supplementary materials
N,N'-Bis(2-hydroxy-3-ethoxybenzylidene)butane-1,4-diamine
The synthetic method has been described earlier (Fun, Kia & Kargar et
al., 2008b), except that 2-hydroxy-3-ethoxysalicylaldehyde was used
. Single crystals suitable for X-ray diffraction were obtained by
evaporation of an ethanol solution at room temperature.
H atom of the hydroxy group was positioned by a freely rotating O—H bond and
constrained with a fixed distance of 0.84 Å. The rest of the hydrogen atoms
were positioned geometrically with a riding model approximation with C—H =
0.95-0.99 Å and Uiso(H) = 1.2 or 1.5 (C & O). A rotating group model was
used for methyl group.
Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009).
N,
N'-Bis(2-hydroxy-3-ethoxybenzylidene)butane-1,4-diamine
top
Crystal data top
| C22H28N2O4 | Z = 1 |
| Mr = 384.46 | F(000) = 206 |
| Triclinic, P1 | Dx = 1.294 Mg m−3 |
| Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
| a = 6.8647 (2) Å | Cell parameters from 2475 reflections |
| b = 6.9052 (2) Å | θ = 2.5–29.4° |
| c = 10.8083 (3) Å | µ = 0.09 mm−1 |
| α = 92.779 (2)° | T = 100 K |
| β = 99.908 (2)° | Plate, yellow |
| γ = 101.239 (2)° | 0.45 × 0.19 × 0.07 mm |
| V = 493.23 (2) Å3 | |
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer | 2954 independent reflections |
| Radiation source: fine-focus sealed tube | 2157 reflections with I > 2σ(I) |
| graphite | Rint = 0.033 |
| φ and ω scans | θmax = 30.4°, θmin = 1.9° |
Absorption correction: multi-scan
(SADABS; Bruker, 2005) | h = −9→9 |
| Tmin = 0.961, Tmax = 0.994 | k = −9→9 |
| 8962 measured reflections | l = −14→15 |
Refinement top
| 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)] = 0.049 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.131 | H-atom parameters constrained |
| S = 1.04 | w = 1/[σ2(Fo2) + (0.0681P)2 + 0.047P]
where P = (Fo2 + 2Fc2)/3 |
| 2954 reflections | (Δ/σ)max < 0.001 |
| 129 parameters | Δρmax = 0.43 e Å−3 |
| 0 restraints | Δρmin = −0.27 e Å−3 |
Crystal data top
| C22H28N2O4 | γ = 101.239 (2)° |
| Mr = 384.46 | V = 493.23 (2) Å3 |
| Triclinic, P1 | Z = 1 |
| a = 6.8647 (2) Å | Mo Kα radiation |
| b = 6.9052 (2) Å | µ = 0.09 mm−1 |
| c = 10.8083 (3) Å | T = 100 K |
| α = 92.779 (2)° | 0.45 × 0.19 × 0.07 mm |
| β = 99.908 (2)° | |
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer | 2954 independent reflections |
Absorption correction: multi-scan
(SADABS; Bruker, 2005) | 2157 reflections with I > 2σ(I) |
| Tmin = 0.961, Tmax = 0.994 | Rint = 0.033 |
| 8962 measured reflections | θmax = 30.4° |
Refinement top
| R[F2 > 2σ(F2)] = 0.049 | H-atom parameters constrained |
| wR(F2) = 0.131 | Δρmax = 0.43 e Å−3 |
| S = 1.04 | Δρmin = −0.27 e Å−3 |
| 2954 reflections | Absolute structure: ? |
| 129 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
Special details top
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems
Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating
at 100.0 (1)K. |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds 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 > 2sigma(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 (Å2) top| | x | y | z | Uiso*/Ueq | |
| O1 | 0.69496 (13) | 0.51130 (12) | 0.23213 (9) | 0.0191 (2) | |
| H1 | 0.5792 | 0.4902 | 0.1870 | 0.029* | |
| O2 | 1.05734 (12) | 0.52787 (12) | 0.36073 (8) | 0.0178 (2) | |
| N1 | 0.35928 (15) | 0.30726 (15) | 0.10848 (10) | 0.0181 (2) | |
| C1 | 0.75200 (17) | 0.33702 (16) | 0.25124 (11) | 0.0149 (2) | |
| C2 | 0.94642 (17) | 0.34181 (16) | 0.32117 (11) | 0.0157 (2) | |
| C3 | 1.00920 (18) | 0.16571 (17) | 0.34438 (12) | 0.0177 (2) | |
| H3A | 1.1398 | 0.1690 | 0.3921 | 0.021* | |
| C4 | 0.88179 (18) | −0.01729 (17) | 0.29812 (12) | 0.0188 (3) | |
| H4A | 0.9259 | −0.1372 | 0.3146 | 0.023* | |
| C5 | 0.69162 (18) | −0.02237 (17) | 0.22845 (12) | 0.0178 (2) | |
| H5A | 0.6058 | −0.1462 | 0.1964 | 0.021* | |
| C6 | 0.62455 (17) | 0.15406 (16) | 0.20476 (11) | 0.0157 (2) | |
| C7 | 0.42169 (18) | 0.14831 (17) | 0.13323 (11) | 0.0169 (2) | |
| H7A | 0.3346 | 0.0238 | 0.1046 | 0.020* | |
| C8 | 0.15522 (17) | 0.29668 (17) | 0.03663 (12) | 0.0185 (3) | |
| H8A | 0.0561 | 0.2041 | 0.0735 | 0.022* | |
| H8B | 0.1478 | 0.2459 | −0.0517 | 0.022* | |
| C9 | 0.10389 (17) | 0.50109 (17) | 0.03934 (11) | 0.0170 (2) | |
| H9A | 0.2076 | 0.5946 | 0.0065 | 0.020* | |
| H9B | 0.1064 | 0.5488 | 0.1276 | 0.020* | |
| C10 | 1.26442 (17) | 0.54481 (17) | 0.42136 (12) | 0.0182 (3) | |
| H10A | 1.3370 | 0.4755 | 0.3676 | 0.022* | |
| H10B | 1.2713 | 0.4857 | 0.5032 | 0.022* | |
| C11 | 1.35712 (19) | 0.76329 (19) | 0.44083 (13) | 0.0227 (3) | |
| H11A | 1.5003 | 0.7823 | 0.4795 | 0.034* | |
| H11B | 1.2866 | 0.8291 | 0.4964 | 0.034* | |
| H11C | 1.3448 | 0.8205 | 0.3593 | 0.034* | |
Atomic displacement parameters (Å2) top| | U11 | U22 | U33 | U12 | U13 | U23 |
| O1 | 0.0164 (4) | 0.0136 (4) | 0.0265 (5) | 0.0048 (3) | −0.0003 (3) | 0.0029 (3) |
| O2 | 0.0134 (4) | 0.0146 (4) | 0.0234 (5) | 0.0009 (3) | 0.0006 (3) | 0.0005 (3) |
| N1 | 0.0145 (5) | 0.0188 (5) | 0.0215 (5) | 0.0055 (4) | 0.0021 (4) | 0.0024 (4) |
| C1 | 0.0163 (6) | 0.0129 (5) | 0.0168 (6) | 0.0040 (4) | 0.0054 (4) | 0.0031 (4) |
| C2 | 0.0154 (6) | 0.0149 (5) | 0.0172 (6) | 0.0021 (4) | 0.0051 (4) | 0.0015 (4) |
| C3 | 0.0143 (6) | 0.0190 (6) | 0.0203 (6) | 0.0050 (4) | 0.0023 (5) | 0.0029 (4) |
| C4 | 0.0194 (6) | 0.0149 (5) | 0.0237 (6) | 0.0069 (4) | 0.0044 (5) | 0.0039 (4) |
| C5 | 0.0175 (6) | 0.0133 (5) | 0.0223 (6) | 0.0030 (4) | 0.0029 (5) | 0.0015 (4) |
| C6 | 0.0142 (6) | 0.0157 (5) | 0.0176 (6) | 0.0038 (4) | 0.0033 (4) | 0.0021 (4) |
| C7 | 0.0154 (6) | 0.0154 (5) | 0.0192 (6) | 0.0019 (4) | 0.0027 (5) | 0.0011 (4) |
| C8 | 0.0137 (6) | 0.0187 (6) | 0.0221 (6) | 0.0043 (4) | 0.0001 (5) | 0.0009 (5) |
| C9 | 0.0157 (6) | 0.0176 (5) | 0.0186 (6) | 0.0055 (4) | 0.0032 (5) | 0.0025 (4) |
