A novel framework of N—H...Br hydrogen bonds forming Br(4,4′-bipyridinium)₄ supra­molecular synthons: bis­(4,4′-bipyridinium) tris­[tetra­bromidoferrate(III)] bromide

In the asymmetric unit of the title compound, (C₁₀H₁₀N₂)₂[FeBr₄]₃Br, the Fe atoms are in a distorted tetra­hedral environment. The crystal structure contains a novel arrangement of Br(4,4′-bipyridinium)₄ supra­molecular synthons assembled via short N—H...Br hydrogen bonds (H...Br = 2.55, 2.40, 2.38 and 2.55 Å), where four cations surround one nonbonded bromide ion in a tetra­hedral arrangement. These synthons are further connected by hydrogen bonds using the remaining terminal NH hydrogens in each cation and the Br⁻ ions to form an adamantoid-like network and thus produce a three-dimensional supra­molecular architecture with the [FeBr₄]⁻ ions located in the cavities. The structure shows no significant inter­molecular Br...Br, Br...aryl or aryl–aryl inter­actions.

S1. Comment

Research in the field of inorganic–organic hybrids is of great interest owing to their magnetic, electronic and optoelectric properties (Cui et al., 2000; Lacroix et al., 1994; Chakravarthy & Guloy, 1997). The interactions governing the crystal organization are expected to affect the packing and then the specific properties of such solids. For example, 4,4'-bipyridine (bpy) and similar ligands have been used through their two N atoms as neutral linkers to generate and stabilize many open one-, two- and three-dimensional coordination polymers to form supramolecular coordination assemblies (Díaz de Vivar et al., 2007a,b; Dong et al., 2007; Lu et al., 2007; Xie et al., 2007, etc.). We report here the crystal structure of the title complex, (I), where the protonated 4,4'-bipyridinium ligand [bpyH₂]²⁺ is not involved in coordination, but in extensive N—H···Br intermolecular interactions, affording a supramolecular assembly structure.

The asymmetric unit of the title compound, (I), contains two [bpyH₂]²⁺ cations, three [FeBr₄]²⁻ anions and one bromide ion (Fig. 1). The [FeBr₄]⁻ anions exhibit a slightly distorted octahedral arrangement around Fe, with Fe—Br bonds in the range 2.3210 (9)–2.3448 (9), 2.3350 (9)–2.3535 (9) and 2.3311 (9)–2.3443 (9) Å for atoms Fe1, Fe2 and Fe3, respectively, leading to mean values of 2.3369 (9), 2.3400 (9) and 2.3366 (9) Å. The Br—Fe—Br angles, in turn, span the range 107.04 (3)–113.81 (4), 107.98 (4)–111.36 (3) and 105.60 (3)–112.80 (4)°, respectively. These values are in accordance with corresponding values in the literature (Garagorri-Benito et al., 2006; Kruszynski & Wyrzykowski, 2006).

As far as the cations are concerned, the bond distances and angles in the protonated cation do not differ from those reported in the neutral units (Diaz de Vivar et al., 2007a,b; Dong et al., 2007; Lu et al., 2007). The rings in the two independent cations are planar, and are twisted around the central C—C bond by 37.32 (19) and 39.32 (17)°. This effect could be the result of packing stress associated with the formation of the Br(bpyH₂)₄ supramolecular synthon (see the description below).

Fig. 2 shows the intermolecular N—H···Br hydrogen bonds in (I). These interactions are significant, with short D···A distances (in the range of 2.38–2.55 Å) and with D—H···A angles spanning 140–155° (Table 2).

The hydrogen bonds cause the formation of a supramolecular architecture, best described as built up by Br(bpyH₂)₄ supramolecular synthons (Fig. 2) assembled via N—H···Br short hydrogen bonds, where four cations surround one (central) nonbonded Br⁻ ion in an approximately tetrahedral arrangement. These synthons are further connected by hydrogen bonds to the Br⁻ ions by way of the remaining terminal NH H atoms in each cation to form an adamantoid-like network that extends into a three-dimensional structure. The molecules of the discrete [FeBr₄]⁻ anionic units occupy the cavities that result from the three-dimensional assembly of the Br(bpyH₂)₄ entities.

