5',11'-Dihydro-dispiro-[cyclo-hexane-1,6'-indolo[3,2-b]carbazole-12',1''-cyclo-hexa-ne].

The title compound, C(28)H(30)N(2), is a symmetrical 2:2 product from the condensation of indole and cyclo-hexa-none. It is the only reported 5,11-dihydro-indolo[3,2-b]carbazole compound in which the spiro atoms are quaternary C atoms. Crystals were grown by vapor diffusion in a three-zone electric furnace. The mol-ecule resides on a crystallographic inversion center. The cyclo-hexyl rings are in a slightly distorted chair conformation, whereas the indole units and the spiro-carbons are coplanar within 0.014 Å.

Related literature

For condensations of indole with cyclo­hexa­none that yield 1:1 or 1:2 products, see: Yadav et al. (2001 ▶). For indole–ketone condensation by forming vinyl­indole followed by a Diels–Alder reaction, see: Noland et al. (1993 ▶). Recrystallization by the vapor-phase diffusion approach is explained in Kloc et al. (1997 ▶). For information on the related compound trans-6,12-diphenyl-5,6,11,12-tetra­hydro­indolo[3,2-b]carbazole dimethyl sulfoxide tetra­hydro­furan solvate, see: Gu et al. (2009 ▶). Related compounds were found in the Cambridge Structural Database (Allen, 2002 ▶). Geometrical parameters were analyzed using Mogul (Bruno et al., 2002 ▶).

Experimental

Crystal data

C28H30N2

M = 394.54

Monoclinic,

a = 7.4655 (2) Å

b = 13.6820 (4) Å

c = 10.5348 (3) Å

β = 109.380 (1)°

V = 1015.08 (5) Å3

Z = 2

Cu Kα radiation

μ = 0.57 mm−1

T = 100 K

0.38 × 0.30 × 0.19 mm

Data collection

Bruker SMART APEXII area-detector diffractometer

Absorption correction: analytical (SADABS; Bruker, 2007 ▶) T min = 0.813, T max = 0.900

20619 measured reflections

1826 independent reflections

1779 reflections with I > 2σ(I)

R int = 0.022

Refinement

R[F 2 > 2σ(F 2)] = 0.041

wR(F 2) = 0.113

S = 0.99

1826 reflections

140 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.35 e Å−3

Δρmin = −0.22 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT-Plus (Bruker, 2007 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL, FCF_filter (Guzei, 2007 ▶) and INSerter (Guzei, 2007 ▶); molecular graphics: SHELXTL and DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: SHELXTL, publCIF (Westrip, 2010 ▶) and modiCIFer (Guzei, 2007 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811051208/nk2127sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811051208/nk2127Isup2.hkl

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

C28H30N2	F(000) = 424
Mr = 394.54	Dx = 1.291 Mg m−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ybc	Cell parameters from 9920 reflections
a = 7.4655 (2) Å	θ = 5.5–67.3°
b = 13.6820 (4) Å	µ = 0.57 mm−1
c = 10.5348 (3) Å	T = 100 K
β = 109.380 (1)°	Block, colourless
V = 1015.08 (5) Å3	0.38 × 0.30 × 0.19 mm
Z = 2

Bruker SMART APEXII area-detector diffractometer	1826 independent reflections
Radiation source: fine-focus sealed tube	1779 reflections with I > 2σ(I)
graphite	Rint = 0.022
0.50° ω and 0.5 ° φ scans	θmax = 67.7°, θmin = 5.5°
Absorption correction: analytical (SADABS; Bruker, 2007)	h = −8→8
Tmin = 0.813, Tmax = 0.900	k = −16→16
20619 measured reflections	l = −12→12

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ2(Fo2) + (0.0708P)2 + 0.5526P] where P = (Fo2 + 2Fc2)/3
1826 reflections	(Δ/σ)max < 0.001
140 parameters	Δρmax = 0.35 e Å−3
0 restraints	Δρmin = −0.22 e Å−3

