(2,2′-Bipyridyl-N,N′)(bi­cyclo­[3.3.1]­nonane-C¹,C⁵)­boronium tri­fluoro­methane­sulfonate

The cations and anions in the title compound, C₁₈H₂₂BN₂⁺·CF₃SO₃⁻, are connected by intermolecular C—H...O hydrogen bonds, with H...O distances between 2.34 and 2.60 Å, into layers parallel to the bc plane.

Key indicators

• Single-crystal X-ray study
• T = 146 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.038
• wR factor = 0.097
• Data-to-parameter ratio = 26.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           34.00
         From the CIF: _reflns_number_total               6966
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         7657
         Completeness (_total/calc)             90.98%
          Alert C: < 95% complete

PLAT_030  Alert C Refined Extinction parameter within range ....       3.12 Sigma


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

---

S1. Comment

2,2'-Bipyridylboronium ions, [I]⁺, are structurally related to the electron-acceptor diquat, which possesses an ethylene bridge instead of the BRR' unit and behaves as perfectly reversible two-step redox system (see scheme). [I]⁺ exhibits a similar electrochemical behavior as diquat. The degree of reversibility of the two reduction processes, however, depends on the solvent employed, as well as on the nature of the substituents R and R' (Hünig & Wehner, 1989). Currently, we are exploring the potential of 2,2'-bipyridylboronium cations as acceptor units in electron transfer salts and as redox catalysts (Fabrizi de Biani et al., 1997; Ding, Ma, Fabrizi de Biani et al., 2001; Ding, Ma, Bolte et al., 2001). In contrast to diquat, [I]⁺ is convenient to derivatize and can easily be incorporated into a wide variety of molecular aggregates. To generate electrochemically stable acceptor molecules possessing high solubility in organic solvents, we are currently investigating 2,2'-bipyridylboronium salts with bulky organic substituents at the boron center. In this context, the title derivative, [II], appeared to be particularly well suited. The corresponding hexafluorophosphate salt has already been shown to possess the desired electrochemical properties (Hünig & Wehner, 1989). Structural information about this molecule, however, is lacking. We report here the results of an X-ray crystal structure analysis of the trifluoromethanesulfonate salt, [II] (Fig. 1).

The dimensions of the 9-borabicyclo[3.3.1]nonane group are comparable to those found in related structures (Brock et al., 1992; Fraenk et al., 1999; Yalpani et al., 1990; Wrackmeyer et al., 1995). The B—C bond lengths are 1.6150 (16) and 1.6188 (16) Å. The B—N bond lengths are 1.6125 (14) and 1.6136 (14) Å. The angle between the two pyridyl planes is 2.88 (5)°. The bipyridyl group is slightly tilted with respect to the 9-borabicyclo[3.3.1]nonane group; the angle between the plane through N1/C5/C6/N2 and the plane bisecting C11—B—C15 is 8.5 (1)°. This tilting may result from crystal-packing effects. The B atom lies 0.114 (2) Å outside the plane through N1/C5/C6/N2. The molecule shows three short intramolecular H···H contacts: H1···H12A 2.02 Å, H10···H18A 2.03 Å and H13A···H17A 2.04 Å. The crystal packing shows seven intermolecular C—H···O contacts with H···O distances between 2.34 and 2.60 Å. Each cation is connected by these C—H···O contacts to three neighbouring anions and in a similar way. each anion is connected to three neighbouring cations, resulting in hydrogen-bonded layers of cations and anions parallel to the yz plane (Fig. 2). These layers are connected in the a direction by two very long intermolecular C—H···F contacts with H···F distances of 2.73 and 2.80 Å. These contacts are very weak. As a result, the crystals can easily be split along [100].