A number of structures containing both bpyH₂ and Br⁻ groups have been reported, but few of them exhibit multiple bpyH₂···Br⁻ interactions. In fact, in the more simple structures, such as 4,4'-bipyridin-1-ium bromide monohydrate (Iyere et al., 2002, 2003) and 2,2'-bipyridinium(1+) bromide monohydrate (Bowen et al., 2004), no N—H···Br interactions are present at all in the structures.

We could trace a few examples of complex hydrogen-bonding schemes of a similar sort to, but rather different from, that reported here, for example, 6-oxo-1,6-dihydro-3,4'-bipyridine-5-carbonitrile hydrogen bromide (Cody & Wojtczak, 1991), where the bromide ion connects, as in (I), four cations via hydrogen-bonding interactions, but only one of them is of the N—H···Br type, the remaining four being C—H···Br interactions. Another example is that of 4,4'-bipyridinediium dibromide (Ilyukhin & Petrosyants, 2006), where the N—H···Br hydrogen bonds are present as a bridging motif, leading to ···bpyH₂···2Br⁻···bpyH₂···2Br⁻··· infinite linear layers. The same motif is observed in the corresponding dichloride cation (Iyere et al., 2003).

Finally, the structure of (I) shows no significant intermolecular Br···Br, Br···aryl and/or aryl–aryl interactions

Related literature

For related literature, see: Garagorri-Benito, Kirchner & Mereiter (2006); Bowen et al. (2004); Chakravarthy & Guloy (1997); Cody & Wojtczak (1991); Cui et al. (2000); Díaz de Vivar, Baggio, Garland & Baggio (2007a, 2007b); Dong et al. (2007); Ilyukhin & Petrosyants (2006); Iyere et al. (2002, 2003); Kruszynski & Wyrzykowski (2006); Lacroix et al. (1994); Lu et al. (2007); Xie et al. (2007).

S2. Experimental

For the preparation of (I), FeCl₃·6H₂O (0.811 g, 3 mmol) dissolved in absolute ethanol (15 ml) and liquid Br₂ (80%, 1 ml) was added dropwise to a (stirred) hot solution of 4,4'-dipyridyl (0.3124 g, 2 mmol) dissolved in ethanol (15 ml) and HBr (60%, 3 ml). After heating for 2 h, the mixture was filtered and allowed to stand undisturbed at room temperature. The salt crystallized out over 2 d as red block-like cubes. Crystals were filtered off, washed with ethanol and then diethyl ether, and dried under vacuum (yield 0.95 g, 62.4%).

S3. Refinement

H atoms were positioned geometrically (N—H = 0.88 Å and C—H = 0.95 Å) and constrained to ride on their parent atoms, with U_iso(H) = xU_eq(C,N), where x = 1.2 for all H atoms.

Computing details

Data collection: CrystalClear (Rigaku, 2000); cell refinement: CrystalClear (Rigaku, 2000); data reduction: CrystalClear (Rigaku, 2000); program(s) used to solve structure: XS in SHELXTL (Sheldrick, 1997); program(s) used to refine structure: XL in SHELXTL (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Sheldrick, 1997); software used to prepare material for publication: XCIF in SHELXTL (Sheldrick, 1997).

Figures

	Fig. 1. The structure of the title compuond, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The Br(bpyH2)4 tetrahedral synthons in (I). The N—H···Br interactions are shown as dashed lines. [Symmetry codes: (i) −1/2 − x, 1 − y, 1/2 + z; (ii) 1 − x, −1/2 + y, 1/2 − z; (iii) x, y, 1 + z; (iv) −3/2 + x, 3/2 − y, 1 − z.]

bis(4,4'-bipyridinium) tris[tetrabromidoferrate(III)] bromide

Crystal data

(C10H10N2)2[FeBr4]3Br	F(000) = 2804
Mr = 1522.65	Dx = 2.499 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 7249 reflections
a = 11.5536 (6) Å	θ = 2.3–26.8°
b = 18.4508 (9) Å	µ = 13.92 mm^−1
c = 18.9844 (10) Å	T = 84 K
V = 4047.0 (4) Å^3	Cube, red
Z = 4	0.23 × 0.21 × 0.20 mm