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	0.79965 (15)	0.12731 (8)	0.03500 (11)	0.0165 (3)
H1	0.837 (2)	0.1597 (11)	−0.0234 (16)	0.017 (4)*
C1	0.87673 (18)	0.13818 (9)	0.17213 (13)	0.0164 (3)
C2	1.02992 (18)	0.19577 (9)	0.24794 (13)	0.0182 (3)
H2	1.0995	0.2347	0.2059	0.022*
C3	1.07633 (18)	0.19384 (9)	0.38671 (13)	0.0191 (3)
H3	1.1790	0.2324	0.4410	0.023*
C4	0.97353 (19)	0.13558 (9)	0.44782 (13)	0.0190 (3)
H4	1.0083	0.1353	0.5431	0.023*
C5	0.82312 (18)	0.07871 (9)	0.37278 (13)	0.0173 (3)
H5	0.7556	0.0394	0.4160	0.021*
C6	0.77079 (18)	0.07954 (9)	0.23203 (13)	0.0157 (3)
C7	0.62336 (17)	0.03331 (9)	0.12319 (12)	0.0154 (3)
C8	0.64558 (17)	0.06437 (9)	0.00578 (13)	0.0151 (3)
C9	0.47366 (17)	−0.03714 (9)	0.13577 (12)	0.0153 (3)
C10	0.57699 (18)	−0.12878 (9)	0.21510 (13)	0.0170 (3)
H10A	0.6210	−0.1696	0.1537	0.020*
H10B	0.6910	−0.1065	0.2886	0.020*
C11	0.45854 (19)	−0.19262 (9)	0.27583 (13)	0.0189 (3)
H11A	0.3571	−0.2254	0.2027	0.023*
H11B	0.5403	−0.2438	0.3329	0.023*
C12	0.3696 (2)	−0.13171 (10)	0.36026 (13)	0.0217 (3)
H12A	0.4709	−0.1009	0.4354	0.026*
H12B	0.2941	−0.1746	0.3990	0.026*
C13	0.24144 (19)	−0.05256 (10)	0.27410 (13)	0.0194 (3)
H13A	0.1855	−0.0135	0.3306	0.023*
H13B	0.1362	−0.0837	0.2020	0.023*
C14	0.35216 (18)	0.01490 (9)	0.21105 (13)	0.0172 (3)
H14A	0.4375	0.0562	0.2831	0.021*
H14B	0.2607	0.0589	0.1468	0.021*

	U11	U22	U33	U12	U13	U23
N1	0.0180 (6)	0.0177 (6)	0.0138 (6)	−0.0033 (4)	0.0054 (4)	0.0008 (4)
C1	0.0180 (6)	0.0154 (6)	0.0148 (6)	0.0033 (5)	0.0041 (5)	0.0004 (5)
C2	0.0191 (7)	0.0160 (6)	0.0192 (7)	−0.0008 (5)	0.0058 (5)	0.0009 (5)
C3	0.0178 (6)	0.0174 (6)	0.0181 (7)	−0.0022 (5)	0.0007 (5)	−0.0022 (5)
C4	0.0214 (7)	0.0188 (7)	0.0149 (6)	0.0021 (5)	0.0036 (5)	−0.0005 (5)
C5	0.0196 (6)	0.0158 (6)	0.0166 (6)	0.0006 (5)	0.0063 (5)	0.0002 (5)
C6	0.0160 (6)	0.0130 (6)	0.0183 (6)	0.0021 (5)	0.0061 (5)	−0.0006 (5)
C7	0.0156 (6)	0.0147 (6)	0.0144 (6)	0.0027 (5)	0.0032 (5)	−0.0015 (5)
C8	0.0140 (6)	0.0133 (6)	0.0177 (6)	0.0008 (4)	0.0050 (5)	−0.0007 (5)
C9	0.0171 (6)	0.0151 (6)	0.0138 (6)	0.0007 (5)	0.0055 (5)	0.0003 (5)
C10	0.0178 (6)	0.0167 (7)	0.0152 (6)	0.0004 (5)	0.0039 (5)	−0.0008 (5)
C11	0.0223 (7)	0.0159 (6)	0.0159 (6)	−0.0017 (5)	0.0030 (5)	0.0019 (5)
C12	0.0276 (7)	0.0224 (7)	0.0169 (6)	−0.0049 (5)	0.0099 (6)	0.0016 (5)
C13	0.0204 (7)	0.0224 (7)	0.0176 (6)	−0.0027 (5)	0.0090 (5)	−0.0032 (5)
C14	0.0191 (6)	0.0169 (6)	0.0158 (6)	−0.0002 (5)	0.0060 (5)	−0.0013 (5)

