5-Amino-2,4,6-tribromo­isophthalic acid: the MAD triangle for experimental phasing

The title compound, C₈H₄Br₃NO₄, shows an extensive hydrogen-bond network. In the crystal structure, mol­ecules are linked into chains by COO—H...O bonds, and pairs of chains are connected by additional COO—H...O bonds. This chain bundle shows stacking inter­actions and weak N—H...O hydrogen bonds with adjacent chain bundles. The three Br atoms present in the mol­ecule form an equilateral triangle. This can be easily identified in the heavy-atom substructure when this compound is used as a heavy-atom derivative for experimental phasing of macromolecules. The title compound crystallizes as a nonmerohedral twin.

S1. Comment

Heavy atoms are utilized for the derivatization of biological macromolecules to enable experimental phase determination. Nowadays, techniques are commonly used that exploit the anomalous scattering of certain atoms. SAD (single-wavelength anomalous dispersion) is suitable for in-house phasing if the atoms concerned have an appreciable anomalous signal at the Cu Kα wavelength. At a synchrotron, a series of experiments may be carried out close to the absorption edge of the particular heavy atom, maximizing the sum of the anomalous signals and the difference of the dispersive signals (multi-wavelength anomalous dispersion, MAD).

Incorporation of heavy atoms is required if the biomolecule does not possess sufficient intrinsic anomalous scatterers. Expression of a selenomethionine derivative enables structure solution by MAD or SAD methods. Incorporation of other anomalous scatterers such as halides (Dauter et al., 2000) or the tantalum bromide cluster (Schneider & Lindqvist, 1994) is achieved using less demanding approaches, e.g. soaking or cocrystallization of the native protein with the heavy-atom salt. However, most heavy-atom derivatives show low occupancies of the heavy-atom sites due to non-specific binding.

We have recently reported the synthesis and characterization of 5-amino-2,4,6-triiodoisophthalic acid, hereinafter (I3C) (Beck & Sheldrick, 2008). This is a representative of a new class of compounds that can be used for heavy-atom derivatization. It combines functional groups for hydrogen bonding to the protein with an easily recognizable arrangement of heavy atoms. It has been applied for SAD phasing (Beck et al., 2008). There is also a report of a novel structure that was solved using (I3C) (Sippel et al., 2008). Unfortunately, (I3C) cannot be used for multi-wavelength experiments since the energy of the iodine absorption edge is not accessible at a typical macromolecular crystallography synchrotron beamline.

Since MAD experiments yield better phase information, we were also interested in the analogous bromine compound (the bromine absorption edge falls within the normal energy range of a synchrotron beamline). This report characterizes the new phasing tool 5-amino-2,4,6-tribromoisophthalic acid, (B3C). Two carboxyl groups and one amino group for hydrogen bonding, combined with three Br atoms arranged in an equilateral triangle, render (B3C) a suitable phasing tool for MAD experiments. Compound (B3C) has been used for MAD phasing with synchrotron data (Beck et al., 2009) and also for SAD phasing using data collected only at Cu Kα (Beck et al., unpublished results).

Compound (B3C) has no internal symmetry and crystallizes in the space group P2₁/c with four molecules in the asymmetric unit. The bond lengths and angles fall within normal ranges. A displacement ellipsoid plot is shown in Fig. 1. In the crystal structure, molecules are linked to chains via COO—H···O bonds (Fig. 2). The first carboxyl group of each molecule forms cyclic dimers with a neighbouring carboxyl group (e.g. O8—H8···O51 and O52—H52···O9; see Table 2 for details of hydrogen-bond geometry), as observed frequently for carboxylic acids in the solid state (Leiserowitz, 1976). The second carboxyl group is also involved in hydrogen bonding to form a one-dimensional chain (e.g. O12—H12···O48ⁱ; see Table 2 for symmetry code). Instead of a dimeric interaction, one hydrogen bond is also formed to an adjacent chain (e.g. O29—H29···O11; Table 2). Therefore, a one-dimensional hydrogen-bond network is found in the crystal structure of (B3C). In trimesic acid, with its three carboxyl groups, a two-dimensional network is found, not limited to chains but extending within a plane (Duchamp & Marsh, 1969).

A bundle of chains of (B3C) shows weak hydrogen bonding via one amino group (N33) to adjacent chain bundles (Table 2). In addition, stacking of benzene rings (ring C41–C46 with symmetry-equivalent ring C21–C26; Symmetry code?) is also observed as a contact between the chain bundles. No direct face-to-face contact is present, but rather an offset geometry, favoured by decreased π–π repulsion and increased σ–π attraction (Hunter & Sanders, 1990). Close C···C contacts are observed between atoms C42 and C25^iv [3.690 (5) Å], C42 and C26^iv [3.889 (5) Å], C43 and C25^iv [3.803 (5) Å] and C43 and C26^iv [3.843 (5) Å] [symmetry code: (iv) -x + 1, 1/2 + y, 3/2 - z]. In addition, a close C···Br distance is also observed [C46···Br6^iv = 3.620 (4) Å]. The angle between the two benzene ring planes is 7.9 (2)°.

