1,6-Bis(2-amino­phen­oxy)hexa­ne

In the structure of the title compound, C₁₄H₂₄N₂O₂, the two benzene rings are linked by a 1,6-dioxy­hexyl chain to form a centrosymmetric nonplanar structure, the dihedral angle between the two rings being 0.00 (9)°. The structure displays an intra­molecular N—H...O hydrogen bond and the mol­ecular packing is controlled by N—H...π and C—H...π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.036
• wR factor = 0.109
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

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Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT420_ALERT_2_C D-H Without Acceptor       N1     -   H1A    ...          ?

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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   0 ALERT level B = Potentially serious problem
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   2 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
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S1. Comment

Diamine compounds not only are the materials of preparing dyes, paints, oil dope, but also are the important intermediate of synthesizing Schiff base compounds. Recently, Schiff base metal complexes have been widely investigated for their properties and applications in different fields, such as catalysis (Sabater et al., 2001) and materials chemistry (Lacroix, 2001).

In the crystal structure of the title compound (I), the two phenyl rings are linked by 1,6-dioxyhexyl chain with form a non-coplanar structure (Fig. 1). Both of the benzene rings in the same molecules are parallel one another. The molecule placed in the center of symmetry position in the middle of C9—C9ⁱ bond [symmetry codes: (i) 1 - x, -y, 1 - z]. In the crystal, strong N—H···π and C—H···π interactions occur between adjacent molecules, with an N1—H1A···Cg(1)ⁱⁱ angle of 142.07°, H1A···Cg(1)ⁱⁱ distance of 2.6439 Å, N1···Cg(1)ⁱⁱ distances of 3.3641 (15) Å and C9—H9A···Cg(1)ⁱⁱⁱ angle of 136.68°, H9A···Cg(1)ⁱⁱⁱ distance of 3.0068 Å, C9···Cg (1)ⁱⁱⁱ distances of 3.7718 (15) Å, respectively. Cg(1)ⁱⁱ and Cg(1)ⁱⁱⁱ are the centroid of the C1/C6-benzene rings [symmetry codes: (ii) -x, 1/2 + y, 1/2 - z; (iii) 1 - x, -1/2 + y, 1/2 - z]. Simultaneously, the structure displays intramolecular N1—H1B···O1 hydrogen bonding with parameters: N1—-H1B = 0.86 Å, H1B···O1 = 2.27 Å, N···O = 2.609 (15) Å, and N—H···O = 103.69°.

Related literature

For related literature, see: Lacroix (2001); Sabater et al. (2001).

S2. Experimental

Here, the title compound (I) [1,6-bis(2-aminophenoxy)-hexane] was prepared from 1,6-hexanediol, p-toluenesulfonyl chloride and o-hydroxyaniline: p-toluenesulfonyl chloride (7.62 g, 40 mmol) was added slowly, whilst stirring, to a pyridine solution (50 ml) containing 1,6-hexanediol (2.36 g, 20 mmol). The mixture was stirred for about 4 h in the range of 268–278 K. Water (40 ml) was added to the resulting solution, the precipitate was collected by filtration, the solid product was crystallized using ethanol. The solid product (0.852 g, 2 mmol) dissolved in DMF (100 ml) containing K₂CO₃ (2 g), o-hydroxyaniline(0.38 g, 4 mmol) was added slowly, to the DMF solution, and the mixture was heated at 353 K for 10 h, and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography over silica gel using 80% dichloromethane–hexane to afford pure crystals (I), 0.413 g, in a yield of 82%. Single crystals suitable for X-ray diffraction were obtained from an ethanol–CH₂Cl₂ mixture by slow evaporation at room temperature.

S3. Refinement

All H atoms were placed in calculated positions and refined as riding, with C—H = 0.93–0.97 Å, N—H = 0.86 Å, and with U_iso(H) = 1.2 U_eq(C, N).

