2-[4-(4,5-Dihydro-1H-pyrrol-2-yl)phen­yl]-4,5-dihydro-1H-imidazole

Abstract

The mol­ecule of the title compound, C₁₂H₁₄N₄, lies about a crystallographic inversion centre. The five- and six-membered rings are twisted from each other, forming a dihedral angle of 18.06 (7)°. In the crystal structure, neighbouring mol­ecules are linked by inter­molecular N—H⋯N hydrogen bonds into one-dimensional infinite chains forming 18-membered rings with R ₂ ²(18) motifs. The crystal structure is further stabilized by weak inter­molecular π–π stacking [centroid–centroid distance = 3.8254 (6) Å] and C—H⋯π inter­actions.

Related literature

For details of hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For a related structure and synthesis, see: Stibrany et al. (2004 ▶). For applications, see: Blancafort (1978 ▶); Chan (1993 ▶); Vizi (1986 ▶); Li et al. (1996 ▶); Ueno et al. (1995 ▶); Corey & Grogan (1999 ▶).

Experimental

Crystal data

• C₁₂H₁₄N₄

• M _r = 214.27

• Triclinic,

• a = 4.8863 (2) Å

• b = 5.1472 (2) Å

• c = 10.2295 (4) Å

• α = 104.414 (2)°

• β = 93.885 (2)°

• γ = 94.207 (2)°

• V = 247.52 (2) ų

• Z = 1

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 100.0 (1) K

• 0.56 × 0.17 × 0.15 mm

Data collection

• Bruker SMART APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.950, T _max = 0.986

• 4616 measured reflections

• 1296 independent reflections

• 1208 reflections with I > 2σ(I)

• R _int = 0.026

Refinement

• R[F ² > 2σ(F ²)] = 0.041

• wR(F ²) = 0.116

• S = 1.07

• 1296 reflections

• 101 parameters

• All H-atom parameters refined

• Δρ_max = 0.42 e Å⁻³

• Δρ_min = −0.24 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); 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 ▶).

Supplementary Material

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the N1/C1/C2/N2/C3 imidazoline ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N1⋯N2i	0.87 (2)	2.18 (2)	3.0060 (13)	158.1 (15)
C2—H2B⋯Cg1ii	1.015 (15)	2.980 (15)	3.8882 (11)	149.6 (11)

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

Imidazoline derivatives are of great importance because they exhibit significant biological and pharmacological activities including anti-hypertensive (Blancafort 1978), anti-hyperglycemic (Chan 1993), anti-depressive (Vizi 1986), anti-hypercholesterolemic (Li et al., 1996) and anti-inflammatory (Ueno et al., 1995) activities. These compounds are also used as catalysts and synthetic intermediates in some organic reactions (Corey & Grogan 1999). In consideration of the important applications of imidazolines, herein the crystal structure of the title compound, (I), is reported.

In compound (I), Fig. 1, bond lengths and angles are within the normal ranges and are comparable with a related structure (Stibrany et al., 2004). The molecule lies about a crystallographic inversion centre. The five- and six-membered rings are twisted from each other, forming a dihedral angle of 18.06 (7)°. Intermolecular N—H···N hydrogen bonds form 18-membered rings producing R₂²(18) ring motifs to link molecules into one-dimensional infinite chains along the b-axis, Table 1 and Fig. 2. The crystal structure is further stabilized by weak intermolecular π–π stacking [Cg1···Cg2ⁱ = 3.8254 (6) Å; (i) 1 + x, y, z] and C—H···π (Cg1 and Cg2 are the centroids of the N1/C1/C2/N2/C3 imidazoline ring and the benzene ring, respectively) interactions, Table 1.

Experimental

The synthetic method used for the preparation of (I) was based on previous work (Stibrany et al. 2004), except that 1,4-dicyanobenzene (10 mmol) and ethylenediamine (40 mmol) were used. Single crystals suitable for X-ray diffraction were obtained by evaporation of a methanol solution of (I) held at room temperature.

