo-nitrobicyclo[2.2.1]heptane-2-exo-carbonitrile, (II) (Blom et al., 1980), but owing to the limitations of the techniques available at the time, we were unable to locate hydrogen atoms and to establish unambiguously whether or not the hydrogen bonding was intramolecular. Here we report a redetermination of the crystal structure of compound (II) at low temperature, as well as the structures of three analogous dibrominated endo-nitronorbornanols (III)–(V) and the related 7-oxanorbornanol, (VI), in order to elucidate their hydrogen-bonding patterns and to establish whether there is any intramolecular or intermolecular hydrogen bonding between the alcohol and nitro functionalities.

The distances and angles within the five compounds reported (Fig. 1) are generally as expected (Allen et al., 1987). In all five structures, hydrogen bonds play a part in controlling the supramolecular assembly of the molecules (Desiraju, 1996, 2002). All five compounds contain an alcohol group and a number of good hydrogen-bonding acceptor functional groups including nitro, ester and ether units as well as Br atoms. Furthermore, a number of halogen-type C—Br···A (A = Br or O; Metrangelo et al., 2005) interactions are also present (Fig. 2).

Compound (II) crystallizes in the polar space group Cc. The O1—H1···N2 hydrogen bond forms a C(8) (Bernstein et al., 1995) chain along the [010] direction. Adjacent chains of this type are connected by a Br2···O2 halogen interaction along the [001]direction (Fig. 3) and by a Br1···Br2 halogen interaction (Table 6) along the [100] direction to form a three-dimensional network.

In compound (III) the O1—H1···O2 hydrogen bond forms C(7) chains along the [010] direction, containing molecules related by the twofold screw axis along (0.5, y, 0.75) (Fig. 4). Compound (III) has no short Br···Br contacts and does not form a higher-dimensional network.

In the crystal structure of compound (IV), C(8) chains are formed along the [110] direction, utilizing the O1—H1···O4 hydrogen bond (Fig. 5a). Adjacent chains of this type are connected to form a three-dimensional network by Br2···Br2 interactions along the [001] direction and by Br1···O1 interactions along the [010] direction (Table 6) (Figs. 5a and 5b).

The entire molecule of compound (V) is disordered over two sets of atomic positions and the two parts, labelled A and B (Fig. 1), have equal site-occupancy factors. The only substantial conformational difference between the two disorder components is the orientations of the aromatic rings relative to the nitronorbornanol unit. Molecule A has torsion angles of -46.9 (15)° (C7A—C10A—C17A—C22A) and 120.9 (12)° (C7A—C10A—C11A—C16A), as compared to angles of -61.3 (14)° (C7B—C10B—C17B—C22B) and 139.4 (12)° (C7B—C10B—C11B—C16B) in molecule B. Nonetheless, the intermolecular hydrogen and halogen bonding is similar between the two molecules (Tables 4 and 6). The O1A—H1A···O3A hydrogen bond in molecule A forms C(7) chains from the alcohol O1A to the nitro oxygen O3A. The chains run along the [010] direction (Fig. 6), generated by the twofold screw axis in the space group P2₁/c. The molecules within the chains are further connected by Br2A···O3A halogen bonds (Table 6 and Fig. 6). (V) contains no Br···Br halogen bonds. The hydrogen bonding of molecule B is not shown in Fig. 6.

In the crystal structure of compound (VI) the O1—H1···O4 hydrogen bond forms C(8) chains along the [101] direction (Fig. 7a). Adjacent hydrogen-bonded chains are connected by Br1···O1 interactions along the [100] direction to form sheets (Fig. 7a). Two adjacent sheets are then connected by Br2···Br2 halogen bonds along [010] (Table 6) to form bilayers of sheets (Fig. 7b).

Compound (II), which is the dibromo analogue of (I), does not contain an intramolecular O—H···O(nitro) hydrogen bond as observed in (I). Instead, it forms a C(8) hydrogen-bonded chain with the nitrile N as acceptor atom on a neighbouring molecule. Nonetheless, the O atoms of the nitro group are utilized in intermolecular interactions, in this case halogen bonding with the bromine atoms to form two-dimensional sheets which are further linked into a three-dimensional network via Br···Br interactions. Compound (III) has the nitrile group replaced by a phenyl group, and this seems to have an influence on the lack of any halogen bonding observed in (III) due to the steric increase of the phenyl group next to one of the bromine atoms. The absence of any good hydrogen-bonding acceptor at the 2-position leaves only the nitro group or the alcohol O as candidates, and indeed, in (III) there is an intermolecular O—H···O(nitro) hydrogen bond forming C(7) chains. Similar chains are formed by (V), which at the same time uses the second O atom of the nitro group in halogen bonding to strengthen the chain motif. Compounds (IV) and (VI) have the same intermolecular hydrogen bonding from the alcohol to the ester carbonyl, and similar packing of the chains into larger architectures. (IV) has chains connected in three dimensions by the halogen-bond interactions, whereas (VI) has bilayers of hydrogenbonded sheets using similar Br···Br and Br···O interactions. The halogen bonds observed in these compounds all have X···A distances less than the van der Waals radii sum (3.70 Å for Br···Br contacts and 3.37 Å for Br···O contacts).

Related literature

For related literature, see: Baitinger et al., 1964; Blom et al., 1980; Boeyens et al., 1984a; Boeyens et al., 1984b; Heintz et al., 2007; Litwinienko et al., 2009; Michael et al., 1991; Michael et al., 1994.

S2. Experimental

The syntheses and spectroscopic characterization of the five compounds (II)–(VI) by bromination of the corresponding endo-nitronorbonenes have been reported previously (Michael et al., 1991). In these syntheses, transannular neighbouring group participation by the nitro group during bromination of the alkene bond is responsible for the introduction of the endo hydroxyl group in a regiospecific and totally stereoselective manner. Crystals of (II) were grown from methanol, (III) from benzene, (IV) from benzene, (V) from 1:1 ethylacetate/hexane and (VI) from acetone, by slow evaporation.

S3. Refinement

The whole-molecule disorder of (V) was modelled by finding alternative positions for all the atoms in the molecule. The corresponding bonded distance and the one-angle non-bonded distances in the two disorder components were restrained to have the same values, subject to s.u.s of 0.005 and 0.01 Å, respectively. The atomic displacement parameters were restrained to be equal for each of the atom pairs C1A/C1B, C2A/C2B, C3A/C3B, C5A/C5B, O1A/O1B, C6A/C6B, C7A/C7B, C8A/C8B, C9A/C9B, O2A/O2B, O3A/O3B, C10A/C10B and C11A/C11B. Refinement of the site occupancies gave values of 0.501 (8) and 0.499 (8): the occupancies were thereafter both fixed at 0.50. For all compounds, all C—H atoms were refined using a riding model, with distances of 0.95 Å (aromatic), 1.00 Å (aliphatic CH) and 0.99 Å (CH₂), 0.98 Å (CH₃) and U_iso(H) = 1.2U_eq(C) or 1.5U_eq(C). H atoms on O atoms which are involved in hydrogen-bonding interactions were located in difference maps for all compounds except (IV) and (V) (which where refined using a riding model) and their positions allowed to refine freely, with U_iso(H) = 1.5U_eq(O) for all compounds. The value of the Flack x parameter (Flack, 1983) for (II), 0.003 (19), confirms the correct orientation of the structure with respect to the two polar axis directions in space group Cc.

Computing details

For all compounds, data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus (Bruker, 1999); 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) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structures and atom-labelling schemes for (a) (II), (b) (III), (c) (IV), (d) and (e) respectively, for molecules A and B of (V), and (f) (VI). Displacement ellipsoids are drawn at the 50% probability level and hydrogen atoms are drawn as small spheres of arbitrary radii.
	Fig. 2. The three types of halogen bonding observed in this study of nitronorbornanols.
	Fig. 3. The C(8) hydrogen-bonded chain of (II), showing the Br···O halogen-bonded interactions along the [001] direction. The Br···Br halogen bonds along the [100] direction are not shown. Atoms marked with the superscripts (i) and (ii) are at the symmetry positions (x - 1/2, y + 1/2, z) and (x + 1, -y + 1, z + 1/2), respectively. H atoms not involved in hydrogen-bonding interactions are omitted for clarity.
	Fig. 4. The C(7) hydrogen-bonded chain of (III). Atoms marked with the superscript (i) are at the symmetry position (-x + 1, y + 1/2, -z + 3/2). H atoms not involved in hydrogen-bonding interactions are omitted for clarity.
	Fig. 5. (a) The C(8) hydrogen-bonded chain of (IV) as well as the Br···O halogen bonds [resulting in the formation of?] to form a two-dimensional sheet. (b) The sheets are then connected to a three-dimensional network by Br···Br halogen bonds. Atoms marked with the superscripts (i), (ii) and (iii) are at the symmetry positions (x - 1, y + 1, z), (x, y - 1, z), (-x + 1, -y + 2, -z + 1), respectively. H atoms not involved in hydrogen-bonding interactions are omitted for clarity.
	Fig. 6. The C(7) hydrogen-bonded chain of (V). Note how the halogen bonding connects every second molecule involved in hydrogen-bonded interactions within the chain (by translation only). Only the hydrogen bonding of molecule A is shown. Molecule B has similar interactions but [these?] are not shown in the figure. Atoms marked with the superscripts (i) and (ii) are at the symmetry positions (-x + 1, y + 1/2, -z + 1/2) and (x, y + 1, z), respectively. H atoms not involved in hydrogen-bonding interactions are omitted for clarity.
	Fig. 7. (a) The C(8) hydrogen-bonded chains of (VI) connected by Br···O halogen bonds to form two-dimensional sheets. (b) The sheets form bilayers through further Br···Br halogen bonding. Atoms marked with the superscripts (i), (ii) and (iii) are at the symmetry positions (x - 1, y, z - 1), (x + 1, y, z) and (-x + 2, -y, -z + 2), respectively. H atoms not involved in hydrogenbonding interactions are omitted for clarity.

(II) (±)-3-exo,6-exo-dibromo-5-endo-hydroxy-3-endo- nitrobicyclo[2.2.1]heptane-2-exo-carbonitrile

Crystal data

C8H8Br2N2O3	F(000) = 656
Mr = 339.98	Dx = 2.149 Mg m^−3
Monoclinic, Cc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C -2yc	Cell parameters from 850 reflections
a = 6.6517 (8) Å	θ = 2.5–28.2°
b = 16.084 (2) Å	µ = 7.70 mm^−1
c = 9.8254 (14) Å	T = 173 K
β = 91.825 (6)°	Block, yellow
V = 1050.6 (2) Å^3	0.6 × 0.2 × 0.2 mm
Z = 4

Data collection

Bruker SMART 1K CCD area-detector diffractometer	1945 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.067
ω scans	θmax = 28.0°, θmin = 2.5°
Absorption correction: integration (XPREP; Bruker, 1999)	h = −8→8
Tmin = 0.075, Tmax = 0.301	k = −21→17
3346 measured reflections	l = −10→12
2038 independent reflections

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)] = 0.045	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.116	w = 1/[σ^2(Fo^2) + (0.0914P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
2038 reflections	Δρmax = 1.20 e Å^−3
139 parameters	Δρmin = −0.94 e Å^−3
2 restraints	Absolute structure: Flack (1983), 765 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.003 (19)

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 1999)

