Secondary interactions in 3-bromo­pyridinium tri­bromo­acetate

The title compound, C₅H₅BrN⁺·C₂Br₃O₂⁻, crystallizes with Z′ = 2. The residues pack in two distinct (but interconnected) types of layer, namely, layers parallel to (102), in which the residues are connected by classical N—H...O hydrogen bonds, C—H...O interactions and Br...Br contacts, and anion layers parallel to the ab plane, connected by Br...O interactions. The two formula units are topologically equivalent with respect to all these contacts.

S1. Comment

We are interested in secondary bonding contacts (classical and `weak' hydrogen bonds, and halogen-halogen contacts) in structures of pyridine derivatives, such as 4-iodopyridine (Ahrens & Jones, 1999), hydroxypyridines and pyridones (Jones, 2001; Flakus et al., 2003), pyridinethiones (Flakus et al., 2001), halopyridinium halides (Freytag et al., 1999; Freytag & Jones, 2001; Jones & Lozano, 2003a) and halomethylpyridinium halides (Jones et al., 2002; Jones & Vancea, 2003; Lozano & Jones, 2004). We considered it worthwhile to extend our studies by using halogen-rich anions rather than simple halides, and here report the structure of 3-bromopyridinium tribromoacetate, (I). This is the first structure involving a free tribromoacetate ion; a search of the Cambridge Database (CSD, Version 7/04; Allen, 2002) revealed one structure with a tribromoacetate ligand in a copper(II) complex (CIYFUL; Porter & Doedens, 1984). \sch

The asymmetric unit of (I) contains two formula units (Fig. 1), both consisting of a cation-anion pair linked by a classical N—H···O hydrogen bond. Atom names of the second formula unit are distinguished by an additional initial digit 1. Bond lengths and angles may be considered normal, e.g. the somewhat widened ring angles at N, or the C—Br bond lengths of the anion, which are closely similar to those of the free acid (Jones & Lozano, 2003b). The C—O bond lengths differ significantly, those involving the hydrogen-bonded atoms O1 and O11 being longer (Table 1). Both anions adopt a conformation in which one Br atom (Br2 or Br12) lies in the carboxylate plane, with Br—C—C—O torsion angles 2.3 (4) and −1.7 (4)° [cf. −16.4 (3)° in the free acid; Jones & Lozano, 2003b].

The crystal packing of (I) appears at first sight to be a complex three-dimensional network, but can be analysed in terms of two (interconnected) layer structures associated with different types of non-bonded contacts. The first such layer type (Fig. 2), parallel to (102), involves the classical hydrogen bonds, two very short C—H···O interactions (normalized H···O distances 2.27 and 2.31 Å) from the H atoms at C6 and C16 (Table 2), and the four shortest Br···Br contacts (Table 3). The carboxylate atoms O1 and O11 represent bifurcated systems, each accepting one N—H···O and one C—H···O hydrogen bond. The hydrogen bonds of each of the two formula units combine to form independent ten-membered? centrosymmetric rings of graph set R₄²(10).

Each cation Br atom (Br1 or Br11) is involved in two Br···Br contacts, to an anion Br of two different anions of the other respective formula unit (Br12 and Br13, and Br2 and Br4). This results in two independent eight-membered rings. The ten- and eight-membered rings alternate to connect cations, forming chains in the direction [210] (horizontal in Fig. 2), whereby each cation has its own independent chain. The two independent anions alternate in the same direction.

All four Br···Br contacts correspond approximately to `type II', according to the classification of Pedireddi et al. (1994), with one C—Br···Br angle of ca 180° and one of ca 90°. This is consistent with the concept of a region of positive charge in the extension of the C—Br vector beyond the Br atom, which interacts with the negative region perpendicular to the C—Br bond of the second Br atom. The Br atoms in the cations would be expected to have enhanced positive charge regions and thus preferentially form linear contacts, but, clearly, only one contact from Br1 or Br11 can be linear, and the respective second contacts are therefore linear at Br12 and Br2.