Refinement

All hydrogen atoms were located from a difference Fourier map and refined freely: C—H ranged from 0.961 (16) to 1.015 (15) Å and N—H was 0.874 (18) Å.

Figures

Fig. 1.

The molecular structure of (I) with atom labels and 50% probability ellipsoids for non-H atoms. Unlabelled atoms are related by -x + 1, -y, -z.

Fig. 2.

Partial crystal packing in (I), viewed down the a-axis showing one-dimensional infinite chains along the b-axis mediated by intermolecular N—H···N interactions (dashed lines).

Crystal data

C12H14N4	Z = 1
Mr = 214.27	F000 = 114
Triclinic, P1	Dx = 1.437 Mg m−3
Hall symbol: -P 1	Melting point: 312 K
a = 4.8863 (2) Å	Mo Kα radiation λ = 0.71073 Å
b = 5.1472 (2) Å	Cell parameters from 3789 reflections
c = 10.2295 (4) Å	θ = 2.5–30.3º
α = 104.414 (2)º	µ = 0.09 mm−1
β = 93.885 (2)º	T = 100.0 (1) K
γ = 94.207 (2)º	Block, colourless
V = 247.522 (17) Å3	0.56 × 0.17 × 0.15 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer	1296 independent reflections
Radiation source: fine-focus sealed tube	1208 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.026
T = 100.0(1) K	θmax = 29.0º
φ and ω scans	θmin = 4.1º
Absorption correction: multi-scan(SADABS; Bruker, 2005)	h = −6→6
Tmin = 0.950, Tmax = 0.986	k = −6→6
4616 measured reflections	l = −13→13

Refinement

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)] = 0.041	All H-atom parameters refined
wR(F2) = 0.116	w = 1/[σ2(Fo2) + (0.0717P)2 + 0.0714P] where P = (Fo2 + 2Fc2)/3
S = 1.07	(Δ/σ)max < 0.001
1296 reflections	Δρmax = 0.42 e Å−3
101 parameters	Δρmin = −0.24 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Special details

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

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
N1	0.99649 (17)	0.02202 (18)	0.30177 (9)	0.0140 (2)
N2	1.05027 (18)	0.42785 (18)	0.25064 (9)	0.0161 (2)
C1	1.2376 (2)	0.1595 (2)	0.39310 (10)	0.0148 (2)
C2	1.2547 (2)	0.4433 (2)	0.36664 (10)	0.0158 (2)
C3	0.92585 (19)	0.1869 (2)	0.21989 (10)	0.0124 (2)
C4	0.70754 (19)	0.08912 (19)	0.10716 (10)	0.0124 (2)
C5	0.6787 (2)	0.2263 (2)	0.00581 (10)	0.0138 (2)
C6	0.5270 (2)	−0.1391 (2)	0.09997 (10)	0.0135 (2)
H1A	1.402 (3)	0.062 (3)	0.3667 (15)	0.020 (3)*
H1B	1.212 (3)	0.169 (3)	0.4906 (16)	0.024 (4)*
H2A	1.443 (3)	0.498 (3)	0.3429 (16)	0.026 (4)*
H2B	1.214 (3)	0.587 (3)	0.4488 (15)	0.020 (3)*
H5	0.802 (3)	0.383 (3)	0.0096 (16)	0.025 (4)*
H6	0.537 (3)	−0.239 (3)	0.1687 (15)	0.020 (3)*
H1N1	0.989 (3)	−0.151 (4)	0.2656 (17)	0.029 (4)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0135 (4)	0.0131 (4)	0.0147 (4)	−0.0009 (3)	−0.0033 (3)	0.0041 (3)
N2	0.0147 (4)	0.0150 (4)	0.0177 (5)	−0.0009 (3)	−0.0044 (3)	0.0047 (3)
C1	0.0125 (4)	0.0157 (5)	0.0153 (5)	−0.0008 (3)	−0.0030 (3)	0.0037 (4)
C2	0.0144 (5)	0.0153 (5)	0.0167 (5)	−0.0011 (4)	−0.0038 (3)	0.0041 (4)
C3	0.0102 (4)	0.0142 (5)	0.0130 (4)	0.0015 (3)	0.0006 (3)	0.0036 (3)
C4	0.0098 (4)	0.0134 (5)	0.0133 (4)	0.0009 (3)	0.0000 (3)	0.0025 (3)
C5	0.0109 (4)	0.0143 (5)	0.0159 (5)	−0.0009 (3)	0.0001 (3)	0.0041 (3)
C6	0.0128 (4)	0.0140 (5)	0.0142 (5)	0.0002 (3)	0.0003 (3)	0.0049 (3)

