The photochromic behaviour of two viologen salts modulated by the distances between the halide anions and the cationic N atoms of viologen

In recent years, viologens and their derivatives have received much attention due to their various potential applications, ranging from electro- or photochromic devices to clean energy. Generally, viologen compounds exhibit a colour change upon being subjected to an external stimulus. However, the chromic mechanism is still ambiguous, because there are many electron-transfer pathways for a chromic compound that need to be considered. Thus, exploring new chromic viologen-based compounds with one pathway should be important and meaningful. In this article, two new viologen-based derivatives, namely 1-(2-cyano­benz­yl)-4,4′-bipyridinium chloride (o-CBbpy·Cl), C₁₈H₁₄N₃⁺·Cl⁻ (1), and 1-(2-cyano­benz­yl)-4,4′-bipyridinium bromide (o-CBbpy·Br), C₁₈H₁₄N₃⁺·Br⁻ (2), have been synthesized and characterized. Inter­estingly, both isomorphic compounds possess only one electron-transfer pathway, in which 1-(2-cyano­benz­yl)-4,4′-bi­pyri­din­ium cations (o-CBbpy) and halide anions are employed as electron donors and acceptors, respectively. Salts 1 and 2 consist of o-CBbpy cations involved in π–π inter­actions and hydrogen-bond inter­actions, and halide anions weakly hydrogen bonded to the viologen cations. The salts show different photoresponsive characteristics under identical conditions, which should be mainly related to the distances between the halide cations and the cationic N atoms of o-CBbpy but not the electronegativities of the halogen atoms. These results should not only help in understanding that the distance of the electron-transfer pathway plays an important role in viologen-based photochromism, but should also guide the design and synthesis of additional photochromic materials.

Computing details

Data collection: CrysAlis PRO (Rigaku OD, 2017) for (1); CrysAlis PRO (Rigaku OD, 2015) for (2). Cell refinement: CrysAlis PRO (Rigaku OD, 2017) for (1); CrysAlis PRO (Rigaku OD, 2015) for (2). Data reduction: CrysAlis PRO (Rigaku OD, 2017) for (1); CrysAlis PRO (Rigaku OD, 2015) for (2). Program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007; Palatinus & van der Lee, 2008; Palatinus et al., 2012) for (1); SHELXS97 (Sheldrick, 2008) for (2). For both structures, program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

1-(2-Cyanobenzyl)-4,4'-bipyridin-1-ium chloride (1)

Crystal data

C18H14N3^+·Cl^−	F(000) = 640
Mr = 307.77	Dx = 1.317 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54184 Å
a = 8.1413 (7) Å	Cell parameters from 1475 reflections
b = 19.3495 (17) Å	θ = 6.7–72.5°
c = 9.9395 (7) Å	µ = 2.16 mm^−1
β = 97.440 (8)°	T = 293 K
V = 1552.6 (2) Å^3	Block, colourless
Z = 4	0.42 × 0.32 × 0.29 mm

Data collection

Rigaku Xcalibur Eos Gemini diffractometer	3101 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Cu) X-ray Source	2369 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
Detector resolution: 16.0710 pixels mm^-1	θmax = 73.5°, θmin = 4.6°
ω scans	h = −10→7
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2017)	k = −23→23
Tmin = 0.937, Tmax = 1.000	l = −12→10
8128 measured reflections

Refinement

Refinement on F^2	Primary atom site location: iterative
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.046	H-atom parameters constrained
wR(F^2) = 0.138	w = 1/[σ^2(Fo^2) + (0.0649P)^2 + 0.3167P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
3101 reflections	Δρmax = 0.18 e Å^−3
199 parameters	Δρmin = −0.23 e Å^−3
0 restraints

