2,2',5,5'-Tetra-methyl-1,1'-(hexane-1,6-di-yl)di-1H-pyrrole.

The mol-ecule of the title compound, C(18)H(28)N(2), composed of two 2,5-dimethyl-pyrrole groups linked by a hexane chain, lies across a crystallographic inversion centre. The mean plane of the pyrrole ring is almost perpendicular to the mean plane of the central chain, making a dihedral angle of 89.09 (8)°. The crystal structure is stabilized by inter-molecular C-H⋯π inter-actions.

Related literature

For the use of chain spacers in conductive polymers, see: Zotti et al. (1997 ▶); Chane-Ching et al. (1998 ▶); Just et al. (1999 ▶). For related structures, see: Ramos Silva et al. (2002 ▶, 2005 ▶, 2008 ▶).

Experimental

Crystal data

C18H28N2

M = 272.42

Monoclinic,

a = 7.7608 (3) Å

b = 6.4767 (3) Å

c = 16.7738 (7) Å

β = 94.309 (3)°

V = 840.74 (6) Å3

Z = 2

Mo Kα radiation

μ = 0.06 mm−1

T = 293 K

0.35 × 0.10 × 0.06 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2000 ▶) T min = 0.881, T max = 0.997

12290 measured reflections

3799 independent reflections

2110 reflections with I > 2σ(I)

R int = 0.025

Refinement

R[F 2 > 2σ(F 2)] = 0.053

wR(F 2) = 0.180

S = 1.03

3799 reflections

93 parameters

H-atom parameters constrained

Δρmax = 0.33 e Å−3

Δρmin = −0.24 e Å−3

Data collection: SMART (Bruker, 2003 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809021965/su2118sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809021965/su2118Isup2.hkl

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

C18H28N2	F(000) = 300
Mr = 272.42	Dx = 1.076 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.7608 (3) Å	Cell parameters from 2568 reflections
b = 6.4767 (3) Å	θ = 2.6–30.6°
c = 16.7738 (7) Å	µ = 0.06 mm−1
β = 94.309 (3)°	T = 293 K
V = 840.74 (6) Å3	Needle, yellow
Z = 2	0.35 × 0.10 × 0.06 mm

Bruker SMART APEX CCD area-detector diffractometer	3799 independent reflections
Radiation source: fine-focus sealed tube	2110 reflections with I > 2σ(I)
graphite	Rint = 0.025
φ and ω scans	θmax = 35.4°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −12→12
Tmin = 0.881, Tmax = 0.997	k = −10→10
12290 measured reflections	l = −27→26

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.180	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.084P)2 + 0.0541P] where P = (Fo2 + 2Fc2)/3
3799 reflections	(Δ/σ)max < 0.001
93 parameters	Δρmax = 0.33 e Å−3
0 restraints	Δρmin = −0.24 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	0.36575 (10)	0.90724 (13)	0.13870 (5)	0.0405 (2)
C2	0.15288 (14)	0.71268 (16)	0.04807 (6)	0.0461 (2)
H2A	0.2278	0.7239	0.0045	0.055*
H2B	0.0732	0.8283	0.0444	0.055*
C1	0.05154 (13)	0.51178 (16)	0.03991 (6)	0.0438 (2)
H1A	0.1315	0.3970	0.0471	0.053*
H1B	−0.0269	0.5048	0.0822	0.053*
C7	0.32211 (13)	1.07945 (16)	0.18158 (6)	0.0444 (2)
C3	0.26078 (15)	0.72241 (17)	0.12703 (6)	0.0490 (3)
H3A	0.1842	0.7133	0.1700	0.059*
H3B	0.3363	0.6029	0.1310	0.059*
C4	0.53191 (13)	0.92871 (18)	0.11692 (6)	0.0473 (3)
C6	0.46125 (16)	1.20827 (17)	0.18618 (7)	0.0513 (3)
H6	0.4681	1.3360	0.2116	0.062*
C5	0.59257 (15)	1.1140 (2)	0.14579 (7)	0.0547 (3)
H5	0.7017	1.1684	0.1398	0.066*
C8	0.15291 (18)	1.1023 (3)	0.21603 (10)	0.0741 (4)
H8A	0.1485	1.2332	0.2427	0.111*
H8B	0.1386	0.9932	0.2537	0.111*
H8C	0.0620	1.0952	0.1740	0.111*
C9	0.61868 (19)	0.7690 (3)	0.07002 (9)	0.0770 (5)
H9A	0.7339	0.8135	0.0615	0.116*
H9B	0.5546	0.7496	0.0194	0.116*
H9C	0.6235	0.6411	0.0990	0.116*

