1,2-Di-2-quinolylethene.

The title compound, C(20)H(14)N(2), comprises two crystallographically independent centrosymmetric mol-ecules (A and B) with different conformations due to the disorder of molecule B. The whole of mol-ecule B is disordered over two sets of positions, corresponding to a 180° rotation of the molecule, with a site-occupancy ratio of 0.780 (6):0.220 (6). The minor component of the disordered part in B has the same configuration as mol-ecule A, but the major component is different. The dihedral angle between the planes of mol-ecule A and mol-ecule B (major component) is 63.22 (3)°. The crystal structure is stabilized by inter-molecular C-H⋯π inter-actions.

Related literature

For the biological activities, mol­ecular recognition and catalysis see, for example: Fournet et al. (2003 ▶); Yamada et al., (1981 ▶); Goswami & Mahapatra (1998 ▶); Goswami et al. (1989 ▶).

Experimental

Crystal data

C20H14N2

M = 282.33

Monoclinic,

a = 15.6378 (2) Å

b = 6.0798 (1) Å

c = 16.0860 (2) Å

β = 108.879 (1)°

V = 1447.10 (4) Å3

Z = 4

Mo Kα radiation

μ = 0.08 mm−1

T = 100.0 (1) K

0.34 × 0.33 × 0.09 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (; Bruker, 2005 ▶) T min = 0.863, T max = 0.993

12910 measured reflections

3317 independent reflections

2476 reflections with I > 2σ(I)

R int = 0.030

Refinement

R[F 2 > 2σ(F 2)] = 0.040

wR(F 2) = 0.102

S = 1.04

3317 reflections

245 parameters

H-atom parameters constrained

Δρmax = 0.25 e Å−3

Δρmin = −0.17 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680900186X/pk2144sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680900186X/pk2144Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C20H14N2	F(000) = 592
Mr = 282.33	Dx = 1.296 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3767 reflections
a = 15.6378 (2) Å	θ = 2.7–31.5°
b = 6.0798 (1) Å	µ = 0.08 mm−1
c = 16.0860 (2) Å	T = 100 K
β = 108.879 (1)°	Block, yellow
V = 1447.10 (4) Å3	0.34 × 0.33 × 0.09 mm
Z = 4

Bruker APEXII CCD area-detector diffractometer	3317 independent reflections
Radiation source: fine-focus sealed tube	2476 reflections with I > 2σ(I)
graphite	Rint = 0.030
φ and ω scans	θmax = 27.5°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −20→20
Tmin = 0.863, Tmax = 0.993	k = −7→6
12910 measured reflections	l = −20→18

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.040	H-atom parameters constrained
wR(F2) = 0.102	w = 1/[σ2(Fo2) + (0.0416P)2 + 0.3849P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
3317 reflections	Δρmax = 0.25 e Å−3
245 parameters	Δρmin = −0.17 e Å−3
0 restraints	Extinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0035 (10)

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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.