Special details

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

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

	x	y	z	Uiso*/Ueq
Cl1	−0.03751 (7)	0.15235 (3)	0.19601 (5)	0.0604 (2)
N2	0.0470 (2)	0.34640 (9)	0.30000 (16)	0.0450 (4)
C12	0.3164 (2)	0.28778 (12)	0.38061 (19)	0.0476 (5)
C3	−0.2223 (2)	0.48474 (11)	0.0209 (2)	0.0478 (5)
C6	−0.1285 (2)	0.43689 (11)	0.1188 (2)	0.0463 (5)
C17	0.4346 (3)	0.33361 (12)	0.4451 (2)	0.0526 (5)
N1	−0.4032 (3)	0.57365 (13)	−0.1668 (2)	0.0745 (6)
C11	0.1358 (2)	0.29512 (12)	0.3954 (2)	0.0491 (5)
H11A	0.082557	0.250446	0.380052	0.059*
H11B	0.125570	0.308999	0.487699	0.059*
C10	−0.1056 (3)	0.44884 (14)	0.2576 (2)	0.0648 (7)
H10	−0.150311	0.488406	0.291609	0.078*
C9	−0.0183 (3)	0.40344 (13)	0.3456 (2)	0.0609 (6)
H9	−0.004532	0.412652	0.438209	0.073*
C4	−0.2890 (3)	0.54584 (14)	0.0612 (3)	0.0684 (7)
H4	−0.274914	0.558779	0.152079	0.082*
C13	0.3698 (3)	0.23350 (13)	0.3070 (2)	0.0601 (6)
H13	0.293046	0.202780	0.262945	0.072*
N3	0.3409 (3)	0.43772 (15)	0.5755 (3)	0.0869 (8)
C2	−0.2490 (3)	0.46967 (14)	−0.1169 (2)	0.0630 (6)
H2	−0.206394	0.429397	−0.149889	0.076*
C18	0.3833 (3)	0.39149 (15)	0.5182 (2)	0.0632 (6)
C8	0.0286 (4)	0.33325 (14)	0.1667 (2)	0.0695 (7)
H8	0.075048	0.293390	0.135456	0.083*
C16	0.6029 (3)	0.32352 (16)	0.4379 (3)	0.0694 (7)
H16	0.680945	0.353592	0.482289	0.083*
C14	0.5377 (3)	0.22449 (16)	0.2983 (3)	0.0707 (7)
H14	0.572519	0.188285	0.247302	0.085*
C7	−0.0568 (4)	0.37702 (14)	0.0760 (2)	0.0671 (7)
H7	−0.067383	0.366673	−0.016080	0.080*
C1	−0.3393 (4)	0.51495 (16)	−0.2041 (3)	0.0726 (7)
H1	−0.356628	0.503449	−0.295646	0.087*
C15	0.6523 (3)	0.26905 (17)	0.3649 (3)	0.0753 (8)
H15	0.764444	0.262098	0.360337	0.090*
C5	−0.3770 (4)	0.58741 (16)	−0.0358 (3)	0.0815 (8)
H5	−0.421055	0.628234	−0.006471	0.098*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0572 (3)	0.0769 (4)	0.0472 (3)	−0.0085 (3)	0.0073 (2)	0.0021 (3)
N2	0.0409 (8)	0.0541 (10)	0.0400 (9)	−0.0017 (7)	0.0052 (7)	−0.0015 (7)
C12	0.0441 (10)	0.0602 (13)	0.0380 (9)	−0.0004 (9)	0.0035 (8)	0.0070 (9)
C3	0.0425 (10)	0.0548 (12)	0.0461 (11)	−0.0052 (9)	0.0061 (8)	−0.0004 (9)
C6	0.0418 (10)	0.0552 (12)	0.0424 (10)	−0.0049 (9)	0.0067 (8)	−0.0031 (9)
C17	0.0477 (11)	0.0693 (15)	0.0400 (10)	−0.0057 (10)	0.0023 (8)	0.0021 (10)
N1	0.0773 (14)	0.0759 (15)	0.0676 (14)	0.0039 (12)	−0.0005 (11)	0.0160 (12)
C11	0.0460 (10)	0.0589 (12)	0.0423 (10)	−0.0015 (9)	0.0046 (8)	0.0038 (10)
C10	0.0734 (15)	0.0699 (16)	0.0493 (12)	0.0223 (13)	0.0013 (11)	−0.0105 (11)
C9	0.0661 (14)	0.0743 (16)	0.0414 (11)	0.0134 (12)	0.0033 (10)	−0.0109 (11)
C4	0.0878 (18)	0.0624 (15)	0.0540 (14)	0.0131 (13)	0.0055 (12)	0.0009 (12)
C13	0.0546 (12)	0.0665 (15)	0.0586 (13)	0.0030 (11)	0.0056 (10)	−0.0025 (12)
N3	0.0824 (16)	0.0941 (18)	0.0846 (17)	−0.0142 (14)	0.0121 (13)	−0.0306 (15)
C2	0.0704 (15)	0.0657 (15)	0.0511 (13)	0.0032 (12)	0.0012 (11)	−0.0007 (11)
C18	0.0568 (13)	0.0787 (17)	0.0532 (13)	−0.0137 (12)	0.0037 (11)	−0.0055 (13)
C8	0.0962 (19)	0.0646 (15)	0.0460 (12)	0.0218 (14)	0.0037 (12)	−0.0102 (11)
C16	0.0464 (12)	0.098 (2)	0.0622 (15)	−0.0124 (13)	−0.0004 (11)	0.0019 (14)
C14	0.0606 (14)	0.0816 (18)	0.0714 (16)	0.0157 (13)	0.0139 (12)	−0.0057 (14)
C7	0.0915 (18)	0.0686 (16)	0.0386 (11)	0.0176 (14)	−0.0009 (11)	−0.0084 (11)
C1	0.0792 (17)	0.0827 (19)	0.0525 (14)	−0.0036 (15)	−0.0047 (12)	0.0052 (13)
C15	0.0445 (12)	0.105 (2)	0.0765 (17)	0.0072 (13)	0.0082 (12)	0.0063 (16)
C5	0.102 (2)	0.0679 (17)	0.0738 (18)	0.0191 (16)	0.0088 (16)	0.0068 (15)

