5,11-Dimethyl-6,12-dimeth-oxy-indolo[3,2-b]carbazole.

The title compound, C(22)H(20)N(2)O(2), was prepared in a twofold Cadogan cyclization followed by double N-methyl-ation. The crystal structure is characterized by a zigzag arrangement of centrosymmetric mol-ecules. The indolocarbazole framework is essentially planar [maximum deviation = 0.028 (2) Å] and the meth-oxy groups are orthogonal to this plane [C-C-O-C torsion angle = -88.2 (2)°]. The lengths of the C-N bonds are nearly identical and all C-C bonds of the pyrrole subunit are significantly longer than the C-C bonds in the benzene rings.

Related literature

For the synthesis of starting material see: Wrobel et al. (2012 ▶). For the Cadogan reaction, see: Cadogan (1962 ▶); Peng et al. (2011 ▶). For other approaches to indolocarbazoles, see: Knölker & Reddy (2002 ▶); Katritzky et al. (1995 ▶). For the structure of N-unsubstituted indolocarbazole, see: Wrobel et al. (2013 ▶). For electronic properties of indolocarbazoles, see: Hu et al. (1999 ▶); Wakim et al. (2004 ▶); Nemkovich et al. (2009 ▶). For heteroanalogous carbazoles, see: Dassonneville et al. (2011 ▶); Letessier & Detert (2012 ▶); Nissen & Detert (2011 ▶); Letessier et al. (2012 ▶). For conjugated oligomers, see: Detert et al. (2010 ▶).

Experimental

Crystal data

C22H20N2O2

M = 344.40

Monoclinic,

a = 11.229 (4) Å

b = 7.8561 (7) Å

c = 9.668 (3) Å

β = 94.790 (17)°

V = 849.9 (4) Å3

Z = 2

Cu Kα radiation

μ = 0.69 mm−1

T = 193 K

0.30 × 0.30 × 0.18 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

1716 measured reflections

1612 independent reflections

1410 reflections with I > 2σ(I)

R int = 0.029

3 standard reflections every 60 min intensity decay: 4%

Refinement

R[F 2 > 2σ(F 2)] = 0.049

wR(F 2) = 0.152

S = 1.10

1612 reflections

120 parameters

H-atom parameters constrained

Δρmax = 0.25 e Å−3

Δρmin = −0.27 e Å−3

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: CORINC (Dräger & Gattow, 1971 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Click here for additional data file.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813001463/bt6882sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813001463/bt6882Isup2.hkl

Click here for additional data file.

Supplementary material file. DOI: 10.1107/S1600536813001463/bt6882Isup3.cml

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

C22H20N2O2	F(000) = 364
Mr = 344.40	Dx = 1.346 Mg m−3
Monoclinic, P21/c	Melting point: 530 K
Hall symbol: -P 2ybc	Cu Kα radiation, λ = 1.54178 Å
a = 11.229 (4) Å	Cell parameters from 25 reflections
b = 7.8561 (7) Å	θ = 30–44°
c = 9.668 (3) Å	µ = 0.69 mm−1
β = 94.790 (17)°	T = 193 K
V = 849.9 (4) Å3	Plate, colourless
Z = 2	0.30 × 0.30 × 0.18 mm

Enraf–Nonius CAD-4 diffractometer	Rint = 0.029
Radiation source: rotating anode	θmax = 70.0°, θmin = 4.0°
Graphite monochromator	h = −13→13
ω/2θ scans	k = −9→0
1716 measured reflections	l = −11→0
1612 independent reflections	3 standard reflections every 60 min
1410 reflections with I > 2σ(I)	intensity decay: 4%

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.152	H-atom parameters constrained
S = 1.10	w = 1/[σ2(Fo2) + (0.0969P)2 + 0.1743P] where P = (Fo2 + 2Fc2)/3
1612 reflections	(Δ/σ)max < 0.001
120 parameters	Δρmax = 0.25 e Å−3
0 restraints	Δρmin = −0.27 e Å−3

