Crystal structure of 1,2-bis-[(2-tert-butyl-phen-yl)imino]-ethane.

The whole molecule of the title compound, C22H28N2, (I), is generated by inversion symmetry. The mol-ecule is rather similar to that of 2,3-bis-[(2-tert-butyl-phen-yl)imino]-butane, (II), a di-imine ligand comprising similar structural features [Ferreira et al. (2006 ▶). Acta Cryst. E62, o4282-o4284]. Both ligands crystallize with the -N=C(R)-C(R)=N- group around an inversion centre, in a trans configuration. Comparing the two structures, it may be noted that the independent planar groups in both mol-ecules [the central link, -N=C(R)-C(R)=N-, and the terminal aromatic ring] subtend an angle of 69.6 (1)° in (II) and 49.4 (2)° in (I). Ferreira and co-workers proposed that such angle deviation may be ascribed to the presence of two non-classical intra-molecular hydrogen bonds and steric factors. In fact, in (I), similar non-classical hydrogen bonds are observed, and the larger angular deviation in (II) may be assigned to the presence of methyl groups in the di-imino fragment, which can cause steric hindrance due to the presence of bulky tert-butyl substituents in the aromatic rings. The C=N bond lengths are similar in both compounds and agree with comonly accepted values.

Related literature

For general properties of di­imines, see: Rix & Brookhart (1995 ▸); Hissler et al. (2000 ▸); Ramakrishnan et al. (2011a ▸). For the inter­action of di­imine–metal complexes with DNA, see: Wang et al. (2004 ▸); Tan et al. (2008 ▸); Ramakrishnan et al. (2011b ▸). For a related structure, see: Ferreira et al. (2006 ▸).

Experimental

Crystal data

C22H28N2

M = 320.46

Monoclinic,

a = 12.333 (3) Å

b = 6.4740 (13) Å

c = 12.519 (3) Å

β = 95.22 (3)°

V = 995.5 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.06 mm−1

T = 293 K

0.3 × 0.17 × 0.07 mm

Data collection

Nonius KappaCCD diffractometer

21498 measured reflections

1811 independent reflections

1284 reflections with I > 2σ(I)

R int = 0.072

Refinement

R[F 2 > 2σ(F 2)] = 0.049

wR(F 2) = 0.119

S = 1.06

1811 reflections

109 parameters

H-atom parameters constrained

Δρmax = 0.13 e Å−3

Δρmin = −0.15 e Å−3

Data collection: COLLECT (Nonius, 2004 ▸); cell refinement: DIRAX/LSQ (Duisenberg, 1992 ▸); data reduction: EVALCCD (Duisenberg et al., 2003 ▸); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015008610/bg2548sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015008610/bg2548Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015008610/bg2548Isup3.cml

Click here for additional data file.

x y z . DOI: 10.1107/S2056989015008610/bg2548fig1.tif

View of (I) (50% probability displacement ellipsoids). The dashed lines indicate the proposed non-classical intra­molecular hydrogen bonds. [Symmetry code: (’) 1 − x, 1 − y, −z.]

Click here for additional data file.

a b . DOI: 10.1107/S2056989015008610/bg2548fig2.tif

Comparison of the structures of (a) (I) and (b) (II).

CCDC reference: 1062877

Additional supporting information: crystallographic information; 3D view; checkCIF report

C22H28N2	F(000) = 348
Mr = 320.46	Dx = 1.069 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 21498 reflections
a = 12.333 (3) Å	θ = 3.6–25.4°
b = 6.4740 (13) Å	µ = 0.06 mm−1
c = 12.519 (3) Å	T = 293 K
β = 95.22 (3)°	Plate, yellow
V = 995.5 (3) Å3	0.3 × 0.17 × 0.07 mm
Z = 2

Nonius KappaCCD diffractometer	1284 reflections with I > 2σ(I)
Horizonally mounted graphite crystal monochromator	Rint = 0.072
Detector resolution: 9 pixels mm-1	θmax = 25.4°, θmin = 3.6°
CCD scans	h = −14→14
21498 measured reflections	k = −7→7
1811 independent reflections	l = −15→15