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 > 2sigma(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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1A	0.07166 (7)	0.04930 (18)	0.16586 (7)	0.0216 (3)
C1A	0.10529 (8)	0.3931 (2)	0.10857 (9)	0.0246 (3)
H1AA	0.1003	0.4797	0.0596	0.030*
C2A	0.14983 (8)	0.4706 (2)	0.19043 (9)	0.0247 (3)
H2AA	0.1749	0.6108	0.1977	0.030*
C3A	0.15781 (8)	0.3371 (2)	0.26439 (8)	0.0215 (3)
C4A	0.20530 (8)	0.4010 (2)	0.35202 (9)	0.0263 (3)
H4AA	0.2318	0.5395	0.3631	0.032*
C5A	0.21245 (8)	0.2605 (2)	0.42038 (9)	0.0281 (3)
H5AA	0.2442	0.3033	0.4776	0.034*
C6A	0.17178 (9)	0.0509 (2)	0.40428 (9)	0.0281 (3)
H6AA	0.1770	−0.0437	0.4511	0.034*
C7A	0.12485 (8)	−0.0149 (2)	0.32079 (9)	0.0248 (3)
H7AA	0.0977	−0.1528	0.3114	0.030*
C8A	0.11711 (8)	0.1247 (2)	0.24836 (8)	0.0201 (3)
C9A	0.06639 (8)	0.1799 (2)	0.09801 (8)	0.0218 (3)
C10A	0.01868 (8)	0.0993 (2)	0.00925 (8)	0.0232 (3)
H10A	0.0142	0.1934	−0.0375	0.028*
N1B	0.69538 (18)	0.8831 (3)	0.07847 (10)	0.0206 (5)	0.780 (6)
C1B	0.57855 (14)	0.6355 (5)	0.08990 (15)	0.0210 (5)	0.780 (6)
H1B	0.5174	0.6104	0.0801	0.025*	0.780 (6)
C2B	0.6415 (3)	0.4802 (7)	0.1311 (3)	0.0247 (9)	0.780 (6)
H2B	0.6231	0.3476	0.1486	0.030*	0.780 (6)
C3B	0.7367 (3)	0.5221 (6)	0.1476 (2)	0.0161 (7)	0.780 (6)
C4B	0.8065 (3)	0.3683 (7)	0.1894 (3)	0.0215 (9)	0.780 (6)
H4B	0.7918	0.2321	0.2072	0.026*	0.780 (6)
C5B	0.89117 (17)	0.4192 (6)	0.20252 (17)	0.0241 (6)	0.780 (6)
H5B	0.9360	0.3167	0.2284	0.029*	0.780 (6)
C6B	0.91586 (16)	0.6283 (5)	0.17789 (16)	0.0236 (6)	0.780 (6)
H6B	0.9765	0.6623	0.1891	0.028*	0.780 (6)
C7B	0.8505 (2)	0.7811 (4)	0.13753 (16)	0.0219 (5)	0.780 (6)
H7B	0.8670	0.9174	0.1213	0.026*	0.780 (6)
C8B	0.7575 (3)	0.7292 (7)	0.1208 (2)	0.0182 (7)	0.780 (6)
C9B	0.6082 (2)	0.8361 (4)	0.06227 (11)	0.0192 (5)	0.780 (6)
C10B	0.54504 (13)	1.0039 (3)	0.01229 (11)	0.0208 (6)	0.780 (6)
H10B	0.5703	1.1285	−0.0039	0.025*	0.780 (6)
N1C	0.3376 (6)	1.1411 (12)	−0.0755 (4)	0.0140 (16)*	0.220 (6)
C1C	0.4292 (7)	1.4289 (18)	−0.1047 (6)	0.026 (2)*	0.220 (6)
H1C	0.4870	1.4748	−0.1013	0.031*	0.220 (6)
C2C	0.3606 (11)	1.556 (3)	−0.1416 (11)	0.014 (3)*	0.220 (6)
H2C	0.3687	1.6944	−0.1628	0.017*	0.220 (6)
C3C	0.2813 (9)	1.486 (2)	−0.1479 (10)	0.011 (3)*	0.220 (6)
C4C	0.2057 (13)	1.604 (3)	−0.1817 (12)	0.024 (4)*	0.220 (6)
H4C	0.2120	1.7485	−0.1976	0.029*	0.220 (6)
C5C	0.1046 (7)	1.515 (2)	−0.1969 (7)	0.020 (3)*	0.220 (6)
H5C	0.0529	1.5947	−0.2263	0.025*	0.220 (6)
C6C	0.1025 (8)	1.3099 (17)	−0.1622 (6)	0.022 (2)*	0.220 (6)
H6C	0.0474	1.2482	−0.1645	0.026*	0.220 (6)
C7C	0.1792 (8)	1.197 (2)	−0.1248 (6)	0.026 (3)*	0.220 (6)
H7C	0.1743	1.0569	−0.1035	0.031*	0.220 (6)
C8C	0.2620 (12)	1.271 (4)	−0.1160 (13)	0.030 (5)*	0.220 (6)
C9C	0.4178 (6)	1.2225 (17)	−0.0697 (5)	0.0172 (18)*	0.220 (6)
C10C	0.4987 (5)	1.0882 (12)	−0.0238 (4)	0.023 (2)*	0.220 (6)
H10C	0.5533	1.1342	−0.0294	0.028*	0.220 (6)

