organic compounds
6,6′-Diethoxy-2,2′-[propane-1,3-diyldioxybis(nitrilomethylidyne)]diphenol
aSchool of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, People's Republic of China
*Correspondence e-mail: wangl@mail.lzjtu.cn
The complete molecule of the title compound, C21H26N2O6, is generated by a crystallographic twofold axis and adopts a trans configuration with respect to the azomethine group. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 89.53 (3)°. In the molecular structure, pairs of intramolecular O—H⋯N hydrogen bonds generate two six-membered rings. The is further stabilized by intermolecular C—H⋯O hydrogen bonds, which link four adjacent molecules into a network structure.
Related literature
For background to salen-type bisoxime compounds, see: Dong et al. (2007a,b; Dong & Duan, 2008). For the synthesis, see: Dong et al. (2008, 2009). For background to hydrogen bonding, see: Desiraju (1996). For hydrogen-bond motifs, see: Bernstein et al. (1995).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Siemens, 1996); cell 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.
Supporting information
10.1107/S1600536810003430/hg2634sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810003430/hg2634Isup2.hkl
6,6'-Diethoxy-2,2'-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol was synthesized according to an analogous method reported earlier (Dong et al., 2007b; Dong et al., 2009). To an ethanol solution (4 ml) of 3-ethoxysalicylaldehyde(167.4 mg, 1.00 mmol) was added an ethanol solution (2 ml) of 1,3-bis(aminooxy)propylene (60.07 mg, 0.50 mmol). The mixed solution was stirred at 338 K for 5 h. The precipitate was filtered, and washed successively with ethanol and ether, respectively. The product was dried under vacuum to yield 160.3 mg of (I). Yield, 76.6%. m.p. 462.5-463.5 K. Anal. Calcd. for C21H26N2O6: C, 62.67; H, 6.51; N, 6.96. Found: C, 62.61; H, 6.40; N, 7.01.
Colorless needle-like single crystals suitable for X-ray diffraction studies were obtained after one weeks by slow evaporation from methanol solution of the title compound.
H atoms were placed in calculated positions and non-H atoms were refined anisotropically. The remaining H atoms were treated as riding atoms with distances C—H = 0.96 Å (CH3), 0.97 Å (CH2), 0.93 Å (CH), 0.82 Å (OH), and Uiso(H) = 1.20 Ueq(C), 1.50 Ueq(O). In the absence of significant anomalous scatterers, Friedel pairs were merged before final refinement.
Data collection: SMART (Siemens, 1996); cell
SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); 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 (Sheldrick, 2008).C21H26N2O6 | F(000) = 1712 |
Mr = 402.44 | Dx = 1.302 Mg m−3 |
Orthorhombic, Fdd2 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: F 2 -2d | Cell parameters from 1648 reflections |
a = 25.292 (2) Å | θ = 2.9–25.3° |
b = 34.412 (3) Å | µ = 0.10 mm−1 |
c = 4.7176 (5) Å | T = 298 K |
V = 4105.9 (7) Å3 | Needle-like, colorless |
Z = 8 | 0.45 × 0.18 × 0.17 mm |
Bruker SMART 1000 CCD area-detector diffractometer | 1031 independent reflections |
