![](/logos/buttonlogos/cross.png)
![](/logos/buttonlogos/cross.png)
organic compounds
4′-Formylbenzo-15-crown-5
aInstitut für Organische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, D-09596 Freiberg/Sachsen, Germany, and bInstitute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, H Abdullaev 83, Tashkent 100125, Uzbekistan
*Correspondence e-mail: bahtier@academy.uzsci.net
In the title compound (systematic name: 17-formyl-2,5,8,11,14-pentaoxabicyclo[13.4.0]nonadeca-15,17,19-triene), C15H20O6, the 15-crown-5 ring adopts a twisted conformation. The formyl group is coplanar with the benzene ring. The crystal packing is stabilized by C—H⋯O interactions involving the C=O group and ether O atoms as acceptors and methylene CH groups as donors.
Related literature
The unsubstituted benzocrown ether was characterized by Pedersen (1967) and its structure was described by Hanson (1978
), while Rogers and co-workers reported 4′-amino- and 4′-nitro-substituted compounds (Rogers, Huggins et al., 1992
; Rogers, Henry & Rollins, 1992
). For the synthesis of the title compound, see: Hyde et al. (1978
).
Experimental
Crystal data
|
Refinement
|
|
Data collection: APEX2 (Bruker, 2004); cell SAINT (Bruker, 2004
); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008
); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008
); molecular graphics: ORTEP-3 (Farrugia, 1997
); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536808022186/gk2144sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808022186/gk2144Isup2.hkl
The title compound, 4'-formylbenzo-15-crown-5, was synthesized from benzo-15-crown-5 (Pedersen, 1967) which was reacted with N-methylformanilide and phoshoryl chloride (Hyde et al., 1978). Colourless needles of the title compound suitable for X-ray
were obtained by slow cooling and evaporation of a solution of n-heptane. Fast cooling of the solution resulted in the formation of an orthorhombic polymorph of the title compound.The H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.95 -0.99 Å, and Uiso=1.2–1.5 Ueq (C).
Data collection: APEX2 (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008). ![]() | Fig. 1. Molecular structure of the title compound with ellipsoids drawn at the 50% probability level. |
![]() | Fig. 2. Packing diagram, viewed down the c axis. |
C15H20O6 | F(000) = 632 |
Mr = 296.31 | Dx = 1.395 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 9008 reflections |
a = 18.0091 (8) Å | θ = 2.4–33.3° |
b = 9.6678 (4) Å | µ = 0.11 mm−1 |
c = 8.1028 (3) Å | T = 90 K |
β = 91.262 (2)° | Plate, colourless |
V = 1410.42 (10) Å3 | 0.60 × 0.39 × 0.05 mm |
Z = 4 |
Bruker Kappa APEXII CCD diffractometer | 4523 independent reflections |
Radiation source: fine-focus sealed tube | 3716 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
ϕ and ω scans | θmax = 31.1°, θmin = 3.1° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | h = −26→23 |
Tmin = 0.857, Tmax = 0.995 | k = −14→12 |
18190 measured reflections | l = −11→11 |