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	0.5593 (9)	0.3530 (4)	0.5982 (6)	0.0187 (11)
H1A	0.6952	0.3306	0.6247	0.022*
C2	0.4484 (9)	0.3079 (4)	0.4748 (6)	0.0195 (11)
H2	0.479	0.3385	0.3892	0.023*
C3	0.2221 (8)	0.3221 (3)	0.5061 (6)	0.0176 (11)
C4	0.2295 (9)	0.3867 (4)	0.6192 (6)	0.0197 (11)
H4	0.1001	0.3943	0.6666	0.024*
C5	0.3266 (10)	0.4690 (4)	0.5676 (7)	0.0218 (11)
H5	0.3106	0.5143	0.6362	0.026*
C6	0.5531 (9)	0.4451 (3)	0.5579 (7)	0.0212 (12)
H6	0.5968	0.4518	0.4621	0.025*
C7	0.4034 (8)	0.3507 (4)	0.7097 (6)	0.0200 (11)
H7A	0.4399	0.387	0.788	0.024*
H7B	0.3757	0.2935	0.7416	0.024*
C8	0.5089 (10)	0.2208 (4)	0.4591 (7)	0.0218 (12)
N1	0.0955 (8)	0.3456 (3)	0.3808 (6)	0.0238 (11)
N2	0.5591 (10)	0.1542 (4)	0.4456 (7)	0.0319 (13)
O1	0.2507 (9)	0.4953 (3)	0.4383 (6)	0.0294 (11)
H1	0.185 (17)	0.541 (7)	0.449 (11)	0.044*
O2	−0.0749 (8)	0.3697 (4)	0.3984 (6)	0.0370 (12)
O3	0.1674 (8)	0.3368 (4)	0.2676 (5)	0.0363 (12)
Br1	0.08836 (7)	0.22101 (4)	0.56746 (6)	0.02728 (18)
Br2	0.72707 (9)	0.51130 (4)	0.68145 (7)	0.03009 (19)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.022 (3)	0.019 (2)	0.015 (3)	0.003 (2)	0.001 (2)	0.002 (2)
C2	0.021 (2)	0.020 (3)	0.018 (3)	0.005 (2)	0.003 (2)	0.000 (2)
C3	0.019 (2)	0.021 (2)	0.013 (3)	0.002 (2)	0.003 (2)	0.000 (2)
C4	0.023 (2)	0.024 (3)	0.012 (3)	0.005 (2)	0.005 (2)	0.000 (2)
C5	0.028 (3)	0.020 (2)	0.018 (3)	0.002 (2)	0.003 (2)	−0.004 (2)
C6	0.025 (3)	0.019 (2)	0.020 (3)	0.000 (2)	0.005 (2)	−0.001 (2)
C7	0.023 (3)	0.020 (3)	0.017 (3)	0.001 (2)	0.000 (2)	0.002 (2)
C8	0.024 (3)	0.027 (3)	0.015 (3)	0.006 (2)	0.003 (2)	−0.004 (2)
N1	0.027 (2)	0.027 (3)	0.018 (3)	0.006 (2)	−0.004 (2)	0.0000 (19)
N2	0.037 (3)	0.025 (3)	0.034 (4)	0.007 (2)	0.010 (3)	−0.002 (2)
O1	0.043 (3)	0.025 (2)	0.020 (2)	0.012 (2)	0.002 (2)	0.0058 (17)
O2	0.023 (2)	0.052 (3)	0.036 (3)	0.012 (2)	−0.002 (2)	0.005 (2)
O3	0.042 (3)	0.056 (3)	0.011 (2)	0.010 (3)	0.000 (2)	−0.004 (2)
Br1	0.0276 (3)	0.0262 (3)	0.0282 (3)	−0.0045 (2)	0.0032 (2)	0.0022 (2)
Br2	0.0306 (3)	0.0264 (3)	0.0334 (4)	−0.0056 (3)	0.0014 (2)	−0.0062 (3)

Geometric parameters (Å, º)

C1—C6	1.533 (8)	C4—H4	1
C1—C7	1.533 (8)	C5—O1	1.416 (9)
C1—C2	1.576 (9)	C5—C6	1.561 (8)
C1—H1A	1	C5—H5	1
C2—C8	1.468 (8)	C6—Br2	1.964 (6)
C2—C3	1.562 (7)	C6—H6	1
C2—H2	1	C7—H7A	0.99
C3—N1	1.516 (8)	C7—H7B	0.99
C3—C4	1.521 (8)	C8—N2	1.131 (9)
C3—Br1	1.957 (6)	N1—O2	1.215 (7)
C4—C7	1.548 (8)	N1—O3	1.233 (7)
C4—C5	1.565 (9)	O1—H1	0.86 (12)
C6—C1—C7	101.3 (4)	O1—C5—C6	109.6 (5)
C6—C1—C2	103.8 (5)	O1—C5—C4	113.8 (5)
C7—C1—C2	103.2 (5)	C6—C5—C4	102.7 (5)
C6—C1—H1A	115.6	O1—C5—H5	110.2
C7—C1—H1A	115.6	C6—C5—H5	110.2
C2—C1—H1A	115.6	C4—C5—H5	110.2
C8—C2—C3	115.4 (5)	C1—C6—C5	103.9 (5)
C8—C2—C1	113.4 (5)	C1—C6—Br2	110.7 (4)
C3—C2—C1	102.2 (4)	C5—C6—Br2	112.3 (4)
C8—C2—H2	108.5	C1—C6—H6	109.9
C3—C2—H2	108.5	C5—C6—H6	109.9
C1—C2—H2	108.5	Br2—C6—H6	109.9
N1—C3—C4	115.3 (5)	C1—C7—C4	95.2 (5)
N1—C3—C2	113.0 (5)	C1—C7—H7A	112.7
C4—C3—C2	103.6 (5)	C4—C7—H7A	112.7
N1—C3—Br1	102.2 (4)	C1—C7—H7B	112.7
C4—C3—Br1	110.3 (4)	C4—C7—H7B	112.7
C2—C3—Br1	112.9 (4)	H7A—C7—H7B	110.2
C3—C4—C7	99.8 (5)	N2—C8—C2	178.5 (7)
C3—C4—C5	110.2 (4)	O2—N1—O3	123.7 (6)
C7—C4—C5	101.2 (5)	O2—N1—C3	117.4 (5)
C3—C4—H4	114.6	O3—N1—C3	118.9 (5)
C7—C4—H4	114.6	C5—O1—H1	108 (7)
C5—C4—H4	114.6
C6—C1—C2—C8	154.7 (5)	C7—C4—C5—C6	32.8 (6)
C7—C1—C2—C8	−100.0 (5)	C7—C1—C6—C5	−36.9 (6)
C6—C1—C2—C3	−80.4 (5)	C2—C1—C6—C5	69.8 (6)
C7—C1—C2—C3	24.9 (5)	C7—C1—C6—Br2	83.8 (5)
C8—C2—C3—N1	−99.2 (6)	C2—C1—C6—Br2	−169.5 (3)
C1—C2—C3—N1	137.3 (5)	O1—C5—C6—C1	−119.1 (6)
C8—C2—C3—C4	135.5 (5)	C4—C5—C6—C1	2.2 (6)
C1—C2—C3—C4	11.9 (5)	O1—C5—C6—Br2	121.2 (5)
C8—C2—C3—Br1	16.2 (7)	C4—C5—C6—Br2	−117.5 (4)
C1—C2—C3—Br1	−107.4 (4)	C6—C1—C7—C4	56.4 (5)
N1—C3—C4—C7	−168.0 (5)	C2—C1—C7—C4	−50.8 (5)
C2—C3—C4—C7	−44.1 (5)	C3—C4—C7—C1	58.4 (5)
Br1—C3—C4—C7	77.0 (5)	C5—C4—C7—C1	−54.6 (5)
N1—C3—C4—C5	−62.1 (6)	C4—C3—N1—O2	−50.6 (8)
C2—C3—C4—C5	61.8 (6)	C2—C3—N1—O2	−169.4 (6)
Br1—C3—C4—C5	−177.1 (4)	Br1—C3—N1—O2	69.0 (6)
C3—C4—C5—O1	46.3 (6)	C4—C3—N1—O3	131.7 (6)
C7—C4—C5—O1	151.2 (5)	C2—C3—N1—O3	12.9 (8)
C3—C4—C5—C6	−72.2 (6)	Br1—C3—N1—O3	−108.7 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N2^i	0.86 (12)	2.01 (12)	2.858 (8)	169 (10)

Symmetry code: (i) x−1/2, y+1/2, z.

(III) (±)-3-exo,6-exo-dibromo-6-endo-nitro-5-exo- phenylbicyclo[2.2.1]heptan-2-endo-ol

Crystal data

C13H13Br2NO3	F(000) = 768
Mr = 391.06	Dx = 1.917 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1017 reflections
a = 15.945 (2) Å	θ = 3.1–28.3°
b = 6.7578 (10) Å	µ = 5.99 mm^−1
c = 13.194 (2) Å	T = 173 K
β = 107.655 (9)°	Block, colourless
V = 1354.7 (4) Å^3	0.4 × 0.3 × 0.14 mm
Z = 4

Data collection

Bruker SMART 1K CCD area-detector diffractometer	2786 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
ω scans	θmax = 28°, θmin = 2.7°
Absorption correction: integration (XPREP; Bruker, 1999)	h = −21→21
Tmin = 0.110, Tmax = 0.467	k = −8→8
18725 measured reflections	l = −17→17
3256 independent reflections

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)] = 0.022	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.052	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0279P)^2 + 0.2753P] where P = (Fo^2 + 2Fc^2)/3
3256 reflections	(Δ/σ)max = 0.001
175 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.64 e Å^−3

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 1999)

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	0.27775 (12)	0.6233 (3)	0.57508 (14)	0.0177 (4)
H1A	0.2464	0.752	0.5536	0.021*
C2	0.26315 (12)	0.5247 (3)	0.67562 (14)	0.0162 (3)
H2	0.3126	0.5677	0.7387	0.019*
C3	0.27825 (12)	0.3023 (3)	0.65528 (14)	0.0170 (4)
C4	0.31402 (12)	0.3024 (3)	0.55985 (14)	0.0175 (4)
H4	0.3133	0.1705	0.5252	0.021*
C5	0.40313 (12)	0.4131 (3)	0.58711 (14)	0.0184 (4)
H5	0.4287	0.3992	0.527	0.022*
C6	0.37772 (12)	0.6322 (3)	0.59711 (15)	0.0185 (4)
H6	0.4065	0.6807	0.6711	0.022*
C7	0.25286 (12)	0.4594 (3)	0.48955 (14)	0.0190 (4)
H7A	0.2694	0.4928	0.4251	0.023*
H7B	0.1899	0.4223	0.47	0.023*
C8	0.17800 (12)	0.5797 (3)	0.69702 (15)	0.0183 (4)
C9	0.10191 (13)	0.6295 (3)	0.61630 (16)	0.0231 (4)
H9	0.1018	0.6243	0.5443	0.028*
C10	0.02572 (14)	0.6869 (3)	0.63967 (19)	0.0300 (5)
H10	−0.0254	0.7225	0.5837	0.036*
C11	0.02444 (15)	0.6920 (3)	0.7441 (2)	0.0315 (5)
H11	−0.0273	0.7318	0.7601	0.038*
C12	0.09923 (15)	0.6388 (3)	0.82525 (18)	0.0311 (5)
H12	0.0982	0.6393	0.8969	0.037*
C13	0.17549 (14)	0.5849 (3)	0.80255 (16)	0.0255 (4)
H13	0.2266	0.5511	0.859	0.031*
N1	0.33908 (11)	0.1948 (2)	0.75250 (13)	0.0215 (3)
O1	0.46362 (9)	0.3399 (2)	0.68204 (12)	0.0265 (3)
H1	0.5070 (18)	0.397 (4)	0.697 (2)	0.04*
O2	0.36379 (9)	0.0287 (2)	0.73598 (12)	0.0284 (3)
O3	0.35737 (11)	0.2750 (2)	0.83909 (11)	0.0316 (3)
Br1	0.171486 (13)	0.13845 (3)	0.624805 (16)	0.02452 (6)
Br2	0.410813 (13)	0.80248 (3)	0.494432 (17)	0.02799 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0166 (9)	0.0155 (9)	0.0211 (9)	0.0021 (7)	0.0060 (7)	0.0008 (7)
C2	0.0148 (8)	0.0156 (9)	0.0178 (8)	0.0002 (7)	0.0044 (7)	−0.0019 (7)
C3	0.0152 (9)	0.0161 (9)	0.0183 (9)	−0.0003 (7)	0.0028 (7)	−0.0001 (7)
C4	0.0176 (9)	0.0168 (9)	0.0179 (9)	0.0015 (7)	0.0051 (7)	−0.0032 (7)
C5	0.0162 (9)	0.0201 (10)	0.0192 (9)	0.0037 (7)	0.0058 (7)	0.0019 (7)
C6	0.0180 (9)	0.0195 (10)	0.0195 (9)	−0.0004 (7)	0.0080 (7)	0.0013 (7)
C7	0.0180 (9)	0.0212 (10)	0.0162 (9)	0.0017 (7)	0.0029 (7)	−0.0005 (7)
C8	0.0188 (9)	0.0133 (9)	0.0240 (9)	−0.0006 (7)	0.0082 (7)	−0.0017 (7)
C9	0.0210 (10)	0.0241 (10)	0.0255 (10)	0.0024 (8)	0.0092 (8)	0.0032 (8)
C10	0.0192 (10)	0.0283 (12)	0.0426 (13)	0.0042 (8)	0.0093 (9)	0.0061 (9)
C11	0.0256 (11)	0.0255 (11)	0.0518 (14)	0.0016 (9)	0.0243 (10)	−0.0019 (10)
C12	0.0334 (12)	0.0353 (13)	0.0308 (11)	−0.0033 (10)	0.0188 (10)	−0.0080 (9)
C13	0.0240 (10)	0.0276 (11)	0.0252 (10)	−0.0011 (8)	0.0078 (8)	−0.0056 (8)
N1	0.0187 (8)	0.0223 (9)	0.0239 (8)	0.0019 (7)	0.0072 (7)	0.0052 (7)
O1	0.0144 (7)	0.0310 (8)	0.0290 (8)	−0.0004 (6)	−0.0011 (6)	0.0094 (6)
O2	0.0258 (8)	0.0197 (7)	0.0380 (8)	0.0073 (6)	0.0071 (6)	0.0047 (6)
O3	0.0399 (9)	0.0345 (9)	0.0175 (7)	0.0037 (7)	0.0041 (6)	0.0018 (6)
Br1	0.01824 (10)	0.01887 (11)	0.03580 (12)	−0.00312 (7)	0.00719 (8)	−0.00286 (8)
Br2	0.02564 (11)	0.02399 (12)	0.03997 (13)	0.00349 (8)	0.01839 (9)	0.00903 (9)