| C10 | 0.0128 (6) | 0.0193 (6) | 0.0221 (6) | 0.0029 (4) | 0.0030 (5) | 0.0009 (4) |
| C11 | 0.0150 (6) | 0.0219 (6) | 0.0291 (7) | 0.0006 (4) | 0.0021 (5) | 0.0027 (5) |
Geometric parameters (Å, °) top
| O1—C1 | 1.3507 (12) | C6—C7 | 1.4641 (15) |
| O1—H1 | 0.8400 | C7—H7A | 0.9500 |
| O2—C2 | 1.3662 (13) | C8—C9 | 1.5201 (15) |
| O2—C10 | 1.4391 (13) | C8—H8A | 0.9900 |
| N1—C7 | 1.2776 (14) | C8—H8B | 0.9900 |
| N1—C8 | 1.4666 (14) | C9—C9i | 1.527 (2) |
| C1—C6 | 1.4037 (16) | C9—H9A | 0.9900 |
| C1—C2 | 1.4096 (16) | C9—H9B | 0.9900 |
| C2—C3 | 1.3871 (15) | C10—C11 | 1.5081 (17) |
| C3—C4 | 1.4033 (17) | C10—H10A | 0.9900 |
| C3—H3A | 0.9500 | C10—H10B | 0.9900 |
| C4—C5 | 1.3833 (16) | C11—H11A | 0.9800 |
| C4—H4A | 0.9500 | C11—H11B | 0.9800 |
| C5—C6 | 1.4036 (15) | C11—H11C | 0.9800 |
| C5—H5A | 0.9500 | | |
| | | |
| C1—O1—H1 | 109.5 | N1—C8—C9 | 109.97 (10) |
| C2—O2—C10 | 117.43 (9) | N1—C8—H8A | 109.7 |
| C7—N1—C8 | 120.11 (11) | C9—C8—H8A | 109.7 |
| O1—C1—C6 | 122.32 (10) | N1—C8—H8B | 109.7 |
| O1—C1—C2 | 118.03 (10) | C9—C8—H8B | 109.7 |
| C6—C1—C2 | 119.65 (10) | H8A—C8—H8B | 108.2 |
| O2—C2—C3 | 125.83 (11) | C8—C9—C9i | 111.80 (13) |
| O2—C2—C1 | 114.48 (9) | C8—C9—H9A | 109.3 |
| C3—C2—C1 | 119.70 (11) | C9i—C9—H9A | 109.3 |
| C2—C3—C4 | 120.70 (11) | C8—C9—H9B | 109.3 |
| C2—C3—H3A | 119.7 | C9i—C9—H9B | 109.3 |
| C4—C3—H3A | 119.7 | H9A—C9—H9B | 107.9 |
| C5—C4—C3 | 119.72 (11) | O2—C10—C11 | 106.44 (9) |
| C5—C4—H4A | 120.1 | O2—C10—H10A | 110.4 |
| C3—C4—H4A | 120.1 | C11—C10—H10A | 110.4 |
| C4—C5—C6 | 120.48 (11) | O2—C10—H10B | 110.4 |
| C4—C5—H5A | 119.8 | C11—C10—H10B | 110.4 |
| C6—C5—H5A | 119.8 | H10A—C10—H10B | 108.6 |
| C5—C6—C1 | 119.75 (10) | C10—C11—H11A | 109.5 |
| C5—C6—C7 | 120.42 (11) | C10—C11—H11B | 109.5 |
| C1—C6—C7 | 119.83 (10) | H11A—C11—H11B | 109.5 |
| N1—C7—C6 | 121.38 (11) | C10—C11—H11C | 109.5 |
| N1—C7—H7A | 119.3 | H11A—C11—H11C | 109.5 |
| C6—C7—H7A | 119.3 | H11B—C11—H11C | 109.5 |
| | | |
| C10—O2—C2—C3 | 6.39 (17) | C4—C5—C6—C7 | −178.73 (11) |
| C10—O2—C2—C1 | −173.76 (10) | O1—C1—C6—C5 | −179.51 (11) |
| O1—C1—C2—O2 | −0.84 (16) | C2—C1—C6—C5 | 0.09 (17) |
| C6—C1—C2—O2 | 179.55 (10) | O1—C1—C6—C7 | −0.25 (17) |
| O1—C1—C2—C3 | 179.02 (10) | C2—C1—C6—C7 | 179.35 (10) |
| C6—C1—C2—C3 | −0.60 (17) | C8—N1—C7—C6 | −179.99 (10) |
| O2—C2—C3—C4 | −179.65 (11) | C5—C6—C7—N1 | −178.57 (11) |
| C1—C2—C3—C4 | 0.51 (18) | C1—C6—C7—N1 | 2.18 (18) |
| C2—C3—C4—C5 | 0.10 (18) | C7—N1—C8—C9 | 170.13 (11) |
| C3—C4—C5—C6 | −0.61 (18) | N1—C8—C9—C9i | 177.44 (12) |
| C4—C5—C6—C1 | 0.51 (18) | C2—O2—C10—C11 | 173.37 (10) |
| Symmetry codes: (i) −x, −y+1, −z. |
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| O1—H1···N1 | 0.84 | 1.82 | 2.5638 (14) | 147 |
| C5—H5A···O1ii | 0.95 | 2.59 | 3.2268 (14) | 125 |
| C11—H11B···Cg1iii | 0.98 | 2.96 | 3.5403 (15) | 145 |