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) = 0.116 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0681P)2 + 0.3911P] where P = (Fo2 + 2Fc2)/3 |
4523 reflections | (Δ/σ)max < 0.001 |
190 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
C15H20O6 | V = 1410.42 (10) Å3 |
Mr = 296.31 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 18.0091 (8) Å | µ = 0.11 mm−1 |
b = 9.6678 (4) Å | T = 90 K |
c = 8.1028 (3) Å | 0.60 × 0.39 × 0.05 mm |
β = 91.262 (2)° |
Bruker Kappa APEXII CCD diffractometer | 4523 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | 3716 reflections with I > 2σ(I) |
Tmin = 0.857, Tmax = 0.995 | Rint = 0.027 |
18190 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.116 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.28 e Å−3 |
4523 reflections | Δρmin = −0.22 e Å−3 |
190 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. |
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 | ||
O1 | −0.03932 (4) | 0.76211 (8) | 0.74777 (10) | 0.02453 (17) | |
O2 | 0.18803 (4) | 0.54926 (7) | 0.45384 (9) | 0.01606 (14) | |
O3 | 0.25972 (4) | 0.29979 (8) | 0.55829 (10) | 0.02217 (17) | |
O4 | 0.42078 (4) | 0.40116 (8) | 0.32578 (9) | 0.01872 (15) | |
O5 | 0.41719 (4) | 0.72035 (7) | 0.34545 (8) | 0.01730 (15) | |
O6 | 0.26420 (4) | 0.75557 (7) | 0.36194 (9) | 0.01609 (14) | |
C1 | 0.15926 (5) | 0.67447 (9) | 0.49388 (11) | 0.01361 (17) | |
C2 | 0.09428 (5) | 0.69566 (10) | 0.57629 (11) | 0.01540 (17) | |
H2 | 0.0650 | 0.6190 | 0.6084 | 0.018* | |
C3 | 0.07132 (5) | 0.83094 (10) | 0.61289 (11) | 0.01618 (18) | |
C4 | 0.11385 (6) | 0.94299 (10) | 0.56708 (12) | 0.01868 (19) | |
H4 | 0.0984 | 1.0340 | 0.5940 | 0.022* | |
C5 | 0.17961 (6) | 0.92303 (10) | 0.48118 (12) | 0.01756 (18) | |
H5 | 0.2085 | 1.0002 | 0.4487 | 0.021* | |
C6 | 0.20225 (5) | 0.78964 (9) | 0.44389 (11) | 0.01396 (17) | |
C7 | 0.00239 (5) | 0.85268 (11) | 0.70205 (12) | 0.02018 (19) | |
H7 | −0.0109 | 0.9455 | 0.7262 | 0.024* | |
C8 | 0.14823 (5) | 0.43015 (9) | 0.50768 (13) | 0.01689 (18) | |
H8A | 0.0984 | 0.4269 | 0.4539 | 0.020* | |
H8B | 0.1422 | 0.4329 | 0.6288 | 0.020* | |
C9 | 0.19286 (5) | 0.30593 (10) | 0.46010 (14) | 0.0203 (2) | |
H9A | 0.1633 | 0.2209 | 0.4769 | 0.024* | |
H9B | 0.2052 | 0.3116 | 0.3418 | 0.024* | |
C10 | 0.32608 (5) | 0.28738 (10) | 0.46689 (14) | 0.0204 (2) | |
H10A | 0.3193 | 0.2140 | 0.3827 | 0.025* | |
H10B | 0.3672 | 0.2589 | 0.5425 | 0.025* | |
C11 | 0.34702 (5) | 0.42146 (10) | 0.38202 (12) | 0.01686 (18) | |
H11A | 0.3126 | 0.4408 | 0.2879 | 0.020* | |
H11B | 0.3453 | 0.4999 | 0.4604 | 0.020* | |
C12 | 0.44456 (5) | 0.49820 (11) | 0.20613 (12) | 0.01883 (19) | |
H12A | 0.4024 | 0.5185 | 0.1295 | 0.023* | |
H12B | 0.4844 | 0.4554 | 0.1410 | 0.023* | |
C13 | 0.47328 (5) | 0.63335 (11) | 0.27812 (12) | 0.01947 (19) | |
H13A | 0.5106 | 0.6122 | 0.3662 | 0.023* | |
H13B | 0.4988 | 0.6851 | 0.1905 | 0.023* | |
C14 | 0.37553 (5) | 0.79418 (10) | 0.22314 (11) | 0.01733 (18) | |
H14A | 0.3570 | 0.7297 | 0.1367 | 0.021* | |
H14B | 0.4074 | 0.8642 | 0.1705 | 0.021* | |