The molecular arrangement in the crystal lattice differs from the packing found in crystals of the iodine derivative, (I3C) (Beck & Sheldrick, 2008). In (B3C), no solvent water molecule is present. Increased halogen–carbon bond lengths and van der Waals radii (2.1 Å for I versus 1.9 Å for Br; Reference?) explain why the cyclic dimeric hydrogen bonds of two neighbouring carboxyl groups found in (B3C) are not favoured for (I3C): the I atoms of two molecules would come in close proximity and repel each other. Hydrogen bonds to the solvent water molecule are observed for (I3C). These are also present in the unsubstituted 5-aminoisophthalic acid (Dobson & Gerkin, 1998), where, since the substituents are missing, the packing is different from that observed in (I3C) and (B3C). The unsubstituted acid crystallizes as a zwitterion, with one carboxylate and an –NH₃⁺ group. The carboxyl groups are in plane with the aromatic ring. The negative charge of the carboxylate group can therefore be delocalized across the π system, leading to an increase in acid strength compared with (B3C) and (I3C). Here, clear indications for protonated carboxyl groups can be found (Table 1). In all carboxyl groups, one C—O bond is significantly shorter than the other, indicating one double bond and one single bond. Interestingly, the bond lengths for C30—O31/C30—O32 and C67—O68/C67—O69 do not show such large differences, but still indicate protonation of O31 and O68, respectively (Table 1).

The distance between Br atoms in (B3C) varies from 5.652 (1) to 5.695 (1) Å. For each (B3C) molecule, the Br atoms form an equilateral triangle that can be easily identified in the heavy-atom substructure when this compound is used as a heavy-atom derivative for experimental phasing of macromolecules. The geometry of (B3C) as determined by this crystal structure has been used to generate restraints for the refinement of (B3C) in macromolecules (Beck et al., 2009). These restraints are available by email request from author TB.

The crystal is non-merohedrally twinned. The first and second domains are related by a twofold axis about the real axis 1 0 0. Integration using both orientation matrices simultaneously was carried out using SAINT (Bruker, 2007). The fractional contribution of the second domain was refined to 0.3468 (6).

S2. Experimental

The title compound, (B3C), was prepared according to the method shown in the scheme. 5-Aminoisophthalic acid (3.32 g, 18 mmol) was added to water (100 ml). Bromine (9.6 g, 3.0 ml, 60 mmol) was added dropwise while stirring the reaction mixture. After stirring for 24 h the resulting precipitate was filtered off, washed with small amounts of water and dried in vacuo. Compound (B3C) was obtained as a pink–white solid (yield 4.98 g, 66%) and was recrystallized from a methanol–acetonitrile solution (Solvent ratio?) by slowly evaporating the solvents to obtain crystals suitable for single-crystal X-ray diffraction.

S3. Refinement

H atoms were located in a difference Fourier map. N—H and O—H bond lengths for amino and carboxyl H atoms were restrained to be equal, respectively. Benzene rings and carboxylate groups were restrained to planarity. U_iso(H) = 1.5U_eq(parent).

Computing details

Data collection: APEX2 (Bruker 2007); cell refinement: SAINT (Bruker 2007); data reduction: SAINT (Bruker 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and pyMOL (DeLano, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The asymmetric unit of (B3C), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The hydrogen bonding of (B3C). Molecules form chains that are connected pairwise to each other. Symmetry-equivalent C atoms are depicted in a lighter shade. For symmetry operators, please refer to Table 2.

5-Amino-2,4,6-tribromoisophthalic acid

Crystal data

C8H4Br3NO4	F(000) = 3136
Mr = 417.85	Dx = 2.487 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ybc	Cell parameters from 9995 reflections
a = 16.728 (2) Å	θ = 2.7–73.4°
b = 11.449 (2) Å	µ = 13.44 mm^−1
c = 23.649 (3) Å	T = 100 K
β = 99.69 (3)°	Plate, colourless
V = 4464.6 (11) Å^3	0.10 × 0.10 × 0.05 mm
Z = 16

Data collection

Bruker SMART 6000 diffractometer	8717 independent reflections
Radiation source: rotating anode	8413 reflections with I > 2σ(I)
INCOATEC multilayer optics monochromator	Rint = 0.048
Detector resolution: 5.602 pixels mm^-1	θmax = 74.0°, θmin = 2.7°
ω scans	h = −20→20
Absorption correction: multi-scan (TWINABS; Sheldrick 1996)	k = −13→13
Tmin = 0.347, Tmax = 0.553	l = −28→27
97602 measured 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)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.064	H atoms treated by a mixture of independent and constrained refinement
S = 1.13	w = 1/[σ^2(Fo^2) + (0.0207P)^2 + 12.7819P] where P = (Fo^2 + 2Fc^2)/3
8717 reflections	(Δ/σ)max = 0.002
626 parameters	Δρmax = 0.64 e Å^−3
106 restraints	Δρmin = −0.55 e Å^−3

Special details

Experimental. Intensities were measured on a Bruker SMART 6000 area detector.

