organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

N,N′-Bis(2-hydr­­oxy-3-eth­oxybenzyl­­idene)butane-1,4-di­amine

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and bDepartment of Chemistry, School of Science, Payame Noor University (PNU), Ardakan, Yazd, Iran
*Correspondence e-mail: hkfun@usm.my

(Received 27 February 2009; accepted 2 March 2009; online 6 March 2009)

The title Schiff base compound, C22H28N2O4, lies across a crystallographic inversion centre and adopts an E configuration with respect to the C=N bond. Pairs of weak inter­molecular C—H⋯O inter­actions link neighbouring mol­ecules into dimers with an R22(28) ring motif. The crystal structure is stabilized by inter­molecular C—H⋯π inter­actions. An intramolecular O—H⋯N hydrogen bond occurs.

Related literature

For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For information on Schiff base ligands and complexes and their applications, see, for example: Calligaris & Randaccio (1987[Calligaris, M. & Randaccio, L. (1987). Comprehensive Coordination Chemistry, Vol. 2, edited by G. Wilkinson, pp. 715-738. London: Pergamon.]); Casellato & Vigato (1977[Casellato, U. & Vigato, P. A. (1977). Coord. Chem. Rev. 23, 31-50.]); Fun & Kia (2008a[Fun, H.-K. & Kia, R. (2008a). Acta Cryst. E64, m1081-m1082.],b[Fun, H.-K. & Kia, R. (2008b). Acta Cryst. E64, m1116-m1117.]). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]).

[Scheme 1]

Experimental

Crystal data
  • C22H28N2O4

  • Mr = 384.46

  • Triclinic, [P \overline 1]

  • a = 6.8647 (2) Å

  • b = 6.9052 (2) Å

  • c = 10.8083 (3) Å

  • α = 92.779 (2)°

  • β = 99.908 (2)°

  • γ = 101.239 (2)°

  • V = 493.23 (2) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 100 K

  • 0.45 × 0.19 × 0.07 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.961, Tmax = 0.994

  • 8962 measured reflections

  • 2954 independent reflections

  • 2157 reflections with I > 2σ(I)

  • Rint = 0.033

Refinement
  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.131

  • S = 1.04

  • 2954 reflections

  • 129 parameters

  • H-atom parameters constrained

  • Δρmax = 0.43 e Å−3

  • Δρmin = −0.27 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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—H11BCg1ii 0.98 2.96 3.5403 (15) 145
Symmetry codes: (i) x, y-1, z; (ii) -x+2, -y+1, -z+1. Cg1 is the centroid of the C1–C6 benzene ring.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

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 (CN) 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).

Related literature top

For hydrogen-bond motifs, see: Bernstein et al. (1995). For information on Schiff base ligands and complexes and their applications, see, for example: Calligaris & Randaccio (1987); Casellato & Vigato (1977); Fun & Kia (2008a,b). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986). Cg1 is the centroid of the C1–C6 benzene ring.

Experimental top

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.

Refinement top

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.