Experimental. H-NMR (400 MHz, CDCl3): 8.25 (d, J = 7.7 Hz, 2 H), 7.58 (d, J = 7.7 Hz, 2 H), 7.50 (dt, J = 7.7 Hz, J= 1.0 Hz, 2 H), 7.26 - 7.22 (m, 2 H), 4.17 (s, 6 H, CH3), 4.15 (s, CH3).C-NMR (75 MHz, CDCl3): 145.2 (s), 136.4 (s), 128.5 (s), 125.6 (d), 122.7 (d), 121.5 (s), 118.7 (d), 117.8 (s), 108.0 (d), 61.8 (q), 31.2 (q).IR (ATR) 3043, 2926, 2850, 2828, 1733, 1608, 1530, 1465, 1438, 1390, 1324, 1289, 1247, 1200, 1154, 1117, 1078, 1006, 933 cm-1.MS (EI): 344 (100%) [M]+.ESI-HRMS: C22H21N2O2 calcd.: 345.1603, found 345.1580.UV-Vis (dichloromethane): λ = 393 nm, λmax = 412 nm; Fluorescence: λmax = 428 nm (dichloromethane).

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.

	x	y	z	Uiso*/Ueq
N1	0.25894 (13)	0.42605 (18)	0.48867 (15)	0.0346 (4)
C2	0.21698 (16)	0.4933 (2)	0.36211 (18)	0.0342 (4)
C3	0.10013 (17)	0.4953 (2)	0.3004 (2)	0.0416 (5)
H3	0.0365	0.4447	0.3445	0.050*
C4	0.08055 (19)	0.5736 (3)	0.1724 (2)	0.0476 (5)
H4	0.0018	0.5763	0.1282	0.057*
C5	0.1729 (2)	0.6487 (2)	0.1064 (2)	0.0475 (5)
H5	0.1561	0.7023	0.0188	0.057*
C6	0.28932 (18)	0.6459 (2)	0.16765 (19)	0.0397 (5)
H6	0.3524	0.6961	0.1223	0.048*
C7	0.31206 (16)	0.56790 (19)	0.29716 (18)	0.0330 (4)
C8	0.41824 (15)	0.54265 (19)	0.38964 (17)	0.0303 (4)
C9	0.38140 (15)	0.45609 (19)	0.50808 (17)	0.0307 (4)
C10	0.18776 (17)	0.3313 (3)	0.5793 (2)	0.0480 (5)
H10A	0.1158	0.2886	0.5262	0.072*
H10B	0.1648	0.4056	0.6540	0.072*
H10C	0.2344	0.2351	0.6194	0.072*
C11	0.53766 (15)	0.58538 (19)	0.38040 (17)	0.0306 (4)
O12	0.57194 (11)	0.66686 (14)	0.26343 (12)	0.0364 (4)
C13	0.6004 (2)	0.5500 (3)	0.15737 (19)	0.0480 (5)
H13A	0.6734	0.4877	0.1882	0.072*
H13B	0.6128	0.6130	0.0723	0.072*
H13C	0.5344	0.4693	0.1391	0.072*

	U11	U22	U33	U12	U13	U23
N1	0.0362 (8)	0.0301 (7)	0.0376 (8)	−0.0027 (6)	0.0035 (6)	0.0014 (6)
C2	0.0405 (9)	0.0242 (8)	0.0376 (9)	0.0030 (7)	0.0014 (7)	−0.0048 (7)
C3	0.0375 (9)	0.0346 (9)	0.0524 (11)	0.0047 (7)	0.0018 (8)	−0.0054 (8)
C4	0.0440 (10)	0.0399 (10)	0.0564 (12)	0.0108 (8)	−0.0101 (9)	−0.0038 (9)
C5	0.0569 (12)	0.0346 (10)	0.0486 (11)	0.0073 (8)	−0.0107 (9)	0.0039 (8)
C6	0.0507 (11)	0.0269 (8)	0.0404 (10)	0.0003 (7)	−0.0032 (8)	0.0018 (7)
C7	0.0414 (9)	0.0209 (7)	0.0362 (9)	−0.0002 (6)	0.0008 (7)	−0.0032 (6)
C8	0.0414 (9)	0.0197 (7)	0.0297 (8)	−0.0015 (6)	0.0018 (6)	−0.0019 (6)
C9	0.0381 (9)	0.0211 (7)	0.0332 (9)	−0.0027 (6)	0.0044 (7)	−0.0023 (6)
C10	0.0382 (10)	0.0556 (12)	0.0509 (12)	−0.0064 (9)	0.0085 (8)	0.0114 (9)
C11	0.0425 (9)	0.0202 (7)	0.0295 (8)	−0.0030 (6)	0.0049 (7)	0.0001 (6)
O12	0.0488 (8)	0.0283 (6)	0.0327 (7)	−0.0052 (5)	0.0060 (5)	0.0053 (5)
C13	0.0740 (14)	0.0391 (10)	0.0323 (10)	−0.0070 (9)	0.0123 (9)	0.0010 (7)