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 > 2 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. Only composite and single reflections from domain 1 were used for refinement (SHELXL option HKLF 5).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.76858 (3)	1.05153 (4)	0.838008 (17)	0.01823 (9)
Br2	0.90200 (3)	0.77141 (4)	1.029830 (19)	0.02257 (10)
Br3	0.56589 (3)	0.86912 (4)	0.98543 (2)	0.02519 (10)
Br4	0.64571 (3)	0.60368 (4)	0.904198 (19)	0.02267 (10)
Br5	0.56822 (3)	0.22804 (4)	0.749209 (18)	0.01939 (9)
Br6	0.89510 (3)	0.37978 (4)	0.809858 (19)	0.02070 (9)
Br7	0.30715 (3)	0.88711 (4)	0.893986 (19)	0.02120 (10)
Br8	0.31319 (3)	1.28060 (4)	0.749327 (18)	0.02129 (10)
Br9	0.01216 (3)	1.10091 (4)	0.79249 (2)	0.02637 (10)
Br10	0.15775 (3)	0.44910 (4)	0.841601 (17)	0.01817 (9)
Br11	0.11675 (3)	0.75056 (4)	1.026098 (19)	0.02112 (10)
Br12	0.43125 (3)	0.63902 (4)	0.98528 (2)	0.02353 (10)
C1	0.6798 (3)	0.9498 (3)	0.91806 (17)	0.0167 (8)
C2	0.7560 (3)	0.9621 (3)	0.90358 (17)	0.0160 (8)
C3	0.8230 (3)	0.9105 (3)	0.93721 (17)	0.0166 (8)
C4	0.8123 (2)	0.8504 (3)	0.98608 (17)	0.0155 (8)
C5	0.7365 (3)	0.8375 (3)	1.00379 (17)	0.0179 (8)
C6	0.6713 (2)	0.8890 (3)	0.96729 (17)	0.0178 (8)
C7	0.6050 (2)	1.0021 (4)	0.88183 (18)	0.0183 (8)
O8	0.57574 (19)	0.9368 (3)	0.83757 (13)	0.0238 (7)
H8	0.536 (2)	0.963 (5)	0.824 (2)	0.036*
O9	0.57613 (18)	1.0938 (3)	0.89427 (13)	0.0223 (6)
C10	0.9040 (2)	0.9133 (3)	0.91817 (17)	0.0162 (8)
O11	0.92055 (19)	0.8445 (3)	0.88246 (14)	0.0238 (7)
O12	0.95320 (19)	0.9935 (3)	0.94279 (14)	0.0232 (7)
H12	0.994 (2)	0.979 (5)	0.935 (2)	0.035*
N13	0.7277 (2)	0.7801 (4)	1.05272 (17)	0.0241 (8)
H13	0.6770 (16)	0.757 (4)	1.051 (2)	0.036*
H13A	0.769 (2)	0.745 (4)	1.073 (2)	0.036*
C21	0.7600 (3)	0.4797 (3)	0.85018 (16)	0.0162 (8)
C22	0.6789 (3)	0.4883 (3)	0.85471 (16)	0.0160 (8)
C23	0.6225 (2)	0.4136 (3)	0.82545 (16)	0.0153 (8)
C24	0.6476 (2)	0.3303 (3)	0.78926 (16)	0.0153 (8)
C25	0.7280 (3)	0.3201 (3)	0.78067 (16)	0.0159 (8)
C26	0.7833 (2)	0.3956 (3)	0.81371 (17)	0.0157 (8)
C27	0.8232 (2)	0.5593 (4)	0.88267 (17)	0.0166 (8)
O28	0.86495 (18)	0.5320 (3)	0.92774 (12)	0.0219 (6)
O29	0.8266 (2)	0.6583 (3)	0.85552 (14)	0.0260 (7)
H29	0.861 (3)	0.693 (5)	0.873 (2)	0.039*
C30	0.5351 (2)	0.4202 (3)	0.83260 (16)	0.0149 (8)
O31	0.51670 (18)	0.3518 (3)	0.87166 (13)	0.0203 (6)
H31	0.4737 (19)	0.355 (5)	0.878 (2)	0.031*
O32	0.48697 (19)	0.4879 (3)	0.80339 (13)	0.0247 (7)
N33	0.7523 (2)	0.2377 (3)	0.74472 (16)	0.0195 (7)
H33	0.8012 (18)	0.253 (5)	0.738 (2)	0.029*
H33A	0.716 (2)	0.200 (4)	0.7204 (18)	0.029*
C41	0.1668 (3)	1.0069 (4)	0.83694 (17)	0.0184 (8)
C42	0.2508 (3)	1.0023 (4)	0.84464 (17)	0.0177 (8)
C43	0.2945 (2)	1.0834 (3)	0.81878 (16)	0.0149 (8)
C44	0.2523 (3)	1.1710 (3)	0.78541 (16)	0.0178 (8)
C45	0.1678 (3)	1.1811 (3)	0.77678 (16)	0.0173 (8)
C46	0.1274 (2)	1.0955 (4)	0.80361 (16)	0.0166 (8)
C47	0.1197 (2)	0.9208 (4)	0.86638 (18)	0.0186 (8)
O48	0.09844 (19)	0.9431 (3)	0.91146 (13)	0.0256 (7)
O49	0.1056 (2)	0.8220 (3)	0.83753 (14)	0.0252 (7)