N1—C1	1.3743 (16)	C9—C8i	1.5080 (17)
N1—C8	1.3872 (16)	C9—C14	1.5608 (16)
N1—H1	0.876 (17)	C9—C10	1.5612 (17)
C1—C2	1.4001 (18)	C10—C11	1.5264 (17)
C1—C6	1.4137 (18)	C10—H10A	0.9900
C2—C3	1.3862 (19)	C10—H10B	0.9900
C2—H2	0.9500	C11—C12	1.5227 (19)
C3—C4	1.4024 (19)	C11—H11A	0.9900
C3—H3	0.9500	C11—H11B	0.9900
C4—C5	1.3791 (18)	C12—C13	1.5282 (19)
C4—H4	0.9500	C12—H12A	0.9900
C5—C6	1.4026 (18)	C12—H12B	0.9900
C5—H5	0.9500	C13—C14	1.5299 (17)
C6—C7	1.4452 (17)	C13—H13A	0.9900
C7—C8	1.3690 (18)	C13—H13B	0.9900
C7—C9	1.5146 (17)	C14—H14A	0.9900
C8—C9i	1.5080 (17)	C14—H14B	0.9900
C1—N1—C8	109.12 (11)	C14—C9—C10	111.20 (10)
C1—N1—H1	124.3 (10)	C11—C10—C9	115.59 (10)
C8—N1—H1	126.3 (10)	C11—C10—H10A	108.4
N1—C1—C2	129.67 (12)	C9—C10—H10A	108.4
N1—C1—C6	107.86 (11)	C11—C10—H10B	108.4
C2—C1—C6	122.47 (12)	C9—C10—H10B	108.4
C3—C2—C1	117.50 (12)	H10A—C10—H10B	107.4
C3—C2—H2	121.2	C12—C11—C10	110.94 (11)
C1—C2—H2	121.2	C12—C11—H11A	109.5
C2—C3—C4	120.77 (12)	C10—C11—H11A	109.5
C2—C3—H3	119.6	C12—C11—H11B	109.5
C4—C3—H3	119.6	C10—C11—H11B	109.5
C5—C4—C3	121.54 (12)	H11A—C11—H11B	108.0
C5—C4—H4	119.2	C11—C12—C13	110.44 (10)
C3—C4—H4	119.2	C11—C12—H12A	109.6
C4—C5—C6	119.31 (12)	C13—C12—H12A	109.6
C4—C5—H5	120.3	C11—C12—H12B	109.6
C6—C5—H5	120.3	C13—C12—H12B	109.6
C5—C6—C1	118.40 (11)	H12A—C12—H12B	108.1
C5—C6—C7	134.98 (12)	C12—C13—C14	111.31 (10)
C1—C6—C7	106.61 (11)	C12—C13—H13A	109.4
C8—C7—C6	106.99 (11)	C14—C13—H13A	109.4
C8—C7—C9	126.21 (11)	C12—C13—H13B	109.4
C6—C7—C9	126.79 (11)	C14—C13—H13B	109.4
C7—C8—N1	109.41 (11)	H13A—C13—H13B	108.0
C7—C8—C9i	127.44 (12)	C13—C14—C9	115.74 (10)
N1—C8—C9i	123.14 (11)	C13—C14—H14A	108.3
C8i—C9—C7	106.34 (10)	C9—C14—H14A	108.3
C8i—C9—C14	111.30 (10)	C13—C14—H14B	108.3
C7—C9—C14	108.92 (10)	C9—C14—H14B	108.3
C8i—C9—C10	110.83 (10)	H14A—C14—H14B	107.4
C7—C9—C10	108.06 (10)
C8—N1—C1—C2	−178.37 (13)	C9—C7—C8—C9i	0.9 (2)
C8—N1—C1—C6	0.86 (13)	C1—N1—C8—C7	−0.72 (14)
N1—C1—C2—C3	179.13 (12)	C1—N1—C8—C9i	179.29 (11)
C6—C1—C2—C3	−0.01 (19)	C8—C7—C9—C8i	−0.78 (18)
C1—C2—C3—C4	0.44 (19)	C6—C7—C9—C8i	−179.97 (11)
C2—C3—C4—C5	−0.2 (2)	C8—C7—C9—C14	−120.82 (13)
C3—C4—C5—C6	−0.40 (19)	C6—C7—C9—C14	59.99 (15)
C4—C5—C6—C1	0.80 (18)	C8—C7—C9—C10	118.26 (13)
C4—C5—C6—C7	−178.16 (13)	C6—C7—C9—C10	−60.93 (15)
N1—C1—C6—C5	−179.91 (11)	C8i—C9—C10—C11	−82.20 (13)
C2—C1—C6—C5	−0.61 (18)	C7—C9—C10—C11	161.65 (10)
N1—C1—C6—C7	−0.68 (13)	C14—C9—C10—C11	42.16 (14)
C2—C1—C6—C7	178.62 (11)	C9—C10—C11—C12	−52.32 (14)
C5—C6—C7—C8	179.29 (14)	C10—C11—C12—C13	59.53 (14)
C1—C6—C7—C8	0.25 (13)	C11—C12—C13—C14	−58.68 (14)
C5—C6—C7—C9	−1.4 (2)	C12—C13—C14—C9	50.47 (14)
C1—C6—C7—C9	179.57 (11)	C8i—C9—C14—C13	82.87 (13)
C6—C7—C8—N1	0.27 (14)	C7—C9—C14—C13	−160.20 (10)
C9—C7—C8—N1	−179.06 (11)	C10—C9—C14—C13	−41.22 (14)
C6—C7—C8—C9i	−179.73 (11)

N1—C1	1.3743 (16)
N1—C8	1.3872 (16)

C1—N1—C8

109.12 (11)