Computing details top

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).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with atom labels and 50% probability ellipsoids for non-H atoms. The suffix A corresponds to symmetry code (-x + 2, -y + 1, -z + 2).
[Figure 2] Fig. 2. The crystal packing of the title compound, viewed down the c axis showing dimer formation by R22(28) ring motif.
N,N'-Bis(2-hydroxy-3-ethoxybenzylidene)butane-1,4-diamine top
Crystal data top
C22H28N2O4Z = 1
Mr = 384.46F(000) = 206
Triclinic, P1Dx = 1.294 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 6.8647 (2) ÅCell parameters from 2475 reflections
b = 6.9052 (2) Åθ = 2.5–29.4°
c = 10.8083 (3) ŵ = 0.09 mm1
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 tube2157 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.033
ϕ and ω scansθmax = 30.4°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 99
Tmin = 0.961, Tmax = 0.994k = 99
8962 measured reflectionsl = 1415
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.131H-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 parametersΔρmax = 0.43 e Å3
0 restraintsΔρmin = 0.27 e Å3
Crystal data top
C22H28N2O4γ = 101.239 (2)°
Mr = 384.46V = 493.23 (2) Å3
Triclinic, P1Z = 1
a = 6.8647 (2) ÅMo Kα radiation
b = 6.9052 (2) ŵ = 0.09 mm1
c = 10.8083 (3) ÅT = 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 = 0.994Rint = 0.033
8962 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.131H-atom parameters constrained
S = 1.04Δρmax = 0.43 e Å3
2954 reflectionsΔρmin = 0.27 e Å3
129 parameters
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
xyzUiso*/Ueq
O10.69496 (13)0.51130 (12)0.23213 (9)0.0191 (2)
H10.57920.49020.18700.029*
O21.05734 (12)0.52787 (12)0.36073 (8)0.0178 (2)
N10.35928 (15)0.30726 (15)0.10848 (10)0.0181 (2)
C10.75200 (17)0.33702 (16)0.25124 (11)0.0149 (2)
C20.94642 (17)0.34181 (16)0.32117 (11)0.0157 (2)
C31.00920 (18)0.16571 (17)0.34438 (12)0.0177 (2)
H3A1.13980.16900.39210.021*
C40.88179 (18)0.01729 (17)0.29812 (12)0.0188 (3)
H4A0.92590.13720.31460.023*
C50.69162 (18)0.02237 (17)0.22845 (12)0.0178 (2)
H5A0.60580.14620.19640.021*
C60.62455 (17)0.15406 (16)0.20476 (11)0.0157 (2)
C70.42169 (18)0.14831 (17)0.13323 (11)0.0169 (2)
H7A0.33460.02380.10460.020*
C80.15522 (17)0.29668 (17)0.03663 (12)0.0185 (3)
H8A0.05610.20410.07350.022*
H8B0.14780.24590.05170.022*
C90.10389 (17)0.50109 (17)0.03934 (11)0.0170 (2)
H9A0.20760.59460.00650.020*
H9B0.10640.54880.12760.020*
C101.26442 (17)0.54481 (17)0.42136 (12)0.0182 (3)
H10A1.33700.47550.36760.022*
H10B1.27130.48570.50320.022*
C111.35712 (19)0.76329 (19)0.44083 (13)0.0227 (3)
H11A1.50030.78230.47950.034*
H11B1.28660.82910.49640.034*
H11C1.34480.82050.35930.034*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0164 (4)0.0136 (4)0.0265 (5)0.0048 (3)0.0003 (3)0.0029 (3)
O20.0134 (4)0.0146 (4)0.0234 (5)0.0009 (3)0.0006 (3)0.0005 (3)
N10.0145 (5)0.0188 (5)0.0215 (5)0.0055 (4)0.0021 (4)0.0024 (4)
C10.0163 (6)0.0129 (5)0.0168 (6)0.0040 (4)0.0054 (4)0.0031 (4)
C20.0154 (6)0.0149 (5)0.0172 (6)0.0021 (4)0.0051 (4)0.0015 (4)
C30.0143 (6)0.0190 (6)0.0203 (6)0.0050 (4)0.0023 (5)0.0029 (4)
C40.0194 (6)0.0149 (5)0.0237 (6)0.0069 (4)0.0044 (5)0.0039 (4)
C50.0175 (6)0.0133 (5)0.0223 (6)0.0030 (4)0.0029 (5)0.0015 (4)
C60.0142 (6)0.0157 (5)0.0176 (6)0.0038 (4)0.0033 (4)0.0021 (4)
C70.0154 (6)0.0154 (5)0.0192 (6)0.0019 (4)0.0027 (5)0.0011 (4)
C80.0137 (6)0.0187 (6)0.0221 (6)0.0043 (4)0.0001 (5)0.0009 (5)
C90.0157 (6)0.0176 (5)0.0186 (6)0.0055 (4)0.0032 (5)0.0025 (4)
C100.0128 (6)0.0193 (6)0.0221 (6)0.0029 (4)0.0030 (5)0.0009 (4)
C110.0150 (6)0.0219 (6)0.0291 (7)0.0006 (4)0.0021 (5)0.0027 (5)
Geometric parameters (Å, º) top
O1—C11.3507 (12)C6—C71.4641 (15)