Geometric parameters (Å, º)

C1—C6	1.532 (2)	C6—H6	1
C1—C7	1.545 (3)	C7—H7A	0.99
C1—C2	1.564 (2)	C7—H7B	0.99
C1—H1A	1	C8—C9	1.391 (3)
C2—C8	1.515 (2)	C8—C13	1.405 (3)
C2—C3	1.558 (2)	C9—C10	1.396 (3)
C2—H2	1	C9—H9	0.95
C3—C4	1.532 (2)	C10—C11	1.385 (3)
C3—N1	1.536 (2)	C10—H10	0.95
C3—Br1	1.9676 (18)	C11—C12	1.387 (3)
C4—C7	1.546 (3)	C11—H11	0.95
C4—C5	1.549 (3)	C12—C13	1.386 (3)
C4—H4	1	C12—H12	0.95
C5—O1	1.418 (2)	C13—H13	0.95
C5—C6	1.551 (3)	N1—O3	1.217 (2)
C5—H5	1	N1—O2	1.231 (2)
C6—Br2	1.9675 (18)	O1—H1	0.76 (3)
C6—C1—C7	100.87 (14)	C5—C6—Br2	111.61 (12)
C6—C1—C2	105.65 (14)	C1—C6—H6	110
C7—C1—C2	104.04 (14)	C5—C6—H6	110
C6—C1—H1A	114.9	Br2—C6—H6	110
C7—C1—H1A	114.9	C1—C7—C4	94.51 (13)
C2—C1—H1A	114.9	C1—C7—H7A	112.8
C8—C2—C3	117.58 (15)	C4—C7—H7A	112.8
C8—C2—C1	115.21 (15)	C1—C7—H7B	112.8
C3—C2—C1	101.22 (13)	C4—C7—H7B	112.8
C8—C2—H2	107.4	H7A—C7—H7B	110.3
C3—C2—H2	107.4	C9—C8—C13	118.17 (18)
C1—C2—H2	107.4	C9—C8—C2	122.65 (17)
C4—C3—N1	112.85 (14)	C13—C8—C2	119.16 (17)
C4—C3—C2	104.89 (14)	C8—C9—C10	120.89 (19)
N1—C3—C2	113.81 (14)	C8—C9—H9	119.6
C4—C3—Br1	110.30 (12)	C10—C9—H9	119.6
N1—C3—Br1	101.10 (11)	C11—C10—C9	120.2 (2)
C2—C3—Br1	114.13 (12)	C11—C10—H10	119.9
C3—C4—C7	99.72 (14)	C9—C10—H10	119.9
C3—C4—C5	110.68 (15)	C10—C11—C12	119.53 (19)
C7—C4—C5	100.08 (15)	C10—C11—H11	120.2
C3—C4—H4	114.8	C12—C11—H11	120.2
C7—C4—H4	114.8	C13—C12—C11	120.4 (2)
C5—C4—H4	114.8	C13—C12—H12	119.8
O1—C5—C4	111.54 (15)	C11—C12—H12	119.8
O1—C5—C6	112.53 (16)	C12—C13—C8	120.7 (2)
C4—C5—C6	103.66 (14)	C12—C13—H13	119.6
O1—C5—H5	109.7	C8—C13—H13	119.6
C4—C5—H5	109.7	O3—N1—O2	124.99 (17)
C6—C5—H5	109.7	O3—N1—C3	118.98 (16)
C1—C6—C5	103.30 (14)	O2—N1—C3	116.00 (15)
C1—C6—Br2	111.91 (12)	C5—O1—H1	112 (2)
C6—C1—C2—C8	153.54 (15)	C4—C5—C6—C1	0.19 (17)
C7—C1—C2—C8	−100.68 (17)	O1—C5—C6—Br2	119.16 (14)
C6—C1—C2—C3	−78.50 (16)	C4—C5—C6—Br2	−120.20 (13)
C7—C1—C2—C3	27.28 (17)	C6—C1—C7—C4	57.05 (16)
C8—C2—C3—C4	135.65 (16)	C2—C1—C7—C4	−52.28 (16)
C1—C2—C3—C4	9.25 (17)	C3—C4—C7—C1	56.91 (15)
C8—C2—C3—N1	−100.53 (18)	C5—C4—C7—C1	−56.32 (15)
C1—C2—C3—N1	133.06 (15)	C3—C2—C8—C9	−89.7 (2)
C8—C2—C3—Br1	14.8 (2)	C1—C2—C8—C9	29.6 (3)
C1—C2—C3—Br1	−111.58 (13)	C3—C2—C8—C13	91.6 (2)
N1—C3—C4—C7	−166.71 (15)	C1—C2—C8—C13	−149.18 (18)
C2—C3—C4—C7	−42.28 (17)	C13—C8—C9—C10	1.3 (3)
Br1—C3—C4—C7	81.04 (15)	C2—C8—C9—C10	−177.45 (19)
N1—C3—C4—C5	−61.97 (19)	C8—C9—C10—C11	−1.0 (3)
C2—C3—C4—C5	62.46 (18)	C9—C10—C11—C12	−0.3 (3)
Br1—C3—C4—C5	−174.21 (12)	C10—C11—C12—C13	1.4 (3)
C3—C4—C5—O1	52.3 (2)	C11—C12—C13—C8	−1.2 (3)
C7—C4—C5—O1	156.77 (15)	C9—C8—C13—C12	−0.2 (3)
C3—C4—C5—C6	−69.04 (18)	C2—C8—C13—C12	178.59 (19)
C7—C4—C5—C6	35.46 (16)	C4—C3—N1—O3	132.10 (18)
C7—C1—C6—C5	−35.91 (17)	C2—C3—N1—O3	12.7 (2)
C2—C1—C6—C5	72.17 (17)	Br1—C3—N1—O3	−110.11 (16)
C7—C1—C6—Br2	84.28 (15)	C4—C3—N1—O2	−49.8 (2)
C2—C1—C6—Br2	−167.64 (12)	C2—C3—N1—O2	−169.18 (15)
O1—C5—C6—C1	−120.45 (16)	Br1—C3—N1—O2	68.00 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^i	0.76 (3)	2.17 (3)	2.927 (2)	171 (3)

Symmetry code: (i) −x+1, y+1/2, −z+3/2.

(IV) (±)-methyl 3-exo,6-exo-dibromo-5-endo-hydroxy-3-endo- nitrobicyclo[2.2.1]heptane-2-exo-carboxylate

Crystal data

C9H11Br2NO5	Z = 2
Mr = 373.01	F(000) = 364
Triclinic, P1	Dx = 2.125 Mg m^−3 Dm = 0 Mg m^−3 Dm measured by not measured
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.7221 (2) Å	Cell parameters from 3264 reflections
b = 7.7353 (3) Å	θ = 2.8–28.1°
c = 12.1546 (5) Å	µ = 6.96 mm^−1
α = 88.296 (3)°	T = 173 K
β = 80.595 (3)°	Plate, colourless
γ = 69.323 (3)°	0.28 × 0.12 × 0.04 mm
V = 583.08 (4) Å^3

Data collection

Bruker SMART 1K CCD area-detector diffractometer	2244 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.083
ω scans	θmax = 28°, θmin = 1.7°
Absorption correction: integration (XPREP; Bruker, 1999)	h = −8→8
Tmin = 0.318, Tmax = 0.770	k = −10→10
7104 measured reflections	l = −16→16
2805 independent reflections

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.07	H-atom parameters constrained
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0307P)^2] where P = (Fo^2 + 2Fc^2)/3
2805 reflections	(Δ/σ)max = 0.001
155 parameters	Δρmax = 1.44 e Å^−3
0 restraints	Δρmin = −1.41 e Å^−3

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 1999)

