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The title compound, C
15H
11Cl
2NO, was synthesized from
N-benzylisatin. The compound crystallizes as stacks of molecules running down the
c axis. Molecules within each of these stacks interact with each other through π–π and C—H
π interactions, and interact with neighbouring stacks through C—H
O interactions.
Supporting information
CCDC reference: 641801
The dione (III) (6.40 g, 27.00 mmol) was dissolved in C6H6 (70 ml) in a
round-bottomed flask and cooled to 273 K. PCl5 (12.80 g, 62.10 mmol, 2.3
equivalents) was added and the solution was warmed to 298 K for 24 h. The
solvent was removed in vacuo to obtain a yellow–brown residue, which
was further purified by column chromatography (5% EtOAc/hexane) to afford (II)
as a light-yellow oil. On addition of EtOH, (II) precipitated as a
white solid [yield 6.37 g, 81%; m.p. 398–399 K (literature m.p.
399–400 K; Palazzo, 1953)]. 1H NMR (300 MHz, CDCl3, Me4Si): δH 4.94
(2H, s, PhCH2N), 6.72 (1H, d, J = 7.9 Hz,
ArH), 7.14 (1H, t, J = 7.6 Hz, ArH), 7.22–7.39
(6H, m, 6 × ArH) and 7.64 (1H, d, J =
7.5 Hz, ArH). 13C NMR (75 MHz, CDCl3): δC 44.5 (PhCH2N), 110.1
(ArCCl2), 124.2 (CH), 124.9 (CH), 127.1 (2 × CH), 128.1 (CH), 129.0 (2
× CH), 129.3 (C), 131.8 (CH), 134.4 (C), 139.8 (C) and 169.2 (C═O)
(one CH not observed in spectrum).
H atoms were positioned geometrically and allowed to ride on their respective
parent atoms, with C—H bond lengths of 0.95 (aromatic CH) or 0.99 Å
(CH2), and isotropic displacement parameters equal to 1.2 times Ueq
of the parent atom.
Data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Bruker, 1999); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997) and SCHAKAL99 (Keller, 1999); software used to prepare material for publication: PLATON (Spek, 2003) and SHELXTL (Bruker, 1999b).
1-Benzyl-3,3-dichloro-1
H-indol-2(3
H)-one
top
Crystal data top
C15H11Cl2NO | F(000) = 600 |
Mr = 292.15 | Dx = 1.453 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 918 reflections |
a = 10.4847 (13) Å | θ = 2.5–28.1° |
b = 14.4641 (18) Å | µ = 0.48 mm−1 |
c = 9.2203 (11) Å | T = 173 K |
β = 107.244 (2)° | Irregular, colourless |
V = 1335.4 (3) Å3 | 0.48 × 0.30 × 0.26 mm |
Z = 4 | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 2603 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.028 |
Graphite monochromator | θmax = 28.0°, θmin = 2.0° |
ϕ and ω scans | h = −13→11 |
8835 measured reflections | k = −19→17 |
3213 independent reflections | l = −11→12 |
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)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0453P)2 + 0.2606P] where P = (Fo2 + 2Fc2)/3 |
3213 reflections | (Δ/σ)max = 0.001 |
172 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.35 e Å−3 |
Crystal data top
C15H11Cl2NO | V = 1335.4 (3) Å3 |