	U11	U22	U33	U12	U13	U23
N1A	0.0207 (5)	0.0220 (6)	0.0214 (6)	0.0007 (4)	0.0058 (4)	−0.0004 (5)
C1A	0.0220 (6)	0.0249 (7)	0.0272 (7)	0.0016 (5)	0.0083 (5)	0.0051 (6)
C2A	0.0214 (6)	0.0195 (7)	0.0330 (8)	−0.0017 (5)	0.0084 (6)	−0.0009 (6)
C3A	0.0174 (6)	0.0220 (7)	0.0253 (7)	0.0022 (5)	0.0072 (5)	−0.0030 (5)
C4A	0.0227 (6)	0.0248 (7)	0.0301 (8)	0.0003 (5)	0.0068 (5)	−0.0085 (6)
C5A	0.0248 (7)	0.0365 (8)	0.0213 (7)	0.0032 (6)	0.0052 (5)	−0.0089 (6)
C6A	0.0282 (7)	0.0344 (8)	0.0222 (7)	0.0036 (6)	0.0088 (5)	0.0023 (6)
C7A	0.0250 (7)	0.0245 (7)	0.0251 (7)	−0.0009 (5)	0.0083 (5)	0.0005 (6)
C8A	0.0163 (6)	0.0215 (7)	0.0226 (7)	0.0012 (5)	0.0064 (5)	−0.0013 (5)
C9A	0.0189 (6)	0.0225 (7)	0.0236 (7)	0.0022 (5)	0.0065 (5)	0.0017 (5)
C10A	0.0214 (6)	0.0265 (7)	0.0209 (7)	0.0029 (5)	0.0058 (5)	0.0034 (6)
N1B	0.0168 (11)	0.0220 (9)	0.0217 (8)	−0.0001 (7)	0.0045 (7)	0.0001 (6)
C1B	0.0193 (9)	0.0226 (15)	0.0203 (10)	−0.0011 (9)	0.0051 (7)	−0.0014 (10)
C2B	0.0308 (15)	0.0216 (19)	0.0228 (16)	−0.0083 (12)	0.0103 (11)	−0.0013 (13)
C3B	0.0110 (15)	0.0222 (13)	0.0160 (11)	−0.0003 (12)	0.0056 (11)	−0.0020 (7)
C4B	0.0253 (17)	0.0185 (15)	0.0189 (14)	0.0117 (12)	0.0048 (11)	0.0069 (10)
C5B	0.0255 (12)	0.0219 (15)	0.0244 (11)	0.0049 (11)	0.0074 (8)	0.0034 (11)
C6B	0.0194 (11)	0.0273 (14)	0.0233 (11)	0.0025 (11)	0.0057 (8)	0.0023 (10)
C7B	0.0179 (13)	0.0234 (11)	0.0258 (11)	−0.0020 (11)	0.0089 (10)	−0.0010 (9)
C8B	0.022 (2)	0.0188 (13)	0.0133 (12)	0.0004 (14)	0.0051 (12)	−0.0022 (7)
C9B	0.0188 (11)	0.0192 (11)	0.0195 (9)	−0.0017 (9)	0.0061 (8)	−0.0012 (7)
C10B	0.0214 (11)	0.0190 (10)	0.0214 (9)	−0.0012 (7)	0.0061 (7)	0.0009 (7)