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	0.3951 (5)	0.5479 (4)	0.3174 (2)	0.0160 (6)
H1A	0.5446	0.4904	0.3347	0.019*
C2	0.3608 (4)	0.4824 (4)	0.2044 (2)	0.0134 (5)
H2	0.3888	0.5654	0.1439	0.016*
C3	0.1156 (4)	0.5112 (4)	0.2278 (2)	0.0148 (6)
C4	0.0339 (5)	0.6194 (4)	0.3391 (2)	0.0159 (6)
H4	−0.1122	0.624	0.3759	0.019*
C5	0.0621 (5)	0.8099 (4)	0.3296 (2)	0.0166 (6)
H5	−0.0098	0.8851	0.4	0.02*
C6	0.3099 (5)	0.7587 (4)	0.3168 (2)	0.0159 (6)
H6	0.3662	0.8023	0.2441	0.019*
C7	0.2179 (5)	0.5129 (4)	0.4032 (2)	0.0187 (6)
H7A	0.2378	0.3802	0.4096	0.022*
H7B	0.2019	0.5693	0.4777	0.022*
C8	0.5091 (5)	0.2857 (4)	0.1755 (2)	0.0167 (6)
C9	0.6991 (6)	0.0704 (4)	0.0305 (3)	0.0297 (7)
H9A	0.7142	0.0555	−0.0506	0.044*
H9B	0.6508	−0.0258	0.0671	0.044*
H9C	0.8384	0.0594	0.0504	0.044*
N1	−0.0081 (4)	0.6094 (3)	0.1355 (2)	0.0171 (5)
O1	−0.0071 (3)	0.9136 (3)	0.23726 (18)	0.0201 (4)
H1	−0.1391	0.9764	0.253	0.03*
O2	−0.2044 (3)	0.6620 (3)	0.15927 (19)	0.0247 (5)
O3	0.0929 (4)	0.6255 (3)	0.04607 (18)	0.0252 (5)
O4	0.5898 (4)	0.1785 (3)	0.24275 (19)	0.0243 (5)
O5	0.5423 (3)	0.2503 (3)	0.06654 (17)	0.0214 (5)
Br1	0.05890 (5)	0.27961 (4)	0.23778 (3)	0.02055 (9)
Br2	0.39158 (5)	0.86070 (5)	0.44082 (3)	0.02960 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0126 (14)	0.0165 (14)	0.0170 (14)	−0.0015 (12)	−0.0048 (11)	0.0001 (11)
C2	0.0122 (13)	0.0117 (13)	0.0154 (14)	−0.0031 (11)	−0.0022 (10)	0.0002 (11)
C3	0.0147 (14)	0.0124 (13)	0.0180 (14)	−0.0051 (12)	−0.0044 (11)	0.0022 (11)
C4	0.0156 (14)	0.0170 (14)	0.0158 (14)	−0.0063 (12)	−0.0034 (11)	0.0017 (11)
C5	0.0174 (15)	0.0124 (13)	0.0164 (14)	−0.0010 (12)	−0.0016 (11)	−0.0047 (11)
C6	0.0160 (14)	0.0150 (14)	0.0174 (14)	−0.0042 (12)	−0.0071 (11)	−0.0034 (11)
C7	0.0204 (15)	0.0200 (15)	0.0157 (14)	−0.0059 (13)	−0.0052 (11)	0.0017 (12)
C8	0.0142 (14)	0.0153 (14)	0.0203 (15)	−0.0057 (12)	−0.0002 (11)	−0.0033 (12)
C9	0.0285 (18)	0.0214 (17)	0.0286 (19)	0.0024 (15)	0.0001 (14)	−0.0070 (14)
N1	0.0215 (14)	0.0106 (12)	0.0215 (14)	−0.0068 (11)	−0.0076 (10)	0.0004 (10)
O1	0.0192 (11)	0.0146 (10)	0.0270 (12)	−0.0046 (9)	−0.0089 (9)	0.0036 (9)
O2	0.0151 (12)	0.0245 (12)	0.0342 (13)	−0.0039 (10)	−0.0101 (9)	0.0009 (10)
O3	0.0317 (13)	0.0302 (13)	0.0182 (11)	−0.0150 (11)	−0.0084 (9)	0.0047 (10)
O4	0.0239 (12)	0.0170 (11)	0.0265 (12)	0.0008 (10)	−0.0067 (9)	0.0003 (9)
O5	0.0244 (12)	0.0153 (11)	0.0190 (11)	−0.0016 (9)	−0.0002 (9)	−0.0033 (9)
Br1	0.02076 (16)	0.01412 (15)	0.02957 (18)	−0.00897 (12)	−0.00580 (12)	0.00232 (12)
Br2	0.02740 (19)	0.02775 (19)	0.0349 (2)	−0.00640 (15)	−0.01387 (14)	−0.01265 (15)

Geometric parameters (Å, º)

C1—C6	1.526 (4)	C5—H5	1
C1—C7	1.544 (4)	C6—Br2	1.961 (3)
C1—C2	1.556 (4)	C6—H6	1
C1—H1A	1	C7—H7A	0.99
C2—C8	1.509 (4)	C7—H7B	0.99
C2—C3	1.562 (4)	C8—O4	1.199 (4)
C2—H2	1	C8—O5	1.327 (4)
C3—C4	1.527 (4)	C9—O5	1.446 (4)
C3—N1	1.528 (4)	C9—H9A	0.98
C3—Br1	1.955 (3)	C9—H9B	0.98
C4—C7	1.540 (4)	C9—H9C	0.98
C4—C5	1.549 (4)	N1—O3	1.212 (3)
C4—H4	1	N1—O2	1.222 (3)
C5—O1	1.405 (4)	O1—H1	0.84
C5—C6	1.552 (4)
C6—C1—C7	100.8 (2)	C4—C5—H5	109.8
C6—C1—C2	106.0 (2)	C6—C5—H5	109.8
C7—C1—C2	103.5 (2)	C1—C6—C5	103.5 (2)
C6—C1—H1A	115	C1—C6—Br2	110.54 (19)
C7—C1—H1A	115	C5—C6—Br2	111.78 (19)
C2—C1—H1A	115	C1—C6—H6	110.3
C8—C2—C1	110.6 (2)	C5—C6—H6	110.3
C8—C2—C3	114.9 (2)	Br2—C6—H6	110.3
C1—C2—C3	101.8 (2)	C4—C7—C1	94.4 (2)
C8—C2—H2	109.7	C4—C7—H7A	112.9
C1—C2—H2	109.7	C1—C7—H7A	112.9
C3—C2—H2	109.7	C4—C7—H7B	112.9
C4—C3—N1	112.7 (2)	C1—C7—H7B	112.9
C4—C3—C2	103.9 (2)	H7A—C7—H7B	110.3
N1—C3—C2	114.1 (2)	O4—C8—O5	125.1 (3)
C4—C3—Br1	110.72 (17)	O4—C8—C2	123.8 (3)
N1—C3—Br1	102.39 (16)	O5—C8—C2	111.1 (3)
C2—C3—Br1	113.37 (19)	O5—C9—H9A	109.5
C3—C4—C7	99.8 (2)	O5—C9—H9B	109.5
C3—C4—C5	111.1 (2)	H9A—C9—H9B	109.5
C7—C4—C5	100.7 (2)	O5—C9—H9C	109.5
C3—C4—H4	114.5	H9A—C9—H9C	109.5
C7—C4—H4	114.5	H9B—C9—H9C	109.5
C5—C4—H4	114.5	O3—N1—O2	125.7 (3)
O1—C5—C4	116.1 (2)	O3—N1—C3	118.7 (2)
O1—C5—C6	107.8 (2)	O2—N1—C3	115.5 (2)
C4—C5—C6	103.2 (2)	C5—O1—H1	109.5
O1—C5—H5	109.8	C8—O5—C9	114.6 (2)
C6—C1—C2—C8	158.6 (2)	C7—C1—C6—Br2	83.1 (2)
C7—C1—C2—C8	−95.7 (3)	C2—C1—C6—Br2	−169.26 (16)
C6—C1—C2—C3	−78.8 (2)	O1—C5—C6—C1	−121.9 (2)
C7—C1—C2—C3	26.8 (3)	C4—C5—C6—C1	1.4 (3)
C8—C2—C3—C4	129.5 (2)	O1—C5—C6—Br2	119.1 (2)
C1—C2—C3—C4	10.0 (3)	C4—C5—C6—Br2	−117.6 (2)
C8—C2—C3—N1	−107.4 (3)	C3—C4—C7—C1	58.0 (2)
C1—C2—C3—N1	133.0 (2)	C5—C4—C7—C1	−55.9 (2)
C8—C2—C3—Br1	9.3 (3)	C6—C1—C7—C4	57.2 (2)
C1—C2—C3—Br1	−110.3 (2)	C2—C1—C7—C4	−52.4 (3)
N1—C3—C4—C7	−167.3 (2)	C1—C2—C8—O4	21.4 (4)
C2—C3—C4—C7	−43.2 (2)	C3—C2—C8—O4	−93.2 (3)
Br1—C3—C4—C7	78.8 (2)	C1—C2—C8—O5	−156.8 (2)
N1—C3—C4—C5	−61.7 (3)	C3—C2—C8—O5	88.6 (3)
C2—C3—C4—C5	62.3 (3)	C4—C3—N1—O3	131.6 (2)
Br1—C3—C4—C5	−175.64 (18)	C2—C3—N1—O3	13.5 (3)
C3—C4—C5—O1	47.2 (3)	Br1—C3—N1—O3	−109.5 (2)
C7—C4—C5—O1	152.2 (3)	C4—C3—N1—O2	−49.8 (3)
C3—C4—C5—C6	−70.5 (3)	C2—C3—N1—O2	−168.0 (2)
C7—C4—C5—C6	34.5 (3)	Br1—C3—N1—O2	69.1 (2)
C7—C1—C6—C5	−36.7 (3)	O4—C8—O5—C9	−3.8 (4)
C2—C1—C6—C5	70.9 (3)	C2—C8—O5—C9	174.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4^i	0.84	1.96	2.752 (3)	157

Symmetry code: (i) x−1, y+1, z.

(V) (±)-methyl 3-exo,6-exo-dibromo-7-(diphenylmethylidene)-5-endo- hydroxy-3-endo-nitrobicyclo[2.2.1]heptane-2-exo-carboxylate

Crystal data

C22H19Br2NO5	F(000) = 1072
Mr = 537.2	Dx = 1.675 Mg m^−3 Dm = 0 Mg m^−3 Dm measured by not measured
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3493 reflections
a = 15.8724 (8) Å	θ = 2.6–26.1°
b = 9.0341 (4) Å	µ = 3.84 mm^−1
c = 15.0064 (7) Å	T = 173 K
β = 98.219 (2)°	Needle, brown
V = 2129.71 (17) Å^3	0.3 × 0.1 × 0.06 mm
Z = 4

Data collection

Bruker SMART 1K CCD area-detector diffractometer	3059 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.078
ω scans	θmax = 28°, θmin = 1.3°
Absorption correction: integration (XPREP; Bruker, 1999)	h = −20→15
Tmin = 0.509, Tmax = 0.817	k = −11→11
17671 measured reflections	l = −19→19
5119 independent reflections

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.057	H-atom parameters constrained
S = 0.82	w = 1/[σ^2(Fo^2) + (0.0158P)^2] where P = (Fo^2 + 2Fc^2)/3
5119 reflections	(Δ/σ)max = 0.001
467 parameters	Δρmax = 0.45 e Å^−3
83 restraints	Δρmin = −0.43 e Å^−3

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 1999)