S2. Experimental

A toluene solution of 2,2'-bipyridine (3.90 g, 25.0 mmol) was added dropwise with stirring at 195 K to a solution of 9-boroniumbicyclo[3.3.1]nonane trifluoromethanesulfonate (6.74 g, 25.0 mmol) in 50 ml of hexane. The white precipitate gradually formed upon warming to ambient temperature and the resulting slurry was stirred for another 2 h. The white solid material was collected on a frit, extracted three times with toluene (10 ml) and dried in vacuo. The yield was 9.69 g (91%) of [II], melting point 503 K. Colourless crystals suitable for the X-ray measurements were obtained by slow evaporation of a solution in acetonitril at ambient temperature.

S3. Refinement

The H atoms were refined with fixed individual displacement parameters [U(H) = 1.2U_eq(C)] using a riding model with fixed distances: H—C(primary) = 1.00 Å, H—C(secondary) = 0.99 Å and H—C(aromatic) = 0.95 Å.

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Sheldrick, 1996); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The structure of [II] with 50% probability displacement ellipsoids.
	Fig. 2. A layer of [II] with 0 < x < 0.5 viewed down a. Intermolecular C—H···O interactions are shown as dotted lines.

2,2'-bipyridyl-9-boroniumbicyclo[3.3.1]nonane trifluoromethanesulfonate

Crystal data

C18H22BN2^+·CF3O3S^−	Z = 2
Mr = 426.26	F(000) = 444
Triclinic, P1	Dx = 1.511 Mg m^−3
a = 9.2198 (19) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.3158 (14) Å	Cell parameters from 211 reflections
c = 10.7956 (11) Å	θ = 3–23°
α = 112.511 (9)°	µ = 0.23 mm^−1
β = 96.598 (10)°	T = 146 K
γ = 93.007 (10)°	Rod, colourless
V = 937.0 (3) Å^3	0.50 × 0.28 × 0.27 mm

Data collection

Siemens SMART CCD diffractometer	6966 independent reflections
Radiation source: normal-focus sealed tube	5659 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
ω scans	θmax = 34.0°, θmin = 2.1°
Absorption correction: numerical (SHELXTL; Sheldrick, 1996)	h = −13→14
Tmin = 0.907, Tmax = 0.946	k = −16→16
21094 measured reflections	l = −16→16

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)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.098	w = 1/[σ^2(Fo^2) + (0.04P)^2 + 0.3P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.001
6966 reflections	Δρmax = 0.46 e Å^−3
263 parameters	Δρmin = −0.43 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0050 (16)

