organic compounds
Ethyl 4-[(3,5-di-tert-butyl-2-hydroxybenzylidene)amino]benzoate
aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: seikweng@um.edu.my
The title compound, a Schiff base, C24H31NO3, has a substituted aromatic ring at both ends of the azomethine linkage and these make a dihedral angle of 24.9 (1)°. There is an intramolecular hydrogen bond between the hydroxy group (donor) and the N atom of themazomethine linkage.
Related literature
For the use of the methyl ester analog of the title compound as a second-harmonic generation material, see: Sliwa et al. (2008).
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: APEX2 (Bruker, 2009); cell SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
https://doi.org/10.1107/S1600536810041383/fl2320sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810041383/fl2320Isup2.hkl
Ethyl 4-aminobenzoate (0.35 g) dissolved in ethanol (5 ml) was added to 3,5-di-tert-butyl-2-hydroxybenzaldehyde (0.5 g) dissolved in ethanol (20 ml). Several drops of acetic acid were added. The solution was heated for 3 h. The solvent was evaporated and the product recrystallized from ethanol to yield orange prisms in 80% yield that were suitable for data collection.
Carbon-bound H-atoms were placed in calculated positions (C—H 0.95–0.98 Å) and were included in the
in the riding model approximation, with U iso(H) set to 1.2–1.5U eq(C).The hydroxy H-atom was located in a difference Fourier map, and was refined with the O–H distance restrained to 0.84±0.01 Å; its temperature factor was refined.
In the final difference Fourier map, the largest peak was in the vicinity of an aromatic H-atom.
The Schiff base, methyl 4-(di-3,5-tert-butyl-2-hydroxybenzylideneamino)benzoate, is a material suitable for second-harmonic generation as it has electron-donating and electron-withdrawing components that are critical for the manifestation of a permanent dipole (Sliwa et al., 2008). Replacing the methyl group with an ethyl moiety leads to (I), an intensely orange-colored compound (Scheme I, Fig. 1) that crystallizes in a centric
and is, therefore, not suitable as an SHG material. The azomethine bond has an E-configuration; the two aromatic rings are aligned at 24.9 (1) °. The compound is neutral as the hydroxy group bears a hydrogen atom which is a donor in an intra-molecular H bond to the azomethine nitrogen atom (Table 1). There are no important intermolecular contacts; on the other hand, the compound appears to pack in such a way as to accomodate the bulky t-butyl groups as far as possible (Fig. 2).For the use of the methyl ester analog of the title compound as a second-harmonic generation material, see: Sliwa et al. (2008).
Data collection: APEX2 (Bruker, 2009); cell
SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).C24H31NO3 | F(000) = 824 |