H49	0.085 (4)	0.780 (4)	0.855 (2)	0.038*
C50	0.3855 (3)	1.0774 (3)	0.82770 (17)	0.0167 (8)
O51	0.42168 (18)	1.0111 (3)	0.80107 (13)	0.0225 (6)
O52	0.41920 (18)	1.1482 (3)	0.86847 (13)	0.0202 (6)
H52	0.4648 (16)	1.141 (5)	0.876 (2)	0.030*
N53	0.1271 (2)	1.2725 (3)	0.74634 (15)	0.0191 (7)
H53	0.0747 (16)	1.258 (4)	0.736 (2)	0.029*
H53A	0.153 (2)	1.314 (4)	0.7235 (18)	0.029*
C61	0.2851 (3)	0.5531 (3)	0.92061 (17)	0.0154 (8)
C62	0.2014 (3)	0.5432 (3)	0.90586 (16)	0.0159 (8)
C63	0.1511 (2)	0.5998 (3)	0.93785 (16)	0.0147 (8)
C64	0.1848 (2)	0.6649 (3)	0.98473 (17)	0.0162 (8)
C65	0.2690 (3)	0.6774 (3)	1.00245 (17)	0.0168 (8)
C66	0.3172 (2)	0.6195 (3)	0.96801 (17)	0.0164 (8)
C67	0.3418 (2)	0.4961 (3)	0.88611 (18)	0.0164 (8)
O68	0.35356 (19)	0.5548 (3)	0.84175 (13)	0.0227 (6)
H68	0.388 (3)	0.531 (5)	0.829 (2)	0.034*
O69	0.37485 (18)	0.4021 (3)	0.90131 (14)	0.0230 (7)
C70	0.0602 (2)	0.5937 (4)	0.91988 (17)	0.0167 (8)
O71	0.02428 (18)	0.6549 (3)	0.88189 (13)	0.0208 (6)
O72	0.02670 (18)	0.5167 (3)	0.94889 (14)	0.0234 (7)
H72	−0.0190 (16)	0.519 (5)	0.939 (2)	0.035*
N73	0.3012 (2)	0.7405 (3)	1.04913 (16)	0.0225 (8)
H73	0.3514 (17)	0.753 (4)	1.047 (2)	0.034*
H73A	0.270 (3)	0.782 (4)	1.067 (2)	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0202 (2)	0.0166 (2)	0.0178 (2)	−0.00023 (17)	0.00283 (16)	0.00192 (15)
Br2	0.0189 (2)	0.0224 (2)	0.0254 (2)	0.00392 (18)	0.00083 (17)	0.00649 (17)
Br3	0.0160 (2)	0.0314 (3)	0.0297 (2)	−0.00180 (18)	0.00833 (18)	0.00217 (18)
Br4	0.0240 (2)	0.0191 (2)	0.0264 (2)	−0.00184 (18)	0.00865 (18)	−0.00984 (17)
Br5	0.0187 (2)	0.0186 (2)	0.0210 (2)	−0.00361 (17)	0.00377 (16)	−0.00653 (16)
Br6	0.0150 (2)	0.0251 (2)	0.0226 (2)	0.00129 (17)	0.00500 (16)	−0.00091 (16)
Br7	0.0194 (2)	0.0198 (2)	0.0236 (2)	0.00126 (17)	0.00142 (17)	0.00887 (16)
Br8	0.0246 (2)	0.0186 (2)	0.0201 (2)	−0.00439 (18)	0.00205 (17)	0.00556 (16)
Br9	0.0149 (2)	0.0312 (3)	0.0325 (3)	0.00459 (18)	0.00227 (18)	0.00300 (19)
Br10	0.0189 (2)	0.0190 (2)	0.0164 (2)	−0.00048 (17)	0.00248 (16)	−0.00463 (15)
Br11	0.0218 (2)	0.0214 (2)	0.0213 (2)	0.00409 (17)	0.00689 (17)	−0.00547 (16)
Br12	0.0139 (2)	0.0287 (2)	0.0274 (2)	−0.00256 (18)	0.00156 (17)	−0.00196 (17)
C1	0.0166 (19)	0.0145 (19)	0.018 (2)	−0.0018 (16)	0.0013 (16)	−0.0043 (15)
C2	0.020 (2)	0.0136 (19)	0.0159 (19)	0.0004 (16)	0.0056 (15)	−0.0017 (14)
C3	0.018 (2)	0.0130 (19)	0.019 (2)	−0.0001 (16)	0.0030 (15)	−0.0013 (15)
C4	0.0156 (19)	0.0124 (19)	0.0173 (19)	0.0003 (15)	−0.0002 (16)	0.0006 (14)
C5	0.020 (2)	0.015 (2)	0.020 (2)	−0.0030 (16)	0.0059 (16)	−0.0031 (15)
C6	0.0124 (18)	0.020 (2)	0.022 (2)	−0.0028 (16)	0.0058 (16)	−0.0012 (16)
C7	0.0134 (19)	0.020 (2)	0.022 (2)	−0.0045 (17)	0.0021 (16)	−0.0019 (16)
O8	0.0192 (15)	0.0243 (17)	0.0253 (16)	0.0034 (13)	−0.0042 (13)	−0.0069 (12)
O9	0.0175 (15)	0.0173 (15)	0.0300 (17)	0.0003 (12)	−0.0020 (12)	−0.0043 (12)
C10	0.017 (2)	0.0146 (19)	0.017 (2)	0.0008 (16)	0.0030 (15)	0.0020 (15)
O11	0.0214 (15)	0.0186 (15)	0.0329 (17)	−0.0014 (13)	0.0089 (13)	−0.0085 (13)
O12	0.0165 (15)	0.0291 (17)	0.0263 (16)	−0.0052 (13)	0.0102 (13)	−0.0105 (13)