Radiation source: fine-focus sealed tube | 817 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.048 |
phi and ω scans | θmax = 25.0°, θmin = 2.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −30→29 |
Tmin = 0.958, Tmax = 0.984 | k = −30→40 |
5348 measured reflections | l = −5→5 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.090 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.051P)2] where P = (Fo2 + 2Fc2)/3 |
1031 reflections | (Δ/σ)max < 0.001 |
133 parameters | Δρmax = 0.16 e Å−3 |
1 restraint | Δρmin = −0.14 e Å−3 |
C21H26N2O6 | V = 4105.9 (7) Å3 |
Mr = 402.44 | Z = 8 |
Orthorhombic, Fdd2 | Mo Kα radiation |
a = 25.292 (2) Å | µ = 0.10 mm−1 |
b = 34.412 (3) Å | T = 298 K |
c = 4.7176 (5) Å | 0.45 × 0.18 × 0.17 mm |
Bruker SMART 1000 CCD area-detector diffractometer | 1031 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 817 reflections with I > 2σ(I) |
Tmin = 0.958, Tmax = 0.984 | Rint = 0.048 |
5348 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 1 restraint |
wR(F2) = 0.090 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.16 e Å−3 |
1031 reflections | Δρmin = −0.14 e Å−3 |
133 parameters |
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 > 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 | Occ. (<1) | |
N1 | 0.23158 (9) | 0.17094 (6) | 0.6113 (5) | 0.0506 (6) | |
O1 | 0.21889 (7) | 0.20179 (5) | 0.4290 (5) | 0.0556 (5) | |
O2 | 0.28824 (6) | 0.11584 (5) | 0.8533 (5) | 0.0577 (6) | |
H2 | 0.2826 | 0.1334 | 0.7399 | 0.087* | |
O3 | 0.29360 (7) | 0.05913 (6) | 1.2148 (5) | 0.0613 (6) | |
C1 | 0.26566 (10) | 0.21504 (7) | 0.2881 (7) | 0.0518 (7) | |
H1A | 0.2796 | 0.1948 | 0.1660 | 0.062* | |
H1B | 0.2926 | 0.2220 | 0.4255 | 0.062* | |
C2 | 0.2500 | 0.2500 | 0.1155 (10) | 0.0525 (10) | |
H2A | 0.2794 | 0.2571 | −0.0059 | 0.063* | 0.50 |
H2B | 0.2206 | 0.2429 | −0.0059 | 0.063* | 0.50 |
C3 | 0.19084 (11) | 0.15810 (7) | 0.7412 (6) | 0.0485 (7) | |
H3 | 0.1580 | 0.1692 | 0.7050 | 0.058* | |
C4 | 0.19489 (10) | 0.12638 (7) | 0.9451 (6) | 0.0445 (7) | |
C5 | 0.24271 (10) | 0.10703 (7) | 0.9928 (6) | 0.0437 (7) | |
C6 | 0.24500 (10) | 0.07660 (7) | 1.1909 (6) | 0.0456 (7) | |
C7 | 0.20034 (10) | 0.06695 (8) | 1.3422 (7) | 0.0532 (7) | |
H7 | 0.2021 | 0.0474 | 1.4782 | 0.064* | |
C8 | 0.15281 (11) | 0.08595 (8) | 1.2947 (7) | 0.0555 (8) | |
H8 | 0.1228 | 0.0788 | 1.3960 | 0.067* | |
C9 | 0.15006 (10) | 0.11522 (8) | 1.0988 (7) | 0.0514 (7) | |
H9 | 0.1181 | 0.1278 | 1.0674 | 0.062* | |
C10 | 0.29937 (10) | 0.02900 (8) | 1.4204 (7) | 0.0603 (9) | |
H10A | 0.2739 | 0.0085 | 1.3867 | 0.072* | |
H10B | 0.2939 | 0.0392 | 1.6100 | 0.072* | |
C11 | 0.35463 (10) | 0.01383 (9) | 1.3886 (11) | 0.0812 (12) | |
H11A | 0.3609 | 0.0072 | 1.1938 | 0.122* | |
H11B | 0.3590 | −0.0088 | 1.5048 | 0.122* | |
H11C | 0.3793 | 0.0335 | 1.4467 | 0.122* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0629 (14) | 0.0383 (12) | 0.0506 (15) | −0.0003 (10) | −0.0073 (13) | 0.0030 (13) |
O1 | 0.0583 (11) | 0.0451 (10) | 0.0635 (14) | −0.0006 (8) | −0.0057 (10) | 0.0129 (10) |
O2 | 0.0507 (11) | 0.0625 (12) | 0.0599 (14) | 0.0013 (8) | 0.0034 (10) | 0.0155 (12) |