Geometric parameters (Å, º)

N2—C11	1.493 (3)	C17—C16	1.395 (3)
N2—C9	1.330 (3)	N1—C1	1.322 (4)
N2—C8	1.338 (3)	N1—C5	1.319 (4)
C12—C17	1.401 (3)	C10—C9	1.372 (3)
C12—C11	1.503 (3)	C4—C5	1.383 (4)
C12—C13	1.382 (3)	C13—C14	1.392 (3)
C3—C6	1.481 (3)	N3—C18	1.138 (3)
C3—C4	1.382 (3)	C2—C1	1.376 (4)
C3—C2	1.390 (3)	C8—C7	1.361 (3)
C6—C10	1.388 (3)	C16—C15	1.369 (4)
C6—C7	1.388 (3)	C14—C15	1.375 (4)
C17—C18	1.426 (4)
C9—N2—C11	121.14 (18)	C5—N1—C1	115.5 (2)
C9—N2—C8	119.8 (2)	N2—C11—C12	113.58 (16)
C8—N2—C11	119.03 (19)	C9—C10—C6	121.3 (2)
C17—C12—C11	121.2 (2)	N2—C9—C10	120.7 (2)
C13—C12—C17	118.6 (2)	C3—C4—C5	118.9 (2)
C13—C12—C11	120.2 (2)	C12—C13—C14	120.5 (2)
C4—C3—C6	122.2 (2)	C1—C2—C3	119.3 (3)
C4—C3—C2	116.6 (2)	N3—C18—C17	179.2 (3)
C2—C3—C6	121.2 (2)	N2—C8—C7	121.3 (2)
C10—C6—C3	122.7 (2)	C15—C16—C17	119.5 (2)
C10—C6—C7	115.8 (2)	C15—C14—C13	120.1 (3)
C7—C6—C3	121.44 (19)	C8—C7—C6	121.0 (2)
C12—C17—C18	120.1 (2)	N1—C1—C2	124.6 (3)
C16—C17—C12	120.6 (2)	C16—C15—C14	120.7 (2)
C16—C17—C18	119.4 (2)	N1—C5—C4	125.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Cl1^i	0.93	2.70	3.581 (3)	159
C10—H10···N3^ii	0.93	2.59	3.473 (4)	158
C11—H11A···Cl1	0.97	2.73	3.581 (2)	147
C11—H11B···Cl1^iii	0.97	2.71	3.612 (2)	156

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

1-(2-Cyanobenzyl)-4,4'-bipyridin-1-ium bromide (2)