C15 | 0.31127 (5) | 0.86389 (10) | 0.30465 (11) | 0.01632 (18) | |
H15A | 0.3291 | 0.9217 | 0.3982 | 0.020* | |
H15B | 0.2840 | 0.9236 | 0.2247 | 0.020* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0197 (3) | 0.0272 (4) | 0.0269 (4) | −0.0004 (3) | 0.0049 (3) | −0.0043 (3) |
O2 | 0.0180 (3) | 0.0094 (3) | 0.0211 (3) | −0.0007 (2) | 0.0051 (2) | 0.0003 (2) |
O3 | 0.0173 (3) | 0.0243 (4) | 0.0250 (4) | 0.0025 (3) | 0.0044 (3) | 0.0089 (3) |
O4 | 0.0157 (3) | 0.0198 (3) | 0.0208 (3) | 0.0011 (2) | 0.0037 (2) | 0.0046 (3) |
O5 | 0.0187 (3) | 0.0205 (3) | 0.0127 (3) | −0.0001 (3) | 0.0001 (2) | 0.0022 (2) |
O6 | 0.0177 (3) | 0.0122 (3) | 0.0186 (3) | −0.0023 (2) | 0.0052 (2) | 0.0007 (2) |
C1 | 0.0164 (4) | 0.0108 (4) | 0.0137 (4) | 0.0004 (3) | −0.0004 (3) | 0.0002 (3) |
C2 | 0.0164 (4) | 0.0140 (4) | 0.0158 (4) | −0.0003 (3) | 0.0005 (3) | 0.0001 (3) |
C3 | 0.0175 (4) | 0.0163 (4) | 0.0148 (4) | 0.0023 (3) | −0.0001 (3) | −0.0014 (3) |
C4 | 0.0233 (4) | 0.0129 (4) | 0.0199 (4) | 0.0028 (3) | 0.0012 (3) | −0.0017 (3) |
C5 | 0.0222 (4) | 0.0119 (4) | 0.0186 (4) | −0.0003 (3) | 0.0011 (3) | 0.0007 (3) |
C6 | 0.0159 (4) | 0.0133 (4) | 0.0127 (4) | −0.0004 (3) | 0.0002 (3) | 0.0006 (3) |
C7 | 0.0195 (4) | 0.0209 (5) | 0.0201 (4) | 0.0039 (3) | 0.0009 (3) | −0.0053 (4) |
C8 | 0.0161 (4) | 0.0112 (4) | 0.0235 (5) | −0.0019 (3) | 0.0035 (3) | 0.0015 (3) |
C9 | 0.0171 (4) | 0.0124 (4) | 0.0314 (5) | −0.0006 (3) | 0.0021 (4) | −0.0001 (4) |
C10 | 0.0169 (4) | 0.0171 (4) | 0.0274 (5) | 0.0023 (3) | 0.0044 (3) | 0.0054 (4) |
C11 | 0.0162 (4) | 0.0154 (4) | 0.0191 (4) | −0.0003 (3) | 0.0033 (3) | −0.0001 (3) |
C12 | 0.0193 (4) | 0.0218 (5) | 0.0156 (4) | 0.0005 (3) | 0.0043 (3) | 0.0017 (3) |
C13 | 0.0156 (4) | 0.0230 (5) | 0.0199 (4) | −0.0019 (3) | 0.0023 (3) | 0.0025 (4) |
C14 | 0.0185 (4) | 0.0208 (4) | 0.0127 (4) | −0.0019 (3) | 0.0009 (3) | 0.0043 (3) |
C15 | 0.0194 (4) | 0.0141 (4) | 0.0156 (4) | −0.0040 (3) | 0.0008 (3) | 0.0027 (3) |
O1—C7 | 1.2168 (13) | C7—H7 | 0.9500 |
O2—C1 | 1.3589 (11) | C8—C9 | 1.5001 (13) |
O2—C8 | 1.4296 (11) | C8—H8A | 0.9900 |
O3—C10 | 1.4249 (12) | C8—H8B | 0.9900 |
O3—C9 | 1.4297 (13) | C9—H9A | 0.9900 |
O4—C12 | 1.4219 (12) | C9—H9B | 0.9900 |
O4—C11 | 1.4275 (11) | C10—C11 | 1.5189 (13) |
O5—C14 | 1.4219 (12) | C10—H10A | 0.9900 |
O5—C13 | 1.4318 (12) | C10—H10B | 0.9900 |
O6—C6 | 1.3516 (11) | C11—H11A | 0.9900 |
O6—C15 | 1.4311 (11) | C11—H11B | 0.9900 |
C1—C2 | 1.3755 (12) | C12—C13 | 1.5171 (15) |
C1—C6 | 1.4202 (12) | C12—H12A | 0.9900 |
C2—C3 | 1.4052 (13) | C12—H12B | 0.9900 |
C2—H2 | 0.9500 | C13—H13A | 0.9900 |
C3—C4 | 1.3822 (13) | C13—H13B | 0.9900 |
C3—C7 | 1.4651 (13) | C14—C15 | 1.5044 (13) |
C4—C5 | 1.4003 (13) | C14—H14A | 0.9900 |
C4—H4 | 0.9500 | C14—H14B | 0.9900 |
C5—C6 | 1.3877 (13) | C15—H15A | 0.9900 |
C5—H5 | 0.9500 | C15—H15B | 0.9900 |
C1—O2—C8 | 116.64 (7) | H9A—C9—H9B | 108.2 |
C10—O3—C9 | 114.84 (8) | O3—C10—C11 | 112.51 (8) |
C12—O4—C11 | 115.04 (7) | O3—C10—H10A | 109.1 |
C14—O5—C13 | 113.27 (7) | C11—C10—H10A | 109.1 |