N13	0.0220 (19)	0.027 (2)	0.025 (2)	−0.0006 (17)	0.0072 (15)	0.0065 (15)
C21	0.0188 (19)	0.015 (2)	0.0134 (19)	−0.0027 (16)	0.0002 (15)	0.0007 (14)
C22	0.0196 (19)	0.0140 (19)	0.0155 (19)	0.0002 (16)	0.0056 (15)	0.0012 (14)
C23	0.0152 (19)	0.016 (2)	0.0152 (19)	0.0038 (16)	0.0036 (15)	0.0029 (14)
C24	0.0176 (19)	0.0156 (19)	0.0121 (18)	−0.0027 (16)	0.0006 (15)	0.0016 (14)
C25	0.020 (2)	0.0147 (19)	0.0140 (19)	0.0024 (16)	0.0050 (15)	0.0016 (14)
C26	0.0101 (18)	0.017 (2)	0.020 (2)	0.0024 (15)	0.0020 (15)	0.0025 (15)
C27	0.0155 (19)	0.020 (2)	0.016 (2)	−0.0017 (16)	0.0073 (16)	−0.0004 (15)
O28	0.0191 (15)	0.0279 (17)	0.0188 (15)	−0.0031 (13)	0.0032 (12)	0.0025 (12)
O29	0.0306 (18)	0.0202 (16)	0.0246 (16)	−0.0105 (14)	−0.0029 (14)	0.0031 (12)
C30	0.0173 (19)	0.0135 (19)	0.0143 (19)	−0.0011 (15)	0.0041 (15)	−0.0049 (14)
O31	0.0181 (15)	0.0176 (15)	0.0276 (16)	−0.0001 (13)	0.0104 (13)	0.0038 (11)
O32	0.0229 (16)	0.0271 (17)	0.0244 (16)	0.0085 (13)	0.0049 (13)	0.0071 (12)
N33	0.0209 (18)	0.0167 (18)	0.0222 (19)	0.0022 (15)	0.0070 (15)	−0.0039 (13)
C41	0.019 (2)	0.018 (2)	0.019 (2)	−0.0024 (17)	0.0054 (16)	−0.0013 (15)
C42	0.019 (2)	0.018 (2)	0.016 (2)	0.0014 (17)	0.0028 (16)	−0.0002 (15)
C43	0.0136 (19)	0.0151 (19)	0.0163 (19)	−0.0004 (15)	0.0028 (15)	−0.0043 (14)
C44	0.024 (2)	0.016 (2)	0.0139 (19)	−0.0010 (17)	0.0036 (16)	−0.0032 (14)
C45	0.023 (2)	0.0133 (19)	0.0146 (19)	0.0040 (17)	−0.0001 (16)	−0.0019 (14)
C46	0.0111 (18)	0.020 (2)	0.018 (2)	−0.0005 (16)	0.0003 (15)	−0.0032 (15)
C47	0.0118 (18)	0.020 (2)	0.023 (2)	−0.0004 (16)	0.0008 (16)	0.0028 (16)
O48	0.0212 (16)	0.0351 (18)	0.0223 (17)	−0.0010 (14)	0.0092 (13)	0.0015 (13)
O49	0.0303 (17)	0.0230 (17)	0.0231 (16)	−0.0065 (14)	0.0068 (13)	0.0039 (12)
C50	0.020 (2)	0.016 (2)	0.0130 (19)	−0.0014 (17)	0.0012 (15)	0.0039 (14)
O51	0.0171 (14)	0.0282 (17)	0.0218 (15)	0.0026 (13)	0.0021 (12)	−0.0072 (12)
O52	0.0149 (14)	0.0211 (15)	0.0235 (15)	−0.0012 (13)	−0.0004 (12)	−0.0050 (12)
N53	0.0234 (18)	0.0152 (17)	0.0184 (18)	0.0033 (15)	0.0022 (14)	0.0022 (13)
C61	0.0174 (19)	0.0108 (19)	0.018 (2)	0.0014 (16)	0.0029 (16)	0.0024 (14)
C62	0.019 (2)	0.016 (2)	0.0131 (19)	0.0003 (16)	0.0030 (15)	0.0005 (14)
C63	0.0140 (19)	0.0143 (19)	0.0165 (19)	0.0002 (15)	0.0049 (15)	0.0032 (14)
C64	0.018 (2)	0.0134 (19)	0.018 (2)	0.0015 (16)	0.0076 (16)	−0.0006 (15)
C65	0.019 (2)	0.0137 (19)	0.018 (2)	−0.0008 (16)	0.0037 (16)	0.0008 (14)
C66	0.0108 (18)	0.017 (2)	0.022 (2)	−0.0021 (16)	0.0029 (15)	0.0035 (15)
C67	0.0132 (18)	0.015 (2)	0.021 (2)	−0.0015 (16)	0.0015 (15)	0.0010 (15)
O68	0.0205 (15)	0.0262 (17)	0.0237 (16)	0.0055 (13)	0.0107 (13)	0.0095 (12)
O69	0.0212 (15)	0.0193 (15)	0.0313 (17)	0.0023 (13)	0.0129 (13)	0.0054 (12)
C70	0.0149 (19)	0.018 (2)	0.018 (2)	0.0000 (16)	0.0058 (15)	−0.0056 (15)
O71	0.0188 (14)	0.0184 (15)	0.0242 (15)	−0.0003 (12)	0.0008 (12)	0.0053 (12)
O72	0.0131 (14)	0.0303 (17)	0.0272 (17)	−0.0033 (13)	0.0049 (12)	0.0092 (13)
N73	0.0217 (18)	0.024 (2)	0.0208 (19)	−0.0021 (16)	0.0008 (15)	−0.0084 (14)