The second layer type in the structure of (I) is associated with Br···O contacts. These may be regarded as a type of `halogen bond' (Metrangelo & Resnati, 2001). We had expected these to be formed between cations and anions (charge-assisted contacts) but were surprised to observe, despite the unfavourable electrostatic effects, that the anions associate amongst themselves. We have, however, frequently observed a similar effect with C—H···O contacts between di(methanesulfonyl)amide anions (e.g. Moers Lange et al., 2001; Moers Wijaya et al., 2001; Henschel et al., 2002).

The independent anions alternate in chains parallel to the b axis, and these chains are linked by translation along a to form a layer, consisting of two independent but topologically identical types of 12-membered ring, parallel to the ab plane (Fig. 3). The four independent contacts (Table 3) involve those Br atoms not coplanar with the carboxylate groups (Br3, Br4, Br13 and Br14), together with the O atoms not involved in hydrogen bonds (O2 and O12, both double acceptors), and are all short: cf. 3.009 (2) Å in tribromoacetic acid (Jones & Lozano, 2003b), 2.974 (4) Å in sodium bromate (Abrahams & Bernstein, 1977), or 3.197 (3)–3.338 (4) Å in two modifications of di(4-bromobenzenesulfonyl)amine (Lozano et al., 2004). All C—Br···O angles are, as expected (Lommerse et al., 1996), approximately linear. For Br4 and Br13, this complements their perpendicular Br···Br—C angles, whereas Br2 and Br12 (and of course Br1 and Br11 of the cations) have already `used up' their linear contacts in the Br···Br interactions (see above), and thus are no longer available for Br···O contacts. The Br···O—C angles are close to the expected values of 120°, corresponding to the lone-pair directions, but this is not always the case, as pointed out by Lommerse et al. (1996).

There are also two approximately linear C—H···Br contacts that might be regarded as weak hydrogen bonds. These connect neighbouring layers parallel to (102), but we attribute to them a subordinate role in determining the packing. Two further such contacts, but with very narrow angles, are included in Table 2 for completeness.

There is considerable current interest in structures with Z' > 1, in view of their implications for crystal engineering (see, for example, Steed, 2003). We note that, neglecting the C—H···Br interactions, the two formula units of (I) are exactly equivalent in their topology; each secondary contact finds a topological counterpart on exchanging the atoms of the two formula units. Thus, there is no obvious explanation for the Z' value of 2.

S2. Experimental

A solution of 3-bromopyridine (0.24 ml, 2.5 mmol) and tribromoacetic acid (0.742 g, 2.5 mmol) in dichloromethane (10 ml) was stirred for 1 h and the product, (I), was precipitated (0.523 g, Please give % yield) by adding petroleum ether (b.p. 313–333 K). Text changed by Coeditor - please check. Single crystals were obtained by diffusion of petroleum ether (b.p. 313–333 K) into a dichloromethane solution of (I).

S3. Refinement

The H atoms bonded to N were refined freely. Other H atoms were included using a riding model, with C—H distances of 0.95 Å and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The formula unit of (I) in the crystal. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Dashed lines represent hydrogen bonds.
	Fig. 2. A packing diagram for (I), illustrating the layer structure formed via classical hydrogen bonds, C—H···O interactions and Br···Br contacts (all shown as dashed lines), viewed perpendicular to (102). H atoms not involved in hydrogen bonds have been omitted for clarity. Atom Br2 is at the symmetry position (1 − x, 1 − y, 1 − z), Br4 and C6 are at (1 + x, y, z), Br1, N1 and O1 are at (1 − x, 1 − y, −z), and Br13 is at (-x, 2 − y, −z). Other labelled atoms are those of the asymmetric unit.
	Fig. 3. A packing diagram for (I), illustrating the tribromoacetate network at c ≈ 1/4, viewed perpendicular to the ab plane. Dashed lines indicate Br···O interactions. All labelled atoms are those of the reference asymmetric unit.