Data collection

Rigaku Mercury CCD diffractometer	9303 independent reflections
Radiation source: fine-focus sealed tube	7964 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
Detector resolution: 14.6306 pixels mm^-1	θmax = 27.5°, θmin = 1.5°
dtintegrate.ref scans	h = −15→15
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −24→23
Tmin = 0.056, Tmax = 0.064	l = −24→24
46358 measured 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)] = 0.030	H-atom parameters constrained
wR(F^2) = 0.055	w = 1/[σ^2(Fo^2) + (0.0102P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max = 0.001
9301 reflections	Δρmax = 0.60 e Å^−3
361 parameters	Δρmin = −0.43 e Å^−3
0 restraints	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.010 (8)

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Br1	0.70120 (5)	0.68069 (3)	0.58041 (3)	0.03134 (14)
Fe1	0.52451 (6)	0.73137 (4)	0.61138 (4)	0.01899 (16)
Br2	0.49110 (5)	0.73429 (3)	0.73317 (3)	0.03115 (13)
Fe2	0.60188 (6)	0.51062 (4)	0.29076 (4)	0.02360 (17)
Br3	0.52488 (5)	0.85094 (3)	0.57010 (3)	0.02466 (12)
Fe3	0.71984 (6)	0.14571 (4)	0.48993 (4)	0.01945 (16)
Br4	0.38068 (5)	0.66366 (3)	0.55474 (3)	0.02856 (13)
Br5	0.73296 (5)	0.42392 (3)	0.24995 (3)	0.02921 (13)
Br6	0.69959 (5)	0.61290 (3)	0.33493 (3)	0.02980 (13)
Br7	0.48778 (5)	0.54736 (3)	0.19571 (3)	0.02809 (12)
C7'	0.4099 (4)	0.7252 (3)	0.3108 (3)	0.0177 (11)
C7	0.4983 (4)	0.7832 (2)	0.3151 (2)	0.0167 (10)
Br8	0.48967 (5)	0.45804 (3)	0.37944 (3)	0.03209 (13)
C8'	0.3373 (4)	0.7212 (3)	0.2533 (3)	0.0213 (11)
H8'	0.3411	0.7565	0.2169	0.026*
C8	0.5220 (4)	0.8162 (3)	0.3790 (3)	0.0211 (11)
H8	0.4798	0.8031	0.4200	0.025*
Br9	0.89754 (4)	0.15765 (3)	0.43200 (3)	0.02596 (12)
C9'	0.2590 (4)	0.6648 (3)	0.2496 (3)	0.0261 (12)
H9'	0.2091	0.6605	0.2101	0.031*
C9	0.6078 (4)	0.8686 (3)	0.3826 (3)	0.0249 (12)
H9	0.6254	0.8915	0.4261	0.030*
Br10	0.72903 (5)	0.19874 (3)	0.60201 (3)	0.02505 (12)
N10'	0.2537 (4)	0.6167 (2)	0.3016 (2)	0.0272 (11)
H10'	0.2033	0.5812	0.2981	0.033*
N10	0.6653 (4)	0.8865 (2)	0.3242 (2)	0.0216 (9)
H10	0.7198	0.9196	0.3272	0.026*