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
S	0.28394 (3)	0.10353 (3)	0.37175 (2)	0.01749 (7)
F1	0.03745 (9)	0.02535 (10)	0.20239 (8)	0.0376 (2)
F2	0.01180 (9)	0.14961 (9)	0.40925 (8)	0.03575 (19)
F3	0.05361 (9)	−0.06772 (9)	0.35077 (10)	0.0403 (2)
O1	0.34394 (9)	−0.01788 (9)	0.28190 (9)	0.02628 (18)
O2	0.29850 (11)	0.22755 (9)	0.34096 (9)	0.02922 (19)
O3	0.31605 (9)	0.13000 (9)	0.51371 (8)	0.02438 (17)
N1	0.28336 (10)	0.85522 (9)	0.84367 (9)	0.01741 (16)
N2	0.29379 (10)	0.66711 (9)	0.63222 (9)	0.01736 (16)
C1	0.27764 (13)	0.94595 (11)	0.97175 (11)	0.0218 (2)
H1	0.2619	0.9099	1.0385	0.026*
C2	0.29428 (13)	1.09040 (12)	1.00780 (11)	0.0229 (2)
H2	0.2901	1.1528	1.0985	0.027*
C3	0.31713 (13)	1.14347 (11)	0.91042 (11)	0.0218 (2)
H3	0.3263	1.2424	0.9336	0.026*
C4	0.32648 (12)	1.05147 (11)	0.77939 (11)	0.01944 (19)
H4	0.3439	1.0856	0.7117	0.023*
C5	0.30970 (11)	0.90808 (11)	0.75019 (10)	0.01614 (18)
C6	0.31666 (11)	0.79326 (11)	0.62118 (10)	0.01614 (18)
C7	0.34425 (12)	0.80496 (12)	0.50243 (10)	0.01906 (19)
H7	0.3583	0.8947	0.4976	0.023*
C8	0.35079 (12)	0.68192 (12)	0.39057 (11)	0.0213 (2)
H8	0.3697	0.6859	0.3074	0.026*
C9	0.32936 (13)	0.55266 (12)	0.40171 (11)	0.0227 (2)
H9	0.3349	0.4676	0.3262	0.027*
C10	0.30001 (13)	0.54798 (11)	0.52281 (11)	0.0211 (2)
H10	0.2839	0.4591	0.5291	0.025*
C11	0.35686 (11)	0.60931 (11)	0.85809 (10)	0.01821 (19)
H11	0.4623	0.6408	0.8617	0.022*
C12	0.32218 (12)	0.65299 (12)	1.00477 (11)	0.0219 (2)
H12A	0.3679	0.7506	1.0585	0.026*
H12B	0.3699	0.5911	1.0444	0.026*
C13	0.15756 (13)	0.64706 (13)	1.02178 (12)	0.0240 (2)
H13A	0.1257	0.5513	1.0154	0.029*
H13B	0.1484	0.7140	1.1144	0.029*
C14	0.04999 (13)	0.68084 (12)	0.92023 (12)	0.0227 (2)
H14A	−0.0495	0.6377	0.9173	0.027*
H14B	0.0469	0.7843	0.9551	0.027*
C15	0.08620 (12)	0.63007 (11)	0.77404 (11)	0.01934 (19)
H15	0.0214	0.6726	0.7223	0.023*
C16	0.06209 (12)	0.46784 (12)	0.70004 (12)	0.0228 (2)
H16A	−0.0390	0.4356	0.7059	0.027*
H16B	0.0693	0.4431	0.6030	0.027*
C17	0.16958 (13)	0.38617 (11)	0.75413 (12)	0.0227 (2)
H17A	0.1411	0.3849	0.8394	0.027*
H17B	0.1604	0.2873	0.6876	0.027*
C18	0.33086 (12)	0.44787 (11)	0.78146 (11)	0.0205 (2)
H18A	0.3683	0.4223	0.6937	0.025*
H18B	0.3888	0.4036	0.8347	0.025*