C6—O6—C15 | 118.83 (7) | O3—C10—H10B | 109.1 |
O2—C1—C2 | 125.56 (8) | C11—C10—H10B | 109.1 |
O2—C1—C6 | 114.66 (8) | H10A—C10—H10B | 107.8 |
C2—C1—C6 | 119.78 (8) | O4—C11—C10 | 105.62 (7) |
C1—C2—C3 | 119.90 (9) | O4—C11—H11A | 110.6 |
C1—C2—H2 | 120.0 | C10—C11—H11A | 110.6 |
C3—C2—H2 | 120.0 | O4—C11—H11B | 110.6 |
C4—C3—C2 | 120.36 (9) | C10—C11—H11B | 110.6 |
C4—C3—C7 | 120.03 (9) | H11A—C11—H11B | 108.7 |
C2—C3—C7 | 119.61 (9) | O4—C12—C13 | 114.29 (8) |
C3—C4—C5 | 120.35 (9) | O4—C12—H12A | 108.7 |
C3—C4—H4 | 119.8 | C13—C12—H12A | 108.7 |
C5—C4—H4 | 119.8 | O4—C12—H12B | 108.7 |
C6—C5—C4 | 119.47 (9) | C13—C12—H12B | 108.7 |
C6—C5—H5 | 120.3 | H12A—C12—H12B | 107.6 |
C4—C5—H5 | 120.3 | O5—C13—C12 | 114.52 (8) |
O6—C6—C5 | 125.67 (8) | O5—C13—H13A | 108.6 |
O6—C6—C1 | 114.21 (8) | C12—C13—H13A | 108.6 |
C5—C6—C1 | 120.12 (8) | O5—C13—H13B | 108.6 |
O1—C7—C3 | 125.61 (10) | C12—C13—H13B | 108.6 |
O1—C7—H7 | 117.2 | H13A—C13—H13B | 107.6 |
C3—C7—H7 | 117.2 | O5—C14—C15 | 108.54 (7) |
O2—C8—C9 | 106.94 (7) | O5—C14—H14A | 110.0 |
O2—C8—H8A | 110.3 | C15—C14—H14A | 110.0 |
C9—C8—H8A | 110.3 | O5—C14—H14B | 110.0 |
O2—C8—H8B | 110.3 | C15—C14—H14B | 110.0 |
C9—C8—H8B | 110.3 | H14A—C14—H14B | 108.4 |
H8A—C8—H8B | 108.6 | O6—C15—C14 | 106.35 (7) |
O3—C9—C8 | 109.85 (8) | O6—C15—H15A | 110.5 |
O3—C9—H9A | 109.7 | C14—C15—H15A | 110.5 |
C8—C9—H9A | 109.7 | O6—C15—H15B | 110.5 |
O3—C9—H9B | 109.7 | C14—C15—H15B | 110.5 |
C8—C9—H9B | 109.7 | H15A—C15—H15B | 108.7 |
C8—O2—C1—C2 | −2.33 (13) | C2—C1—C6—C5 | 1.40 (14) |
C8—O2—C1—C6 | 177.50 (8) | C4—C3—C7—O1 | 179.75 (10) |
O2—C1—C2—C3 | 178.83 (9) | C2—C3—C7—O1 | −1.06 (16) |
C6—C1—C2—C3 | −0.99 (14) | C1—O2—C8—C9 | −176.14 (8) |
C1—C2—C3—C4 | −0.25 (14) | C10—O3—C9—C8 | −127.42 (9) |
C1—C2—C3—C7 | −179.43 (9) | O2—C8—C9—O3 | 69.34 (10) |
C2—C3—C4—C5 | 1.12 (15) | C9—O3—C10—C11 | 73.81 (11) |
C7—C3—C4—C5 | −179.71 (9) | C12—O4—C11—C10 | 164.16 (8) |
C3—C4—C5—C6 | −0.71 (15) | O3—C10—C11—O4 | 168.42 (8) |
C15—O6—C6—C5 | −1.01 (14) | C11—O4—C12—C13 | 82.80 (10) |
C15—O6—C6—C1 | 179.48 (8) | C14—O5—C13—C12 | −78.28 (10) |
C4—C5—C6—O6 | 179.97 (9) | O4—C12—C13—O5 | −71.10 (11) |
C4—C5—C6—C1 | −0.54 (14) | C13—O5—C14—C15 | 171.27 (8) |
O2—C1—C6—O6 | 1.10 (12) | C6—O6—C15—C14 | 178.69 (8) |
C2—C1—C6—O6 | −179.06 (8) | O5—C14—C15—O6 | −65.61 (9) |
O2—C1—C6—C5 | −178.45 (8) |
D—H···A | D—H | H···A | D···A | D—H···A |
C13—H13B···O4i | 0.99 | 2.55 | 3.3351 (10) | 137 |
C14—H14A···O5ii | 0.99 | 2.66 | 3.1700 (12) | 112 |
C8—H8A···O1iii | 0.99 | 2.66 | 3.3775 (13) | 130 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x, −y+3/2, z−1/2; (iii) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C15H20O6 |
Mr | 296.31 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 90 |
a, b, c (Å) | 18.0091 (8), 9.6678 (4), 8.1028 (3) |
β (°) | 91.262 (2) |
V (Å3) | 1410.42 (10) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.60 × 0.39 × 0.05 |
Data collection | |
Diffractometer | Bruker Kappa APEXII CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2004) |