Br11	0.57795 (5)	0.21009 (3)	0.42907 (3)	0.03054 (13)
C11'	0.3210 (4)	0.6194 (3)	0.3590 (3)	0.0252 (12)
H11'	0.3136	0.5843	0.3953	0.030*
C11	0.6444 (4)	0.8569 (3)	0.2620 (3)	0.0234 (12)
H11	0.6872	0.8716	0.2218	0.028*
Br12	0.67521 (5)	0.02308 (3)	0.50198 (3)	0.03218 (14)
C12'	0.4012 (4)	0.6746 (3)	0.3642 (2)	0.0192 (11)
H12'	0.4502	0.6778	0.4043	0.023*
C12	0.5596 (4)	0.8044 (3)	0.2562 (3)	0.0211 (11)
H12	0.5436	0.7829	0.2118	0.025*
Br13	0.11751 (4)	0.47839 (3)	0.24346 (2)	0.01787 (10)
C1'	−0.3134 (4)	0.5728 (3)	−0.0197 (2)	0.0180 (11)
C1	−0.2343 (4)	0.5632 (3)	0.0414 (3)	0.0187 (11)
C2'	−0.3547 (4)	0.5138 (3)	−0.0563 (3)	0.0236 (12)
H2'	−0.3329	0.4661	−0.0427	0.028*
C2	−0.1516 (4)	0.5091 (3)	0.0395 (3)	0.0208 (11)
H2	−0.1453	0.4779	−0.0001	0.025*
C3'	−0.4274 (4)	0.5241 (3)	−0.1127 (3)	0.0220 (11)
H3'	−0.4561	0.4837	−0.1383	0.026*
C3	−0.0790 (4)	0.5015 (3)	0.0959 (3)	0.0227 (12)
H3	−0.0209	0.4651	0.0953	0.027*
N4'	−0.4576 (3)	0.5913 (2)	−0.1313 (2)	0.0218 (10)
H4'	−0.5041	0.5970	−0.1676	0.026*
N4	−0.0891 (3)	0.5445 (2)	0.1514 (2)	0.0225 (10)
H4	−0.0421	0.5379	0.1873	0.027*
C5'	−0.4204 (4)	0.6501 (3)	−0.0972 (3)	0.0221 (11)
H5'	−0.4442	0.6970	−0.1119	0.026*
C5	−0.1675 (4)	0.5972 (3)	0.1551 (3)	0.0251 (12)
H5	−0.1711	0.6277	0.1954	0.030*
C6'	−0.3477 (4)	0.6422 (3)	−0.0410 (3)	0.0197 (11)
H6'	−0.3204	0.6837	−0.0164	0.024*
C6	−0.2428 (4)	0.6070 (3)	0.1004 (3)	0.0222 (11)
H6	−0.3005	0.6436	0.1028	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0226 (3)	0.0229 (3)	0.0485 (4)	−0.0010 (2)	−0.0023 (3)	−0.0058 (3)
Fe1	0.0219 (4)	0.0176 (4)	0.0175 (3)	−0.0035 (3)	−0.0020 (3)	0.0026 (3)
Br2	0.0438 (3)	0.0332 (3)	0.0165 (3)	−0.0078 (3)	−0.0020 (3)	0.0053 (2)
Fe2	0.0191 (4)	0.0217 (4)	0.0300 (4)	−0.0013 (3)	0.0003 (3)	−0.0014 (3)
Br3	0.0348 (3)	0.0179 (3)	0.0213 (2)	0.0003 (2)	0.0002 (2)	0.0032 (2)
Fe3	0.0241 (4)	0.0160 (4)	0.0183 (4)	−0.0012 (3)	0.0034 (3)	−0.0015 (3)
Br4	0.0265 (3)	0.0359 (3)	0.0233 (3)	−0.0123 (2)	−0.0058 (2)	0.0027 (2)
Br5	0.0237 (3)	0.0219 (3)	0.0420 (3)	0.0008 (2)	0.0016 (3)	−0.0046 (3)
Br6	0.0238 (3)	0.0224 (3)	0.0433 (3)	−0.0015 (2)	−0.0026 (3)	−0.0063 (3)