3-bromopyridinium tribromoacetate

Crystal data

C5H5BrN^+·C2Br3O2^−	Z = 4
Mr = 454.76	F(000) = 840
Triclinic, P1	Dx = 2.583 Mg m^−3
a = 6.2478 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 12.6754 (8) Å	Cell parameters from 7447 reflections
c = 15.4525 (8) Å	θ = 2.3–30.5°
α = 96.520 (4)°	µ = 13.74 mm^−1
β = 95.900 (4)°	T = 133 K
γ = 103.883 (4)°	Tablet, colourless
V = 1169.53 (12) Å^3	0.16 × 0.13 × 0.07 mm

Data collection

Bruker SMART1000 CCD area-detector diffractometer	6811 independent reflections
Radiation source: fine-focus sealed tube	5031 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
Detector resolution: 8.192 pixels mm^-1	θmax = 30.0°, θmin = 1.3°
ω and ϕ scans	h = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 1998)	k = −17→17
Tmin = 0.168, Tmax = 0.382	l = −21→21
22507 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)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.056	H atoms treated by a mixture of independent and constrained refinement
S = 0.92	w = 1/[σ^2(Fo^2) + (0.0219P)^2] where P = (Fo^2 + 2Fc^2)/3
6811 reflections	(Δ/σ)max = 0.002
261 parameters	Δρmax = 0.74 e Å^−3
0 restraints	Δρmin = −0.92 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Non-bonded contacts:

3.5778 (0.0005) Br1 - Br12_$5 3.6359 (0.0005) Br1 - Br13_$6 3.6935 (0.0005) Br11 - Br2_$7 3.8880 (0.0005) Br11 - Br3_$2 3.7098 (0.0005) Br11 - Br4_$2 3.9196 (0.0007) Br2 - Br2_$8 2.8475 (0.0023) Br13 - O2_$9 2.8486 (0.0022) Br14 - O12_$10 2.8081 (0.0022) Br3 - O2_$10 2.8334 (0.0023) Br4 - O12

102.52 (0.09) C3 - Br1 - Br12_$5 159.82 (0.09) Br1 - Br12_$5 - C17_$5 146.18 (0.10) C3 - Br1 - Br13_$6 92.73 (0.09) Br1 - Br13_$6 - C17_$6 101.64 (0.10) C13 - Br11 - Br2_$7 158.19 (0.09) Br11 - Br2_$7 - C7_$7 136.98 (0.09) C13 - Br11 - Br3_$2 82.47 (0.09) Br11 - Br3_$2 - C7_$2 152.47 (0.10) C13 - Br11 - Br4_$2 87.52 (0.08) Br11 - Br4_$2 - C7_$2 128.26 (0.08) C7 - Br2 - Br2_$8 167.68 (0.10) C17 - Br13 - O2_$9 129.19 (1/5) Br13 - O2_$9 - C8_$9 171.23 (0.10) C17 - Br14 - O12_$10 125.27 (1/5) Br14 - O12_$10 - C18_$10 177.49 (0.10) C7 - Br3 - O2_$10 123.45 (1/5) Br3 - O2_$10 - C8_$10 174.90 (0.10) C7 - Br4 - O12 124.54 (1/5) Br4 - O12 - C18

Operators for generating equivalent atoms:

$2 x + 1, y, z $5 − x + 1, −y + 1, −z $6 x + 1, y − 1, z $7 − x + 1, −y + 1, −z + 1 $8 − x, −y + 1, −z + 1 $9 x, y + 1, z $10 x − 1, y, z

