Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807049367/om2165sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807049367/om2165Isup2.hkl |
CCDC reference: 672819
Key indicators
- Single-crystal X-ray study
- T = 295 K
- Mean (C-C)= 0.002 Å
- R factor = 0.042
- wR factor = 0.131
- Data-to-parameter ratio = 15.1
checkCIF/PLATON results
No syntax errors found No errors found in this datablock
For related literature, see: Brookhart et al. (2000); Bomfim et al.. (2007); Ferreira et al. (2006); Van Koten & Vrieze (1982); Vrieze et al. (1987). Hydrogen-bond calculations were carried out using PLATON (Spek, 2003).
To a solution of 3.72 g (40 mmol) of aniline in 40 ml of dichloromethane, were added 1.29 g (15 mmol) of 2,3-butanedione and a catalytic amount of p-toluene sulfonic acid. The mixture was heated under reflux for 24 h, after which the reaction mixture was cooled to room temperature and filtered. After removing the solvent under reduced pressure, the product was precipitated with cold methanol. The product was filtered and washed with cold ethanol (5 x 10 ml). X-ray diffraction quality crystals were obtained by recrystallization from a methanol/ethanol (1:1) mixture. The diimine was obtained as yellow crystals. Yield: 70%; Mp: 367 K; The compound was characterized by 1H, 13C NMR spectroscopy and infrared spectroscopy.
The hydrogen atoms were fixed geometrically and allowed to ride on their parent atoms; the carbon rings and their respective atoms have been refined with C—H of 0.93 Å and Uiso(H) = 1.2 Ueq(Csp2)·The hydrogen atoms of the methyl group hydrogen atoms were fixed geometrically at a distance of 0.96 Å and refined with Uiso(H) = 1.5Ueq(Csp3).
Data collection: COLLECT (Nonius, 1998); cell refinement: PHICHI (Duisenberg et al., 2000); data reduction: DIRAX (Duisenberg, 1992); 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).
Fig. 1. ORTEP of the title compound with thermal parameters at a level of 50% probability. [Symmetry code: (i) = -x, -y + 1, -z]. In addition, intramolecular interactions are shown. |
C20H24N2 | Z = 2 |
Mr = 292.41 | F(000) = 316 |
Monoclinic, P21/n | Dx = 1.106 Mg m−3 |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 7.1898 (14) Å | θ = 1–27.5° |
b = 8.3807 (17) Å | µ = 0.07 mm−1 |
c = 14.784 (3) Å | T = 295 K |
β = 99.76 (3)° | Block, yellow |
V = 877.9 (3) Å3 | 0.59 × 0.42 × 0.20 mm |
Nonius KappaCCD diffractometer | 1295 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.032 |
Graphite monochromator | θmax = 25.0°, θmin = 2.8° |
ϕ scans, and ω scans with κ | h = −8→8 |
14591 measured reflections | k = −9→9 |
1541 independent reflections | l = −17→17 |
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)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 1.11 | w = 1/[σ2(Fo2) + (0.0709P)2 + 0.1453P] where P = (Fo2 + 2Fc2)/3 |