| Symmetry codes: (ii) x, y−1, z; (iii) −x+2, −y+1, −z+1. |
Table 1
Hydrogen-bond geometry (Å, °) top
| D—H···A | D—H | H···A | D···A | D—H···A |
| O1—H1···N1 | 0.84 | 1.82 | 2.5638 (14) | 147 |
| C5—H5A···O1i | 0.95 | 2.59 | 3.2268 (14) | 125 |
| C11—H11B···Cg1ii | 0.98 | 2.96 | 3.5403 (15) | 145 |
| Symmetry codes: (i) x, y−1, z; (ii) −x+2, −y+1, −z+1. |
HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for the
Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia
for the award of a post-doctoral research fellowship. HK and AJ thank PNU for
financial support. HKF also thanks Universiti Sains Malaysia for the Research
University Golden Goose grant No. 1001/PFIZIK/811012.
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Calligaris, M. & Randaccio, L. (1987). Comprehensive Coordination Chemistry, Vol. 2, edited by G. Wilkinson, pp. 715–738. London: Pergamon.
Casellato, U. & Vigato, P. A. (1977). Coord. Chem. Rev. 23, 31–50.
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107.
Fun, H.-K. & Kia, R. (2008a). Acta Cryst. E64, m1081–m1082.
Fun, H.-K. & Kia, R. (2008b). Acta Cryst. E64, m1116–m1117.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Spek, A. L. (2009). Acta Cryst. D65, 148–155.
O interactions link neighbouring molecules into dimers with an R22(28) ring motif. The crystal structure is stabilized by intermolecular C-H![[pi]](/logos/entities/pi_rmgif.gif)
interactions. An intramolecular O-H![[Figure 1]](./at2734fig1thm.gif)
![[Figure 2]](./at2734fig2thm.gif)
The condensation of primary amines with carbonyl compounds yields Schiff base (Casellato & Vigato, 1977) that are still one of the most prevalent mixed-donor ligands in coordination chemistry. In the past two decades, the synthesis, structure and properties of Schiff base complexes have stimulated much interest for their noteworthy contributions in single molecule-based magnetism, materials science, catalysis of many reactions like carbonylation, hydroformylation, reduction, oxidation, epoxidation and hydrolysis (Casellato & Vigato 1977). In comparison to the Schiff base metal complexes, only a relatively small number of free Schiff base ligands have been characterized (Calligaris & Randaccio, 1987). As an extension of our work (Fun & Kia 2008a,b) on the structural characterization of Schiff base ligands, the title compound is reported here.
The molecule of the title compound, Fig 1, lies across a crystallographic inversion centre and adopts an E configuration with respect to the azomethine (C═N) bond. The asymmetric unit of the compound is composed of one-half of the molecule. The imino group is coplanar with the benzene ring. Pairs of intermolecular C—H···O interactions link neighbouring molecules into dimers with a R22(28) ring motif (Bernstein et al., 1995). The crystal structure is stabilized by intermolecular C—H···π interactions [Cg1 is the centroid of the C1–C6 benzene ring] (Table 1).