1,1′-[(Hexane-1,6-diyldi­oxy)bis­(nitrilo­methyl­idyne)]dinaphthalene

Abstract

The title compound, C₂₈H₂₈N₂O₂, was synthesized by condensation of 1-naphthaldehyde with 1,6-bis­(amino­oxy)hexane in ethanol. The mol­ecule is disposed about a crystallographic centre of symmetry. In the crystal structure, mol­ecules are linked through strong inter­molecular π–π stacking inter­actions [interplana distance = 2.986 (2) Å], forming a three-dimensional network.

Related literature

For related literature, see: Akine et al. (2006 ▶); Dong et al. (2007 ▶); Herzfeld & Nagy (1999 ▶); Shi et al. (2007 ▶); You et al. (2004 ▶).

Experimental

Crystal data

• C₂₈H₂₈N₂O₂

• M _r = 424.52

• Monoclinic,

• a = 9.2925 (16) Å

• b = 6.3938 (12) Å

• c = 19.723 (2) Å

• β = 96.489 (2)°

• V = 1164.3 (3) ų

• Z = 2

• Mo Kα radiation

• μ = 0.08 mm⁻¹

• T = 298 (2) K

• 0.47 × 0.42 × 0.23 mm

Data collection

• Bruker SMART 1000 CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.965, T _max = 0.983

• 5470 measured reflections

• 2050 independent reflections

• 1047 reflections with I > 2σ(I)

• R _int = 0.040

Refinement

• R[F ² > 2σ(F ²)] = 0.053

• wR(F ²) = 0.154

• S = 1.07

• 2050 reflections

• 145 parameters

• H-atom parameters constrained

• Δρ_max = 0.18 e Å⁻³

• Δρ_min = −0.12 e Å⁻³

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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

supplementary crystallographic information

Comment

Schiff-base compounds containing imine groups have been used as modulators of structural and electronic properties of transition matal centres in modern coordination chemistry (You, et al., 2004). The diversity in the coordination environment and structures of transition metal complexes mainly depend on the type of Schiff-base ligands (Herzfeld, et al., 1999). In this research, we report on the synthesis and crystal structure of (I) with the aim of confirming its structural properties, and gaining further insight into its coordinating abilities toward various transition metal ions.

The crystal structure of (I) consists of discrete molecules disposed about a crystallographic centre of symmetry. The six carbon atoms in the (—CH=N—O—(CH₂)₆—O—N=CH—) bridge deviate slightly from the mean plane, with C1, C2 and C3 above by 0.04, 0.04 and 0.08 Å, and C1A, C2A and C3A below by 0.04, 0.04 and 0.08 Å (symmetry code A: -x + 1, -y, -z), respectively. The planes of the two naphthane rings in (I) are parallel with a separation distance of 2.163 (2) Å. In the crystal structure, molecules are linked through strong intermolecular π–π stacking interactions (Inter-molecular plane-to-plane distance, 2.986 (2) Å) to form a three-dimensional network.

Experimental

1,1'-[Hexane-1,6-diyldioxybis(nitrilomethylidyne)]dinaphthalene was synthesized according to an analogous method reported earlier (Shi, et al., 2007; Akine, et al., 2006; Dong, et al., 2007). To an ethanol solution (5 ml) of 1-naphthaldehyde (644.1 mg, 4.00 mmol) was added an ethanol solution (5 ml) of 1, 6-bis(aminooxy)hexane (296.5 mg, 2.00 mmol). The mixed solution was stirred at 328 K for 5 h. When cooled to room temperature, the precipitate was filtered, and washed successively with ethanol and hexane, respectively. The product was dried under vacuum and purified with recrystallization from ethanol to yield 637.4 mg of (I). Yield, 75.1%. mp. 348–349 K. Anal. Calc. for C₂₈H₂₈N₂O₂: C, 79.22; H, 6.65; N, 6.60. Found: C, 79.35; H, 6.75; N, 6.53.

Colorless block-shaped single crystals suitable for X-ray diffraction studies were obtained after several weeks by slow evaporation from an methanol solution of (I).

Refinement

Non-H atoms were refined anisotropically. H atoms were treated as riding atoms with distances C—H = 0.97 (CH₂), or 0.93 Å (CH), and U_iso(H) = 1.2 U_eq(C) and 1.5 U_eq(O).

Figures

Fig. 1.

The molecule structure of (I) with atom numbering (symmetry code A: -x + 1, -y, -z). Displacement ellipsoids for non-hydrogen atoms are drawn at the 30% probability level.

Fig. 2.

Crystal structure of (I) showing the formation of π–π interactions (Inter-molecular plane-to-plane distance, 2.986 (2) Å).