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	0.3573 (4)	0.3060 (6)	0.4454 (5)	0.0254 (6)	0.5
H1A1	0.3535	0.3516	0.5054	0.03*	0.5
C2A	0.3783 (5)	0.1379 (6)	0.4466 (5)	0.0221 (7)	0.5
H2A	0.441	0.1262	0.447	0.027*	0.5
C3A	0.3324 (3)	0.0877 (6)	0.3539 (5)	0.0226 (8)	0.5
C4A	0.3119 (5)	0.2321 (7)	0.3025 (5)	0.019 (3)	0.5
H4A	0.2718	0.2225	0.2449	0.023*	0.5
C5A	0.3951 (7)	0.3174 (8)	0.2950 (6)	0.0247 (8)	0.5
H5A	0.3833	0.4018	0.2519	0.03*	0.5
C6A	0.4217 (5)	0.3767 (5)	0.3921 (6)	0.0269 (6)	0.5
H6A	0.4806	0.3427	0.4159	0.032*	0.5
C7A	0.2779 (4)	0.3197 (9)	0.3760 (4)	0.0225 (7)	0.5
C8A	0.3536 (12)	0.0554 (9)	0.5266 (6)	0.0281 (11)	0.5
C9A	0.351 (2)	−0.1792 (17)	0.5958 (18)	0.0427 (8)	0.5
H9A1	0.2952	−0.1484	0.6106	0.064*	0.5
H9A2	0.3941	−0.1664	0.6487	0.064*	0.5
H9A3	0.3483	−0.2835	0.5777	0.064*	0.5
C10A	0.2049 (5)	0.3894 (13)	0.3769 (4)	0.0273 (7)	0.5
C11A	0.1804 (8)	0.4544 (10)	0.4609 (4)	0.0365 (9)	0.5
C12A	0.1677 (6)	0.3657 (8)	0.5332 (5)	0.049 (3)	0.5
H12A	0.1776	0.2621	0.5313	0.059*	0.5
C13A	0.1404 (6)	0.4292 (10)	0.6084 (5)	0.069 (3)	0.5
H13A	0.136	0.3695	0.6597	0.083*	0.5
C14A	0.1203 (8)	0.5733 (12)	0.6100 (6)	0.072 (4)	0.5
H14A	0.0946	0.6125	0.6583	0.086*	0.5
C15A	0.1375 (6)	0.6655 (10)	0.5396 (5)	0.079 (5)	0.5
H15A	0.131	0.7697	0.5437	0.095*	0.5
C16A	0.1638 (6)	0.6039 (10)	0.4651 (4)	0.059 (3)	0.5
H16A	0.1707	0.6652	0.4152	0.07*	0.5
C17A	0.1434 (4)	0.4138 (9)	0.2933 (4)	0.024 (2)	0.5
C18A	0.0572 (4)	0.3908 (9)	0.2938 (4)	0.047 (2)	0.5
H18A	0.0374	0.3596	0.3476	0.056*	0.5
C19A	−0.0002 (4)	0.4130 (10)	0.2163 (4)	0.062 (2)	0.5
H19A	−0.0591	0.3945	0.2166	0.075*	0.5
C20A	0.0278 (4)	0.4620 (9)	0.1388 (4)	0.053 (2)	0.5
H20A	−0.0119	0.4799	0.0863	0.063*	0.5
C21A	0.1124 (4)	0.4847 (9)	0.1370 (4)	0.041 (2)	0.5
H21A	0.1321	0.5128	0.0826	0.049*	0.5
C22A	0.1695 (4)	0.4664 (11)	0.2154 (5)	0.033 (3)	0.5
H22A	0.2277	0.4907	0.2154	0.039*	0.5
N1A	0.3830 (5)	−0.0234 (9)	0.3053 (6)	0.022 (2)	0.5
O1A	0.4573 (8)	0.2237 (18)	0.2677 (14)	0.0325 (10)	0.5
H1A	0.4949	0.2749	0.2481	0.049*	0.5
O2A	0.3551 (8)	−0.049 (2)	0.2269 (8)	0.036 (2)	0.5
O3A	0.4484 (8)	−0.075 (2)	0.3461 (10)	0.028 (2)	0.5
O4A	0.3141 (16)	0.1077 (19)	0.5811 (11)	0.034 (4)	0.5
O5A	0.3729 (16)	−0.0882 (12)	0.5217 (13)	0.028 (4)	0.5
Br1A	0.22575 (17)	−0.0178 (4)	0.3625 (3)	0.0363 (5)	0.5
Br2A	0.4151 (2)	0.5928 (3)	0.39687 (10)	0.0300 (7)	0.5
C1B	0.3620 (4)	0.3021 (6)	0.4479 (5)	0.0254 (6)	0.5
H1B1	0.3552	0.3489	0.5069	0.03*	0.5
C2B	0.3892 (5)	0.1363 (6)	0.4527 (5)	0.0221 (7)	0.5
H2B	0.4525	0.1309	0.4567	0.027*	0.5
C3B	0.3491 (3)	0.0794 (6)	0.3592 (5)	0.0226 (8)	0.5
C4B	0.3227 (5)	0.2199 (7)	0.3058 (4)	0.026 (4)	0.5
H4B	0.2841	0.2039	0.2479	0.032*	0.5
C5B	0.4021 (7)	0.3157 (8)	0.2985 (6)	0.0247 (8)	0.5
H5B	0.387	0.3983	0.2548	0.03*	0.5
C6B	0.4250 (5)	0.3783 (5)	0.3953 (6)	0.0269 (6)	0.5
H6B	0.4847	0.3507	0.4205	0.032*	0.5
C7B	0.2834 (4)	0.3044 (9)	0.3773 (4)	0.0225 (7)	0.5
C8B	0.3626 (12)	0.0548 (9)	0.5322 (6)	0.0281 (11)	0.5
C9B	0.351 (2)	−0.1818 (17)	0.5959 (18)	0.0427 (8)	0.5
H9B1	0.2887	−0.1814	0.5798	0.064*	0.5
H9B2	0.3659	−0.1451	0.6576	0.064*	0.5
H9B3	0.3722	−0.283	0.5918	0.064*	0.5
C10B	0.2090 (5)	0.3729 (13)	0.3713 (4)	0.0273 (7)	0.5
C11B	0.1810 (9)	0.4593 (10)	0.4464 (4)	0.0365 (9)	0.5
C12B	0.1977 (6)	0.4121 (8)	0.5352 (5)	0.045 (3)	0.5
H12B	0.2275	0.322	0.549	0.054*	0.5
C13B	0.1713 (5)	0.4952 (9)	0.6041 (5)	0.051 (3)	0.5
H13B	0.179	0.4565	0.6636	0.062*	0.5
C14B	0.1353 (7)	0.6289 (9)	0.5883 (6)	0.050 (3)	0.5
H14B	0.1269	0.6931	0.6364	0.06*	0.5
C15B	0.1106 (6)	0.6704 (9)	0.4984 (5)	0.069 (3)	0.5
H15B	0.0743	0.7533	0.4847	0.083*	0.5
C16B	0.1384 (5)	0.5920 (9)	0.4304 (5)	0.047 (2)	0.5
H16B	0.1282	0.6297	0.3708	0.057*	0.5
C17B	0.1479 (4)	0.3639 (9)	0.2859 (4)	0.026 (2)	0.5
C18B	0.0679 (4)	0.3028 (9)	0.2855 (4)	0.052 (2)	0.5
H18B	0.0514	0.2668	0.3399	0.062*	0.5
C19B	0.0117 (4)	0.2940 (10)	0.2059 (5)	0.076 (3)	0.5
H19B	−0.0421	0.248	0.2056	0.091*	0.5
C20B	0.0335 (4)	0.3516 (11)	0.1275 (4)	0.069 (2)	0.5
H20B	−0.0063	0.3491	0.0738	0.082*	0.5
C21B	0.1119 (5)	0.4121 (10)	0.1266 (5)	0.058 (3)	0.5
H21B	0.1275	0.4501	0.0722	0.07*	0.5
C22B	0.1689 (4)	0.4178 (11)	0.2060 (5)	0.030 (3)	0.5
H22B	0.2236	0.4598	0.2051	0.037*	0.5
N1B	0.4068 (5)	−0.0233 (10)	0.3133 (6)	0.024 (2)	0.5
O1B	0.4686 (8)	0.2307 (18)	0.2723 (15)	0.0325 (10)	0.5
H1B	0.4802	0.2618	0.2228	0.049*	0.5
O2B	0.3822 (8)	−0.052 (2)	0.2345 (8)	0.036 (2)	0.5
O3B	0.4723 (8)	−0.069 (2)	0.3570 (10)	0.028 (2)	0.5
O4B	0.3321 (16)	0.1131 (18)	0.5917 (11)	0.032 (4)	0.5
O5B	0.3889 (16)	−0.0859 (11)	0.5337 (13)	0.026 (3)	0.5
Br1B	0.24718 (18)	−0.0420 (4)	0.3638 (3)	0.0327 (4)	0.5
Br2B	0.4108 (2)	0.5935 (3)	0.39699 (15)	0.0510 (9)	0.5

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1A	0.0311 (16)	0.0237 (14)	0.0206 (12)	0.0090 (12)	0.0012 (12)	−0.0045 (11)
C2A	0.025 (2)	0.0225 (13)	0.0173 (14)	0.0043 (12)	−0.0011 (13)	−0.0016 (11)
C3A	0.024 (2)	0.0248 (14)	0.0193 (13)	−0.0001 (15)	0.0050 (16)	−0.0013 (12)
C4A	0.018 (5)	0.014 (5)	0.024 (6)	−0.002 (4)	−0.003 (4)	0.010 (4)
C5A	0.029 (2)	0.0201 (13)	0.0258 (14)	0.0041 (12)	0.0065 (14)	−0.0003 (11)
C6A	0.0317 (17)	0.0179 (13)	0.0295 (14)	0.0062 (11)	−0.0009 (12)	−0.0033 (11)
C7A	0.0261 (16)	0.0224 (18)	0.0184 (12)	0.0007 (12)	0.0016 (12)	0.0014 (12)
C8A	0.029 (3)	0.0330 (17)	0.0192 (16)	0.0079 (14)	−0.0063 (18)	0.0014 (12)
C9A	0.055 (2)	0.0391 (19)	0.0351 (16)	0.0090 (15)	0.0090 (16)	0.0158 (15)
C10A	0.0262 (16)	0.034 (2)	0.0217 (14)	0.0008 (13)	0.0016 (12)	0.0038 (12)
C11A	0.0218 (16)	0.058 (2)	0.029 (2)	0.0145 (15)	0.002 (2)	−0.0001 (19)
C12A	0.039 (6)	0.087 (7)	0.020 (4)	0.019 (5)	0.005 (3)	0.003 (4)
C13A	0.043 (6)	0.133 (10)	0.033 (4)	0.043 (7)	0.007 (4)	0.006 (5)
C14A	0.044 (7)	0.134 (12)	0.040 (5)	0.046 (8)	0.014 (4)	−0.003 (6)
C15A	0.070 (8)	0.126 (11)	0.034 (6)	0.070 (7)	−0.017 (6)	−0.037 (7)
C16A	0.056 (6)	0.089 (7)	0.027 (4)	0.024 (5)	−0.010 (4)	−0.007 (4)
C17A	0.027 (4)	0.024 (6)	0.021 (3)	0.008 (3)	0.002 (3)	−0.002 (3)
C18A	0.033 (4)	0.079 (6)	0.029 (3)	−0.001 (4)	0.004 (3)	0.006 (4)
C19A	0.021 (4)	0.114 (7)	0.047 (4)	−0.010 (4)	−0.008 (3)	−0.004 (5)
C20A	0.052 (5)	0.078 (5)	0.023 (3)	0.012 (4)	−0.012 (3)	−0.003 (4)
C21A	0.037 (5)	0.058 (6)	0.025 (3)	0.002 (4)	0.000 (3)	0.002 (3)
C22A	0.036 (4)	0.025 (7)	0.036 (4)	0.005 (3)	0.001 (3)	−0.001 (3)
N1A	0.029 (4)	0.017 (3)	0.019 (4)	−0.003 (3)	−0.003 (3)	0.000 (3)
O1A	0.035 (3)	0.0252 (15)	0.040 (2)	0.0010 (17)	0.016 (2)	−0.0019 (10)
O2A	0.043 (7)	0.0382 (14)	0.0228 (19)	0.001 (5)	−0.007 (3)	−0.0133 (17)
O3A	0.028 (6)	0.0259 (16)	0.027 (3)	0.008 (5)	−0.006 (3)	−0.0022 (19)
O4A	0.034 (8)	0.044 (5)	0.023 (6)	0.016 (4)	0.003 (6)	0.004 (4)
O5A	0.037 (8)	0.028 (4)	0.018 (5)	−0.001 (3)	−0.001 (6)	0.007 (3)
Br1A	0.0378 (13)	0.0390 (11)	0.0306 (5)	−0.0126 (8)	−0.0002 (9)	0.0037 (7)
Br2A	0.0443 (13)	0.0242 (13)	0.0187 (6)	−0.0016 (10)	−0.0050 (7)	−0.0064 (7)
C1B	0.0311 (16)	0.0237 (14)	0.0206 (12)	0.0090 (12)	0.0012 (12)	−0.0045 (11)
C2B	0.025 (2)	0.0225 (13)	0.0173 (14)	0.0043 (12)	−0.0011 (13)	−0.0016 (11)
C3B	0.024 (2)	0.0248 (14)	0.0193 (13)	−0.0001 (15)	0.0050 (16)	−0.0013 (12)
C4B	0.032 (6)	0.033 (7)	0.012 (6)	0.000 (5)	−0.004 (4)	−0.008 (4)
C5B	0.029 (2)	0.0201 (13)	0.0258 (14)	0.0041 (12)	0.0065 (14)	−0.0003 (11)
C6B	0.0317 (17)	0.0179 (13)	0.0295 (14)	0.0062 (11)	−0.0009 (12)	−0.0033 (11)
C7B	0.0261 (16)	0.0224 (18)	0.0184 (12)	0.0007 (12)	0.0016 (12)	0.0014 (12)
C8B	0.029 (3)	0.0330 (17)	0.0192 (16)	0.0079 (14)	−0.0063 (18)	0.0014 (12)
C9B	0.055 (2)	0.0391 (19)	0.0351 (16)	0.0090 (15)	0.0090 (16)	0.0158 (15)
C10B	0.0262 (16)	0.034 (2)	0.0217 (14)	0.0008 (13)	0.0016 (12)	0.0038 (12)
C11B	0.0218 (16)	0.058 (2)	0.029 (2)	0.0145 (15)	0.002 (2)	−0.0001 (19)
C12B	0.046 (7)	0.048 (4)	0.041 (5)	0.024 (5)	0.009 (4)	0.008 (4)
C13B	0.055 (7)	0.068 (6)	0.032 (4)	0.018 (5)	0.010 (4)	0.006 (4)
C14B	0.057 (7)	0.046 (5)	0.059 (8)	0.009 (4)	0.044 (6)	−0.001 (6)
C15B	0.082 (8)	0.080 (6)	0.050 (6)	0.048 (5)	0.028 (5)	0.013 (5)
C16B	0.051 (6)	0.057 (5)	0.038 (4)	0.030 (4)	0.018 (4)	0.010 (4)
C17B	0.026 (4)	0.015 (5)	0.036 (4)	0.007 (3)	0.002 (3)	0.002 (3)
C18B	0.033 (5)	0.074 (6)	0.047 (4)	−0.017 (4)	−0.003 (3)	0.008 (4)
C19B	0.042 (5)	0.110 (8)	0.070 (6)	−0.023 (5)	−0.008 (4)	−0.010 (6)
C20B	0.051 (6)	0.099 (7)	0.047 (5)	0.001 (5)	−0.022 (4)	0.011 (5)
C21B	0.070 (7)	0.064 (7)	0.036 (4)	−0.003 (5)	−0.009 (4)	0.009 (4)
C22B	0.033 (4)	0.023 (6)	0.034 (4)	0.000 (3)	0.002 (3)	0.003 (4)
N1B	0.021 (4)	0.025 (4)	0.026 (4)	−0.006 (3)	0.003 (4)	−0.010 (3)
O1B	0.035 (3)	0.0252 (15)	0.040 (2)	0.0010 (17)	0.016 (2)	−0.0019 (10)
O2B	0.043 (7)	0.0382 (14)	0.0228 (19)	0.001 (5)	−0.007 (3)	−0.0133 (17)
O3B	0.028 (6)	0.0259 (16)	0.027 (3)	0.008 (5)	−0.006 (3)	−0.0022 (19)
O4B	0.042 (10)	0.042 (4)	0.010 (3)	0.013 (4)	−0.001 (5)	−0.001 (3)
O5B	0.036 (8)	0.028 (4)	0.012 (4)	0.013 (4)	−0.005 (5)	0.002 (2)
Br1B	0.0307 (11)	0.0349 (9)	0.0315 (5)	−0.0055 (6)	0.0011 (8)	0.0044 (6)
Br2B	0.0619 (18)	0.0167 (13)	0.0736 (13)	0.0005 (12)	0.0067 (10)	−0.0048 (10)