N1A—C9A	1.3307 (16)	C4B—H4B	0.9300
N1A—C8A	1.3661 (15)	C5B—C6B	1.422 (4)
C1A—C2A	1.3592 (18)	C5B—H5B	0.9300
C1A—C9A	1.4183 (18)	C6B—C7B	1.378 (3)
C1A—H1AA	0.9300	C6B—H6B	0.9300
C2A—C3A	1.4118 (18)	C7B—C8B	1.426 (5)
C2A—H2AA	0.9300	C7B—H7B	0.9300
C3A—C4A	1.4183 (17)	C9B—C10B	1.466 (3)
C3A—C8A	1.4259 (18)	C10B—C10Bii	1.335 (4)
C4A—C5A	1.3683 (19)	C10B—H10B	0.9300
C4A—H4AA	0.9300	N1C—C9C	1.324 (9)
C5A—C6A	1.411 (2)	N1C—C8C	1.40 (2)
C5A—H5AA	0.9300	C1C—C2C	1.30 (2)
C6A—C7A	1.3652 (18)	C1C—C9C	1.410 (10)
C6A—H6AA	0.9300	C1C—H1C	0.9300
C7A—C8A	1.4146 (18)	C2C—C3C	1.28 (2)
C7A—H7AA	0.9300	C2C—H2C	0.9300
C9A—C10A	1.4650 (17)	C3C—C4C	1.34 (2)
C10A—C10Ai	1.332 (3)	C3C—C8C	1.47 (3)
C10A—H10A	0.9300	C4C—C5C	1.61 (2)
N1B—C9B	1.333 (3)	C4C—H4C	0.9300
N1B—C8B	1.362 (5)	C5C—C6C	1.371 (13)
C1B—C2B	1.370 (5)	C5C—H5C	0.9300
C1B—C9B	1.426 (3)	C6C—C7C	1.344 (11)
C1B—H1B	0.9300	C6C—H6C	0.9300
C2B—C3B	1.448 (6)	C7C—C8C	1.335 (18)
C2B—H2B	0.9300	C7C—H7C	0.9300
C3B—C8B	1.403 (6)	C9C—C10C	1.486 (11)
C3B—C4B	1.429 (5)	C10C—C10Cii	1.311 (15)
C4B—C5B	1.308 (6)	C10C—H10C	0.9300
C9A—N1A—C8A	118.11 (11)	C7B—C6B—C5B	120.5 (2)
C2A—C1A—C9A	119.88 (12)	C7B—C6B—H6B	119.8
C2A—C1A—H1AA	120.1	C5B—C6B—H6B	119.8
C9A—C1A—H1AA	120.1	C6B—C7B—C8B	119.7 (2)
C1A—C2A—C3A	119.68 (12)	C6B—C7B—H7B	120.2
C1A—C2A—H2AA	120.2	C8B—C7B—H7B	120.2
C3A—C2A—H2AA	120.2	N1B—C8B—C3B	124.8 (4)
C2A—C3A—C4A	123.73 (12)	N1B—C8B—C7B	117.5 (3)
C2A—C3A—C8A	117.09 (11)	C3B—C8B—C7B	117.7 (3)
C4A—C3A—C8A	119.16 (12)	N1B—C9B—C1B	122.53 (17)
C5A—C4A—C3A	120.54 (13)	N1B—C9B—C10B	115.0 (2)
C5A—C4A—H4AA	119.7	C1B—C9B—C10B	122.4 (2)
C3A—C4A—H4AA	119.7	C10Bii—C10B—C9B	126.7 (2)
C4A—C5A—C6A	120.12 (12)	C10Bii—C10B—H10B	116.7
C4A—C5A—H5AA	119.9	C9B—C10B—H10B	116.7
C6A—C5A—H5AA	119.9	C9C—N1C—C8C	117.5 (11)
C7A—C6A—C5A	120.80 (13)	C2C—C1C—C9C	121.4 (10)