O3 | 0.0545 (10) | 0.0622 (12) | 0.0670 (15) | 0.0057 (8) | −0.0027 (11) | 0.0205 (12) |
C1 | 0.0586 (17) | 0.0438 (15) | 0.0529 (18) | −0.0020 (12) | −0.0020 (15) | −0.0035 (15) |
C2 | 0.060 (2) | 0.051 (2) | 0.046 (2) | −0.0072 (17) | 0.000 | 0.000 |
C3 | 0.0545 (16) | 0.0413 (15) | 0.0499 (18) | 0.0027 (12) | −0.0071 (15) | −0.0030 (15) |
C4 | 0.0535 (15) | 0.0354 (14) | 0.0444 (17) | −0.0013 (11) | −0.0055 (14) | −0.0053 (13) |
C5 | 0.0455 (14) | 0.0428 (14) | 0.0427 (17) | −0.0046 (11) | −0.0020 (13) | −0.0031 (14) |
C6 | 0.0487 (14) | 0.0417 (14) | 0.0465 (17) | −0.0014 (11) | −0.0037 (13) | −0.0011 (14) |
C7 | 0.0617 (17) | 0.0478 (15) | 0.0500 (18) | −0.0069 (12) | 0.0014 (16) | 0.0036 (15) |
C8 | 0.0526 (15) | 0.0552 (16) | 0.059 (2) | −0.0083 (13) | 0.0075 (15) | 0.0010 (17) |
C9 | 0.0460 (15) | 0.0499 (15) | 0.0582 (19) | 0.0011 (11) | −0.0019 (14) | −0.0040 (16) |
C10 | 0.0656 (19) | 0.0518 (17) | 0.063 (2) | −0.0042 (12) | −0.0133 (16) | 0.0170 (17) |
C11 | 0.0635 (19) | 0.070 (2) | 0.110 (3) | 0.0007 (15) | −0.017 (2) | 0.032 (3) |
N1—C3 | 1.278 (3) | C4—C5 | 1.399 (3) |
N1—O1 | 1.403 (3) | C4—C9 | 1.400 (4) |
O1—C1 | 1.431 (3) | C5—C6 | 1.405 (4) |
O2—C5 | 1.361 (3) | C6—C7 | 1.377 (4) |
O2—H2 | 0.8200 | C7—C8 | 1.387 (4) |
O3—C6 | 1.373 (3) | C7—H7 | 0.9300 |
O3—C10 | 1.427 (3) | C8—C9 | 1.369 (4) |
C1—C2 | 1.506 (4) | C8—H8 | 0.9300 |
C1—H1A | 0.9700 | C9—H9 | 0.9300 |
C1—H1B | 0.9700 | C10—C11 | 1.500 (4) |
C2—C1i | 1.506 (4) | C10—H10A | 0.9700 |
C2—H2A | 0.9700 | C10—H10B | 0.9700 |
C2—H2B | 0.9700 | C11—H11A | 0.9600 |
C3—C4 | 1.459 (4) | C11—H11B | 0.9600 |
C3—H3 | 0.9300 | C11—H11C | 0.9600 |
C3—N1—O1 | 111.8 (2) | O3—C6—C7 | 125.9 (2) |
N1—O1—C1 | 109.68 (18) | O3—C6—C5 | 114.7 (2) |
C5—O2—H2 | 109.5 | C7—C6—C5 | 119.4 (2) |
C6—O3—C10 | 117.7 (2) | C6—C7—C8 | 120.9 (3) |
O1—C1—C2 | 106.76 (19) | C6—C7—H7 | 119.5 |
O1—C1—H1A | 110.4 | C8—C7—H7 | 119.5 |
C2—C1—H1A | 110.4 | C9—C8—C7 | 120.0 (3) |
O1—C1—H1B | 110.4 | C9—C8—H8 | 120.0 |
C2—C1—H1B | 110.4 | C7—C8—H8 | 120.0 |
H1A—C1—H1B | 108.6 | C8—C9—C4 | 120.7 (2) |
C1i—C2—C1 | 114.5 (4) | C8—C9—H9 | 119.6 |
C1i—C2—H2A | 108.6 | C4—C9—H9 | 119.6 |
C1—C2—H2A | 108.6 | O3—C10—C11 | 106.3 (3) |
C1i—C2—H2B | 108.6 | O3—C10—H10A | 110.5 |
C1—C2—H2B | 108.6 | C11—C10—H10A | 110.5 |
H2A—C2—H2B | 107.6 | O3—C10—H10B | 110.5 |
N1—C3—C4 | 121.2 (2) | C11—C10—H10B | 110.5 |
N1—C3—H3 | 119.4 | H10A—C10—H10B | 108.7 |
C4—C3—H3 | 119.4 | C10—C11—H11A | 109.5 |
C5—C4—C9 | 119.1 (3) | C10—C11—H11B | 109.5 |
C5—C4—C3 | 121.5 (2) | H11A—C11—H11B | 109.5 |
C9—C4—C3 | 119.3 (2) | C10—C11—H11C | 109.5 |
O2—C5—C4 | 123.2 (2) | H11A—C11—H11C | 109.5 |
O2—C5—C6 | 116.9 (2) | H11B—C11—H11C | 109.5 |
C4—C5—C6 | 119.8 (2) | ||
C3—N1—O1—C1 | −179.8 (2) | O2—C5—C6—O3 | −0.9 (3) |
N1—O1—C1—C2 | −175.5 (2) | C4—C5—C6—O3 | 178.4 (2) |
O1—C1—C2—C1i | 67.48 (19) | O2—C5—C6—C7 | 178.7 (2) |
O1—N1—C3—C4 | −179.0 (2) | C4—C5—C6—C7 | −1.9 (4) |
N1—C3—C4—C5 | −4.3 (4) | O3—C6—C7—C8 | −178.2 (3) |
N1—C3—C4—C9 | 175.1 (3) | C5—C6—C7—C8 | 2.2 (4) |
C9—C4—C5—O2 | 179.9 (3) | C6—C7—C8—C9 | −1.2 (4) |
C3—C4—C5—O2 | −0.7 (4) | C7—C8—C9—C4 | −0.1 (4) |
C9—C4—C5—C6 | 0.6 (4) | C5—C4—C9—C8 | 0.4 (4) |