C19	0.08665 (13)	0.04982 (13)	0.33230 (12)	0.0243 (2)
B	0.25542 (13)	0.68520 (12)	0.77959 (11)	0.0173 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S	0.02033 (12)	0.01653 (11)	0.01514 (11)	0.00096 (8)	0.00277 (8)	0.00576 (9)
F1	0.0285 (4)	0.0526 (5)	0.0231 (4)	0.0030 (3)	−0.0050 (3)	0.0080 (3)
F2	0.0262 (4)	0.0459 (5)	0.0323 (4)	0.0149 (3)	0.0085 (3)	0.0097 (4)
F3	0.0342 (4)	0.0343 (4)	0.0538 (5)	−0.0090 (3)	0.0073 (4)	0.0199 (4)
O1	0.0263 (4)	0.0250 (4)	0.0232 (4)	0.0069 (3)	0.0065 (3)	0.0033 (3)
O2	0.0419 (5)	0.0211 (4)	0.0271 (4)	−0.0020 (3)	0.0047 (4)	0.0130 (3)
O3	0.0289 (4)	0.0274 (4)	0.0159 (3)	0.0019 (3)	0.0016 (3)	0.0081 (3)
N1	0.0208 (4)	0.0160 (4)	0.0159 (4)	0.0001 (3)	0.0040 (3)	0.0067 (3)
N2	0.0185 (4)	0.0168 (4)	0.0169 (4)	0.0010 (3)	0.0029 (3)	0.0067 (3)
C1	0.0303 (6)	0.0190 (5)	0.0167 (4)	0.0001 (4)	0.0055 (4)	0.0075 (4)
C2	0.0315 (6)	0.0176 (5)	0.0176 (4)	−0.0003 (4)	0.0048 (4)	0.0049 (4)
C3	0.0276 (5)	0.0161 (4)	0.0208 (5)	−0.0006 (4)	0.0029 (4)	0.0068 (4)
C4	0.0226 (5)	0.0178 (4)	0.0191 (4)	−0.0001 (4)	0.0030 (4)	0.0088 (4)
C5	0.0160 (4)	0.0174 (4)	0.0158 (4)	0.0005 (3)	0.0025 (3)	0.0075 (3)
C6	0.0148 (4)	0.0180 (4)	0.0160 (4)	0.0009 (3)	0.0024 (3)	0.0073 (4)
C7	0.0185 (5)	0.0224 (5)	0.0183 (4)	0.0022 (4)	0.0035 (4)	0.0099 (4)
C8	0.0217 (5)	0.0263 (5)	0.0167 (4)	0.0035 (4)	0.0044 (4)	0.0087 (4)
C9	0.0249 (5)	0.0239 (5)	0.0167 (4)	0.0041 (4)	0.0037 (4)	0.0047 (4)
C10	0.0250 (5)	0.0178 (4)	0.0188 (5)	0.0017 (4)	0.0024 (4)	0.0056 (4)
C11	0.0167 (4)	0.0189 (4)	0.0197 (4)	−0.0003 (3)	0.0019 (3)	0.0089 (4)
C12	0.0250 (5)	0.0225 (5)	0.0190 (5)	0.0010 (4)	0.0014 (4)	0.0097 (4)
C13	0.0275 (6)	0.0254 (5)	0.0220 (5)	0.0011 (4)	0.0071 (4)	0.0115 (4)
C14	0.0219 (5)	0.0222 (5)	0.0273 (5)	0.0032 (4)	0.0084 (4)	0.0118 (4)
C15	0.0187 (5)	0.0189 (4)	0.0224 (5)	0.0022 (3)	0.0027 (4)	0.0103 (4)
C16	0.0184 (5)	0.0210 (5)	0.0269 (5)	−0.0022 (4)	0.0000 (4)	0.0087 (4)
C17	0.0231 (5)	0.0163 (4)	0.0288 (5)	−0.0002 (4)	0.0039 (4)	0.0091 (4)
C18	0.0197 (5)	0.0190 (5)	0.0243 (5)	0.0038 (4)	0.0031 (4)	0.0098 (4)
C19	0.0224 (5)	0.0261 (5)	0.0222 (5)	0.0024 (4)	0.0026 (4)	0.0073 (4)
B	0.0219 (5)	0.0144 (5)	0.0162 (5)	0.0006 (4)	0.0040 (4)	0.0063 (4)