Mr = 381.50 | Dx = 1.197 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 18.4789 (18) Å | Cell parameters from 2280 reflections |
b = 10.7194 (11) Å | θ = 2.2–23.8° |
c = 10.7768 (10) Å | µ = 0.08 mm−1 |
β = 97.437 (2)° | T = 100 K |
V = 2116.7 (4) Å3 | Prism, orange |
Z = 4 | 0.30 × 0.05 × 0.05 mm |
Bruker SMART APEX diffractometer | 3123 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.065 |
Graphite monochromator | θmax = 27.5°, θmin = 2.2° |
ω scans | h = −24→23 |
19941 measured reflections | k = −13→13 |
4855 independent reflections | l = −13→14 |
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)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0558P)2 + 1.1473P] where P = (Fo2 + 2Fc2)/3 |
4855 reflections | (Δ/σ)max = 0.001 |
257 parameters | Δρmax = 0.64 e Å−3 |
1 restraint | Δρmin = −0.26 e Å−3 |
C24H31NO3 | V = 2116.7 (4) Å3 |
Mr = 381.50 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 18.4789 (18) Å | µ = 0.08 mm−1 |
b = 10.7194 (11) Å | T = 100 K |
c = 10.7768 (10) Å | 0.30 × 0.05 × 0.05 mm |
β = 97.437 (2)° |
Bruker SMART APEX diffractometer | 3123 reflections with I > 2σ(I) |
19941 measured reflections | Rint = 0.065 |
4855 independent reflections |
R[F2 > 2σ(F2)] = 0.053 | 1 restraint |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.64 e Å−3 |
4855 reflections | Δρmin = −0.26 e Å−3 |
257 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.78175 (8) | 0.89233 (13) | 0.62825 (14) | 0.0252 (3) | |
H1 | 0.7466 (13) | 0.885 (3) | 0.567 (2) | 0.086 (12)* | |
O2 | 0.42198 (8) | 0.93692 (14) | 0.03223 (14) | 0.0291 (4) | |
O3 | 0.43875 (7) | 0.73467 (13) | −0.01081 (13) | 0.0237 (3) | |
N1 | 0.67954 (9) | 0.79668 (16) | 0.46645 (16) | 0.0222 (4) | |
C1 | 0.78970 (11) | 0.77878 (18) | 0.68363 (19) | 0.0203 (4) | |
C2 | 0.84179 (10) | 0.76051 (18) | 0.78972 (18) | 0.0186 (4) | |
C3 | 0.85050 (10) | 0.63866 (18) | 0.83515 (18) | 0.0180 (4) | |
H3 | 0.8862 | 0.6243 | 0.9054 | 0.022* | |
C4 | 0.80999 (10) | 0.53616 (18) | 0.78384 (18) | 0.0183 (4) | |
C5 | 0.75592 (10) | 0.56031 (19) | 0.68469 (18) | 0.0199 (4) | |
H5 | 0.7253 | 0.4941 | 0.6509 | 0.024* | |
C6 | 0.74560 (10) | 0.67938 (19) | 0.63368 (18) | 0.0201 (4) | |
C7 | 0.94204 (12) | 0.9088 (2) | 0.7566 (2) | 0.0290 (5) | |
H7A | 0.9137 | 0.9359 | 0.6780 | 0.044* | |
H7B | 0.9735 | 0.8388 | 0.7402 | 0.044* | |
H7C | 0.9722 | 0.9782 | 0.7930 | 0.044* | |
C8 | 0.88965 (11) | 0.86740 (19) | 0.84883 (19) | 0.0219 (4) | |
C9 | 0.84263 (13) | 0.9784 (2) | 0.8811 (2) | 0.0295 (5) | |
H9A | 0.8124 | 1.0072 | 0.8051 | 0.044* | |
H9B | 0.8744 | 1.0464 | 0.9158 | 0.044* | |
H9C | 0.8112 | 0.9521 | 0.9428 | 0.044* | |
C10 | 0.93590 (13) | 0.8274 (2) | 0.9709 (2) | 0.0304 (5) | |
H10A | 0.9670 | 0.7569 | 0.9542 | 0.046* | |
H10B | 0.9037 | 0.8024 | 1.0320 | 0.046* | |
H10C | 0.9665 | 0.8974 | 1.0044 | 0.046* | |
C11 | 0.82432 (11) | 0.40232 (18) | 0.82969 (18) | 0.0197 (4) | |