Geometric parameters (Å, º)

Br1—C2	1.899 (4)	O29—H29	0.76 (3)
Br2—C4	1.902 (4)	C30—O32	1.240 (5)
Br3—C6	1.898 (4)	C30—O31	1.288 (5)
Br4—C22	1.908 (4)	O31—H31	0.76 (3)
Br5—C24	1.899 (4)	N33—H33	0.88 (2)
Br6—C26	1.897 (4)	N33—H33A	0.88 (2)
Br7—C42	1.903 (4)	C41—C46	1.382 (6)
Br8—C44	1.906 (4)	C41—C42	1.387 (6)
Br9—C46	1.903 (4)	C41—C47	1.504 (6)
Br10—C62	1.905 (4)	C42—C43	1.387 (6)
Br11—C64	1.895 (4)	C43—C44	1.393 (6)
Br12—C66	1.895 (4)	C43—C50	1.502 (6)
C1—C2	1.383 (6)	C44—C45	1.399 (6)
C1—C6	1.384 (6)	C45—N53	1.383 (5)
C1—C7	1.516 (6)	C45—C46	1.401 (6)
C2—C3	1.392 (6)	C47—O48	1.207 (5)
C3—C4	1.382 (6)	C47—O49	1.321 (5)
C3—C10	1.499 (6)	O49—H49	0.75 (3)
C4—C5	1.408 (6)	C50—O51	1.212 (5)
C5—N13	1.360 (6)	C50—O52	1.312 (5)
C5—C6	1.401 (6)	O52—H52	0.76 (3)
C7—O9	1.212 (5)	N53—H53	0.88 (2)
C7—O8	1.312 (5)	N53—H53A	0.88 (2)
O8—H8	0.75 (3)	C61—C66	1.386 (6)
C10—O11	1.219 (5)	C61—C62	1.390 (6)
C10—O12	1.303 (5)	C61—C67	1.500 (6)
O12—H12	0.76 (3)	C62—C63	1.383 (6)
N13—H13	0.88 (2)	C63—C64	1.375 (6)
N13—H13A	0.87 (2)	C63—C70	1.511 (5)
C21—C22	1.382 (6)	C64—C65	1.407 (6)
C21—C26	1.391 (6)	C65—N73	1.353 (5)
C21—C27	1.505 (6)	C65—C66	1.405 (6)
C22—C23	1.371 (6)	C67—O69	1.236 (5)
C23—C24	1.393 (6)	C67—O68	1.289 (5)
C23—C30	1.502 (5)	O68—H68	0.75 (3)
C24—C25	1.399 (6)	C70—O71	1.215 (5)
C25—N33	1.377 (5)	C70—O72	1.300 (5)
C25—C26	1.403 (6)	O72—H72	0.76 (3)
C27—O28	1.213 (5)	N73—H73	0.86 (2)
C27—O29	1.309 (5)	N73—H73A	0.86 (2)
C2—C1—C6	119.2 (4)	C46—C41—C42	118.5 (4)
C2—C1—C7	121.9 (4)	C46—C41—C47	120.6 (4)
C6—C1—C7	118.9 (4)	C42—C41—C47	120.8 (4)
C1—C2—C3	120.2 (4)	C43—C42—C41	121.0 (4)
C1—C2—Br1	119.4 (3)	C43—C42—Br7	119.4 (3)
C3—C2—Br1	120.4 (3)	C41—C42—Br7	119.5 (3)
C4—C3—C2	118.9 (4)	C42—C43—C44	118.5 (4)
C4—C3—C10	120.9 (4)	C42—C43—C50	120.3 (4)
C2—C3—C10	120.1 (4)	C44—C43—C50	121.2 (4)
C3—C4—C5	123.4 (4)	C43—C44—C45	123.1 (4)
C3—C4—Br2	119.3 (3)	C43—C44—Br8	118.0 (3)
C5—C4—Br2	117.1 (3)	C45—C44—Br8	118.9 (3)
N13—C5—C6	122.9 (4)	N53—C45—C44	122.4 (4)
N13—C5—C4	122.3 (4)	N53—C45—C46	122.2 (4)
C6—C5—C4	114.7 (4)	C44—C45—C46	115.4 (4)
C1—C6—C5	123.4 (4)	C41—C46—C45	123.5 (4)
C1—C6—Br3	118.7 (3)	C41—C46—Br9	118.5 (3)
C5—C6—Br3	117.8 (3)	C45—C46—Br9	118.0 (3)
O9—C7—O8	125.3 (4)	O48—C47—O49	125.7 (4)
O9—C7—C1	122.0 (4)	O48—C47—C41	121.7 (4)
O8—C7—C1	112.8 (4)	O49—C47—C41	112.6 (4)
C7—O8—H8	107 (5)	C47—O49—H49	108 (5)
O11—C10—O12	124.4 (4)	O51—C50—O52	125.3 (4)
O11—C10—C3	121.1 (4)	O51—C50—C43	122.6 (4)
O12—C10—C3	114.5 (3)	O52—C50—C43	112.0 (4)
C10—O12—H12	105 (5)	C50—O52—H52	113 (4)
C5—N13—H13	111 (3)	C45—N53—H53	112 (3)