Mr = 292.15 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.4847 (13) Å | µ = 0.48 mm−1 |
b = 14.4641 (18) Å | T = 173 K |
c = 9.2203 (11) Å | 0.48 × 0.30 × 0.26 mm |
β = 107.244 (2)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 2603 reflections with I > 2σ(I) |
8835 measured reflections | Rint = 0.028 |
3213 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.33 e Å−3 |
3213 reflections | Δρmin = −0.35 e Å−3 |
172 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.81611 (13) | 0.08784 (10) | 0.34296 (15) | 0.0290 (3) | |
C2 | 0.70179 (13) | 0.07206 (9) | 0.41592 (15) | 0.0277 (3) | |
C3 | 0.65767 (13) | 0.16757 (9) | 0.44019 (15) | 0.0255 (3) | |
C4 | 0.55791 (14) | 0.19881 (10) | 0.49812 (16) | 0.0317 (3) | |
H4 | 0.5008 | 0.1566 | 0.5278 | 0.038* | |
C5 | 0.54361 (15) | 0.29423 (11) | 0.51175 (17) | 0.0353 (3) | |
H5 | 0.4755 | 0.3175 | 0.5505 | 0.042* | |
C6 | 0.62796 (14) | 0.35510 (10) | 0.46923 (16) | 0.0332 (3) | |
H6 | 0.6171 | 0.4196 | 0.4806 | 0.040* | |
C7 | 0.72862 (14) | 0.32418 (9) | 0.41007 (15) | 0.0287 (3) | |
H7 | 0.7857 | 0.3663 | 0.3804 | 0.034* | |
C8 | 0.74163 (12) | 0.22953 (9) | 0.39654 (14) | 0.0242 (3) | |
C9 | 0.93948 (14) | 0.22510 (11) | 0.29027 (16) | 0.0307 (3) | |
H9A | 0.8999 | 0.2752 | 0.2176 | 0.037* | |
H9B | 0.9785 | 0.1789 | 0.2365 | 0.037* | |
C10 | 1.04906 (13) | 0.26494 (9) | 0.42161 (15) | 0.0258 (3) | |
C11 | 1.08127 (15) | 0.35817 (10) | 0.42543 (18) | 0.0348 (3) | |
H11 | 1.0333 | 0.3979 | 0.3458 | 0.042* | |
C12 | 1.18380 (16) | 0.39374 (11) | 0.5457 (2) | 0.0432 (4) | |
H12 | 1.2049 | 0.4577 | 0.5485 | 0.052* | |
C13 | 1.25468 (15) | 0.33616 (12) | 0.66092 (19) | 0.0413 (4) | |
H13 | 1.3248 | 0.3605 | 0.7425 | 0.050* | |
C14 | 1.22367 (14) | 0.24302 (12) | 0.65765 (17) | 0.0379 (4) | |
H14 | 1.2728 | 0.2034 | 0.7366 | 0.046* | |
C15 | 1.12072 (14) | 0.20756 (10) | 0.53890 (16) | 0.0305 (3) | |
H15 | 1.0990 | 0.1437 | 0.5376 | 0.037* | |
N | 0.83419 (11) | 0.18114 (8) | 0.34084 (13) | 0.0264 (2) | |
O | 0.87652 (11) | 0.02811 (8) | 0.29883 (14) | 0.0436 (3) | |
Cl1 | 0.77076 (4) | 0.01204 (3) | 0.59136 (4) | 0.03919 (12) | |
Cl2 | 0.57445 (4) | 0.00267 (2) | 0.29337 (4) | 0.03877 (12) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0271 (7) | 0.0296 (7) | 0.0291 (7) | −0.0042 (5) | 0.0066 (6) | −0.0071 (6) |
C2 | 0.0272 (6) | 0.0251 (7) | 0.0283 (7) | −0.0046 (5) | 0.0044 (5) | −0.0006 (5) |
C3 | 0.0236 (6) | 0.0261 (6) | 0.0243 (6) | −0.0017 (5) | 0.0032 (5) | 0.0003 (5) |
C4 | 0.0261 (7) | 0.0374 (8) | 0.0320 (7) | −0.0016 (6) | 0.0092 (6) | 0.0021 (6) |
C5 | 0.0300 (7) | 0.0419 (9) | 0.0344 (8) | 0.0082 (6) | 0.0100 (6) | −0.0003 (6) |
C6 | 0.0357 (8) | 0.0290 (7) | 0.0304 (7) | 0.0088 (6) | 0.0031 (6) | 0.0011 (6) |
C7 | 0.0323 (7) | 0.0251 (7) | 0.0269 (7) | −0.0017 (5) | 0.0059 (6) | 0.0025 (5) |
C8 | 0.0231 (6) | 0.0272 (7) | 0.0205 (6) | −0.0011 (5) | 0.0036 (5) | −0.0009 (5) |