C12 | 0.75683 (11) | 0.3511 (2) | 0.8825 (2) | 0.0254 (5) | |
H12A | 0.7465 | 0.4030 | 0.9529 | 0.038* | |
H12B | 0.7662 | 0.2652 | 0.9111 | 0.038* | |
H12C | 0.7148 | 0.3526 | 0.8169 | 0.038* | |
C13 | 0.84080 (12) | 0.3212 (2) | 0.7192 (2) | 0.0259 (5) | |
H13A | 0.8838 | 0.3540 | 0.6858 | 0.039* | |
H13B | 0.7988 | 0.3225 | 0.6535 | 0.039* | |
H13C | 0.8502 | 0.2352 | 0.7479 | 0.039* | |
C14 | 0.88904 (11) | 0.3930 (2) | 0.9334 (2) | 0.0247 (5) | |
H14A | 0.9330 | 0.4251 | 0.9025 | 0.037* | |
H14B | 0.8966 | 0.3056 | 0.9583 | 0.037* | |
H14C | 0.8789 | 0.4423 | 1.0057 | 0.037* | |
C15 | 0.68922 (11) | 0.69415 (19) | 0.52586 (19) | 0.0219 (4) | |
H15 | 0.6589 | 0.6250 | 0.4995 | 0.026* | |
C16 | 0.62487 (10) | 0.8028 (2) | 0.36008 (19) | 0.0213 (4) | |
C17 | 0.59190 (11) | 0.9167 (2) | 0.3314 (2) | 0.0235 (5) | |
H17 | 0.6062 | 0.9876 | 0.3815 | 0.028* | |
C18 | 0.53831 (11) | 0.9279 (2) | 0.23032 (19) | 0.0228 (5) | |
H18 | 0.5157 | 1.0064 | 0.2116 | 0.027* | |
C19 | 0.51707 (10) | 0.82475 (19) | 0.15535 (19) | 0.0202 (4) | |
C20 | 0.55214 (11) | 0.7112 (2) | 0.18075 (19) | 0.0214 (4) | |
H20 | 0.5391 | 0.6411 | 0.1286 | 0.026* | |
C21 | 0.60615 (11) | 0.7002 (2) | 0.28224 (19) | 0.0234 (5) | |
H21 | 0.6305 | 0.6228 | 0.2990 | 0.028* | |
C22 | 0.45526 (11) | 0.84073 (19) | 0.05346 (19) | 0.0209 (4) | |
C23 | 0.37799 (11) | 0.7442 (2) | −0.1100 (2) | 0.0265 (5) | |
H23A | 0.3908 | 0.8002 | −0.1768 | 0.032* | |
H23B | 0.3347 | 0.7788 | −0.0767 | 0.032* | |
C24 | 0.36159 (12) | 0.6163 (2) | −0.1613 (2) | 0.0281 (5) | |
H24A | 0.3206 | 0.6204 | −0.2286 | 0.042* | |
H24B | 0.3488 | 0.5616 | −0.0945 | 0.042* | |
H24C | 0.4046 | 0.5830 | −0.1944 | 0.042* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0265 (8) | 0.0202 (8) | 0.0271 (8) | −0.0029 (6) | −0.0030 (7) | 0.0048 (6) |
O2 | 0.0308 (8) | 0.0244 (8) | 0.0291 (8) | 0.0063 (7) | −0.0075 (7) | 0.0009 (7) |
O3 | 0.0216 (7) | 0.0233 (8) | 0.0235 (8) | 0.0036 (6) | −0.0069 (6) | −0.0009 (6) |
N1 | 0.0198 (8) | 0.0244 (9) | 0.0225 (9) | 0.0007 (7) | 0.0031 (7) | 0.0006 (8) |
C1 | 0.0218 (10) | 0.0195 (10) | 0.0202 (10) | 0.0052 (8) | 0.0057 (8) | 0.0059 (8) |
C2 | 0.0173 (9) | 0.0200 (10) | 0.0187 (10) | 0.0001 (8) | 0.0031 (8) | 0.0001 (8) |
C3 | 0.0162 (9) | 0.0229 (10) | 0.0143 (9) | 0.0016 (8) | −0.0008 (8) | 0.0021 (8) |
C4 | 0.0165 (9) | 0.0206 (10) | 0.0178 (10) | 0.0008 (8) | 0.0023 (8) | 0.0009 (8) |
C5 | 0.0173 (9) | 0.0229 (11) | 0.0191 (10) | −0.0008 (8) | 0.0011 (8) | −0.0032 (8) |
C6 | 0.0154 (9) | 0.0273 (11) | 0.0173 (10) | 0.0025 (8) | 0.0004 (8) | 0.0000 (9) |
C7 | 0.0294 (12) | 0.0291 (12) | 0.0286 (12) | −0.0085 (9) | 0.0037 (10) | 0.0017 (10) |
C8 | 0.0252 (10) | 0.0193 (10) | 0.0204 (10) | −0.0026 (8) | 0.0000 (8) | 0.0017 (8) |
C9 | 0.0393 (13) | 0.0220 (11) | 0.0273 (12) | −0.0012 (10) | 0.0047 (10) | −0.0015 (9) |