Computing details

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. The molecular structure of (I), shown with 50% probability displacement ellipsoids. H atoms are shown as spheres of arbitrary radius.

1,6-Bis(2-aminophenoxy)hexane

Crystal data

C18H24N2O2	F(000) = 324
Mr = 300.39	Dx = 1.196 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1488 reflections
a = 8.9200 (13) Å	θ = 1.0–25.1°
b = 6.4935 (9) Å	µ = 0.08 mm^−1
c = 14.464 (2) Å	T = 293 K
β = 95.378 (6)°	Prism, colourless
V = 834.1 (2) Å^3	0.17 × 0.13 × 0.09 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer	1488 independent reflections
Radiation source: fine-focus sealed tube	1260 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
φ and ω scans	θmax = 25.1°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −10→10
Tmin = 0.987, Tmax = 0.993	k = −7→7
6624 measured reflections	l = −17→17

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.036	H-atom parameters constrained
wR(F^2) = 0.109	w = 1/[σ^2(Fo^2) + (0.059P)^2 + 0.0859P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
1488 reflections	Δρmax = 0.20 e Å^−3
101 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.030 (5)

Special details

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 > 2σ(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
C3	0.91315 (15)	0.3758 (2)	0.14192 (9)	0.0571 (4)
H3	0.9703	0.4957	0.1438	0.069*
C2	0.84506 (13)	0.31610 (19)	0.21986 (8)	0.0467 (3)
C1	0.76042 (13)	0.13443 (19)	0.21573 (8)	0.0467 (3)
C6	0.74420 (16)	0.0200 (2)	0.13524 (10)	0.0611 (4)
H6	0.6869	−0.0998	0.1326	0.073*
C5	0.81346 (18)	0.0835 (3)	0.05801 (9)	0.0701 (4)
H5	0.8027	0.0059	0.0038	0.084*
C4	0.89747 (17)	0.2600 (2)	0.06157 (9)	0.0667 (4)
H4	0.9440	0.3021	0.0098	0.080*
C7	0.62464 (16)	−0.1047 (2)	0.30452 (10)	0.0633 (4)
H7A	0.6828	−0.2159	0.2809	0.076*
H7B	0.5271	−0.1002	0.2688	0.076*
C8	0.60592 (16)	−0.1384 (2)	0.40572 (10)	0.0650 (4)
H8A	0.7047	−0.1372	0.4400	0.078*
H8B	0.5630	−0.2741	0.4130	0.078*
C9	0.50761 (14)	0.0188 (2)	0.44852 (9)	0.0597 (4)
H9A	0.4082	0.0166	0.4151	0.072*
H9B	0.5498	0.1548	0.4411	0.072*
N1	0.85419 (15)	0.43023 (19)	0.30098 (8)	0.0683 (4)
H1A	0.9039	0.5439	0.3046	0.082*
H1B	0.8102	0.3875	0.3478	0.082*
O1	0.70143 (10)	0.08709 (14)	0.29728 (6)	0.0582 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C3	0.0590 (8)	0.0561 (8)	0.0569 (8)	−0.0084 (6)	0.0092 (6)	0.0084 (6)
C2	0.0455 (6)	0.0477 (7)	0.0470 (7)	0.0010 (5)	0.0049 (5)	0.0012 (5)
C1	0.0449 (6)	0.0505 (7)	0.0453 (7)	−0.0008 (5)	0.0082 (5)	0.0019 (5)
C6	0.0674 (8)	0.0588 (9)	0.0572 (8)	−0.0141 (7)	0.0066 (6)	−0.0049 (6)
C5	0.0882 (10)	0.0784 (11)	0.0442 (7)	−0.0108 (8)	0.0090 (7)	−0.0077 (7)
C4	0.0778 (9)	0.0782 (10)	0.0460 (7)	−0.0066 (8)	0.0150 (6)	0.0084 (7)
C7	0.0674 (9)	0.0529 (8)	0.0723 (9)	−0.0095 (6)	0.0202 (7)	0.0051 (7)
C8	0.0628 (8)	0.0605 (9)	0.0741 (9)	−0.0016 (6)	0.0191 (7)	0.0182 (7)
C9	0.0514 (7)	0.0659 (9)	0.0635 (8)	−0.0007 (6)	0.0135 (6)	0.0191 (7)
N1	0.0852 (8)	0.0604 (8)	0.0620 (7)	−0.0191 (6)	0.0209 (6)	−0.0143 (6)
O1	0.0653 (6)	0.0570 (6)	0.0556 (6)	−0.0130 (4)	0.0225 (4)	−0.0005 (4)