N1—C2	1.379 (2)	C7—C8	1.443 (2)
N1—C9	1.392 (2)	C8—C11	1.392 (2)
N1—C10	1.442 (2)	C8—C9	1.423 (2)
C2—C3	1.396 (3)	C9—C11i	1.390 (2)
C2—C7	1.410 (3)	C10—H10A	0.9800
C3—C4	1.383 (3)	C10—H10B	0.9800
C3—H3	0.9500	C10—H10C	0.9800
C4—C5	1.393 (3)	C11—O12	1.3818 (19)
C4—H4	0.9500	C11—C9i	1.390 (2)
C5—C6	1.390 (3)	O12—C13	1.432 (2)
C5—H5	0.9500	C13—H13A	0.9800
C6—C7	1.398 (2)	C13—H13B	0.9800
C6—H6	0.9500	C13—H13C	0.9800
C2—N1—C9	108.36 (14)	C11—C8—C7	132.65 (16)
C2—N1—C10	124.86 (16)	C9—C8—C7	106.48 (15)
C9—N1—C10	126.66 (15)	C11i—C9—N1	129.75 (16)
N1—C2—C3	128.54 (17)	C11i—C9—C8	121.42 (16)
N1—C2—C7	109.81 (16)	N1—C9—C8	108.83 (15)
C3—C2—C7	121.65 (17)	N1—C10—H10A	109.5
C4—C3—C2	117.46 (19)	N1—C10—H10B	109.5
C4—C3—H3	121.3	H10A—C10—H10B	109.5
C2—C3—H3	121.3	N1—C10—H10C	109.5
C3—C4—C5	121.99 (19)	H10A—C10—H10C	109.5
C3—C4—H4	119.0	H10B—C10—H10C	109.5
C5—C4—H4	119.0	O12—C11—C9i	122.33 (15)
C6—C5—C4	120.49 (19)	O12—C11—C8	119.98 (15)
C6—C5—H5	119.8	C9i—C11—C8	117.69 (16)
C4—C5—H5	119.8	C11—O12—C13	112.52 (13)
C5—C6—C7	118.92 (19)	O12—C13—H13A	109.5
C5—C6—H6	120.5	O12—C13—H13B	109.5
C7—C6—H6	120.5	H13A—C13—H13B	109.5
C6—C7—C2	119.49 (17)	O12—C13—H13C	109.5
C6—C7—C8	134.00 (17)	H13A—C13—H13C	109.5
C2—C7—C8	106.50 (15)	H13B—C13—H13C	109.5
C11—C8—C9	120.87 (15)
C9—N1—C2—C3	−179.06 (16)	C6—C7—C8—C9	178.78 (17)
C10—N1—C2—C3	4.7 (3)	C2—C7—C8—C9	−1.05 (18)
C9—N1—C2—C7	0.16 (18)	C2—N1—C9—C11i	179.07 (16)
C10—N1—C2—C7	−176.07 (16)	C10—N1—C9—C11i	−4.8 (3)
N1—C2—C3—C4	179.03 (17)	C2—N1—C9—C8	−0.84 (18)
C7—C2—C3—C4	−0.1 (3)	C10—N1—C9—C8	175.30 (16)
C2—C3—C4—C5	−0.1 (3)	C11—C8—C9—C11i	1.4 (3)
C3—C4—C5—C6	0.5 (3)	C7—C8—C9—C11i	−178.75 (14)
C4—C5—C6—C7	−0.6 (3)	C11—C8—C9—N1	−178.63 (14)
C5—C6—C7—C2	0.4 (2)	C7—C8—C9—N1	1.17 (18)
C5—C6—C7—C8	−179.45 (18)	C9—C8—C11—O12	178.89 (13)
N1—C2—C7—C6	−179.29 (15)	C7—C8—C11—O12	−0.9 (3)
C3—C2—C7—C6	−0.0 (2)	C9—C8—C11—C9i	−1.4 (3)
N1—C2—C7—C8	0.57 (18)	C7—C8—C11—C9i	178.86 (16)
C3—C2—C7—C8	179.85 (15)	C9i—C11—O12—C13	92.20 (19)
C6—C7—C8—C11	−1.5 (3)	C8—C11—O12—C13	−88.10 (19)
C2—C7—C8—C11	178.72 (17)