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

	x	y	z	Uiso*/Ueq
N1	0.2666 (5)	0.3606 (2)	0.01628 (18)	0.0195 (6)
H01	0.192 (6)	0.385 (3)	0.043 (3)	0.036 (12)*
C2	0.3737 (5)	0.2933 (3)	0.0520 (2)	0.0206 (7)
H2	0.3457	0.2725	0.1077	0.025*
C3	0.5245 (5)	0.2545 (3)	0.0073 (2)	0.0206 (7)
C4	0.5639 (5)	0.2848 (3)	−0.0737 (2)	0.0222 (7)
H4	0.6707	0.2597	−0.1044	0.027*
C5	0.4455 (5)	0.3524 (3)	−0.1098 (2)	0.0249 (7)
H5	0.4669	0.3725	−0.1662	0.030*
C6	0.2956 (5)	0.3903 (3)	−0.0625 (2)	0.0228 (7)
H6	0.2141	0.4372	−0.0862	0.027*
Br1	0.67862 (7)	0.16420 (4)	0.06202 (2)	0.03651 (10)
N11	0.3039 (5)	0.8782 (2)	0.48251 (18)	0.0201 (6)
H011	0.245 (6)	0.914 (3)	0.453 (3)	0.042 (13)*
C12	0.4472 (5)	0.8286 (3)	0.4468 (2)	0.0197 (7)
H12	0.4845	0.8404	0.3899	0.024*
C13	0.5396 (5)	0.7606 (3)	0.4933 (2)	0.0187 (7)
C14	0.4851 (5)	0.7427 (3)	0.5762 (2)	0.0233 (7)
H14	0.5469	0.6949	0.6082	0.028*
C15	0.3367 (5)	0.7972 (3)	0.6111 (2)	0.0243 (7)
H15	0.2986	0.7881	0.6682	0.029*
C16	0.2454 (5)	0.8643 (3)	0.5622 (2)	0.0226 (7)
H16	0.1419	0.9003	0.5850	0.027*
Br11	0.73370 (6)	0.68930 (3)	0.43950 (2)	0.03000 (9)
C7	0.0055 (5)	0.4965 (3)	0.27340 (19)	0.0170 (6)
C8	0.0984 (5)	0.4347 (3)	0.1980 (2)	0.0175 (6)
Br2	0.11141 (6)	0.46883 (3)	0.38836 (2)	0.02665 (8)
Br3	−0.31699 (5)	0.44636 (3)	0.25431 (2)	0.01900 (7)
Br4	0.09679 (5)	0.65316 (3)	0.26887 (2)	0.02019 (7)
O1	0.0379 (4)	0.45329 (19)	0.12177 (14)	0.0241 (5)
O2	0.2172 (3)	0.37511 (19)	0.21896 (14)	0.0224 (5)
C17	−0.0025 (5)	0.9897 (3)	0.2265 (2)	0.0184 (7)
C18	0.1295 (5)	0.9479 (3)	0.3003 (2)	0.0192 (7)
Br12	0.04550 (6)	0.93276 (3)	0.11044 (2)	0.02841 (9)
Br13	0.09443 (5)	1.14903 (3)	0.23974 (2)	0.02129 (8)
Br14	−0.31807 (5)	0.94628 (3)	0.23634 (2)	0.02114 (8)
O11	0.1076 (4)	0.9856 (2)	0.37772 (14)	0.0270 (6)
O12	0.2401 (3)	0.88441 (18)	0.27873 (14)	0.0228 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0197 (14)	0.0222 (16)	0.0168 (14)	0.0082 (12)	0.0023 (11)	−0.0022 (11)
C2	0.0255 (17)	0.0219 (18)	0.0147 (16)	0.0072 (14)	0.0014 (12)	0.0031 (13)