O1—H10.8400C7—H7A0.9500
O2—C21.3662 (13)C8—C91.5201 (15)
O2—C101.4391 (13)C8—H8A0.9900
N1—C71.2776 (14)C8—H8B0.9900
N1—C81.4666 (14)C9—C9i1.527 (2)
C1—C61.4037 (16)C9—H9A0.9900
C1—C21.4096 (16)C9—H9B0.9900
C2—C31.3871 (15)C10—C111.5081 (17)
C3—C41.4033 (17)C10—H10A0.9900
C3—H3A0.9500C10—H10B0.9900
C4—C51.3833 (16)C11—H11A0.9800
C4—H4A0.9500C11—H11B0.9800
C5—C61.4036 (15)C11—H11C0.9800
C5—H5A0.9500
C1—O1—H1109.5N1—C8—C9109.97 (10)
C2—O2—C10117.43 (9)N1—C8—H8A109.7
C7—N1—C8120.11 (11)C9—C8—H8A109.7
O1—C1—C6122.32 (10)N1—C8—H8B109.7
O1—C1—C2118.03 (10)C9—C8—H8B109.7
C6—C1—C2119.65 (10)H8A—C8—H8B108.2
O2—C2—C3125.83 (11)C8—C9—C9i111.80 (13)
O2—C2—C1114.48 (9)C8—C9—H9A109.3
C3—C2—C1119.70 (11)C9i—C9—H9A109.3
C2—C3—C4120.70 (11)C8—C9—H9B109.3
C2—C3—H3A119.7C9i—C9—H9B109.3
C4—C3—H3A119.7H9A—C9—H9B107.9
C5—C4—C3119.72 (11)O2—C10—C11106.44 (9)
C5—C4—H4A120.1O2—C10—H10A110.4
C3—C4—H4A120.1C11—C10—H10A110.4
C4—C5—C6120.48 (11)O2—C10—H10B110.4
C4—C5—H5A119.8C11—C10—H10B110.4
C6—C5—H5A119.8H10A—C10—H10B108.6
C5—C6—C1119.75 (10)C10—C11—H11A109.5
C5—C6—C7120.42 (11)C10—C11—H11B109.5
C1—C6—C7119.83 (10)H11A—C11—H11B109.5
N1—C7—C6121.38 (11)C10—C11—H11C109.5
N1—C7—H7A119.3H11A—C11—H11C109.5
C6—C7—H7A119.3H11B—C11—H11C109.5
C10—O2—C2—C36.39 (17)C4—C5—C6—C7178.73 (11)
C10—O2—C2—C1173.76 (10)O1—C1—C6—C5179.51 (11)
O1—C1—C2—O20.84 (16)C2—C1—C6—C50.09 (17)
C6—C1—C2—O2179.55 (10)O1—C1—C6—C70.25 (17)
O1—C1—C2—C3179.02 (10)C2—C1—C6—C7179.35 (10)
C6—C1—C2—C30.60 (17)C8—N1—C7—C6179.99 (10)
O2—C2—C3—C4179.65 (11)C5—C6—C7—N1178.57 (11)
C1—C2—C3—C40.51 (18)C1—C6—C7—N12.18 (18)
C2—C3—C4—C50.10 (18)C7—N1—C8—C9170.13 (11)
C3—C4—C5—C60.61 (18)N1—C8—C9—C9i177.44 (12)
C4—C5—C6—C10.51 (18)C2—O2—C10—C11173.37 (10)
Symmetry code: (i) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N10.841.822.5638 (14)147
C5—H5A···O1ii0.952.593.2268 (14)125
C11—H11B···Cg1iii0.982.963.5403 (15)145
Symmetry codes: (ii) x, y1, z; (iii) x+2, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC22H28N2O4
Mr384.46
Crystal system, space groupTriclinic, P1
Temperature (K)100
a, b, c (Å)6.8647 (2), 6.9052 (2), 10.8083 (3)
α, β, γ (°)92.779 (2), 99.908 (2), 101.239 (2)
V3)493.23 (2)
Z1
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.45 × 0.19 × 0.07
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.961, 0.994
No. of measured, independent and
observed [I > 2σ(I)] reflections
8962, 2954, 2157
Rint0.033
(sin θ/λ)max1)0.712
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.131, 1.04
No. of reflections2954
No. of parameters129
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.43, 0.27

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N10.84001.82002.5638 (14)147.00
C5—H5A···O1i0.95002.59003.2268 (14)125.00
C11—H11B···Cg1ii0.98002.96003.5403 (15)145.00
Symmetry codes: (i) x, y1, z; (ii) x+2, y+1, z+1.
 

Footnotes

Additional correspondence author: e-mail: zsrkk@yahoo.com.

Acknowledgements

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.

References

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First citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCalligaris, M. & Randaccio, L. (1987). Comprehensive Coordination Chemistry, Vol. 2, edited by G. Wilkinson, pp. 715–738. London: Pergamon.  Google Scholar
First citationCasellato, U. & Vigato, P. A. (1977). Coord. Chem. Rev. 23, 31–50.  CrossRef CAS Web of Science Google Scholar
First citationCosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationFun, H.-K. & Kia, R. (2008a). Acta Cryst. E64, m1081–m1082.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFun, H.-K. & Kia, R. (2008b). Acta Cryst. E64, m1116–m1117.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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