Br7	0.0226 (3)	0.0306 (3)	0.0310 (3)	−0.0002 (2)	−0.0006 (2)	0.0027 (2)
C7'	0.018 (3)	0.013 (3)	0.023 (3)	0.004 (2)	0.002 (2)	−0.009 (2)
C7	0.014 (2)	0.015 (3)	0.020 (2)	0.004 (2)	−0.005 (2)	0.0000 (19)
Br8	0.0331 (3)	0.0343 (3)	0.0289 (3)	−0.0079 (3)	0.0029 (3)	0.0011 (2)
C8'	0.024 (3)	0.024 (3)	0.016 (2)	0.001 (2)	0.003 (2)	−0.004 (2)
C8	0.018 (3)	0.027 (3)	0.018 (2)	−0.005 (2)	0.003 (2)	−0.003 (2)
Br9	0.0268 (3)	0.0214 (3)	0.0297 (3)	0.0023 (2)	0.0092 (2)	−0.0006 (2)
C9'	0.022 (3)	0.031 (3)	0.025 (3)	0.000 (2)	0.002 (2)	−0.012 (3)
C9	0.024 (3)	0.023 (3)	0.027 (3)	−0.003 (2)	−0.004 (3)	−0.009 (2)
Br10	0.0319 (3)	0.0227 (3)	0.0205 (3)	−0.0039 (2)	0.0015 (2)	−0.0051 (2)
N10'	0.021 (2)	0.025 (3)	0.036 (3)	−0.0086 (19)	0.008 (2)	−0.014 (2)
N10	0.021 (2)	0.015 (2)	0.028 (2)	−0.0059 (18)	−0.004 (2)	−0.0016 (19)
Br11	0.0308 (3)	0.0384 (3)	0.0225 (3)	0.0082 (2)	0.0029 (2)	0.0055 (3)
C11'	0.026 (3)	0.022 (3)	0.028 (3)	0.001 (2)	0.008 (2)	0.004 (2)
C11	0.023 (3)	0.024 (3)	0.023 (3)	−0.003 (2)	0.001 (2)	−0.001 (2)
Br12	0.0471 (4)	0.0175 (3)	0.0320 (3)	−0.0095 (2)	0.0007 (3)	−0.0018 (2)
C12'	0.015 (3)	0.024 (3)	0.018 (3)	−0.001 (2)	0.000 (2)	0.000 (2)
C12	0.025 (3)	0.021 (3)	0.017 (3)	0.000 (2)	0.003 (2)	−0.004 (2)
Br13	0.0153 (2)	0.0178 (3)	0.0206 (2)	−0.00068 (19)	0.0000 (2)	0.0001 (2)
C1'	0.017 (3)	0.018 (3)	0.020 (3)	−0.002 (2)	0.005 (2)	−0.001 (2)
C1	0.015 (3)	0.017 (3)	0.023 (3)	−0.004 (2)	0.000 (2)	0.006 (2)
C2'	0.028 (3)	0.014 (3)	0.029 (3)	−0.001 (2)	−0.005 (2)	0.000 (2)
C2	0.025 (3)	0.014 (3)	0.023 (3)	−0.001 (2)	0.002 (2)	0.006 (2)
C3'	0.028 (3)	0.013 (3)	0.025 (3)	−0.007 (2)	−0.006 (2)	−0.003 (2)
C3	0.020 (3)	0.015 (3)	0.033 (3)	0.003 (2)	−0.002 (2)	0.008 (2)
N4'	0.019 (2)	0.024 (3)	0.023 (2)	0.0004 (19)	−0.0062 (18)	0.0021 (19)
N4	0.019 (2)	0.025 (2)	0.024 (2)	−0.0064 (19)	−0.0048 (19)	0.010 (2)
C5'	0.024 (3)	0.017 (3)	0.025 (3)	0.004 (2)	0.002 (2)	0.000 (2)
C5	0.023 (3)	0.026 (3)	0.026 (3)	−0.004 (2)	0.002 (2)	0.000 (2)
C6'	0.022 (3)	0.014 (3)	0.023 (3)	−0.004 (2)	−0.001 (2)	−0.003 (2)
C6	0.021 (3)	0.021 (3)	0.024 (3)	0.000 (2)	0.005 (2)	0.004 (2)