C5—N13—H13A	121 (4)	C45—N53—H53A	118 (3)
H13—N13—H13A	123 (4)	H53—N53—H53A	120 (3)
C22—C21—C26	118.6 (4)	C66—C61—C62	119.0 (4)
C22—C21—C27	122.1 (4)	C66—C61—C67	119.0 (4)
C26—C21—C27	119.3 (4)	C62—C61—C67	122.0 (4)
C23—C22—C21	121.1 (4)	C63—C62—C61	120.2 (4)
C23—C22—Br4	119.7 (3)	C63—C62—Br10	121.0 (3)
C21—C22—Br4	119.2 (3)	C61—C62—Br10	118.8 (3)
C22—C23—C24	119.0 (4)	C64—C63—C62	119.4 (4)
C22—C23—C30	120.8 (4)	C64—C63—C70	120.5 (4)
C24—C23—C30	120.2 (4)	C62—C63—C70	120.0 (4)
C23—C24—C25	122.9 (4)	C63—C64—C65	123.3 (4)
C23—C24—Br5	118.1 (3)	C63—C64—Br11	119.8 (3)
C25—C24—Br5	119.0 (3)	C65—C64—Br11	116.9 (3)
N33—C25—C24	122.6 (4)	N73—C65—C66	122.4 (4)
N33—C25—C26	122.0 (4)	N73—C65—C64	122.5 (4)
C24—C25—C26	115.3 (4)	C66—C65—C64	115.0 (4)
C21—C26—C25	123.0 (4)	C61—C66—C65	123.0 (4)
C21—C26—Br6	118.5 (3)	C61—C66—Br12	118.5 (3)
C25—C26—Br6	118.5 (3)	C65—C66—Br12	118.4 (3)
O28—C27—O29	126.0 (4)	O69—C67—O68	124.7 (4)
O28—C27—C21	123.0 (4)	O69—C67—C61	120.9 (4)
O29—C27—C21	111.0 (3)	O68—C67—C61	114.4 (3)
C27—O29—H29	107 (5)	C67—O68—H68	112 (5)
O32—C30—O31	124.6 (4)	O71—C70—O72	125.3 (4)
O32—C30—C23	121.5 (4)	O71—C70—C63	122.0 (4)
O31—C30—C23	113.9 (3)	O72—C70—C63	112.7 (3)
C30—O31—H31	117 (4)	C70—O72—H72	109 (5)
C25—N33—H33	111 (3)	C65—N73—H73	107 (4)
C25—N33—H33A	120 (3)	C65—N73—H73A	120 (4)
H33—N33—H33A	122 (3)	H73—N73—H73A	128 (4)
C6—C1—C2—C3	2.1 (6)	C46—C41—C42—C43	−1.1 (6)
C7—C1—C2—C3	−178.5 (4)	C47—C41—C42—C43	−178.3 (4)
C6—C1—C2—Br1	−177.1 (3)	C46—C41—C42—Br7	176.2 (3)
C7—C1—C2—Br1	2.3 (5)	C47—C41—C42—Br7	−1.0 (5)
C1—C2—C3—C4	−2.1 (5)	C41—C42—C43—C44	0.9 (5)
Br1—C2—C3—C4	177.1 (3)	Br7—C42—C43—C44	−176.4 (3)
C1—C2—C3—C10	173.6 (4)	C41—C42—C43—C50	179.8 (4)
Br1—C2—C3—C10	−7.2 (5)	Br7—C42—C43—C50	2.5 (5)
C2—C3—C4—C5	0.5 (6)	C42—C43—C44—C45	0.1 (5)
C10—C3—C4—C5	−175.2 (4)	C50—C43—C44—C45	−178.9 (4)
C2—C3—C4—Br2	176.2 (3)	C42—C43—C44—Br8	−179.2 (3)
C10—C3—C4—Br2	0.5 (5)	C50—C43—C44—Br8	1.9 (5)
C3—C4—C5—N13	−178.6 (4)	C43—C44—C45—N53	176.1 (4)
Br2—C4—C5—N13	5.6 (5)	Br8—C44—C45—N53	−4.7 (5)
C3—C4—C5—C6	1.0 (5)	C43—C44—C45—C46	−0.7 (5)
Br2—C4—C5—C6	−174.7 (3)	Br8—C44—C45—C46	178.5 (3)
C2—C1—C6—C5	−0.4 (6)	C42—C41—C46—C45	0.3 (6)
C7—C1—C6—C5	−179.9 (4)	C47—C41—C46—C45	177.5 (4)
C2—C1—C6—Br3	−178.2 (3)	C42—C41—C46—Br9	179.4 (3)
C7—C1—C6—Br3	2.3 (5)	C47—C41—C46—Br9	−3.4 (5)
N13—C5—C6—C1	178.6 (4)	N53—C45—C46—C41	−176.3 (4)
C4—C5—C6—C1	−1.1 (5)	C44—C45—C46—C41	0.5 (5)
N13—C5—C6—Br3	−3.6 (5)	N53—C45—C46—Br9	4.6 (5)
C4—C5—C6—Br3	176.7 (3)	C44—C45—C46—Br9	−178.6 (3)
C2—C1—C7—O9	−99.1 (5)	C46—C41—C47—O48	−82.0 (5)