C3—C4—C5—C6 | −180.0 (2) | C3—C4—C9—C8 | −179.0 (3) |
C10—O3—C6—C7 | −2.1 (4) | C6—O3—C10—C11 | 176.8 (3) |
C10—O3—C6—C5 | 177.5 (2) |
Symmetry code: (i) −x+1/2, −y+1/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···N1 | 0.82 | 1.92 | 2.636 (2) | 145 |
C11—H11C···O1ii | 0.96 | 2.57 | 3.410 (3) | 146 |
Symmetry code: (ii) x+1/4, −y+1/4, z+5/4. |
Experimental details
Crystal data | |
Chemical formula | C21H26N2O6 |
Mr | 402.44 |
Crystal system, space group | Orthorhombic, Fdd2 |
Temperature (K) | 298 |
a, b, c (Å) | 25.292 (2), 34.412 (3), 4.7176 (5) |
V (Å3) | 4105.9 (7) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.45 × 0.18 × 0.17 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.958, 0.984 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5348, 1031, 817 |
Rint | 0.048 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.090, 1.04 |
No. of reflections | 1031 |
No. of parameters | 133 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.16, −0.14 |
Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···N1 | 0.82 | 1.92 | 2.636 (2) | 145.0 |
C11—H11C···O1i | 0.96 | 2.57 | 3.410 (3) | 146.0 |
Symmetry code: (i) x+1/4, −y+1/4, z+5/4. |
Acknowledgements
This work was supported by the Foundation of the Education Department of Gansu Province (0904–11) and the `Jing Lan' Talent Engineering Funds of Lanzhou Jiaotong University, which are gratefully acknowledged.
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Salicylaldehyde and its derivatives are an important class of compounds which can be used in a variety of studies such as organic synthesis, catalysis, drug design, the spice industry and the life sciences (Dong et al., 2007a; Dong & Duan, 2008). In the past few decades, continuing attention has been drawn to derivatives of the salicylaldehyde and their metal complexes for the investigation of luminescent properties which could be finely tuned by different substituent groups bonded to the phenolic ring (Dong et al., 2008). In this paper, we report synthesis and X-ray structure of 6,6'-diethoxy-2,2'-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol, (I).
As shown in Fig. 1, the single-crystal structure of (I) is built up by only the C21H26N2O6 molecules, in which all bond lengths are in normal ranges. Two benzene rings (C4—C9) of molecule are perpendicular each other with a dihedral angle of 89.53 (3)°. There is a crystallographic twofold rotation axis passing through the middle point of the C—C—C unit. The molecule adopts a trans conguration in which two phenoldoxime moieties adopts an extended form, where the oxime and phenolic alcohols lie in trans positions relative to the C2 atom in the N—-O—CH2—CH2—CH2—O—N linkage. A pair of intramolecular O2—H2···N1 hydrogen bonds generate two six-membered rings, producing two S(6) ring motifs (Table 1, Fig. 1) (Bernstein et al., 1995). Intermolecular C11—H11C···O1 hydrogen bonds (Desiraju et al., 1996) link neighbouring molecules into a supermolecular structure (Fig. 2). Moreover, the packing diagram of the title compound shows a infinete netwok structure viewed along the b-axes (Fig. 3).