C3	0.0244 (17)	0.0226 (18)	0.0156 (16)	0.0102 (14)	−0.0012 (13)	0.0006 (13)
C4	0.0207 (16)	0.026 (2)	0.0216 (17)	0.0102 (14)	0.0049 (13)	0.0009 (14)
C5	0.0278 (18)	0.033 (2)	0.0172 (17)	0.0119 (16)	0.0047 (13)	0.0053 (14)
C6	0.0273 (17)	0.0215 (19)	0.0226 (18)	0.0108 (15)	0.0028 (13)	0.0062 (14)
Br1	0.0506 (2)	0.0499 (3)	0.02473 (19)	0.0372 (2)	0.00974 (16)	0.01408 (17)
N11	0.0239 (15)	0.0193 (16)	0.0171 (14)	0.0070 (12)	−0.0025 (11)	0.0035 (12)
C12	0.0204 (16)	0.0226 (18)	0.0149 (15)	0.0028 (14)	0.0016 (12)	0.0040 (13)
C13	0.0162 (15)	0.0216 (18)	0.0181 (16)	0.0066 (14)	0.0014 (12)	−0.0008 (13)
C14	0.0260 (17)	0.0242 (19)	0.0219 (17)	0.0099 (15)	0.0013 (13)	0.0070 (14)
C15	0.0280 (18)	0.029 (2)	0.0175 (17)	0.0098 (16)	0.0021 (13)	0.0046 (14)
C16	0.0229 (17)	0.027 (2)	0.0189 (17)	0.0115 (15)	0.0001 (13)	0.0005 (14)
Br11	0.02916 (19)	0.0413 (2)	0.02469 (18)	0.02035 (17)	0.00437 (14)	0.00094 (16)
C7	0.0181 (15)	0.0197 (17)	0.0155 (15)	0.0081 (13)	0.0033 (12)	0.0031 (12)
C8	0.0160 (15)	0.0184 (17)	0.0181 (16)	0.0038 (13)	0.0052 (12)	0.0012 (13)
Br2	0.02926 (18)	0.0357 (2)	0.01615 (16)	0.01032 (16)	−0.00010 (13)	0.00693 (14)
Br3	0.01718 (15)	0.02202 (18)	0.01901 (16)	0.00580 (13)	0.00379 (11)	0.00497 (13)
Br4	0.02246 (16)	0.01767 (17)	0.02020 (16)	0.00479 (13)	0.00483 (12)	0.00065 (13)
O1	0.0301 (13)	0.0309 (14)	0.0163 (12)	0.0162 (11)	0.0062 (9)	0.0033 (10)
O2	0.0216 (12)	0.0252 (13)	0.0240 (12)	0.0119 (10)	0.0036 (9)	0.0046 (10)
C17	0.0183 (15)	0.0213 (18)	0.0168 (16)	0.0069 (13)	0.0031 (12)	0.0031 (13)
C18	0.0172 (15)	0.0183 (18)	0.0230 (17)	0.0038 (13)	0.0023 (12)	0.0088 (13)
Br12	0.03159 (19)	0.0393 (2)	0.01593 (16)	0.01265 (16)	0.00574 (13)	0.00050 (15)
Br13	0.02167 (16)	0.02090 (18)	0.02279 (17)	0.00629 (14)	0.00176 (12)	0.00858 (13)
Br14	0.01768 (15)	0.02442 (19)	0.02086 (17)	0.00505 (13)	0.00244 (12)	0.00219 (13)
O11	0.0381 (14)	0.0343 (15)	0.0168 (12)	0.0235 (12)	0.0029 (10)	0.0079 (10)
O12	0.0227 (12)	0.0235 (13)	0.0261 (13)	0.0113 (10)	0.0048 (9)	0.0065 (10)