Geometric parameters (Å, º)

Br1—Fe1	2.3210 (9)	C11'—C12'	1.380 (7)
Fe1—Br4	2.3406 (9)	C11'—H11'	0.9500
Fe1—Br3	2.3411 (8)	C11—C12	1.382 (7)
Fe1—Br2	2.3448 (9)	C11—H11	0.9500
Fe2—Br5	2.3350 (9)	C12'—H12'	0.9500
Fe2—Br7	2.3352 (9)	C12—H12	0.9500
Fe2—Br8	2.3360 (9)	C1'—C2'	1.378 (7)
Fe2—Br6	2.3535 (9)	C1'—C6'	1.400 (7)
Fe3—Br11	2.3311 (9)	C1'—C1	1.486 (7)
Fe3—Br12	2.3319 (9)	C1—C2	1.383 (7)
Fe3—Br9	2.3395 (9)	C1—C6	1.385 (7)
Fe3—Br10	2.3443 (9)	C2'—C3'	1.374 (7)
C7'—C8'	1.379 (6)	C2'—H2'	0.9500
C7'—C12'	1.383 (7)	C2—C3	1.367 (7)
C7'—C7	1.482 (6)	C2—H2	0.9500
C7—C12	1.379 (6)	C3'—N4'	1.335 (6)
C7—C8	1.385 (6)	C3'—H3'	0.9500
C8'—C9'	1.380 (7)	C3—N4	1.324 (6)
C8'—H8'	0.9500	C3—H3	0.9500
C8—C9	1.386 (7)	N4'—C5'	1.335 (6)
C8—H8	0.9500	N4'—H4'	0.8800
C9'—N10'	1.329 (7)	N4—C5	1.331 (6)
C9'—H9'	0.9500	N4—H4	0.8800
C9—N10	1.333 (6)	C5'—C6'	1.366 (7)
C9—H9	0.9500	C5'—H5'	0.9500
N10'—C11'	1.340 (7)	C5—C6	1.367 (7)
N10'—H10'	0.8800	C5—H5	0.9500
N10—C11	1.323 (6)	C6'—H6'	0.9500
N10—H10	0.8800	C6—H6	0.9500
Br1—Fe1—Br4	107.04 (3)	N10—C11—C12	119.4 (5)
Br1—Fe1—Br3	107.06 (3)	N10—C11—H11	120.3
Br4—Fe1—Br3	110.52 (3)	C12—C11—H11	120.3
Br1—Fe1—Br2	113.81 (4)	C11'—C12'—C7'	119.6 (5)
Br4—Fe1—Br2	110.39 (3)	C11'—C12'—H12'	120.2
Br3—Fe1—Br2	107.98 (3)	C7'—C12'—H12'	120.2
Br5—Fe2—Br7	107.98 (4)	C7—C12—C11	119.8 (5)
Br5—Fe2—Br8	108.33 (4)	C7—C12—H12	120.1
Br7—Fe2—Br8	111.36 (3)	C11—C12—H12	120.1
Br5—Fe2—Br6	110.88 (3)	C2'—C1'—C6'	118.6 (4)
Br7—Fe2—Br6	108.27 (4)	C2'—C1'—C1	120.9 (4)
Br8—Fe2—Br6	110.03 (4)	C6'—C1'—C1	120.5 (4)
Br11—Fe3—Br12	112.80 (4)	C2—C1—C6	119.4 (5)
Br11—Fe3—Br9	109.64 (3)	C2—C1—C1'	119.4 (4)
Br12—Fe3—Br9	109.37 (3)	C6—C1—C1'	121.2 (4)
Br11—Fe3—Br10	105.60 (3)	C3'—C2'—C1'	119.7 (5)
Br12—Fe3—Br10	109.03 (3)	C3'—C2'—H2'	120.1
Br9—Fe3—Br10	110.34 (3)	C1'—C2'—H2'	120.1
C8'—C7'—C12'	120.0 (5)	C3—C2—C1	118.6 (5)
C8'—C7'—C7	120.1 (4)	C3—C2—H2	120.7
C12'—C7'—C7	119.8 (4)	C1—C2—H2	120.7
C12—C7—C8	119.0 (4)	N4'—C3'—C2'	119.6 (5)
C12—C7—C7'	120.9 (4)	N4'—C3'—H3'	120.2
C8—C7—C7'	120.1 (4)	C2'—C3'—H3'	120.2