Crystal data

C18H14N3^+·Br^−	F(000) = 712
Mr = 352.23	Dx = 1.469 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54184 Å
a = 8.2921 (3) Å	Cell parameters from 2557 reflections
b = 18.943 (1) Å	θ = 8.0–72.9°
c = 10.2348 (4) Å	µ = 3.50 mm^−1
β = 97.849 (4)°	T = 293 K
V = 1592.59 (12) Å^3	Block, green
Z = 4	0.52 × 0.43 × 0.27 mm

Data collection

Rigaku Xcalibur Eos Gemini diffractometer	3193 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Cu) X-ray Source	2560 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
Detector resolution: 16.0710 pixels mm^-1	θmax = 73.1°, θmin = 4.7°
ω scans	h = −7→10
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2015)	k = −23→23
Tmin = 0.376, Tmax = 1.000	l = −12→12
9143 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.044	H-atom parameters constrained
wR(F^2) = 0.117	w = 1/[σ^2(Fo^2) + (0.0601P)^2 + 0.3099P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max = 0.001
3193 reflections	Δρmax = 0.30 e Å^−3
199 parameters	Δρmin = −0.78 e Å^−3

Special details

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

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

	x	y	z	Uiso*/Ueq
Br1	0.45832 (4)	0.35139 (2)	0.68924 (3)	0.05344 (14)
N2	0.5529 (3)	0.34953 (14)	0.2934 (2)	0.0423 (6)
C17	0.9365 (4)	0.33828 (19)	0.4365 (3)	0.0509 (8)
C12	0.8213 (4)	0.29204 (17)	0.3715 (3)	0.0447 (7)
C6	0.3713 (3)	0.44024 (16)	0.1190 (3)	0.0419 (6)
C3	0.2730 (4)	0.48833 (17)	0.0251 (3)	0.0453 (7)
C8	0.5356 (5)	0.3366 (2)	0.1648 (3)	0.0602 (9)
H8	0.5847	0.2969	0.1340	0.072*
C11	0.6421 (4)	0.29785 (18)	0.3869 (3)	0.0453 (7)
H11A	0.5917	0.2518	0.3724	0.054*
H11B	0.6325	0.3121	0.4765	0.054*
C7	0.4459 (5)	0.3810 (2)	0.0764 (3)	0.0592 (9)
H7	0.4353	0.3709	−0.0133	0.071*
N3	0.8436 (5)	0.4412 (2)	0.5720 (4)	0.0883 (12)
C13	0.8740 (4)	0.2382 (2)	0.2960 (3)	0.0555 (8)
H13	0.7985	0.2073	0.2515	0.067*
N1	0.0861 (4)	0.57836 (19)	−0.1544 (3)	0.0685 (8)
C9	0.4842 (4)	0.4071 (2)	0.3388 (3)	0.0536 (8)
H9	0.4978	0.4161	0.4290	0.064*
C15	1.1509 (4)	0.2755 (2)	0.3524 (4)	0.0717 (11)
H15	1.2610	0.2697	0.3463	0.086*
C18	0.8850 (4)	0.3956 (2)	0.5128 (3)	0.0617 (9)
C16	1.1014 (4)	0.3294 (2)	0.4275 (4)	0.0657 (10)