C10 | 0.0351 (12) | 0.0253 (12) | 0.0275 (12) | −0.0087 (10) | −0.0080 (10) | 0.0024 (10) |
C11 | 0.0201 (10) | 0.0191 (10) | 0.0192 (10) | 0.0004 (8) | 0.0002 (8) | −0.0015 (8) |
C12 | 0.0262 (11) | 0.0220 (11) | 0.0280 (12) | −0.0025 (9) | 0.0031 (9) | 0.0009 (9) |
C13 | 0.0309 (11) | 0.0232 (11) | 0.0232 (11) | 0.0051 (9) | 0.0023 (9) | −0.0025 (9) |
C14 | 0.0269 (11) | 0.0202 (11) | 0.0254 (11) | 0.0022 (9) | −0.0024 (9) | 0.0009 (9) |
C15 | 0.0212 (10) | 0.0212 (11) | 0.0235 (11) | −0.0011 (8) | 0.0039 (8) | −0.0020 (9) |
C16 | 0.0170 (9) | 0.0283 (12) | 0.0184 (10) | 0.0001 (8) | 0.0014 (8) | 0.0009 (9) |
C17 | 0.0216 (10) | 0.0247 (11) | 0.0238 (11) | −0.0014 (9) | 0.0013 (9) | −0.0008 (9) |
C18 | 0.0226 (10) | 0.0227 (11) | 0.0227 (11) | 0.0021 (8) | 0.0012 (9) | 0.0015 (9) |
C19 | 0.0187 (10) | 0.0239 (11) | 0.0174 (10) | 0.0028 (8) | 0.0004 (8) | 0.0021 (8) |
C20 | 0.0205 (10) | 0.0228 (11) | 0.0204 (10) | −0.0005 (8) | 0.0016 (8) | 0.0003 (9) |
C21 | 0.0216 (10) | 0.0241 (11) | 0.0238 (11) | 0.0060 (9) | 0.0004 (8) | 0.0039 (9) |
C22 | 0.0194 (10) | 0.0232 (11) | 0.0198 (10) | 0.0001 (8) | 0.0012 (8) | 0.0020 (9) |
C23 | 0.0240 (11) | 0.0295 (12) | 0.0231 (11) | 0.0018 (9) | −0.0082 (9) | 0.0016 (9) |
C24 | 0.0261 (11) | 0.0306 (12) | 0.0271 (12) | −0.0001 (10) | 0.0012 (9) | −0.0006 (10) |
O1—C1 | 1.355 (2) | C11—C14 | 1.531 (3) |
O1—H1 | 0.866 (10) | C11—C13 | 1.537 (3) |
O2—C22 | 1.207 (2) | C11—C12 | 1.537 (3) |
O3—C22 | 1.346 (2) | C12—H12A | 0.9800 |
O3—C23 | 1.450 (2) | C12—H12B | 0.9800 |
N1—C15 | 1.273 (3) | C12—H12C | 0.9800 |
N1—C16 | 1.428 (3) | C13—H13A | 0.9800 |
C1—C6 | 1.406 (3) | C13—H13B | 0.9800 |
C1—C2 | 1.410 (3) | C13—H13C | 0.9800 |
C2—C3 | 1.397 (3) | C14—H14A | 0.9800 |
C2—C8 | 1.535 (3) | C14—H14B | 0.9800 |
C3—C4 | 1.402 (3) | C14—H14C | 0.9800 |
C3—H3 | 0.9500 | C15—H15 | 0.9500 |
C4—C5 | 1.389 (3) | C16—C17 | 1.381 (3) |
C4—C11 | 1.529 (3) | C16—C21 | 1.399 (3) |
C5—C6 | 1.393 (3) | C17—C18 | 1.379 (3) |
C5—H5 | 0.9500 | C17—H17 | 0.9500 |
C6—C15 | 1.465 (3) | C18—C19 | 1.395 (3) |
C7—C8 | 1.540 (3) | C18—H18 | 0.9500 |
C7—H7A | 0.9800 | C19—C20 | 1.389 (3) |
C7—H7B | 0.9800 | C19—C22 | 1.488 (3) |
C7—H7C | 0.9800 | C20—C21 | 1.387 (3) |
C8—C10 | 1.534 (3) | C20—H20 | 0.9500 |
C8—C9 | 1.539 (3) | C21—H21 | 0.9500 |
C9—H9A | 0.9800 | C23—C24 | 1.494 (3) |
C9—H9B | 0.9800 | C23—H23A | 0.9900 |
C9—H9C | 0.9800 | C23—H23B | 0.9900 |
C10—H10A | 0.9800 | C24—H24A | 0.9800 |
C10—H10B | 0.9800 | C24—H24B | 0.9800 |
C10—H10C | 0.9800 | C24—H24C | 0.9800 |
C1—O1—H1 | 106 (2) | H12A—C12—H12B | 109.5 |
C22—O3—C23 | 114.99 (16) | C11—C12—H12C | 109.5 |
C15—N1—C16 | 118.83 (18) | H12A—C12—H12C | 109.5 |
O1—C1—C6 | 119.20 (18) | H12B—C12—H12C | 109.5 |
O1—C1—C2 | 120.37 (18) | C11—C13—H13A | 109.5 |
C6—C1—C2 | 120.43 (18) | C11—C13—H13B | 109.5 |
C3—C2—C1 | 116.73 (18) | H13A—C13—H13B | 109.5 |