1541 reflections | (Δ/σ)max < 0.001 |
102 parameters | Δρmax = 0.17 e Å−3 |
0 restraints | Δρmin = −0.15 e Å−3 |
C20H24N2 | V = 877.9 (3) Å3 |
Mr = 292.41 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.1898 (14) Å | µ = 0.07 mm−1 |
b = 8.3807 (17) Å | T = 295 K |
c = 14.784 (3) Å | 0.59 × 0.42 × 0.20 mm |
β = 99.76 (3)° |
Nonius KappaCCD diffractometer | 1295 reflections with I > 2σ(I) |
14591 measured reflections | Rint = 0.032 |
1541 independent reflections |
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.17 e Å−3 |
1541 reflections | Δρmin = −0.15 e Å−3 |
102 parameters |
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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) - 4.2173 (0.0061) x + 6.2054 (0.0072) y - 3.3116 (0.0107) z = 3.1390 (0.0047) * -0.0075 (0.0003) C1 * 0.0171 (0.0008) N1 * -0.0170 (0.0008) C7 * 0.0074 (0.0003) C8 Rms deviation of fitted atoms = 0.0132 4.1020 (0.0043) x + 6.1247 (0.0048) y - 6.8890 (0.0086) z = 2.4256 (0.0042) Angle to previous plane (with approximate e.s.d.) = 70.77 (0.06) * 0.0027 (0.0010) C1 * -0.0047 (0.0010) C2 * 0.0029 (0.0010) C3 * 0.0010 (0.0011) C4 * -0.0031 (0.0011) C5 * 0.0012 (0.0011) C6 Rms deviation of fitted atoms = 0.0029 - 2.2590 (0.0157) x + 5.3706 (0.0113) y + 10.9924 (0.0126) z = 6.6238 (0.0055) Angle to previous plane (with approximate e.s.d.) = 88.48 (0.10) * 0.0000 (0.0000) C2 * 0.0000 (0.0000) C9 * 0.0000 (0.0000) C10 Rms deviation of fitted atoms = 0.0000 |
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 | ||
C1 | 0.00541 (18) | 0.61257 (16) | 0.19534 (8) | 0.0418 (3) | |
C2 | −0.11601 (18) | 0.72533 (17) | 0.22436 (9) | 0.0453 (4) | |
C3 | −0.0656 (2) | 0.79142 (18) | 0.31205 (9) | 0.0525 (4) | |
H3 | −0.1439 | 0.8673 | 0.3320 | 0.063* | |
C4 | 0.0974 (2) | 0.74664 (19) | 0.36952 (9) | 0.0574 (4) | |
H4 | 0.1280 | 0.7917 | 0.4276 | 0.069* | |
C5 | 0.2150 (2) | 0.6345 (2) | 0.34047 (10) | 0.0606 (4) | |
H5 | 0.3248 | 0.6036 | 0.3792 | 0.073* | |
C6 | 0.1701 (2) | 0.56783 (19) | 0.25387 (10) | 0.0542 (4) | |
H6 | 0.2503 | 0.4928 | 0.2346 | 0.065* | |
C7 | 0.03553 (16) | 0.54972 (15) | 0.04211 (8) | 0.0388 (3) | |
C8 | 0.1974 (2) | 0.6616 (2) | 0.03814 (10) | 0.0566 (4) | |
H8A | 0.2124 | 0.7317 | 0.0902 | 0.085* | |
H8B | 0.1721 | 0.7233 | −0.0173 | 0.085* | |
H8C | 0.3111 | 0.6011 | 0.0390 | 0.085* | |
C9 | −0.2913 (2) | 0.7804 (2) | 0.16144 (12) | 0.0681 (5) | |
H9A | −0.3851 | 0.8122 | 0.1979 | 0.082* | |
H9B | −0.3429 | 0.6923 | 0.1225 | 0.082* | |
C10 | −0.2522 (3) | 0.9194 (3) | 0.10155 (13) | 0.0905 (7) | |
H10A | −0.2031 | 1.0075 | 0.1398 | 0.136* | |
H10B | −0.3672 | 0.9509 | 0.0628 | 0.136* | |
H10C | −0.1616 | 0.8877 | 0.0642 | 0.136* | |