Geometric parameters (Å, º)

C1A—C7A	1.520 (4)	C1B—C7B	1.518 (4)
C1A—C6A	1.525 (4)	C1B—C6B	1.524 (4)
C1A—C2A	1.555 (4)	C1B—C2B	1.557 (4)
C1A—H1A1	1	C1B—H1B1	1
C2A—C8A	1.511 (4)	C2B—C8B	1.512 (4)
C2A—C3A	1.544 (4)	C2B—C3B	1.543 (4)
C2A—H2A	1	C2B—H2B	1
C3A—C4A	1.527 (5)	C3B—C4B	1.527 (5)
C3A—N1A	1.534 (4)	C3B—N1B	1.535 (4)
C3A—Br1A	1.963 (3)	C3B—Br1B	1.963 (3)
C4A—C7A	1.518 (4)	C4B—C7B	1.522 (4)
C4A—C5A	1.546 (4)	C4B—C5B	1.545 (4)
C4A—H4A	1	C4B—H4B	1
C5A—O1A	1.406 (4)	C5B—O1B	1.406 (4)
C5A—C6A	1.553 (4)	C5B—C6B	1.553 (4)
C5A—H5A	1	C5B—H5B	1
C6A—Br2A	1.957 (3)	C6B—Br2B	1.957 (3)
C6A—H6A	1	C6B—H6B	1
C7A—C10A	1.321 (4)	C7B—C10B	1.325 (4)
C8A—O4A	1.197 (4)	C8B—O4B	1.197 (4)
C8A—O5A	1.338 (4)	C8B—O5B	1.337 (4)
C9A—O5A	1.465 (6)	C9B—O5B	1.466 (6)
C9A—H9A1	0.98	C9B—H9B1	0.98
C9A—H9A2	0.98	C9B—H9B2	0.98
C9A—H9A3	0.98	C9B—H9B3	0.98
C10A—C17A	1.492 (4)	C10B—C11B	1.490 (4)
C10A—C11A	1.492 (4)	C10B—C17B	1.495 (4)
C11A—C16A	1.379 (6)	C11B—C16B	1.381 (6)
C11A—C12A	1.387 (6)	C11B—C12B	1.387 (6)
C12A—C13A	1.390 (5)	C12B—C13B	1.390 (5)
C12A—H12A	0.95	C12B—H12B	0.95
C13A—C14A	1.341 (9)	C13B—C14B	1.343 (9)
C13A—H13A	0.95	C13B—H13B	0.95
C14A—C15A	1.403 (9)	C14B—C15B	1.401 (9)
C14A—H14A	0.95	C14B—H14B	0.95
C15A—C16A	1.366 (7)	C15B—C16B	1.366 (7)
C15A—H15A	0.95	C15B—H15B	0.95
C16A—H16A	0.95	C16B—H16B	0.95
C17A—C22A	1.378 (5)	C17B—C22B	1.379 (5)
C17A—C18A	1.384 (5)	C17B—C18B	1.384 (5)
C18A—C19A	1.387 (6)	C18B—C19B	1.387 (6)
C18A—H18A	0.95	C18B—H18B	0.95
C19A—C20A	1.376 (6)	C19B—C20B	1.376 (6)
C19A—H19A	0.95	C19B—H19B	0.95
C20A—C21A	1.361 (6)	C20B—C21B	1.361 (6)
C20A—H20A	0.95	C20B—H20B	0.95
C21A—C22A	1.389 (5)	C21B—C22B	1.390 (5)
C21A—H21A	0.95	C21B—H21B	0.95
C22A—H22A	0.95	C22B—H22B	0.95
N1A—O2A	1.219 (4)	N1B—O2B	1.220 (4)
N1A—O3A	1.221 (5)	N1B—O3B	1.221 (5)
O1A—H1A	0.84	O1B—H1B	0.84
C7A—C1A—C6A	99.2 (3)	C6B—C1B—H1B1	115.4
C7A—C1A—C2A	104.1 (3)	C2B—C1B—H1B1	115.4
C6A—C1A—C2A	104.9 (3)	C8B—C2B—C3B	115.4 (5)
C7A—C1A—H1A1	115.6	C8B—C2B—C1B	113.5 (4)
C6A—C1A—H1A1	115.6	C3B—C2B—C1B	101.7 (3)
C2A—C1A—H1A1	115.6	C8B—C2B—H2B	108.6
C8A—C2A—C3A	115.4 (5)	C3B—C2B—H2B	108.6
C8A—C2A—C1A	114.4 (4)	C1B—C2B—H2B	108.6
C3A—C2A—C1A	101.7 (3)	C4B—C3B—N1B	113.8 (4)
C8A—C2A—H2A	108.3	C4B—C3B—C2B	104.3 (3)
C3A—C2A—H2A	108.3	N1B—C3B—C2B	114.5 (4)
C1A—C2A—H2A	108.3	C4B—C3B—Br1B	108.5 (4)
C4A—C3A—N1A	114.0 (4)	N1B—C3B—Br1B	103.0 (3)
C4A—C3A—C2A	104.1 (3)	C2B—C3B—Br1B	112.9 (3)
N1A—C3A—C2A	114.1 (4)	C7B—C4B—C3B	99.0 (3)
C4A—C3A—Br1A	109.0 (3)	C7B—C4B—C5B	101.0 (3)
N1A—C3A—Br1A	103.2 (3)	C3B—C4B—C5B	109.8 (4)
C2A—C3A—Br1A	112.6 (3)	C7B—C4B—H4B	115
C7A—C4A—C3A	98.6 (3)	C3B—C4B—H4B	115
C7A—C4A—C5A	100.9 (3)	C5B—C4B—H4B	115
C3A—C4A—C5A	109.9 (4)	O1B—C5B—C4B	111.5 (5)
C7A—C4A—H4A	115.1	O1B—C5B—C6B	112.0 (5)
C3A—C4A—H4A	115.1	C4B—C5B—C6B	102.8 (3)
C5A—C4A—H4A	115.1	O1B—C5B—H5B	110.1
O1A—C5A—C4A	111.3 (5)	C4B—C5B—H5B	110.1
O1A—C5A—C6A	111.9 (5)	C6B—C5B—H5B	110.1
C4A—C5A—C6A	103.0 (3)	C1B—C6B—C5B	103.7 (3)
O1A—C5A—H5A	110.1	C1B—C6B—Br2B	110.9 (3)
C4A—C5A—H5A	110.1	C5B—C6B—Br2B	111.2 (3)
C6A—C5A—H5A	110.1	C1B—C6B—H6B	110.3
C1A—C6A—C5A	103.5 (3)	C5B—C6B—H6B	110.3
C1A—C6A—Br2A	110.8 (4)	Br2B—C6B—H6B	110.3
C5A—C6A—Br2A	111.7 (3)	C10B—C7B—C1B	133.6 (4)
C1A—C6A—H6A	110.2	C10B—C7B—C4B	129.7 (4)
C5A—C6A—H6A	110.2	C1B—C7B—C4B	96.1 (3)
Br2A—C6A—H6A	110.2	O4B—C8B—O5B	124.3 (5)
C10A—C7A—C4A	131.2 (4)	O4B—C8B—C2B	124.3 (5)
C10A—C7A—C1A	132.4 (4)	O5B—C8B—C2B	110.8 (4)
C4A—C7A—C1A	96.3 (3)	O5B—C9B—H9B1	109.5
O4A—C8A—O5A	124.5 (6)	O5B—C9B—H9B2	109.5
O4A—C8A—C2A	124.7 (5)	H9B1—C9B—H9B2	109.5
O5A—C8A—C2A	110.4 (4)	O5B—C9B—H9B3	109.5
C7A—C10A—C17A	122.1 (4)	H9B1—C9B—H9B3	109.5
C7A—C10A—C11A	122.1 (4)	H9B2—C9B—H9B3	109.5
C17A—C10A—C11A	115.8 (4)	C7B—C10B—C11B	123.6 (4)
C16A—C11A—C12A	118.7 (4)	C7B—C10B—C17B	119.7 (4)
C16A—C11A—C10A	119.9 (5)	C11B—C10B—C17B	116.8 (4)
C12A—C11A—C10A	121.2 (5)	C16B—C11B—C12B	117.1 (4)
C11A—C12A—C13A	119.6 (5)	C16B—C11B—C10B	121.0 (4)
C11A—C12A—H12A	120.2	C12B—C11B—C10B	121.9 (4)
C13A—C12A—H12A	120.2	C11B—C12B—C13B	120.8 (5)
C14A—C13A—C12A	121.2 (6)	C11B—C12B—H12B	119.6
C14A—C13A—H13A	119.4	C13B—C12B—H12B	119.6
C12A—C13A—H13A	119.4	C14B—C13B—C12B	121.3 (6)
C13A—C14A—C15A	119.4 (7)	C14B—C13B—H13B	119.3
C13A—C14A—H14A	120.3	C12B—C13B—H13B	119.3
C15A—C14A—H14A	120.3	C13B—C14B—C15B	117.6 (6)
C16A—C15A—C14A	119.3 (7)	C13B—C14B—H14B	121.2
C16A—C15A—H15A	120.3	C15B—C14B—H14B	121.2
C14A—C15A—H15A	120.3	C16B—C15B—C14B	120.3 (7)
C15A—C16A—C11A	121.2 (6)	C16B—C15B—H15B	119.8
C15A—C16A—H16A	119.4	C14B—C15B—H15B	119.8
C11A—C16A—H16A	119.4	C15B—C16B—C11B	121.5 (6)
C22A—C17A—C18A	118.3 (4)	C15B—C16B—H16B	119.2
C22A—C17A—C10A	121.6 (4)	C11B—C16B—H16B	119.2
C18A—C17A—C10A	120.1 (4)	C22B—C17B—C18B	118.2 (4)
C17A—C18A—C19A	120.3 (4)	C22B—C17B—C10B	121.3 (5)
C17A—C18A—H18A	119.8	C18B—C17B—C10B	120.5 (4)
C19A—C18A—H18A	119.8	C17B—C18B—C19B	120.2 (5)
C20A—C19A—C18A	120.1 (5)	C17B—C18B—H18B	119.9
C20A—C19A—H19A	119.9	C19B—C18B—H18B	119.9
C18A—C19A—H19A	119.9	C20B—C19B—C18B	120.4 (5)
C21A—C20A—C19A	120.3 (5)	C20B—C19B—H19B	119.8