Tmin, Tmax | 0.857, 0.995 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 18190, 4523, 3716 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.727 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.116, 1.00 |
No. of reflections | 4523 |
No. of parameters | 190 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.28, −0.22 |
Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
C13—H13B···O4i | 0.99 | 2.55 | 3.3351 (10) | 137 |
C14—H14A···O5ii | 0.99 | 2.66 | 3.1700 (12) | 112 |
C8—H8A···O1iii | 0.99 | 2.66 | 3.3775 (13) | 130 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x, −y+3/2, z−1/2; (iii) −x, −y+1, −z+1. |
Acknowledgements
Financial support from the German Federal Ministry of Economics and Technology (BMWi) under grant No. 16IN0218 `ChemoChips' is gratefully acknowledged. We thank Dr Tobias Gruber for fruitful discussions.
References
Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Hanson, I. R. (1978). Acta Cryst. B34, 1026–1028. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Hyde, E. M., Shaw, B. L. & Shepherd, I. (1978). J. Chem. Soc. Dalton Trans. pp. 1696–1705. CrossRef Web of Science Google Scholar
Pedersen, C. J. (1967). J. Am. Chem. Soc. 89, 7017–7036. CrossRef CAS Web of Science Google Scholar
Rogers, R. D., Henry, R. F. & Rollins, A. N. (1992). J. Inclusion Phenom. Macrocycl. Chem. 13, 219–232. CrossRef CAS Google Scholar
Rogers, R. D., Huggins, S. E., Henry, R. F. & Bond, A. H. (1992). Supramol. Chem. 1, 59–63. CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2004). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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.
The title compound is a derivative of benzo-15-crown-5 (Pedersen, 1967). It was prepared as part of our studies concerning fluorogenic receptor molecules with possible analytical applications. The O-C-C-O torsion angles within the polyether ring are (±)gauche [69.34° (10), -71.10°(8), -65.61°(11)) and anti (168.42°(9)]) resulting in a twisted crown ether conformation. In the title molecule, the dihedral angle between the aromatic ring plane and the mean plane of ether oxygen atoms is 20.67 (5)°. Worth to note, the torsion angle C3—C4—C7—O1 is 179.75 (10)°, indicating only a very small twist of the formyl group relative to the aromatic ring. Thus, in agreement with a previous report (Rogers, Huggins et al., 1992; Rogers, Henry & Rollins, 1992), the substituent on the benzene ring has negligible influence on the conformation of the benzo-15-crown-5 (Hanson, 1978). Owing to the absence of strong hydrogen bond donors, the crystal packing is stabilized by weak C—H···O hydrogen bonds, involving the O atoms of the crown ether and C==O group as acceptors, and the methylene C-H groups as donors (Table 1). In addition, π—π interaction has also been detected, resulting in a stacking of the molecules along the crystallographic c axis with a distance of 4.211 (2) Å between the centroids of two neighboring aromatic rings (Fig.2).