N1 | −0.05162 (15) | 0.53221 (14) | 0.10996 (7) | 0.0434 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0463 (7) | 0.0458 (7) | 0.0351 (7) | −0.0058 (5) | 0.0123 (5) | −0.0023 (5) |
C2 | 0.0473 (7) | 0.0491 (8) | 0.0422 (7) | −0.0015 (6) | 0.0155 (6) | −0.0036 (6) |
C3 | 0.0656 (9) | 0.0501 (8) | 0.0455 (8) | −0.0015 (7) | 0.0205 (7) | −0.0081 (6) |
C4 | 0.0792 (10) | 0.0572 (9) | 0.0364 (7) | −0.0109 (8) | 0.0112 (7) | −0.0061 (6) |
C5 | 0.0645 (9) | 0.0701 (10) | 0.0435 (8) | 0.0023 (8) | −0.0013 (7) | 0.0013 (7) |
C6 | 0.0555 (8) | 0.0607 (9) | 0.0465 (8) | 0.0102 (7) | 0.0087 (6) | −0.0034 (7) |
C7 | 0.0390 (6) | 0.0410 (7) | 0.0370 (6) | 0.0026 (5) | 0.0076 (5) | −0.0020 (5) |
C8 | 0.0607 (9) | 0.0634 (9) | 0.0480 (8) | −0.0185 (7) | 0.0155 (6) | −0.0104 (7) |
C9 | 0.0516 (8) | 0.0871 (12) | 0.0645 (10) | 0.0169 (8) | 0.0069 (7) | −0.0202 (9) |
C10 | 0.1110 (16) | 0.0836 (14) | 0.0669 (11) | 0.0429 (12) | −0.0134 (11) | −0.0018 (10) |
N1 | 0.0452 (6) | 0.0483 (7) | 0.0382 (6) | −0.0015 (5) | 0.0112 (5) | −0.0064 (5) |
C1—C6 | 1.394 (2) | C7—N1 | 1.2780 (16) |
C1—C2 | 1.4023 (19) | C7—C8 | 1.5032 (19) |
C1—N1 | 1.4280 (16) | C7—C7i | 1.513 (2) |
C2—C3 | 1.3998 (19) | C8—H8A | 0.9600 |
C2—C9 | 1.506 (2) | C8—H8B | 0.9600 |
C3—C4 | 1.378 (2) | C8—H8C | 0.9600 |
C3—H3 | 0.9300 | C9—C10 | 1.518 (3) |
C4—C5 | 1.381 (2) | C9—H9A | 0.9700 |
C4—H4 | 0.9300 | C9—H9B | 0.9700 |
C5—C6 | 1.384 (2) | C10—H10A | 0.9600 |
C5—H5 | 0.9300 | C10—H10B | 0.9600 |
C6—H6 | 0.9300 | C10—H10C | 0.9600 |
C6—C1—C2 | 119.91 (12) | C8—C7—C7i | 117.84 (13) |
C6—C1—N1 | 120.54 (12) | C7—C8—H8A | 109.5 |
C2—C1—N1 | 119.20 (12) | C7—C8—H8B | 109.5 |
C3—C2—C1 | 118.23 (13) | H8A—C8—H8B | 109.5 |
C3—C2—C9 | 120.60 (13) | C7—C8—H8C | 109.5 |
C1—C2—C9 | 121.10 (12) | H8A—C8—H8C | 109.5 |
C4—C3—C2 | 121.54 (14) | H8B—C8—H8C | 109.5 |
C4—C3—H3 | 119.2 | C2—C9—C10 | 112.15 (15) |
C2—C3—H3 | 119.2 | C2—C9—H9A | 109.2 |
C3—C4—C5 | 119.69 (13) | C10—C9—H9A | 109.2 |
C3—C4—H4 | 120.2 | C2—C9—H9B | 109.2 |
C5—C4—H4 | 120.2 | C10—C9—H9B | 109.2 |
C4—C5—C6 | 120.22 (14) | H9A—C9—H9B | 107.9 |
C4—C5—H5 | 119.9 | C9—C10—H10A | 109.5 |
C6—C5—H5 | 119.9 | C9—C10—H10B | 109.5 |
C5—C6—C1 | 120.39 (14) | H10A—C10—H10B | 109.5 |
C5—C6—H6 | 119.8 | C9—C10—H10C | 109.5 |
C1—C6—H6 | 119.8 | H10A—C10—H10C | 109.5 |
N1—C7—C8 | 126.02 (12) | H10B—C10—H10C | 109.5 |
N1—C7—C7i | 116.13 (13) | C7—N1—C1 | 122.28 (11) |
C6—C1—C2—C3 | 0.8 (2) | C2—C1—C6—C5 | −0.2 (2) |
N1—C1—C2—C3 | 173.99 (12) | N1—C1—C6—C5 | −173.36 (13) |
C6—C1—C2—C9 | 177.77 (14) | C3—C2—C9—C10 | 90.00 (18) |
N1—C1—C2—C9 | −9.0 (2) | C1—C2—C9—C10 | −86.93 (19) |
C1—C2—C3—C4 | −0.8 (2) | C8—C7—N1—C1 | −4.4 (2) |
C9—C2—C3—C4 | −177.81 (14) | C7i—C7—N1—C1 | 176.99 (13) |
C2—C3—C4—C5 | 0.3 (2) | C6—C1—N1—C7 | −71.49 (18) |
C3—C4—C5—C6 | 0.3 (2) | C2—C1—N1—C7 | 115.32 (14) |
C4—C5—C6—C1 | −0.3 (2) |