Crystal data

C28H28N2O2	F000 = 452
Mr = 424.52	Dx = 1.211 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1078 reflections
a = 9.2925 (16) Å	θ = 2.2–22.9º
b = 6.3938 (12) Å	µ = 0.08 mm−1
c = 19.723 (2) Å	T = 298 (2) K
β = 96.489 (2)º	Block-shaped, colorless
V = 1164.3 (3) Å3	0.47 × 0.42 × 0.23 mm
Z = 2

Data collection

Bruker SMART 1000 CCD area-detector diffractometer	2050 independent reflections
Radiation source: fine-focus sealed tube	1047 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.040
T = 298(2) K	θmax = 25.0º
φ and ω scans	θmin = 2.1º
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)	h = −11→10
Tmin = 0.965, Tmax = 0.983	k = −7→3
5470 measured reflections	l = −22→23

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)] = 0.053	H-atom parameters constrained
wR(F2) = 0.155	w = 1/[σ2(Fo2) + 0.4185P] where P = (Fo2 + 2Fc2)/3
S = 1.08	(Δ/σ)max < 0.001
2050 reflections	Δρmax = 0.18 e Å−3
145 parameters	Δρmin = −0.12 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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 > 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	0.2373 (3)	0.6843 (4)	0.09525 (11)	0.0619 (7)
O1	0.2359 (2)	0.5082 (3)	0.05242 (10)	0.0696 (6)
C1	0.3666 (3)	0.3957 (4)	0.06716 (14)	0.0599 (8)
H1A	0.3749	0.3439	0.1137	0.072*
H1B	0.4486	0.4861	0.0624	0.072*
C2	0.3651 (3)	0.2176 (5)	0.01842 (14)	0.0608 (8)
H2A	0.3492	0.2722	−0.0277	0.073*
H2B	0.2840	0.1272	0.0250	0.073*
C3	0.5006 (3)	0.0891 (4)	0.02526 (13)	0.0633 (9)
H3A	0.5156	0.0321	0.0711	0.076*
H3B	0.5820	0.1798	0.0195	0.076*
C4	0.1146 (4)	0.7770 (5)	0.08649 (13)	0.0580 (8)
H4	0.0423	0.7156	0.0565	0.070*
C5	0.0789 (3)	0.9699 (5)	0.11943 (13)	0.0526 (7)
C6	−0.0446 (3)	1.0682 (5)	0.09222 (15)	0.0658 (9)
H6	−0.1010	1.0040	0.0562	0.079*
C7	−0.0904 (4)	1.2583 (6)	0.11549 (17)	0.0755 (10)
H7	−0.1745	1.3205	0.0947	0.091*
C8	−0.0126 (4)	1.3520 (5)	0.16820 (17)	0.0721 (10)
H8	−0.0436	1.4792	0.1842	0.086*
C9	0.1160 (3)	1.2596 (5)	0.19969 (14)	0.0562 (8)
C10	0.1637 (3)	1.0647 (5)	0.17612 (13)	0.0498 (7)
C11	0.2900 (3)	0.9759 (5)	0.21026 (14)	0.0661 (9)
H11	0.3231	0.8479	0.1959	0.079*
C12	0.3639 (4)	1.0755 (7)	0.26392 (17)	0.0859 (11)
H12	0.4470	1.0142	0.2861	0.103*
C13	0.3182 (5)	1.2668 (7)	0.28634 (18)	0.0911 (12)
H13	0.3713	1.3338	0.3228	0.109*
C14	0.1975 (4)	1.3554 (6)	0.25544 (18)	0.0798 (11)
H14	0.1672	1.4832	0.2713	0.096*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0736 (19)	0.0517 (16)	0.0629 (16)	−0.0071 (14)	0.0189 (13)	−0.0125 (13)
O1	0.0779 (15)	0.0602 (14)	0.0711 (13)	0.0002 (12)	0.0109 (11)	−0.0154 (12)
C1	0.067 (2)	0.0532 (19)	0.0614 (18)	−0.0088 (17)	0.0143 (15)	−0.0052 (16)
C2	0.071 (2)	0.0524 (18)	0.0598 (18)	−0.0114 (17)	0.0115 (15)	−0.0068 (16)
C3	0.073 (2)	0.056 (2)	0.0618 (18)	−0.0078 (18)	0.0109 (16)	−0.0047 (15)
C4	0.065 (2)	0.057 (2)	0.0525 (17)	−0.0090 (18)	0.0092 (15)	−0.0024 (16)
C5	0.0578 (18)	0.0535 (19)	0.0489 (15)	−0.0051 (16)	0.0166 (14)	0.0034 (15)
C6	0.062 (2)	0.074 (2)	0.0617 (19)	−0.0002 (19)	0.0080 (16)	0.0071 (18)
C7	0.067 (2)	0.080 (3)	0.080 (2)	0.011 (2)	0.0131 (19)	0.010 (2)
C8	0.079 (2)	0.061 (2)	0.083 (2)	0.007 (2)	0.039 (2)	0.007 (2)
C9	0.062 (2)	0.059 (2)	0.0526 (17)	−0.0102 (18)	0.0249 (15)	−0.0031 (16)
C10	0.0535 (18)	0.0528 (19)	0.0455 (15)	−0.0091 (16)	0.0160 (13)	−0.0003 (14)
C11	0.068 (2)	0.069 (2)	0.0614 (18)	0.0025 (18)	0.0087 (16)	−0.0055 (18)
C12	0.071 (2)	0.116 (3)	0.068 (2)	0.001 (2)	−0.0050 (18)	−0.016 (2)
C13	0.087 (3)	0.118 (4)	0.069 (2)	−0.025 (3)	0.010 (2)	−0.037 (2)
C14	0.086 (3)	0.079 (3)	0.080 (2)	−0.014 (2)	0.034 (2)	−0.020 (2)