C21A—C20A—H20A	119.9	C18B—C19B—H19B	119.8
C19A—C20A—H20A	119.9	C21B—C20B—C19B	120.1 (5)
C20A—C21A—C22A	119.4 (5)	C21B—C20B—H20B	119.9
C20A—C21A—H21A	120.3	C19B—C20B—H20B	119.9
C22A—C21A—H21A	120.3	C20B—C21B—C22B	119.4 (5)
C17A—C22A—C21A	121.3 (5)	C20B—C21B—H21B	120.3
C17A—C22A—H22A	119.3	C22B—C21B—H21B	120.3
C21A—C22A—H22A	119.3	C17B—C22B—C21B	121.6 (5)
O2A—N1A—O3A	125.2 (5)	C17B—C22B—H22B	119.2
O2A—N1A—C3A	116.2 (5)	C21B—C22B—H22B	119.2
O3A—N1A—C3A	118.5 (5)	O2B—N1B—O3B	125.3 (5)
C8A—O5A—C9A	114.9 (6)	O2B—N1B—C3B	115.8 (5)
C7B—C1B—C6B	99.6 (3)	O3B—N1B—C3B	118.9 (5)
C7B—C1B—C2B	103.8 (3)	C5B—O1B—H1B	109.5
C6B—C1B—C2B	105.1 (3)	C8B—O5B—C9B	114.6 (6)
C7B—C1B—H1B1	115.4
C7A—C1A—C2A—C8A	−103.1 (7)	C7B—C1B—C2B—C8B	−100.9 (7)
C6A—C1A—C2A—C8A	153.3 (7)	C6B—C1B—C2B—C8B	155.0 (7)
C7A—C1A—C2A—C3A	22.0 (5)	C7B—C1B—C2B—C3B	23.8 (5)
C6A—C1A—C2A—C3A	−81.7 (4)	C6B—C1B—C2B—C3B	−80.4 (4)
C8A—C2A—C3A—C4A	138.6 (6)	C8B—C2B—C3B—C4B	135.7 (6)
C1A—C2A—C3A—C4A	14.3 (5)	C1B—C2B—C3B—C4B	12.4 (5)
C8A—C2A—C3A—N1A	−96.4 (6)	C8B—C2B—C3B—N1B	−99.3 (7)
C1A—C2A—C3A—N1A	139.2 (5)	C1B—C2B—C3B—N1B	137.3 (5)
C8A—C2A—C3A—Br1A	20.8 (6)	C8B—C2B—C3B—Br1B	18.1 (7)
C1A—C2A—C3A—Br1A	−103.6 (4)	C1B—C2B—C3B—Br1B	−105.2 (4)
N1A—C3A—C4A—C7A	−170.4 (4)	N1B—C3B—C4B—C7B	−169.4 (5)
C2A—C3A—C4A—C7A	−45.4 (4)	C2B—C3B—C4B—C7B	−44.0 (4)
Br1A—C3A—C4A—C7A	75.0 (4)	Br1B—C3B—C4B—C7B	76.6 (4)
N1A—C3A—C4A—C5A	−65.4 (5)	N1B—C3B—C4B—C5B	−64.2 (5)
C2A—C3A—C4A—C5A	59.6 (4)	C2B—C3B—C4B—C5B	61.2 (4)
Br1A—C3A—C4A—C5A	179.9 (4)	Br1B—C3B—C4B—C5B	−178.2 (3)
C7A—C4A—C5A—O1A	150.3 (7)	C7B—C4B—C5B—O1B	151.3 (7)
C3A—C4A—C5A—O1A	46.9 (8)	C3B—C4B—C5B—O1B	47.5 (8)
C7A—C4A—C5A—C6A	30.3 (5)	C7B—C4B—C5B—C6B	31.1 (5)
C3A—C4A—C5A—C6A	−73.1 (5)	C3B—C4B—C5B—C6B	−72.7 (5)
C7A—C1A—C6A—C5A	−39.6 (5)	C7B—C1B—C6B—C5B	−38.7 (5)
C2A—C1A—C6A—C5A	67.7 (5)	C2B—C1B—C6B—C5B	68.5 (5)
C7A—C1A—C6A—Br2A	80.3 (5)	C7B—C1B—C6B—Br2B	80.7 (5)
C2A—C1A—C6A—Br2A	−172.4 (4)	C2B—C1B—C6B—Br2B	−172.0 (4)
O1A—C5A—C6A—C1A	−113.9 (8)	O1B—C5B—C6B—C1B	−115.2 (8)
C4A—C5A—C6A—C1A	5.8 (5)	C4B—C5B—C6B—C1B	4.6 (6)
O1A—C5A—C6A—Br2A	126.9 (7)	O1B—C5B—C6B—Br2B	125.6 (7)
C4A—C5A—C6A—Br2A	−113.5 (5)	C4B—C5B—C6B—Br2B	−114.6 (5)
C3A—C4A—C7A—C10A	−125.1 (11)	C6B—C1B—C7B—C10B	−113.3 (12)
C5A—C4A—C7A—C10A	122.6 (12)	C2B—C1B—C7B—C10B	138.4 (11)
C3A—C4A—C7A—C1A	57.5 (4)	C6B—C1B—C7B—C4B	57.8 (4)
C5A—C4A—C7A—C1A	−54.8 (4)	C2B—C1B—C7B—C4B	−50.5 (4)
C6A—C1A—C7A—C10A	−119.0 (11)	C3B—C4B—C7B—C10B	−131.0 (11)
C2A—C1A—C7A—C10A	133.0 (11)	C5B—C4B—C7B—C10B	116.7 (11)
C6A—C1A—C7A—C4A	58.4 (4)	C3B—C4B—C7B—C1B	57.4 (4)
C2A—C1A—C7A—C4A	−49.6 (4)	C5B—C4B—C7B—C1B	−55.0 (4)
C3A—C2A—C8A—O4A	−111 (2)	C3B—C2B—C8B—O4B	−125 (2)
C1A—C2A—C8A—O4A	7 (2)	C1B—C2B—C8B—O4B	−8 (2)
C3A—C2A—C8A—O5A	61.7 (17)	C3B—C2B—C8B—O5B	64.3 (17)
C1A—C2A—C8A—O5A	179.2 (15)	C1B—C2B—C8B—O5B	−178.9 (15)
C4A—C7A—C10A—C17A	−10.1 (16)	C1B—C7B—C10B—C11B	−7.8 (18)
C1A—C7A—C10A—C17A	166.4 (7)	C4B—C7B—C10B—C11B	−176.2 (7)
C4A—C7A—C10A—C11A	172.6 (7)	C1B—C7B—C10B—C17B	173.0 (7)
C1A—C7A—C10A—C11A	−10.9 (17)	C4B—C7B—C10B—C17B	4.5 (15)
C7A—C10A—C11A—C16A	120.9 (12)	C7B—C10B—C11B—C16B	139.4 (12)
C17A—C10A—C11A—C16A	−56.6 (14)	C17B—C10B—C11B—C16B	−41.3 (15)
C7A—C10A—C11A—C12A	−64.1 (17)	C7B—C10B—C11B—C12B	−39.3 (18)
C17A—C10A—C11A—C12A	118.5 (11)	C17B—C10B—C11B—C12B	139.9 (11)
C16A—C11A—C12A—C13A	−1.4 (17)	C16B—C11B—C12B—C13B	0.8 (17)
C10A—C11A—C12A—C13A	−176.5 (9)	C10B—C11B—C12B—C13B	179.6 (10)
C11A—C12A—C13A—C14A	4.8 (17)	C11B—C12B—C13B—C14B	−5.5 (16)
C12A—C13A—C14A—C15A	−8.4 (18)	C12B—C13B—C14B—C15B	11.7 (15)
C13A—C14A—C15A—C16A	8.7 (17)	C13B—C14B—C15B—C16B	−13.5 (15)
C14A—C15A—C16A—C11A	−5.5 (15)	C14B—C15B—C16B—C11B	9.3 (16)
C12A—C11A—C16A—C15A	1.8 (16)	C12B—C11B—C16B—C15B	−2.8 (17)
C10A—C11A—C16A—C15A	177.0 (8)	C10B—C11B—C16B—C15B	178.4 (10)
C7A—C10A—C17A—C22A	−46.9 (15)	C7B—C10B—C17B—C22B	−61.3 (14)
C11A—C10A—C17A—C22A	130.6 (9)	C11B—C10B—C17B—C22B	119.4 (9)
C7A—C10A—C17A—C18A	136.4 (10)	C7B—C10B—C17B—C18B	119.7 (11)
C11A—C10A—C17A—C18A	−46.1 (12)	C11B—C10B—C17B—C18B	−59.6 (12)
C22A—C17A—C18A—C19A	3.3 (13)	C22B—C17B—C18B—C19B	1.3 (14)
C10A—C17A—C18A—C19A	−179.9 (8)	C10B—C17B—C18B—C19B	−179.7 (8)
C17A—C18A—C19A—C20A	−1.7 (14)	C17B—C18B—C19B—C20B	−2.8 (15)
C18A—C19A—C20A—C21A	1.9 (14)	C18B—C19B—C20B—C21B	2.8 (16)
C19A—C20A—C21A—C22A	−3.7 (14)	C19B—C20B—C21B—C22B	−1.3 (16)
C18A—C17A—C22A—C21A	−5.2 (14)	C18B—C17B—C22B—C21B	0.2 (15)
C10A—C17A—C22A—C21A	178.0 (8)	C10B—C17B—C22B—C21B	−178.9 (8)
C20A—C21A—C22A—C17A	5.5 (14)	C20B—C21B—C22B—C17B	−0.2 (16)
C4A—C3A—N1A—O2A	−50.0 (14)	C4B—C3B—N1B—O2B	−49.7 (14)
C2A—C3A—N1A—O2A	−169.5 (13)	C2B—C3B—N1B—O2B	−169.5 (13)
Br1A—C3A—N1A—O2A	68.0 (14)	Br1B—C3B—N1B—O2B	67.6 (14)
C4A—C3A—N1A—O3A	127.7 (14)	C4B—C3B—N1B—O3B	130.4 (14)
C2A—C3A—N1A—O3A	8.2 (15)	C2B—C3B—N1B—O3B	10.7 (15)
Br1A—C3A—N1A—O3A	−114.2 (14)	Br1B—C3B—N1B—O3B	−112.3 (15)
O4A—C8A—O5A—C9A	−7 (4)	O4B—C8B—O5B—C9B	22 (4)
C2A—C8A—O5A—C9A	−179 (2)	C2B—C8B—O5B—C9B	−167 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1A—H1A···O3A^i	0.84	2.24	3.03 (2)	157
O1B—H1B···O3B^i	0.84	2.14	2.90 (3)	151