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.049	H-atom parameters constrained
wR(F2) = 0.119	w = 1/[σ2(Fo2) + (0.0452P)2 + 0.2479P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max < 0.001
1811 reflections	Δρmax = 0.13 e Å−3
109 parameters	Δρmin = −0.15 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.

	x	y	z	Uiso*/Ueq
N1	0.46712 (12)	0.1526 (2)	0.10801 (11)	0.0485 (4)
C1	0.47499 (15)	0.0981 (3)	0.01174 (14)	0.0520 (5)
H1	0.4486	0.1842	−0.0442	0.062*
C2	0.41192 (14)	0.3400 (3)	0.12810 (12)	0.0440 (4)
C3	0.31398 (16)	0.3836 (3)	0.06876 (15)	0.0622 (6)
H3	0.2873	0.292	0.0155	0.075*
C4	0.25541 (18)	0.5595 (4)	0.08691 (17)	0.0736 (7)
H4	0.19	0.587	0.0465	0.088*
C5	0.29551 (17)	0.6930 (3)	0.16573 (18)	0.0694 (6)
H5	0.2576	0.8134	0.1783	0.083*
C6	0.39173 (16)	0.6496 (3)	0.22646 (15)	0.0559 (5)
H6	0.4171	0.7428	0.2795	0.067*
C7	0.45274 (13)	0.4721 (2)	0.21188 (13)	0.0413 (4)
C8	0.55778 (14)	0.4249 (3)	0.28333 (14)	0.0476 (4)
C9	0.58580 (19)	0.5962 (4)	0.36621 (18)	0.0777 (7)
H9A	0.5955	0.7244	0.3298	0.117*
H9B	0.6518	0.5612	0.409	0.117*
H9C	0.5276	0.6101	0.4117	0.117*
C10	0.65538 (15)	0.4063 (4)	0.21568 (17)	0.0701 (6)
H10A	0.6639	0.533	0.1775	0.105*
H10B	0.6429	0.295	0.1654	0.105*
H10C	0.7203	0.3791	0.2619	0.105*
C11	0.54410 (18)	0.2230 (3)	0.34482 (16)	0.0684 (6)
H11A	0.4834	0.2354	0.3872	0.103*
H11B	0.6091	0.1959	0.3909	0.103*
H11C	0.5313	0.1113	0.2948	0.103*

	U11	U22	U33	U12	U13	U23
N1	0.0604 (9)	0.0429 (9)	0.0420 (8)	0.0096 (7)	0.0034 (7)	−0.0089 (7)
C1	0.0685 (12)	0.0456 (10)	0.0416 (10)	0.0134 (9)	0.0028 (8)	−0.0051 (8)
C2	0.0546 (10)	0.0405 (10)	0.0380 (9)	0.0103 (8)	0.0092 (7)	−0.0021 (7)
C3	0.0662 (13)	0.0709 (14)	0.0482 (11)	0.0188 (11)	−0.0016 (9)	−0.0108 (10)
C4	0.0681 (14)	0.0872 (17)	0.0650 (13)	0.0346 (13)	0.0029 (11)	0.0000 (12)
C5	0.0734 (14)	0.0550 (13)	0.0827 (15)	0.0288 (11)	0.0235 (12)	0.0000 (11)
C6	0.0639 (12)	0.0415 (11)	0.0650 (12)	0.0040 (9)	0.0201 (10)	−0.0096 (9)
C7	0.0496 (10)	0.0348 (9)	0.0417 (9)	−0.0007 (8)	0.0171 (7)	−0.0024 (7)
C8	0.0514 (10)	0.0432 (10)	0.0489 (10)	−0.0055 (8)	0.0089 (8)	−0.0081 (8)
C9	0.0799 (15)	0.0730 (15)	0.0787 (15)	−0.0088 (12)	−0.0013 (12)	−0.0280 (12)
C10	0.0513 (11)	0.0795 (16)	0.0811 (15)	0.0017 (11)	0.0144 (10)	−0.0068 (12)
C11	0.0809 (14)	0.0659 (14)	0.0554 (12)	−0.0091 (12)	−0.0105 (10)	0.0094 (10)