	U11	U22	U33	U12	U13	U23
N1	0.0412 (4)	0.0383 (4)	0.0410 (4)	0.0004 (3)	−0.0041 (3)	−0.0022 (3)
C2	0.0477 (5)	0.0449 (6)	0.0443 (5)	−0.0050 (4)	−0.0057 (4)	0.0003 (4)
C1	0.0452 (5)	0.0434 (5)	0.0420 (5)	−0.0030 (4)	−0.0018 (4)	−0.0029 (4)
C7	0.0486 (5)	0.0423 (5)	0.0413 (5)	0.0083 (4)	−0.0031 (4)	−0.0014 (4)
C3	0.0554 (6)	0.0420 (5)	0.0475 (6)	−0.0075 (4)	−0.0093 (4)	0.0022 (4)
C4	0.0420 (5)	0.0562 (6)	0.0430 (5)	0.0043 (4)	−0.0008 (4)	0.0002 (4)
C6	0.0670 (7)	0.0383 (5)	0.0463 (6)	−0.0021 (5)	−0.0113 (5)	−0.0001 (4)
C5	0.0489 (6)	0.0623 (7)	0.0514 (6)	−0.0127 (5)	−0.0062 (4)	0.0088 (5)
C8	0.0626 (8)	0.0870 (11)	0.0739 (9)	0.0184 (7)	0.0119 (6)	−0.0092 (8)
C9	0.0652 (8)	0.0941 (11)	0.0722 (9)	0.0247 (8)	0.0077 (7)	−0.0169 (8)

N1—C4	1.3735 (13)	C3—H3B	0.9700
N1—C7	1.3830 (13)	C4—C5	1.3647 (17)
N1—C3	1.4529 (13)	C4—C9	1.4904 (17)
C2—C3	1.5141 (14)	C6—C5	1.4049 (18)
C2—C1	1.5212 (14)	C6—H6	0.9300
C2—H2A	0.9700	C5—H5	0.9300
C2—H2B	0.9700	C8—H8A	0.9600
C1—C1i	1.5149 (18)	C8—H8B	0.9600
C1—H1A	0.9700	C8—H8C	0.9600
C1—H1B	0.9700	C9—H9A	0.9600
C7—C6	1.3622 (16)	C9—H9B	0.9600
C7—C8	1.4812 (17)	C9—H9C	0.9600
C3—H3A	0.9700
C4—N1—C7	109.16 (9)	H3A—C3—H3B	107.5
C4—N1—C3	125.15 (9)	C5—C4—N1	107.48 (10)
C7—N1—C3	125.29 (9)	C5—C4—C9	129.80 (12)
C3—C2—C1	111.26 (8)	N1—C4—C9	122.72 (11)
C3—C2—H2A	109.4	C7—C6—C5	107.90 (10)
C1—C2—H2A	109.4	C7—C6—H6	126.1
C3—C2—H2B	109.4	C5—C6—H6	126.1
C1—C2—H2B	109.4	C4—C5—C6	108.05 (10)
H2A—C2—H2B	108.0	C4—C5—H5	126.0
C1i—C1—C2	113.63 (11)	C6—C5—H5	126.0
C1i—C1—H1A	108.8	C7—C8—H8A	109.5
C2—C1—H1A	108.8	C7—C8—H8B	109.5
C1i—C1—H1B	108.8	H8A—C8—H8B	109.5
C2—C1—H1B	108.8	C7—C8—H8C	109.5
H1A—C1—H1B	107.7	H8A—C8—H8C	109.5
C6—C7—N1	107.41 (10)	H8B—C8—H8C	109.5
C6—C7—C8	129.72 (11)	C4—C9—H9A	109.5
N1—C7—C8	122.84 (11)	C4—C9—H9B	109.5
N1—C3—C2	114.82 (8)	H9A—C9—H9B	109.5
N1—C3—H3A	108.6	C4—C9—H9C	109.5
C2—C3—H3A	108.6	H9A—C9—H9C	109.5
N1—C3—H3B	108.6	H9B—C9—H9C	109.5
C2—C3—H3B	108.6
C3—C2—C1—C1i	−176.89 (11)	C3—N1—C4—C5	−173.23 (9)
C4—N1—C7—C6	0.20 (11)	C7—N1—C4—C9	179.88 (11)
C3—N1—C7—C6	173.26 (9)	C3—N1—C4—C9	6.81 (16)
C4—N1—C7—C8	−178.14 (11)	N1—C7—C6—C5	−0.16 (12)
C3—N1—C7—C8	−5.08 (16)	C8—C7—C6—C5	178.02 (12)
C4—N1—C3—C2	−89.88 (13)	N1—C4—C5—C6	0.06 (12)
C7—N1—C3—C2	98.15 (12)	C9—C4—C5—C6	−179.98 (12)
C1—C2—C3—N1	178.31 (9)	C7—C6—C5—C4	0.06 (13)
C7—N1—C4—C5	−0.16 (12)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···Cg1ii	0.93	2.67	3.4918 (13)	148

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯Cg1i	0.93	2.67	3.4918 (13)	148

Symmetry code: (i) . Cg1 is the centroid of the pyrrole ring.