Geometric parameters (Å, º)

C3—C4	1.3800 (19)	C7—O1	1.4300 (16)
C3—C2	1.3850 (17)	C7—C8	1.505 (2)
C3—H3	0.9300	C7—H7A	0.9700
C2—N1	1.3836 (16)	C7—H7B	0.9700
C2—C1	1.3988 (17)	C8—C9	1.515 (2)
C1—O1	1.3707 (14)	C8—H8A	0.9700
C1—C6	1.3773 (18)	C8—H8B	0.9700
C6—C5	1.3888 (19)	C9—C9^i	1.528 (2)
C6—H6	0.9300	C9—H9A	0.9700
C5—C4	1.368 (2)	C9—H9B	0.9700
C5—H5	0.9300	N1—H1A	0.8600
C4—H4	0.9300	N1—H1B	0.8600
C4—C3—C2	121.04 (12)	C8—C7—H7A	110.3
C4—C3—H3	119.5	O1—C7—H7B	110.3
C2—C3—H3	119.5	C8—C7—H7B	110.3
N1—C2—C3	123.02 (12)	H7A—C7—H7B	108.5
N1—C2—C1	118.46 (11)	C7—C8—C9	114.87 (12)
C3—C2—C1	118.50 (11)	C7—C8—H8A	108.5
O1—C1—C6	126.01 (12)	C9—C8—H8A	108.5
O1—C1—C2	113.68 (10)	C7—C8—H8B	108.5
C6—C1—C2	120.31 (11)	C9—C8—H8B	108.5
C1—C6—C5	120.02 (13)	H8A—C8—H8B	107.5
C1—C6—H6	120.0	C8—C9—C9^i	113.49 (14)
C5—C6—H6	120.0	C8—C9—H9A	108.9
C4—C5—C6	120.14 (13)	C9^i—C9—H9A	108.9
C4—C5—H5	119.9	C8—C9—H9B	108.9
C6—C5—H5	119.9	C9^i—C9—H9B	108.9
C5—C4—C3	119.99 (12)	H9A—C9—H9B	107.7
C5—C4—H4	120.0	C2—N1—H1A	120.0
C3—C4—H4	120.0	C2—N1—H1B	120.0
O1—C7—C8	107.19 (12)	H1A—N1—H1B	120.0
O1—C7—H7A	110.3	C1—O1—C7	118.92 (10)
C4—C3—C2—N1	−178.13 (13)	C1—C6—C5—C4	−0.2 (2)
C4—C3—C2—C1	0.4 (2)	C6—C5—C4—C3	−0.2 (2)
N1—C2—C1—O1	−3.00 (16)	C2—C3—C4—C5	0.1 (2)
C3—C2—C1—O1	178.37 (10)	O1—C7—C8—C9	63.87 (16)
N1—C2—C1—C6	177.78 (12)	C7—C8—C9—C9^i	−179.39 (14)
C3—C2—C1—C6	−0.85 (19)	C6—C1—O1—C7	4.97 (19)
O1—C1—C6—C5	−178.37 (12)	C2—C1—O1—C7	−174.19 (11)
C2—C1—C6—C5	0.7 (2)	C8—C7—O1—C1	166.55 (11)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···O1	0.86	2.27	2.6097 (15)	104