Geometric parameters (Å, °)

N1—C4	1.279 (3)	C6—C7	1.383 (4)
N1—O1	1.407 (3)	C6—H6	0.9300
O1—C1	1.413 (3)	C7—C8	1.339 (4)
C1—C2	1.490 (4)	C7—H7	0.9300
C1—H1A	0.9700	C8—C9	1.412 (4)
C1—H1B	0.9700	C8—H8	0.9300
C2—C3	1.497 (4)	C9—C14	1.404 (4)
C2—H2A	0.9700	C9—C10	1.419 (4)
C2—H2B	0.9700	C10—C11	1.406 (4)
C3—C3i	1.513 (5)	C11—C12	1.354 (4)
C3—H3A	0.9700	C11—H11	0.9300
C3—H3B	0.9700	C12—C13	1.383 (5)
C4—C5	1.450 (4)	C12—H12	0.9300
C4—H4	0.9300	C13—C14	1.340 (5)
C5—C6	1.364 (4)	C13—H13	0.9300
C5—C10	1.428 (4)	C14—H14	0.9300
C4—N1—O1	110.0 (2)	C5—C6—H6	118.3
N1—O1—C1	109.6 (2)	C7—C6—H6	118.3
O1—C1—C2	108.2 (2)	C8—C7—C6	119.4 (3)
O1—C1—H1A	110.1	C8—C7—H7	120.3
C2—C1—H1A	110.1	C6—C7—H7	120.3
O1—C1—H1B	110.1	C7—C8—C9	120.7 (3)
C2—C1—H1B	110.1	C7—C8—H8	119.7
H1A—C1—H1B	108.4	C9—C8—H8	119.7
C1—C2—C3	114.5 (2)	C14—C9—C8	121.1 (3)
C1—C2—H2A	108.6	C14—C9—C10	118.6 (3)
C3—C2—H2A	108.6	C8—C9—C10	120.2 (3)
C1—C2—H2B	108.6	C11—C10—C9	118.2 (3)
C3—C2—H2B	108.6	C11—C10—C5	124.1 (3)
H2A—C2—H2B	107.6	C9—C10—C5	117.7 (3)
C2—C3—C3i	114.2 (3)	C12—C11—C10	120.5 (3)
C2—C3—H3A	108.7	C12—C11—H11	119.8
C3i—C3—H3A	108.7	C10—C11—H11	119.8
C2—C3—H3B	108.7	C11—C12—C13	121.2 (3)
C3i—C3—H3B	108.7	C11—C12—H12	119.4
H3A—C3—H3B	107.6	C13—C12—H12	119.4
N1—C4—C5	125.4 (3)	C14—C13—C12	120.0 (3)
N1—C4—H4	117.3	C14—C13—H13	120.0
C5—C4—H4	117.3	C12—C13—H13	120.0
C6—C5—C10	118.5 (3)	C13—C14—C9	121.4 (3)
C6—C5—C4	116.1 (3)	C13—C14—H14	119.3
C10—C5—C4	125.3 (3)	C9—C14—H14	119.3
C5—C6—C7	123.4 (3)
C4—N1—O1—C1	−174.4 (2)	C8—C9—C10—C11	−178.2 (3)
N1—O1—C1—C2	−176.9 (2)	C14—C9—C10—C5	179.9 (2)
O1—C1—C2—C3	177.0 (2)	C8—C9—C10—C5	1.1 (4)
C1—C2—C3—C3i	−178.9 (3)	C6—C5—C10—C11	177.6 (3)
O1—N1—C4—C5	−176.7 (2)	C4—C5—C10—C11	−3.9 (4)
N1—C4—C5—C6	165.6 (3)	C6—C5—C10—C9	−1.7 (4)
N1—C4—C5—C10	−13.0 (4)	C4—C5—C10—C9	176.8 (2)
C10—C5—C6—C7	1.8 (4)	C9—C10—C11—C12	−0.3 (4)
C4—C5—C6—C7	−176.8 (3)	C5—C10—C11—C12	−179.6 (3)
C5—C6—C7—C8	−1.3 (5)	C10—C11—C12—C13	−0.4 (5)
C6—C7—C8—C9	0.6 (5)	C11—C12—C13—C14	1.0 (5)
C7—C8—C9—C14	−179.3 (3)	C12—C13—C14—C9	−0.8 (5)
C7—C8—C9—C10	−0.6 (4)	C8—C9—C14—C13	178.8 (3)
C14—C9—C10—C11	0.5 (4)	C10—C9—C14—C13	0.0 (5)

Symmetry codes: (i) −x+1, −y, −z.