H16	1.1778	0.3599	0.4722	0.079*
C10	0.3943 (4)	0.4528 (2)	0.2542 (3)	0.0564 (8)
H10	0.3482	0.4925	0.2875	0.068*
C14	1.0389 (4)	0.2300 (2)	0.2861 (4)	0.0681 (10)
H14	1.0731	0.1939	0.2348	0.082*
C4	0.2058 (5)	0.5504 (2)	0.0658 (3)	0.0611 (9)
H4	0.2228	0.5638	0.1541	0.073*
C5	0.1136 (5)	0.5918 (2)	−0.0268 (4)	0.0718 (11)
H5	0.0672	0.6324	0.0030	0.086*
C2	0.2429 (5)	0.4731 (2)	−0.1081 (3)	0.0599 (9)
H2	0.2849	0.4323	−0.1411	0.072*
C1	0.1499 (5)	0.5190 (2)	−0.1917 (4)	0.0680 (10)
H1	0.1307	0.5073	−0.2807	0.082*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0498 (2)	0.0680 (3)	0.0429 (2)	0.00547 (15)	0.00765 (14)	−0.00177 (14)
N2	0.0367 (12)	0.0526 (15)	0.0379 (13)	−0.0027 (10)	0.0065 (10)	−0.0019 (10)
C17	0.0445 (16)	0.073 (2)	0.0349 (15)	−0.0039 (14)	0.0029 (12)	0.0026 (14)
C12	0.0424 (14)	0.0563 (18)	0.0354 (14)	0.0001 (13)	0.0056 (11)	0.0041 (12)
C6	0.0391 (13)	0.0493 (17)	0.0382 (14)	−0.0062 (12)	0.0082 (11)	−0.0039 (12)
C3	0.0422 (15)	0.0556 (18)	0.0398 (15)	−0.0049 (13)	0.0114 (12)	−0.0002 (13)
C8	0.077 (2)	0.062 (2)	0.0412 (17)	0.0163 (18)	0.0065 (16)	−0.0106 (15)
C11	0.0424 (15)	0.0549 (18)	0.0387 (15)	−0.0034 (13)	0.0054 (12)	0.0027 (13)
C7	0.076 (2)	0.063 (2)	0.0370 (17)	0.0102 (18)	0.0031 (15)	−0.0075 (15)
N3	0.076 (2)	0.106 (3)	0.085 (3)	−0.017 (2)	0.0183 (19)	−0.039 (2)
C13	0.0475 (16)	0.062 (2)	0.0560 (19)	0.0022 (15)	0.0049 (14)	−0.0036 (16)
N1	0.071 (2)	0.072 (2)	0.0610 (19)	0.0026 (16)	0.0025 (15)	0.0139 (16)
C9	0.0580 (18)	0.066 (2)	0.0379 (16)	0.0053 (16)	0.0092 (13)	−0.0094 (14)
C15	0.0382 (16)	0.104 (3)	0.074 (3)	0.0042 (19)	0.0105 (16)	0.003 (2)
C18	0.0545 (19)	0.083 (3)	0.0473 (19)	−0.0161 (18)	0.0062 (15)	−0.0125 (18)
C16	0.0419 (17)	0.096 (3)	0.057 (2)	−0.0083 (17)	−0.0020 (15)	−0.0014 (19)
C10	0.064 (2)	0.063 (2)	0.0431 (17)	0.0152 (16)	0.0078 (14)	−0.0074 (15)
C14	0.057 (2)	0.081 (3)	0.069 (2)	0.0176 (18)	0.0170 (17)	−0.0013 (19)
C4	0.076 (2)	0.059 (2)	0.0476 (18)	0.0078 (18)	0.0058 (16)	−0.0043 (15)
C5	0.084 (3)	0.067 (3)	0.063 (2)	0.015 (2)	0.003 (2)	0.0033 (19)
C2	0.067 (2)	0.066 (2)	0.0455 (18)	0.0062 (17)	0.0048 (15)	−0.0044 (15)
C1	0.077 (3)	0.083 (3)	0.0412 (19)	0.000 (2)	−0.0001 (17)	0.0038 (17)