C7A—C6A—H6AA	119.6	C2C—C1C—H1C	119.3
C5A—C6A—H6AA	119.6	C9C—C1C—H1C	119.3
C6A—C7A—C8A	120.67 (13)	C3C—C2C—C1C	118.0 (14)
C6A—C7A—H7AA	119.7	C3C—C2C—H2C	121.0
C8A—C7A—H7AA	119.7	C1C—C2C—H2C	121.0
N1A—C8A—C7A	118.54 (12)	C2C—C3C—C4C	123.7 (16)
N1A—C8A—C3A	122.77 (12)	C2C—C3C—C8C	124.9 (14)
C7A—C8A—C3A	118.69 (11)	C4C—C3C—C8C	111.4 (14)
N1A—C9A—C1A	122.47 (12)	C3C—C4C—C5C	125.1 (14)
N1A—C9A—C10A	118.44 (12)	C3C—C4C—H4C	117.5
C1A—C9A—C10A	119.09 (12)	C5C—C4C—H4C	117.5
C10Ai—C10A—C9A	124.71 (15)	C6C—C5C—C4C	113.2 (10)
C10Ai—C10A—H10A	117.6	C6C—C5C—H5C	123.4
C9A—C10A—H10A	117.6	C4C—C5C—H5C	123.4
C9B—N1B—C8B	118.0 (3)	C7C—C6C—C5C	120.8 (11)
C2B—C1B—C9B	119.0 (2)	C7C—C6C—H6C	119.6
C2B—C1B—H1B	120.5	C5C—C6C—H6C	119.6
C9B—C1B—H1B	120.5	C8C—C7C—C6C	124.7 (14)
C1B—C2B—C3B	120.2 (3)	C8C—C7C—H7C	117.7
C1B—C2B—H2B	119.9	C6C—C7C—H7C	117.7
C3B—C2B—H2B	119.9	C7C—C8C—N1C	120.2 (18)
C8B—C3B—C4B	120.9 (4)	C7C—C8C—C3C	124.4 (16)
C8B—C3B—C2B	115.4 (4)	N1C—C8C—C3C	115.3 (14)
C4B—C3B—C2B	123.7 (4)	N1C—C9C—C1C	122.9 (8)
C5B—C4B—C3B	120.0 (4)	N1C—C9C—C10C	117.7 (9)
C5B—C4B—H4B	120.0	C1C—C9C—C10C	119.3 (9)
C3B—C4B—H4B	120.0	C10Cii—C10C—C9C	126.9 (9)
C4B—C5B—C6B	121.2 (3)	C10Cii—C10C—H10C	116.6
C4B—C5B—H5B	119.4	C9C—C10C—H10C	116.6
C6B—C5B—H5B	119.4
C9A—C1A—C2A—C3A	0.64 (18)	C2B—C3B—C8B—N1B	−2.9 (5)
C1A—C2A—C3A—C4A	178.00 (12)	C4B—C3B—C8B—C7B	−0.6 (5)
C1A—C2A—C3A—C8A	−0.46 (17)	C2B—C3B—C8B—C7B	178.5 (3)
C2A—C3A—C4A—C5A	−178.12 (12)	C6B—C7B—C8B—N1B	−178.1 (2)
C8A—C3A—C4A—C5A	0.32 (18)	C6B—C7B—C8B—C3B	0.6 (4)
C3A—C4A—C5A—C6A	−0.58 (19)	C8B—N1B—C9B—C1B	2.0 (3)
C4A—C5A—C6A—C7A	−0.06 (19)	C8B—N1B—C9B—C10B	−176.8 (2)
C5A—C6A—C7A—C8A	0.96 (19)	C2B—C1B—C9B—N1B	−3.1 (3)
C9A—N1A—C8A—C7A	−178.59 (11)	C2B—C1B—C9B—C10B	175.6 (3)
C9A—N1A—C8A—C3A	0.75 (17)	N1B—C9B—C10B—C10Bii	179.9 (2)