N1—C1	1.268 (2)	C7—C8	1.536 (2)
N1—C2	1.425 (2)	C8—C9	1.537 (2)
C1—H1	0.93	C9—H9A	0.96
C1—C1i	1.454 (3)	C9—H9B	0.96
C2—C3	1.388 (2)	C9—H9C	0.96
C2—C7	1.410 (2)	C8—C10	1.538 (2)
C3—C4	1.378 (3)	C10—H10A	0.96
C3—H3	0.93	C10—H10B	0.96
C4—C5	1.370 (3)	C10—H10C	0.96
C5—H5	0.93	C8—C11	1.534 (3)
C4—H4	0.93	C11—H11A	0.96
C5—C6	1.379 (3)	C11—H11B	0.96
C6—C7	1.395 (2)	C11—H11C	0.96
C6—H6	0.93
C1—N1—C2	118.93 (15)	C11—C8—C9	107.72 (16)
N1—C1—C1i	120.4 (2)	C7—C8—C9	112.06 (15)
N1—C1—H1	119.8	C11—C8—C10	109.68 (16)
C1i—C1—H1	119.8	C7—C8—C10	110.83 (14)
C3—C2—C7	120.59 (16)	C9—C8—C10	106.81 (16)
C3—C2—N1	119.03 (15)	C8—C9—H9A	109.5
C7—C2—N1	120.24 (15)	C8—C9—H9B	109.5
C4—C3—C2	121.56 (19)	H9A—C9—H9B	109.5
C4—C3—H3	119.2	C8—C9—H9C	109.5
C2—C3—H3	119.2	H9A—C9—H9C	109.5
C5—C4—C3	118.67 (19)	H9B—C9—H9C	109.5
C5—C4—H4	120.7	C8—C10—H10A	109.5
C3—C4—H4	120.7	C8—C10—H10B	109.5
C4—C5—C6	120.33 (19)	H10A—C10—H10B	109.5
C4—C5—H5	119.8	C8—C10—H10C	109.5
C6—C5—H5	119.8	H10A—C10—H10C	109.5
C5—C6—C7	122.91 (18)	H10B—C10—H10C	109.5
C5—C6—H6	118.5	C8—C11—H11A	109.5
C7—C6—H6	118.5	C8—C11—H11B	109.5
C6—C7—C2	115.89 (16)	H11A—C11—H11B	109.5
C6—C7—C8	121.60 (15)	C8—C11—H11C	109.5
C2—C7—C8	122.51 (14)	H11A—C11—H11C	109.5
C11—C8—C7	109.64 (14)	H11B—C11—H11C	109.5
C2—N1—C1—C1i	−176.3 (2)	C3—C2—C7—C6	−3.0 (2)
C1—N1—C2—C3	44.2 (2)	N1—C2—C7—C6	−178.76 (15)
C1—N1—C2—C7	−139.97 (18)	C3—C2—C7—C8	176.94 (17)
C7—C2—C3—C4	2.2 (3)	N1—C2—C7—C8	1.2 (2)
N1—C2—C3—C4	178.05 (18)	C6—C7—C8—C11	117.87 (18)
C2—C3—C4—C5	−0.1 (3)	C2—C7—C8—C11	−62.0 (2)
C3—C4—C5—C6	−1.0 (3)	C6—C7—C8—C9	−1.7 (2)
C4—C5—C6—C7	0.1 (3)	C2—C7—C8—C9	178.39 (16)
C5—C6—C7—C2	1.9 (3)	C6—C7—C8—C10	−120.91 (18)
C5—C6—C7—C8	−178.02 (17)	C2—C7—C8—C10	59.2 (2)

Table 1

Hydrogen-bond geometry (, )

-

DHA	DH	HA	DA	DHA
C10H10BN1	0.960	2.405(2)	3.055(3)	124.8(3)
C11H11CN1	0.960	2.414(2)	3.064(3)	124.6(2)