Geometric parameters (Å, °)

N1—C3	1.3780 (13)	C2—H2B	1.015 (15)
N1—C1	1.4700 (12)	C3—C4	1.4787 (13)
N1—H1N1	0.874 (18)	C4—C5	1.3973 (14)
N2—C3	1.2944 (13)	C4—C6	1.4000 (14)
N2—C2	1.4808 (12)	C5—C6i	1.3881 (13)
C1—C2	1.5479 (14)	C5—H5	0.961 (16)
C1—H1A	0.997 (14)	C6—C5i	1.3881 (13)
C1—H1B	1.004 (16)	C6—H6	0.970 (15)
C2—H2A	1.006 (16)
C3—N1—C1	107.38 (8)	C1—C2—H2B	112.1 (9)
C3—N1—H1N1	118.4 (11)	H2A—C2—H2B	106.8 (12)
C1—N1—H1N1	119.9 (10)	N2—C3—N1	116.89 (9)
C3—N2—C2	106.43 (8)	N2—C3—C4	123.28 (9)
N1—C1—C2	102.00 (8)	N1—C3—C4	119.77 (9)
N1—C1—H1A	108.9 (8)	C5—C4—C6	118.99 (9)
C2—C1—H1A	112.8 (9)	C5—C4—C3	119.82 (9)
N1—C1—H1B	112.3 (9)	C6—C4—C3	121.19 (9)
C2—C1—H1B	111.4 (9)	C6i—C5—C4	120.61 (9)
H1A—C1—H1B	109.3 (12)	C6i—C5—H5	119.7 (9)
N2—C2—C1	106.30 (8)	C4—C5—H5	119.6 (9)
N2—C2—H2A	109.2 (9)	C5i—C6—C4	120.40 (9)
C1—C2—H2A	111.9 (9)	C5i—C6—H6	117.6 (9)
N2—C2—H2B	110.6 (8)	C4—C6—H6	122.0 (9)
C3—N1—C1—C2	9.79 (10)	N1—C3—C4—C5	−165.14 (9)
C3—N2—C2—C1	3.06 (11)	N2—C3—C4—C6	−161.93 (10)
N1—C1—C2—N2	−7.84 (10)	N1—C3—C4—C6	15.11 (14)
C2—N2—C3—N1	3.71 (12)	C6—C4—C5—C6i	0.46 (16)
C2—N2—C3—C4	−179.17 (8)	C3—C4—C5—C6i	−179.29 (8)
C1—N1—C3—N2	−9.24 (12)	C5—C4—C6—C5i	−0.46 (16)
C1—N1—C3—C4	173.53 (8)	C3—C4—C6—C5i	179.29 (8)
N2—C3—C4—C5	17.82 (14)

Symmetry codes: (i) −x+1, −y, −z.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···N2ii	0.87 (2)	2.18 (2)	3.0060 (13)	158.1 (15)
C2—H2B···Cg1iii	1.015 (15)	2.980 (15)	3.8882 (11)	149.6 (11)

Symmetry codes: (ii) x, y−1, z; (iii) −x, −y+1, −z+1.