C3—C2—C8 | 121.24 (17) | C11—C13—H13C | 109.5 |
C1—C2—C8 | 121.96 (18) | H13A—C13—H13C | 109.5 |
C2—C3—C4 | 124.26 (18) | H13B—C13—H13C | 109.5 |
C2—C3—H3 | 117.9 | C11—C14—H14A | 109.5 |
C4—C3—H3 | 117.9 | C11—C14—H14B | 109.5 |
C5—C4—C3 | 116.83 (18) | H14A—C14—H14B | 109.5 |
C5—C4—C11 | 120.03 (17) | C11—C14—H14C | 109.5 |
C3—C4—C11 | 123.12 (17) | H14A—C14—H14C | 109.5 |
C4—C5—C6 | 121.49 (19) | H14B—C14—H14C | 109.5 |
C4—C5—H5 | 119.3 | N1—C15—C6 | 122.09 (19) |
C6—C5—H5 | 119.3 | N1—C15—H15 | 119.0 |
C5—C6—C1 | 120.03 (18) | C6—C15—H15 | 119.0 |
C5—C6—C15 | 117.32 (18) | C17—C16—C21 | 119.51 (19) |
C1—C6—C15 | 122.63 (19) | C17—C16—N1 | 117.79 (19) |
C8—C7—H7A | 109.5 | C21—C16—N1 | 122.64 (19) |
C8—C7—H7B | 109.5 | C18—C17—C16 | 120.3 (2) |
H7A—C7—H7B | 109.5 | C18—C17—H17 | 119.8 |
C8—C7—H7C | 109.5 | C16—C17—H17 | 119.8 |
H7A—C7—H7C | 109.5 | C17—C18—C19 | 120.5 (2) |
H7B—C7—H7C | 109.5 | C17—C18—H18 | 119.7 |
C10—C8—C2 | 112.00 (17) | C19—C18—H18 | 119.7 |
C10—C8—C7 | 107.87 (18) | C20—C19—C18 | 119.40 (18) |
C2—C8—C7 | 108.92 (17) | C20—C19—C22 | 122.69 (19) |
C10—C8—C9 | 106.89 (17) | C18—C19—C22 | 117.87 (18) |
C2—C8—C9 | 111.03 (17) | C21—C20—C19 | 120.0 (2) |
C7—C8—C9 | 110.07 (18) | C21—C20—H20 | 120.0 |
C8—C9—H9A | 109.5 | C19—C20—H20 | 120.0 |
C8—C9—H9B | 109.5 | C20—C21—C16 | 120.18 (19) |
H9A—C9—H9B | 109.5 | C20—C21—H21 | 119.9 |
C8—C9—H9C | 109.5 | C16—C21—H21 | 119.9 |
H9A—C9—H9C | 109.5 | O2—C22—O3 | 123.23 (18) |
H9B—C9—H9C | 109.5 | O2—C22—C19 | 124.17 (19) |
C8—C10—H10A | 109.5 | O3—C22—C19 | 112.57 (17) |
C8—C10—H10B | 109.5 | O3—C23—C24 | 107.99 (17) |
H10A—C10—H10B | 109.5 | O3—C23—H23A | 110.1 |
C8—C10—H10C | 109.5 | C24—C23—H23A | 110.1 |
H10A—C10—H10C | 109.5 | O3—C23—H23B | 110.1 |
H10B—C10—H10C | 109.5 | C24—C23—H23B | 110.1 |
C4—C11—C14 | 112.55 (16) | H23A—C23—H23B | 108.4 |
C4—C11—C13 | 108.92 (16) | C23—C24—H24A | 109.5 |
C14—C11—C13 | 108.30 (16) | C23—C24—H24B | 109.5 |
C4—C11—C12 | 109.85 (16) | H24A—C24—H24B | 109.5 |
C14—C11—C12 | 107.53 (17) | C23—C24—H24C | 109.5 |
C13—C11—C12 | 109.64 (17) | H24A—C24—H24C | 109.5 |
C11—C12—H12A | 109.5 | H24B—C24—H24C | 109.5 |
C11—C12—H12B | 109.5 | ||
O1—C1—C2—C3 | −175.11 (17) | C3—C4—C11—C13 | −122.2 (2) |
C6—C1—C2—C3 | 4.6 (3) | C5—C4—C11—C12 | −64.1 (2) |
O1—C1—C2—C8 | 1.8 (3) | C3—C4—C11—C12 | 117.6 (2) |
C6—C1—C2—C8 | −178.52 (18) | C16—N1—C15—C6 | 178.21 (17) |
C1—C2—C3—C4 | −1.5 (3) | C5—C6—C15—N1 | −174.29 (19) |
C8—C2—C3—C4 | −178.36 (18) | C1—C6—C15—N1 | 4.0 (3) |
C2—C3—C4—C5 | −2.7 (3) | C15—N1—C16—C17 | 151.3 (2) |
C2—C3—C4—C11 | 175.58 (19) | C15—N1—C16—C21 | −31.4 (3) |
C3—C4—C5—C6 | 3.9 (3) | C21—C16—C17—C18 | 3.2 (3) |
C11—C4—C5—C6 | −174.44 (18) | N1—C16—C17—C18 | −179.46 (18) |
C4—C5—C6—C1 | −0.9 (3) | C16—C17—C18—C19 | −0.4 (3) |
C4—C5—C6—C15 | 177.43 (18) | C17—C18—C19—C20 | −2.2 (3) |