C6A—C7A—C8A—N1A	178.17 (11)	C1B—C9B—C10B—C10Bii	1.1 (3)
C6A—C7A—C8A—C3A	−1.20 (18)	C9C—C1C—C2C—C3C	−2(2)
C2A—C3A—C8A—N1A	−0.24 (17)	C1C—C2C—C3C—C4C	177.6 (16)
C4A—C3A—C8A—N1A	−178.78 (11)	C1C—C2C—C3C—C8C	0(3)
C2A—C3A—C8A—C7A	179.10 (11)	C2C—C3C—C4C—C5C	175.5 (15)
C4A—C3A—C8A—C7A	0.56 (17)	C8C—C3C—C4C—C5C	−7(2)
C8A—N1A—C9A—C1A	−0.58 (17)	C3C—C4C—C5C—C6C	7(2)
C8A—N1A—C9A—C10A	179.29 (10)	C4C—C5C—C6C—C7C	−3.8 (16)
C2A—C1A—C9A—N1A	−0.11 (19)	C5C—C6C—C7C—C8C	2(2)
C2A—C1A—C9A—C10A	−179.98 (11)	C6C—C7C—C8C—N1C	179.5 (11)
N1A—C9A—C10A—C10Ai	−1.6 (2)	C6C—C7C—C8C—C3C	−1(3)
C1A—C9A—C10A—C10Ai	178.32 (15)	C9C—N1C—C8C—C7C	179.2 (13)
C9B—C1B—C2B—C3B	1.1 (5)	C9C—N1C—C8C—C3C	0.2 (19)
C1B—C2B—C3B—C8B	1.6 (6)	C2C—C3C—C8C—C7C	−178.3 (17)
C1B—C2B—C3B—C4B	−179.3 (4)	C4C—C3C—C8C—C7C	4(3)
C8B—C3B—C4B—C5B	−0.5 (6)	C2C—C3C—C8C—N1C	1(2)
C2B—C3B—C4B—C5B	−179.5 (4)	C4C—C3C—C8C—N1C	−176.8 (15)
C3B—C4B—C5B—C6B	1.6 (6)	C8C—N1C—C9C—C1C	−2.0 (15)
C4B—C5B—C6B—C7B	−1.5 (4)	C8C—N1C—C9C—C10C	177.9 (10)
C5B—C6B—C7B—C8B	0.3 (4)	C2C—C1C—C9C—N1C	3.2 (16)
C9B—N1B—C8B—C3B	1.1 (4)	C2C—C1C—C9C—C10C	−176.7 (11)
C9B—N1B—C8B—C7B	179.8 (2)	N1C—C9C—C10C—C10Cii	−11.3 (12)
C4B—C3B—C8B—N1B	178.1 (3)	C1C—C9C—C10C—C10Cii	168.6 (9)

D—H···A	D—H	H···A	D···A	D—H···A
C2A—H2AA···Cg1iii	0.93	2.77	3.3409 (14)	121
C6A—H6AA···Cg2iv	0.93	2.65	3.5328 (18)	159
C4B—H4B···Cg3v	0.93	2.85	3.376 (12)	116
C6A—H6AA···Cg3vi	0.93	2.76	3.613 (10)	152

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2A—H2AA⋯Cg1i	0.93	2.77	3.3409 (14)	121
C6A—H6AA⋯Cg2ii	0.93	2.65	3.5328 (18)	159
C4B—H4B⋯Cg3iii	0.93	2.85	3.376 (12)	116
C6A—H6AA⋯Cg3iv	0.93	2.76	3.613 (10)	152

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) . Cg1, Cg2 and Cg3 are the centroids of the C3A–C8A, N1B/C8B/C3B/C2B/C1B/C9B and N1C/C8C/C3C/C2C/C1C/C9C rings, respectively.