C6—C1—C7—O9	80.3 (5)	C42—C41—C47—O48	95.1 (5)
C2—C1—C7—O8	82.0 (5)	C46—C41—C47—O49	98.1 (4)
C6—C1—C7—O8	−98.6 (4)	C42—C41—C47—O49	−84.7 (5)
C4—C3—C10—O11	95.5 (5)	C42—C43—C50—O51	80.9 (5)
C2—C3—C10—O11	−80.2 (5)	C44—C43—C50—O51	−100.2 (5)
C4—C3—C10—O12	−84.5 (5)	C42—C43—C50—O52	−96.8 (4)
C2—C3—C10—O12	99.8 (4)	C44—C43—C50—O52	82.2 (4)
C26—C21—C22—C23	2.0 (6)	C66—C61—C62—C63	0.6 (5)
C27—C21—C22—C23	−178.9 (4)	C67—C61—C62—C63	−178.1 (4)
C26—C21—C22—Br4	−179.7 (3)	C66—C61—C62—Br10	−178.7 (3)
C27—C21—C22—Br4	−0.6 (5)	C67—C61—C62—Br10	2.5 (5)
C21—C22—C23—C24	−2.0 (5)	C61—C62—C63—C64	−0.8 (5)
Br4—C22—C23—C24	179.7 (3)	Br10—C62—C63—C64	178.6 (3)
C21—C22—C23—C30	177.3 (4)	C61—C62—C63—C70	176.9 (4)
Br4—C22—C23—C30	−1.0 (5)	Br10—C62—C63—C70	−3.8 (5)
C22—C23—C24—C25	−0.9 (5)	C62—C63—C64—C65	−0.1 (6)
C30—C23—C24—C25	179.8 (4)	C70—C63—C64—C65	−177.7 (4)
C22—C23—C24—Br5	−180.0 (3)	C62—C63—C64—Br11	176.2 (3)
C30—C23—C24—Br5	0.7 (5)	C70—C63—C64—Br11	−1.5 (5)
C23—C24—C25—N33	−179.9 (4)	C63—C64—C65—N73	−179.2 (4)
Br5—C24—C25—N33	−0.8 (5)	Br11—C64—C65—N73	4.5 (5)
C23—C24—C25—C26	3.5 (5)	C63—C64—C65—C66	1.0 (5)
Br5—C24—C25—C26	−177.4 (3)	Br11—C64—C65—C66	−175.4 (3)
C22—C21—C26—C25	0.9 (6)	C62—C61—C66—C65	0.4 (5)
C27—C21—C26—C25	−178.2 (4)	C67—C61—C66—C65	179.2 (4)
C22—C21—C26—Br6	−177.6 (3)	C62—C61—C66—Br12	−176.8 (3)
C27—C21—C26—Br6	3.4 (5)	C67—C61—C66—Br12	2.0 (5)
N33—C25—C26—C21	179.8 (4)	N73—C65—C66—C61	179.0 (4)
C24—C25—C26—C21	−3.5 (5)	C64—C65—C66—C61	−1.1 (5)
N33—C25—C26—Br6	−1.7 (5)	N73—C65—C66—Br12	−3.9 (5)
C24—C25—C26—Br6	174.9 (3)	C64—C65—C66—Br12	176.0 (3)
C22—C21—C27—O28	97.1 (5)	C66—C61—C67—O69	82.4 (5)
C26—C21—C27—O28	−83.8 (5)	C62—C61—C67—O69	−98.9 (5)
C22—C21—C27—O29	−83.4 (5)	C66—C61—C67—O68	−95.8 (4)
C26—C21—C27—O29	95.7 (4)	C62—C61—C67—O68	83.0 (5)
C22—C23—C30—O32	86.2 (5)	C64—C63—C70—O71	97.8 (5)
C24—C23—C30—O32	−94.5 (5)	C62—C63—C70—O71	−79.8 (5)
C22—C23—C30—O31	−92.7 (4)	C64—C63—C70—O72	−82.8 (5)
C24—C23—C30—O31	86.6 (4)	C62—C63—C70—O72	99.6 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8···O51	0.75 (3)	1.97 (3)	2.713 (4)	167 (6)
O12—H12···O48^i	0.76 (3)	1.96 (3)	2.719 (4)	177 (6)
O52—H52···O9	0.76 (3)	1.92 (3)	2.667 (4)	170 (6)
O49—H49···O71	0.75 (3)	1.93 (3)	2.664 (4)	165 (7)
O31—H31···O69	0.76 (3)	1.91 (3)	2.649 (4)	165 (6)
O68—H68···O32	0.75 (3)	1.91 (3)	2.659 (4)	171 (6)
O72—H72···O28^ii	0.76 (3)	1.92 (3)	2.673 (4)	171 (6)
O29—H29···O11	0.76 (3)	1.99 (4)	2.662 (4)	147 (6)
N33—H33A···O68^iii	0.88 (2)	2.39 (3)	3.237 (5)	164 (5)

Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z; (iii) −x+1, y−1/2, −z+3/2.