Geometric parameters (Å, º)

N2—C8	1.327 (4)	C13—H13	0.9300
N2—C11	1.493 (4)	C13—C14	1.394 (5)
N2—C9	1.342 (4)	N1—C5	1.320 (5)
C17—C12	1.396 (4)	N1—C1	1.321 (5)
C17—C18	1.436 (5)	C9—H9	0.9300
C17—C16	1.393 (5)	C9—C10	1.370 (5)
C12—C11	1.519 (4)	C15—H15	0.9300
C12—C13	1.386 (5)	C15—C16	1.374 (6)
C6—C3	1.484 (4)	C15—C14	1.376 (6)
C6—C7	1.381 (5)	C16—H16	0.9300
C6—C10	1.392 (4)	C10—H10	0.9300
C3—C4	1.389 (5)	C14—H14	0.9300
C3—C2	1.382 (4)	C4—H4	0.9300
C8—H8	0.9300	C4—C5	1.379 (5)
C8—C7	1.377 (5)	C5—H5	0.9300
C11—H11A	0.9700	C2—H2	0.9300
C11—H11B	0.9700	C2—C1	1.379 (5)
C7—H7	0.9300	C1—H1	0.9300
N3—C18	1.135 (5)
C8—N2—C11	119.4 (3)	C5—N1—C1	115.4 (3)
C8—N2—C9	120.0 (3)	N2—C9—H9	119.5
C9—N2—C11	120.5 (3)	N2—C9—C10	121.0 (3)
C12—C17—C18	119.9 (3)	C10—C9—H9	119.5
C16—C17—C12	120.4 (3)	C16—C15—H15	119.7
C16—C17—C18	119.6 (3)	C16—C15—C14	120.6 (3)
C17—C12—C11	121.3 (3)	C14—C15—H15	119.7
C13—C12—C17	118.7 (3)	N3—C18—C17	179.3 (5)
C13—C12—C11	119.9 (3)	C17—C16—H16	120.1
C7—C6—C3	121.6 (3)	C15—C16—C17	119.8 (4)
C7—C6—C10	116.5 (3)	C15—C16—H16	120.1
C10—C6—C3	121.9 (3)	C6—C10—H10	119.7
C4—C3—C6	122.1 (3)	C9—C10—C6	120.6 (3)
C2—C3—C6	121.3 (3)	C9—C10—H10	119.7
C2—C3—C4	116.5 (3)	C13—C14—H14	120.1
N2—C8—H8	119.5	C15—C14—C13	119.8 (4)
N2—C8—C7	120.9 (3)	C15—C14—H14	120.1
C7—C8—H8	119.5	C3—C4—H4	120.6
N2—C11—C12	112.8 (2)	C5—C4—C3	118.9 (3)
N2—C11—H11A	109.0	C5—C4—H4	120.6
N2—C11—H11B	109.0	N1—C5—C4	125.1 (4)
C12—C11—H11A	109.0	N1—C5—H5	117.4
C12—C11—H11B	109.0	C4—C5—H5	117.4
H11A—C11—H11B	107.8	C3—C2—H2	120.3
C6—C7—H7	119.5	C1—C2—C3	119.4 (4)
C8—C7—C6	121.0 (3)	C1—C2—H2	120.3
C8—C7—H7	119.5	N1—C1—C2	124.7 (4)
C12—C13—H13	119.7	N1—C1—H1	117.6
C12—C13—C14	120.6 (3)	C2—C1—H1	117.6
C14—C13—H13	119.7
N2—C8—C7—C6	0.0 (6)	C7—C6—C10—C9	−1.2 (5)
N2—C9—C10—C6	0.4 (6)	C13—C12—C11—N2	−97.1 (4)
C17—C12—C11—N2	85.6 (3)	C9—N2—C8—C7	−0.9 (6)
C17—C12—C13—C14	0.6 (5)	C9—N2—C11—C12	−117.4 (3)
C12—C17—C16—C15	1.1 (6)	C18—C17—C12—C11	−4.1 (5)
C12—C13—C14—C15	0.3 (6)	C18—C17—C12—C13	178.5 (3)
C6—C3—C4—C5	−178.9 (3)	C18—C17—C16—C15	−178.7 (4)
C6—C3—C2—C1	179.5 (3)	C16—C17—C12—C11	176.0 (3)
C3—C6—C7—C8	−179.5 (3)	C16—C17—C12—C13	−1.3 (5)
C3—C6—C10—C9	179.3 (3)	C16—C15—C14—C13	−0.6 (6)
C3—C4—C5—N1	−1.8 (7)	C10—C6—C3—C4	3.5 (5)
C3—C2—C1—N1	0.5 (7)	C10—C6—C3—C2	−176.1 (3)
C8—N2—C11—C12	65.6 (4)	C10—C6—C7—C8	1.0 (6)
C8—N2—C9—C10	0.7 (5)	C14—C15—C16—C17	−0.2 (6)
C11—N2—C8—C7	176.1 (3)	C4—C3—C2—C1	−0.1 (5)
C11—N2—C9—C10	−176.3 (3)	C5—N1—C1—C2	−1.5 (7)
C11—C12—C13—C14	−176.8 (3)	C2—C3—C4—C5	0.7 (5)
C7—C6—C3—C4	−175.9 (3)	C1—N1—C5—C4	2.2 (7)
C7—C6—C3—C2	4.5 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Br1^i	0.93	2.85	3.718 (4)	156
C10—H10···N3^ii	0.93	2.61	3.471 (5)	155
C11—H11A···Br1^iii	0.97	2.83	3.683 (3)	148
C11—H11B···Br1	0.97	2.87	3.770 (3)	155

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