Symmetry code: (i) −x, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | C20H24N2 |
Mr | 292.41 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 295 |
a, b, c (Å) | 7.1898 (14), 8.3807 (17), 14.784 (3) |
β (°) | 99.76 (3) |
V (Å3) | 877.9 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.59 × 0.42 × 0.20 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14591, 1541, 1295 |
Rint | 0.032 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.131, 1.11 |
No. of reflections | 1541 |
No. of parameters | 102 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.17, −0.15 |
Computer programs: COLLECT (Nonius, 1998), PHICHI (Duisenberg et al., 2000), DIRAX (Duisenberg, 1992), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
The full text of this article is available to subscribers to the journal.
- Information on subscribing
- Sample issue
- If you have already subscribed, you may need to register
Coordinated 1,4-diaza-1,3-butadiene groups have attracted much interest in relation to their electron donor and acceptor properties (Van Koten & Vrieze, 1982; Vrieze et al., 1987) and, more recently, due to their application to olefin homo- and co- polymerizations [Brookhart et al., 2000].
The present communication describes the chief characteristics of 2,3-bis(2-ethylphenylimino)butane, Scheme 1. The molecule is centrosymmetric, crystallizing with the diimino group –N=C(CH3)-C(CH3)=N– in a trans configuration, Fig. 1.
The carbon and nitrogen atoms in the –N=C(CH3)-C(CH3)=N– moiety present bond lengths of 1.2780 (16) Å for C9=N1, 1.4279 (17) Å for C8—N1, and 1.514 (2) Å for C9—C9i [Symmetry code: (i)= -x,-y + 1,-z]. These values are in good agreement with the distances found in the recently reported crystalline structure of the compound 2,3-bis(2-trifluoromethyl- phenylimino)butane in which the following bond lengths were observed: 1.423 (3) Å for C—N, 1.280 (3) Å for C=N, and 1.513 (4) Å for C—C (Bomfim et al., 2007). The isolated molecules show intramolecular non-classical hydrogen bonds including the nitrogen atom (N1) of the –N=C(CH3)-C(CH3)=N– moiety as acceptor, (Fig. 1). The C9—H9B···N1 distance is 2.885 (2) Å and the angle is 102° (Spek, 2003).
The observed torsion angles are -4.4 (2)° for C10—C9—N1—C8, -9.0 (2)° for N1—C8—C3—C2, 115.32 (15)° for C9—N1—C8—C3, and -86.88 (19)° for C8—C3—C2—C1. These values can be considered as consequence of the intramolecular interaction described above. The observed deviations between the C8/N1/C9/C10 and C3/C4/C5/C6/C7/C8 planes [70,8(1)°] can be related to steric factors because the presence of the ethyl groups in the phenyl rings. This kind of deviation was also observed in the crystalline structure of the similar compound 2,3-bis(2-tert-butylphenylimino)butane, 69.6 (1)° (Ferreira et al., 2006).