C7'—C8'—C9'	118.7 (5)	N4—C3—C2	120.5 (5)
C7'—C8'—H8'	120.7	N4—C3—H3	119.7
C9'—C8'—H8'	120.7	C2—C3—H3	119.7
C7—C8—C9	119.4 (5)	C3'—N4'—C5'	122.8 (4)
C7—C8—H8	120.3	C3'—N4'—H4'	118.6
C9—C8—H8	120.3	C5'—N4'—H4'	118.6
N10'—C9'—C8'	119.7 (5)	C3—N4—C5	122.6 (4)
N10'—C9'—H9'	120.1	C3—N4—H4	118.7
C8'—C9'—H9'	120.1	C5—N4—H4	118.7
N10—C9—C8	119.2 (5)	N4'—C5'—C6'	119.4 (5)
N10—C9—H9	120.4	N4'—C5'—H5'	120.3
C8—C9—H9	120.4	C6'—C5'—H5'	120.3
C9'—N10'—C11'	123.6 (5)	N4—C5—C6	119.4 (5)
C9'—N10'—H10'	118.2	N4—C5—H5	120.3
C11'—N10'—H10'	118.2	C6—C5—H5	120.3
C11—N10—C9	123.3 (4)	C5'—C6'—C1'	119.8 (5)
C11—N10—H10	118.4	C5'—C6'—H6'	120.1
C9—N10—H10	118.4	C1'—C6'—H6'	120.1
N10'—C11'—C12'	118.4 (5)	C5—C6—C1	119.5 (5)
N10'—C11'—H11'	120.8	C5—C6—H6	120.3
C12'—C11'—H11'	120.8	C1—C6—H6	120.3
C8'—C7'—C7—C12	−39.7 (7)	C2'—C1'—C1—C2	37.1 (7)
C12'—C7'—C7—C12	139.7 (5)	C6'—C1'—C1—C2	−143.0 (5)
C8'—C7'—C7—C8	141.5 (5)	C2'—C1'—C1—C6	−142.2 (5)
C12'—C7'—C7—C8	−39.2 (7)	C6'—C1'—C1—C6	37.7 (7)
C12'—C7'—C8'—C9'	−1.8 (7)	C6'—C1'—C2'—C3'	0.3 (7)
C7—C7'—C8'—C9'	177.5 (4)	C1—C1'—C2'—C3'	−179.8 (5)
C12—C7—C8—C9	−1.1 (7)	C6—C1—C2—C3	−1.2 (7)
C7'—C7—C8—C9	177.7 (4)	C1'—C1—C2—C3	179.5 (4)
C7'—C8'—C9'—N10'	1.2 (7)	C1'—C2'—C3'—N4'	−0.2 (8)
C7—C8—C9—N10	0.4 (8)	C1—C2—C3—N4	0.9 (7)
C8'—C9'—N10'—C11'	0.2 (8)	C2'—C3'—N4'—C5'	−0.2 (7)
C8—C9—N10—C11	0.4 (8)	C2—C3—N4—C5	−1.1 (7)
C9'—N10'—C11'—C12'	−0.9 (8)	C3'—N4'—C5'—C6'	0.3 (7)
C9—N10—C11—C12	−0.5 (8)	C3—N4—C5—C6	1.4 (7)
N10'—C11'—C12'—C7'	0.2 (7)	N4'—C5'—C6'—C1'	−0.2 (7)
C8'—C7'—C12'—C11'	1.1 (7)	C2'—C1'—C6'—C5'	−0.1 (7)
C7—C7'—C12'—C11'	−178.2 (4)	C1—C1'—C6'—C5'	180.0 (4)
C8—C7—C12—C11	1.0 (7)	N4—C5—C6—C1	−1.6 (7)
C7'—C7—C12—C11	−177.8 (4)	C2—C1—C6—C5	1.6 (7)
N10—C11—C12—C7	−0.3 (7)	C1'—C1—C6—C5	−179.1 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4′—H4′···Br13^i	0.88	2.55	3.274 (4)	140
N4—H4···Br13	0.88	2.40	3.199 (4)	152
N10′—H10′···Br13	0.88	2.38	3.195 (4)	155
N10—H10···Br13^ii	0.88	2.55	3.290 (4)	142

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