Geometric parameters (Å, º)

S—O3	1.4414 (8)	C9—C10	1.3830 (15)
S—O1	1.4427 (9)	C9—H9	0.9500
S—O2	1.4432 (9)	C10—H10	0.9500
S—C19	1.8255 (13)	C11—C18	1.5404 (15)
F1—C19	1.3443 (14)	C11—C12	1.5485 (15)
F2—C19	1.3332 (14)	C11—B	1.6150 (16)
F3—C19	1.3279 (14)	C11—H11	1.0000
N1—C1	1.3497 (14)	C12—C13	1.5505 (17)
N1—C5	1.3560 (13)	C12—H12A	0.9900
N1—B	1.6136 (14)	C12—H12B	0.9900
N2—C10	1.3492 (14)	C13—C14	1.5446 (17)
N2—C6	1.3593 (13)	C13—H13A	0.9900
N2—B	1.6125 (14)	C13—H13B	0.9900
C1—C2	1.3833 (15)	C14—C15	1.5437 (16)
C1—H1	0.9500	C14—H14A	0.9900
C2—C3	1.3888 (16)	C14—H14B	0.9900
C2—H2	0.9500	C15—C16	1.5442 (15)
C3—C4	1.3849 (15)	C15—B	1.6188 (16)
C3—H3	0.9500	C15—H15	1.0000
C4—C5	1.3852 (14)	C16—C17	1.5376 (16)
C4—H4	0.9500	C16—H16A	0.9900
C5—C6	1.4533 (14)	C16—H16B	0.9900
C6—C7	1.3832 (14)	C17—C18	1.5361 (16)
C7—C8	1.3871 (15)	C17—H17A	0.9900
C7—H7	0.9500	C17—H17B	0.9900
C8—C9	1.3900 (16)	C18—H18A	0.9900
C8—H8	0.9500	C18—H18B	0.9900
O3—S—O1	115.08 (5)	C11—C12—H12B	108.2
O3—S—O2	114.73 (5)	C13—C12—H12B	108.2
O1—S—O2	115.07 (6)	H12A—C12—H12B	107.3
O3—S—C19	103.26 (5)	C14—C13—C12	116.99 (9)
O1—S—C19	102.91 (6)	C14—C13—H13A	108.1
O2—S—C19	103.39 (6)	C12—C13—H13A	108.1
C1—N1—C5	118.74 (9)	C14—C13—H13B	108.1
C1—N1—B	128.76 (9)	C12—C13—H13B	108.1
C5—N1—B	112.44 (8)	H13A—C13—H13B	107.3
C10—N2—C6	118.49 (9)	C15—C14—C13	115.76 (9)
C10—N2—B	129.29 (9)	C15—C14—H14A	108.3
C6—N2—B	112.16 (8)	C13—C14—H14A	108.3
N1—C1—C2	121.34 (10)	C15—C14—H14B	108.3
N1—C1—H1	119.3	C13—C14—H14B	108.3
C2—C1—H1	119.3	H14A—C14—H14B	107.4
C1—C2—C3	119.48 (10)	C14—C15—C16	112.32 (9)
C1—C2—H2	120.3	C14—C15—B	108.61 (9)
C3—C2—H2	120.3	C16—C15—B	109.77 (9)
C4—C3—C2	119.70 (10)	C14—C15—H15	108.7
C4—C3—H3	120.2	C16—C15—H15	108.7
C2—C3—H3	120.2	B—C15—H15	108.7
C3—C4—C5	117.90 (10)	C17—C16—C15	115.51 (9)
C3—C4—H4	121.0	C17—C16—H16A	108.4
C5—C4—H4	121.0	C15—C16—H16A	108.4
N1—C5—C4	122.80 (10)	C17—C16—H16B	108.4
N1—C5—C6	109.81 (9)	C15—C16—H16B	108.4
C4—C5—C6	127.39 (9)	H16A—C16—H16B	107.5
N2—C6—C7	122.99 (9)	C18—C17—C16	114.03 (9)
N2—C6—C5	110.10 (9)	C18—C17—H17A	108.7
C7—C6—C5	126.91 (9)	C16—C17—H17A	108.7
C6—C7—C8	118.10 (10)	C18—C17—H17B	108.7
C6—C7—H7	121.0	C16—C17—H17B	108.7
C8—C7—H7	121.0	H17A—C17—H17B	107.6
C7—C8—C9	119.18 (10)	C17—C18—C11	114.56 (9)
C7—C8—H8	120.4	C17—C18—H18A	108.6
C9—C8—H8	120.4	C11—C18—H18A	108.6