O1—C1—C6—C5 | 176.18 (18) | C17—C18—C19—C22 | 175.61 (19) |
C2—C1—C6—C5 | −3.5 (3) | C18—C19—C20—C21 | 2.0 (3) |
O1—C1—C6—C15 | −2.1 (3) | C22—C19—C20—C21 | −175.68 (18) |
C2—C1—C6—C15 | 178.18 (18) | C19—C20—C21—C16 | 0.8 (3) |
C3—C2—C8—C10 | −9.4 (3) | C17—C16—C21—C20 | −3.4 (3) |
C1—C2—C8—C10 | 173.86 (19) | N1—C16—C21—C20 | 179.43 (18) |
C3—C2—C8—C7 | 109.8 (2) | C23—O3—C22—O2 | 0.8 (3) |
C1—C2—C8—C7 | −66.9 (2) | C23—O3—C22—C19 | 178.95 (17) |
C3—C2—C8—C9 | −128.8 (2) | C20—C19—C22—O2 | 177.1 (2) |
C1—C2—C8—C9 | 54.5 (2) | C18—C19—C22—O2 | −0.6 (3) |
C5—C4—C11—C14 | 176.14 (18) | C20—C19—C22—O3 | −1.0 (3) |
C3—C4—C11—C14 | −2.1 (3) | C18—C19—C22—O3 | −178.74 (18) |
C5—C4—C11—C13 | 56.0 (2) | C22—O3—C23—C24 | −173.52 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.87 (1) | 1.80 (2) | 2.609 (2) | 154 (3) |
Experimental details
Crystal data | |
Chemical formula | C24H31NO3 |
Mr | 381.50 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 18.4789 (18), 10.7194 (11), 10.7768 (10) |
β (°) | 97.437 (2) |
V (Å3) | 2116.7 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.30 × 0.05 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART APEX diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 19941, 4855, 3123 |
Rint | 0.065 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.142, 1.01 |
No. of reflections | 4855 |
No. of parameters | 257 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.64, −0.26 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.87 (1) | 1.80 (2) | 2.609 (2) | 154 (3) |
Acknowledgements
We thank the University of Malaya for supporting this study.
References
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sliwa, M., Spangenberg, A., Metivier, R., Letard, S., Nakatani, K. & Yu, P. (2008). Res. Chem. Intermed. 34, 181–190. Web of Science CrossRef CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
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The Schiff base, methyl 4-(di-3,5-tert-butyl-2-hydroxybenzylideneamino)benzoate, is a material suitable for second-harmonic generation as it has electron-donating and electron-withdrawing components that are critical for the manifestation of a permanent dipole (Sliwa et al., 2008). Replacing the methyl group with an ethyl moiety leads to (I), an intensely orange-colored compound (Scheme I, Fig. 1) that crystallizes in a centric space group and is, therefore, not suitable as an SHG material. The azomethine bond has an E-configuration; the two aromatic rings are aligned at 24.9 (1) °. The compound is neutral as the hydroxy group bears a hydrogen atom which is a donor in an intra-molecular H bond to the azomethine nitrogen atom (Table 1). There are no important intermolecular contacts; on the other hand, the compound appears to pack in such a way as to accomodate the bulky t-butyl groups as far as possible (Fig. 2).