Geometric parameters (Å, º)

N1—C6	1.332 (4)	C8—O2	1.225 (4)
N1—C2	1.336 (4)	C8—O1	1.265 (4)
C2—C3	1.373 (4)	C17—C18	1.553 (4)
C3—C4	1.380 (4)	C17—Br12	1.937 (3)
C3—Br1	1.880 (3)	C17—Br13	1.944 (3)
C4—C5	1.385 (5)	C17—Br14	1.943 (3)
C5—C6	1.385 (4)	C18—O12	1.221 (3)
N11—C16	1.339 (4)	C18—O11	1.270 (4)
N11—C12	1.340 (4)	N1—H01	0.75 (3)
C12—C13	1.374 (4)	C2—H2	0.9500
C13—C14	1.388 (4)	C4—H4	0.9500
C13—Br11	1.881 (3)	C5—H5	0.9500
C14—C15	1.398 (4)	C6—H6	0.9500
C15—C16	1.382 (4)	N11—H011	0.80 (4)
C7—C8	1.567 (4)	C12—H12	0.9500
C7—Br2	1.931 (3)	C14—H14	0.9500
C7—Br3	1.942 (3)	C15—H15	0.9500
C7—Br4	1.941 (3)	C16—H16	0.9500
C6—N1—C2	122.8 (3)	Br12—C17—Br14	109.16 (15)
N1—C2—C3	119.4 (3)	C18—C17—Br13	109.3 (2)
C2—C3—C4	120.1 (3)	Br12—C17—Br13	107.78 (15)
C2—C3—Br1	117.8 (2)	Br14—C17—Br13	109.01 (14)
C4—C3—Br1	122.1 (2)	O12—C18—O11	127.5 (3)
C3—C4—C5	119.0 (3)	O12—C18—C17	118.2 (3)
C6—C5—C4	119.3 (3)	O11—C18—C17	114.3 (3)
N1—C6—C5	119.5 (3)	C6—N1—H01	119 (3)
C16—N11—C12	122.8 (3)	C2—N1—H01	119 (3)
N11—C12—C13	119.2 (3)	N1—C2—H2	120.3
C12—C13—C14	120.7 (3)	C3—C2—H2	120.3
C12—C13—Br11	117.9 (2)	C3—C4—H4	120.5
C14—C13—Br11	121.4 (2)	C5—C4—H4	120.5
C13—C14—C15	118.0 (3)	C6—C5—H5	120.4
C16—C15—C14	119.8 (3)	C4—C5—H5	120.4
N11—C16—C15	119.5 (3)	N1—C6—H6	120.2
C8—C7—Br2	112.4 (2)	C5—C6—H6	120.2
C8—C7—Br4	108.9 (2)	C16—N11—H011	120 (3)
Br2—C7—Br4	108.89 (15)	C12—N11—H011	117 (3)
C8—C7—Br3	108.22 (19)	N11—C12—H12	120.4
Br2—C7—Br3	108.63 (14)	C13—C12—H12	120.4
Br4—C7—Br3	109.83 (14)	C13—C14—H14	121.0
O2—C8—O1	128.1 (3)	C15—C14—H14	121.0
O2—C8—C7	117.6 (3)	C16—C15—H15	120.1
O1—C8—C7	114.3 (3)	C14—C15—H15	120.1
C18—C17—Br12	112.1 (2)	N11—C16—H16	120.2
C18—C17—Br14	109.5 (2)	C15—C16—H16	120.2
C6—N1—C2—C3	1.6 (5)	C12—N11—C16—C15	0.7 (5)
N1—C2—C3—C4	−0.2 (5)	C14—C15—C16—N11	−1.4 (5)
N1—C2—C3—Br1	177.8 (2)	Br2—C7—C8—O2	2.3 (4)
C2—C3—C4—C5	−1.5 (5)	Br4—C7—C8—O2	123.0 (3)
Br1—C3—C4—C5	−179.4 (2)	Br3—C7—C8—O2	−117.7 (3)
C3—C4—C5—C6	1.8 (5)	Br2—C7—C8—O1	−178.0 (2)
C2—N1—C6—C5	−1.2 (5)	Br4—C7—C8—O1	−57.3 (3)
C4—C5—C6—N1	−0.5 (5)	Br3—C7—C8—O1	62.0 (3)
C16—N11—C12—C13	−0.1 (5)	Br12—C17—C18—O12	−1.7 (4)
N11—C12—C13—C14	0.2 (5)	Br14—C17—C18—O12	119.5 (3)
N11—C12—C13—Br11	178.3 (2)	Br13—C17—C18—O12	−121.2 (3)
C12—C13—C14—C15	−0.9 (5)	Br12—C17—C18—O11	178.3 (2)
Br11—C13—C14—C15	−178.9 (2)	Br14—C17—C18—O11	−60.5 (3)
C13—C14—C15—C16	1.5 (5)	Br13—C17—C18—O11	58.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H01···O1	0.75 (3)	1.89 (4)	2.632 (3)	172 (4)
N11—H011···O11	0.80 (4)	1.82 (4)	2.621 (4)	175 (4)
C6—H6···O1^i	0.95	2.40	3.334 (4)	168
C16—H16···O11^ii	0.95	2.44	3.373 (4)	169
C2—H2···Br13^iii	0.95	3.05	3.939 (3)	157
C12—H12···Br14^iv	0.95	3.08	3.997 (3)	163
C16—H16···Br14^ii	0.95	3.12	3.626 (3)	115
C5—H5···Br3^i	0.95	3.08	3.748 (3)	129

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