C10—C9—C8	119.91 (10)	C17—C18—H18B	108.6
C10—C9—H9	120.0	C11—C18—H18B	108.6
C8—C9—H9	120.0	H18A—C18—H18B	107.6
N2—C10—C9	121.31 (10)	F3—C19—F2	108.03 (10)
N2—C10—H10	119.3	F3—C19—F1	107.56 (10)
C9—C10—H10	119.3	F2—C19—F1	107.25 (10)
C18—C11—C12	110.63 (9)	F3—C19—S	111.48 (8)
C18—C11—B	110.10 (8)	F2—C19—S	111.53 (8)
C12—C11—B	109.73 (9)	F1—C19—S	110.79 (8)
C18—C11—H11	108.8	N2—B—N1	95.07 (7)
C12—C11—H11	108.8	N2—B—C11	115.65 (9)
B—C11—H11	108.8	N1—B—C11	114.54 (8)
C11—C12—C13	116.51 (9)	N2—B—C15	112.26 (8)
C11—C12—H12A	108.2	N1—B—C15	111.87 (9)
C13—C12—H12A	108.2	C11—B—C15	107.27 (8)
C5—N1—C1—C2	1.68 (17)	C12—C11—C18—C17	67.01 (12)
B—N1—C1—C2	−175.24 (11)	B—C11—C18—C17	−54.45 (12)
N1—C1—C2—C3	0.10 (18)	O3—S—C19—F3	−62.31 (9)
C1—C2—C3—C4	−1.54 (18)	O1—S—C19—F3	57.74 (10)
C2—C3—C4—C5	1.16 (17)	O2—S—C19—F3	177.83 (8)
C1—N1—C5—C4	−2.09 (16)	O3—S—C19—F2	58.55 (9)
B—N1—C5—C4	175.31 (9)	O1—S—C19—F2	178.59 (8)
C1—N1—C5—C6	177.92 (9)	O2—S—C19—F2	−61.32 (10)
B—N1—C5—C6	−4.67 (12)	O3—S—C19—F1	177.94 (8)
C3—C4—C5—N1	0.67 (16)	O1—S—C19—F1	−62.02 (10)
C3—C4—C5—C6	−179.35 (10)	O2—S—C19—F1	58.07 (9)
C10—N2—C6—C7	0.81 (15)	C10—N2—B—N1	176.76 (10)
B—N2—C6—C7	−176.80 (9)	C6—N2—B—N1	−5.95 (10)
C10—N2—C6—C5	−178.34 (9)	C10—N2—B—C11	56.42 (14)
B—N2—C6—C5	4.05 (11)	C6—N2—B—C11	−126.29 (9)
N1—C5—C6—N2	0.39 (12)	C10—N2—B—C15	−67.11 (14)
C4—C5—C6—N2	−179.59 (10)	C6—N2—B—C15	110.18 (10)
N1—C5—C6—C7	−178.71 (10)	C1—N1—B—N2	−176.71 (10)
C4—C5—C6—C7	1.30 (18)	C5—N1—B—N2	6.21 (10)
N2—C6—C7—C8	−0.96 (16)	C1—N1—B—C11	−55.49 (15)
C5—C6—C7—C8	178.04 (10)	C5—N1—B—C11	127.43 (10)
C6—C7—C8—C9	0.11 (16)	C1—N1—B—C15	66.84 (14)
C7—C8—C9—C10	0.85 (16)	C5—N1—B—C15	−110.23 (10)
C6—N2—C10—C9	0.20 (16)	C18—C11—B—N2	−65.97 (11)
B—N2—C10—C9	177.35 (10)	C12—C11—B—N2	172.04 (8)
C8—C9—C10—N2	−1.03 (17)	C18—C11—B—N1	−175.06 (8)
C18—C11—C12—C13	−75.09 (12)	C12—C11—B—N1	62.95 (11)
B—C11—C12—C13	46.58 (12)	C18—C11—B—C15	60.14 (11)
C11—C12—C13—C14	−33.03 (14)	C12—C11—B—C15	−61.85 (11)
C12—C13—C14—C15	35.72 (14)	C14—C15—B—N2	−167.59 (8)
C13—C14—C15—C16	70.04 (12)	C16—C15—B—N2	69.26 (11)
C13—C14—C15—B	−51.57 (12)	C14—C15—B—N1	−62.09 (11)
C14—C15—C16—C17	−68.37 (13)	C16—C15—B—N1	174.76 (8)
B—C15—C16—C17	52.57 (13)	C14—C15—B—C11	64.31 (11)
C15—C16—C17—C18	−45.03 (14)	C16—C15—B—C11	−58.84 (11)
C16—C17—C18—C11	45.66 (13)