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

(VI) (±)-methyl 3-exo,6-exo-dibromo-5-endo-hydroxy-3-endo-nitro- 7-oxabicyclo[2.2.1]heptane-2-exo-carboxylate

Crystal data

C8H9Br2NO6	F(000) = 728
Mr = 374.98	Dx = 2.209 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 921 reflections
a = 7.8071 (13) Å	θ = 3.2–28.4°
b = 22.760 (4) Å	µ = 7.21 mm^−1
c = 6.7673 (10) Å	T = 173 K
β = 110.32 (1)°	Block, colourless
V = 1127.7 (3) Å^3	0.42 × 0.4 × 0.2 mm
Z = 4

Data collection

Bruker SMART 1K CCD area-detector diffractometer	2453 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.085
ω scans	θmax = 28°, θmin = 2.8°
Absorption correction: integration (XPREP; Bruker, 1999)	h = −10→9
Tmin = 0.092, Tmax = 0.290	k = −30→30
12168 measured reflections	l = −8→8
2715 independent reflections

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.076	H atoms treated by a mixture of independent and constrained refinement
S = 1.22	w = 1/[σ^2(Fo^2) + 1.494P] where P = (Fo^2 + 2Fc^2)/3
2715 reflections	(Δ/σ)max = 0.001
158 parameters	Δρmax = 0.47 e Å^−3
0 restraints	Δρmin = −0.92 e Å^−3

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 1999)

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	0.4596 (4)	0.08700 (13)	0.8249 (4)	0.0151 (5)
H1A	0.5191	0.078	0.9782	0.018*
C2	0.5255 (4)	0.14527 (13)	0.7547 (4)	0.0149 (5)
H2	0.4442	0.1785	0.7618	0.018*
C3	0.4978 (4)	0.13033 (13)	0.5217 (4)	0.0157 (5)
C4	0.3934 (4)	0.07166 (13)	0.4912 (4)	0.0165 (6)
H4	0.3931	0.0491	0.3643	0.02*
C5	0.2012 (4)	0.07874 (14)	0.5083 (4)	0.0178 (6)
H5	0.1302	0.0415	0.4642	0.021*
C6	0.2510 (4)	0.08814 (13)	0.7492 (4)	0.0171 (5)
H6	0.2061	0.1271	0.7788	0.02*
C7	0.7230 (4)	0.15867 (13)	0.8883 (4)	0.0177 (6)
C8	0.9566 (4)	0.22856 (17)	0.9698 (6)	0.0302 (7)
H8A	0.9912	0.2171	1.1181	0.045*
H8B	0.9735	0.271	0.9603	0.045*
H8C	1.0334	0.2076	0.9052	0.045*
N1	0.3988 (3)	0.17724 (11)	0.3625 (4)	0.0180 (5)
O1	0.0960 (3)	0.12686 (10)	0.4001 (4)	0.0221 (5)
H1	0.029 (6)	0.1174 (19)	0.269 (7)	0.033*
O2	0.3489 (3)	0.16231 (11)	0.1774 (3)	0.0270 (5)
O3	0.3757 (3)	0.22552 (10)	0.4268 (4)	0.0286 (5)
O4	0.8248 (3)	0.12368 (10)	1.0054 (4)	0.0251 (5)
O5	0.7660 (3)	0.21368 (10)	0.8594 (3)	0.0229 (5)
O6	0.4935 (3)	0.04365 (9)	0.6866 (3)	0.0183 (4)
Br1	0.72464 (4)	0.118459 (15)	0.46861 (5)	0.02389 (10)
Br2	0.16270 (4)	0.025117 (16)	0.88365 (5)	0.02651 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0163 (13)	0.0148 (13)	0.0129 (12)	−0.0008 (10)	0.0035 (10)	−0.0011 (10)
C2	0.0173 (13)	0.0132 (13)	0.0138 (12)	0.0008 (10)	0.0049 (10)	−0.0008 (10)
C3	0.0156 (13)	0.0179 (14)	0.0136 (12)	0.0022 (10)	0.0049 (10)	0.0002 (11)
C4	0.0185 (13)	0.0152 (14)	0.0148 (12)	0.0007 (11)	0.0043 (11)	−0.0025 (11)
C5	0.0132 (12)	0.0198 (14)	0.0170 (13)	−0.0006 (11)	0.0011 (10)	0.0019 (11)
C6	0.0193 (13)	0.0156 (14)	0.0165 (12)	−0.0021 (11)	0.0064 (11)	0.0010 (11)
C7	0.0200 (14)	0.0182 (14)	0.0149 (12)	−0.0021 (11)	0.0061 (11)	−0.0023 (11)
C8	0.0223 (15)	0.0312 (18)	0.0323 (17)	−0.0119 (14)	0.0037 (13)	−0.0040 (15)
N1	0.0182 (11)	0.0177 (12)	0.0183 (11)	−0.0012 (10)	0.0065 (10)	0.0031 (10)
O1	0.0178 (10)	0.0269 (12)	0.0182 (10)	0.0058 (9)	0.0019 (8)	0.0042 (9)
O2	0.0322 (12)	0.0320 (13)	0.0139 (10)	0.0021 (10)	0.0043 (9)	0.0024 (9)
O3	0.0377 (13)	0.0173 (11)	0.0289 (12)	0.0041 (10)	0.0091 (10)	0.0018 (10)
O4	0.0201 (11)	0.0254 (12)	0.0229 (11)	−0.0031 (9)	−0.0012 (9)	0.0047 (9)
O5	0.0202 (10)	0.0196 (11)	0.0251 (11)	−0.0041 (9)	0.0033 (9)	−0.0005 (9)
O6	0.0220 (10)	0.0151 (10)	0.0158 (9)	0.0046 (8)	0.0039 (8)	−0.0002 (8)
Br1	0.01801 (14)	0.03388 (19)	0.02190 (16)	0.00381 (12)	0.00963 (12)	−0.00164 (13)
Br2	0.02506 (16)	0.03039 (18)	0.02249 (16)	−0.00843 (13)	0.00624 (12)	0.00615 (13)

Geometric parameters (Å, º)

C1—O6	1.446 (3)	C5—C6	1.554 (4)
C1—C6	1.528 (4)	C5—H5	1
C1—C2	1.555 (4)	C6—Br2	1.948 (3)
C1—H1A	1	C6—H6	1
C2—C7	1.523 (4)	C7—O4	1.207 (4)
C2—C3	1.553 (4)	C7—O5	1.328 (4)
C2—H2	1	C8—O5	1.454 (4)
C3—N1	1.523 (4)	C8—H8A	0.98
C3—C4	1.540 (4)	C8—H8B	0.98
C3—Br1	1.944 (3)	C8—H8C	0.98
C4—O6	1.431 (3)	N1—O3	1.218 (4)
C4—C5	1.553 (4)	N1—O2	1.223 (3)
C4—H4	1	O1—H1	0.89 (4)
C5—O1	1.411 (4)
O6—C1—C6	102.0 (2)	C4—C5—C6	101.3 (2)
O6—C1—C2	103.3 (2)	O1—C5—H5	109.9
C6—C1—C2	108.1 (2)	C4—C5—H5	109.9
O6—C1—H1A	114.1	C6—C5—H5	109.9
C6—C1—H1A	114.1	C1—C6—C5	101.4 (2)
C2—C1—H1A	114.1	C1—C6—Br2	109.9 (2)
C7—C2—C3	113.7 (2)	C5—C6—Br2	112.9 (2)
C7—C2—C1	111.3 (2)	C1—C6—H6	110.8
C3—C2—C1	100.3 (2)	C5—C6—H6	110.8
C7—C2—H2	110.4	Br2—C6—H6	110.8
C3—C2—H2	110.4	O4—C7—O5	125.2 (3)
C1—C2—H2	110.4	O4—C7—C2	123.9 (3)
N1—C3—C4	113.5 (2)	O5—C7—C2	110.9 (2)
N1—C3—C2	115.0 (2)	O5—C8—H8A	109.5
C4—C3—C2	101.9 (2)	O5—C8—H8B	109.5
N1—C3—Br1	103.75 (18)	H8A—C8—H8B	109.5
C4—C3—Br1	109.16 (19)	O5—C8—H8C	109.5
C2—C3—Br1	113.77 (19)	H8A—C8—H8C	109.5
O6—C4—C3	99.7 (2)	H8B—C8—H8C	109.5
O6—C4—C5	102.1 (2)	O3—N1—O2	125.6 (3)
C3—C4—C5	112.3 (2)	O3—N1—C3	118.8 (2)
O6—C4—H4	113.8	O2—N1—C3	115.6 (2)
C3—C4—H4	113.8	C5—O1—H1	111 (3)
C5—C4—H4	113.8	C7—O5—C8	114.2 (3)
O1—C5—C4	116.4 (2)	C4—O6—C1	97.5 (2)
O1—C5—C6	109.0 (2)
O6—C1—C2—C7	−93.9 (3)	O6—C1—C6—Br2	84.0 (2)
C6—C1—C2—C7	158.5 (2)	C2—C1—C6—Br2	−167.60 (18)
O6—C1—C2—C3	26.7 (2)	O1—C5—C6—C1	−121.4 (2)
C6—C1—C2—C3	−80.8 (3)	C4—C5—C6—C1	1.9 (3)
C7—C2—C3—N1	−109.0 (3)	O1—C5—C6—Br2	121.1 (2)
C1—C2—C3—N1	132.1 (2)	C4—C5—C6—Br2	−115.6 (2)
C7—C2—C3—C4	127.8 (2)	C3—C2—C7—O4	−99.5 (3)
C1—C2—C3—C4	8.9 (3)	C1—C2—C7—O4	12.9 (4)
C7—C2—C3—Br1	10.5 (3)	C3—C2—C7—O5	81.0 (3)
C1—C2—C3—Br1	−108.5 (2)	C1—C2—C7—O5	−166.5 (2)
N1—C3—C4—O6	−166.4 (2)	C4—C3—N1—O3	128.5 (3)
C2—C3—C4—O6	−42.2 (2)	C2—C3—N1—O3	11.8 (4)
Br1—C3—C4—O6	78.4 (2)	Br1—C3—N1—O3	−113.1 (2)
N1—C3—C4—C5	−59.0 (3)	C4—C3—N1—O2	−51.5 (3)
C2—C3—C4—C5	65.2 (3)	C2—C3—N1—O2	−168.2 (2)
Br1—C3—C4—C5	−174.12 (18)	Br1—C3—N1—O2	66.9 (3)
O6—C4—C5—O1	150.8 (2)	O4—C7—O5—C8	4.9 (4)
C3—C4—C5—O1	44.9 (3)	C2—C7—O5—C8	−175.6 (3)
O6—C4—C5—C6	32.7 (3)	C3—C4—O6—C1	59.7 (2)
C3—C4—C5—C6	−73.2 (3)	C5—C4—O6—C1	−55.8 (2)
O6—C1—C6—C5	−35.7 (3)	C6—C1—O6—C4	57.5 (2)
C2—C1—C6—C5	72.8 (3)	C2—C1—O6—C4	−54.6 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4^i	0.89 (4)	1.94 (4)	2.774 (3)	156 (4)

Symmetry code: (i) x−1, y, z−1.