C9 | 0.0304 (7) | 0.0376 (8) | 0.0260 (7) | −0.0071 (6) | 0.0115 (6) | −0.0027 (6) |
C10 | 0.0244 (6) | 0.0302 (7) | 0.0262 (6) | −0.0035 (5) | 0.0129 (5) | −0.0033 (5) |
C11 | 0.0340 (8) | 0.0300 (7) | 0.0414 (8) | −0.0037 (6) | 0.0129 (6) | 0.0027 (6) |
C12 | 0.0397 (9) | 0.0343 (8) | 0.0588 (11) | −0.0140 (7) | 0.0197 (8) | −0.0142 (7) |
C13 | 0.0266 (7) | 0.0573 (10) | 0.0403 (9) | −0.0072 (7) | 0.0104 (6) | −0.0191 (8) |
C14 | 0.0271 (7) | 0.0534 (10) | 0.0333 (8) | 0.0047 (7) | 0.0089 (6) | −0.0007 (7) |
C15 | 0.0303 (7) | 0.0283 (7) | 0.0354 (7) | 0.0005 (5) | 0.0138 (6) | −0.0014 (6) |
N | 0.0251 (6) | 0.0272 (6) | 0.0278 (6) | −0.0052 (4) | 0.0089 (5) | −0.0048 (5) |
O | 0.0453 (6) | 0.0340 (6) | 0.0566 (7) | −0.0010 (5) | 0.0231 (6) | −0.0132 (5) |
Cl1 | 0.0488 (2) | 0.0328 (2) | 0.0331 (2) | 0.00729 (15) | 0.00766 (16) | 0.00495 (14) |
Cl2 | 0.0370 (2) | 0.0331 (2) | 0.0417 (2) | −0.01408 (14) | 0.00464 (16) | −0.00475 (15) |
Geometric parameters (Å, º) top
C1—O | 1.2107 (17) | C8—N | 1.4109 (17) |
C1—N | 1.3637 (18) | C9—N | 1.4647 (17) |
C1—C2 | 1.5555 (19) | C9—C10 | 1.5145 (18) |
C2—C3 | 1.4945 (19) | C9—H9A | 0.9900 |
C2—Cl2 | 1.7811 (13) | C9—H9B | 0.9900 |
C2—Cl1 | 1.7888 (14) | C10—C11 | 1.388 (2) |
C3—C4 | 1.3837 (19) | C10—C15 | 1.393 (2) |
C3—C8 | 1.3966 (18) | C11—C12 | 1.394 (2) |
C4—C5 | 1.398 (2) | C11—H11 | 0.9500 |
C4—H4 | 0.9500 | C12—C13 | 1.380 (2) |
C5—C6 | 1.384 (2) | C12—H12 | 0.9500 |
C5—H5 | 0.9500 | C13—C14 | 1.384 (2) |
C6—C7 | 1.397 (2) | C13—H13 | 0.9500 |
C6—H6 | 0.9500 | C14—C15 | 1.388 (2) |
C7—C8 | 1.3851 (19) | C14—H14 | 0.9500 |
C7—H7 | 0.9500 | C15—H15 | 0.9500 |
| | | |
O—C1—N | 127.78 (13) | N—C9—C10 | 112.05 (11) |
O—C1—C2 | 125.98 (13) | N—C9—H9A | 109.2 |
N—C1—C2 | 106.23 (11) | C10—C9—H9A | 109.2 |
C3—C2—C1 | 103.98 (11) | N—C9—H9B | 109.2 |
C3—C2—Cl2 | 114.13 (10) | C10—C9—H9B | 109.2 |
C1—C2—Cl2 | 109.70 (9) | H9A—C9—H9B | 107.9 |
C3—C2—Cl1 | 111.92 (9) | C11—C10—C15 | 119.20 (13) |
C1—C2—Cl1 | 107.79 (9) | C11—C10—C9 | 120.74 (13) |
Cl2—C2—Cl1 | 109.04 (7) | C15—C10—C9 | 120.05 (13) |
C4—C3—C8 | 120.99 (13) | C10—C11—C12 | 120.20 (15) |
C4—C3—C2 | 131.50 (13) | C10—C11—H11 | 119.9 |
C8—C3—C2 | 107.49 (11) | C12—C11—H11 | 119.9 |
C3—C4—C5 | 118.07 (13) | C13—C12—C11 | 120.12 (15) |
C3—C4—H4 | 121.0 | C13—C12—H12 | 119.9 |
C5—C4—H4 | 121.0 | C11—C12—H12 | 119.9 |
C6—C5—C4 | 120.52 (14) | C12—C13—C14 | 120.07 (14) |
C6—C5—H5 | 119.7 | C12—C13—H13 | 120.0 |
C4—C5—H5 | 119.7 | C14—C13—H13 | 120.0 |
C5—C6—C7 | 121.79 (14) | C13—C14—C15 | 119.97 (15) |
C5—C6—H6 | 119.1 | C13—C14—H14 | 120.0 |
C7—C6—H6 | 119.1 | C15—C14—H14 | 120.0 |
C8—C7—C6 | 117.22 (13) | C14—C15—C10 | 120.44 (14) |
C8—C7—H7 | 121.4 | C14—C15—H15 | 119.8 |
C6—C7—H7 | 121.4 | C10—C15—H15 | 119.8 |
C7—C8—C3 | 121.40 (12) | C1—N—C8 | 111.85 (11) |
C7—C8—N | 128.30 (12) | C1—N—C9 | 123.72 (12) |
C3—C8—N | 110.30 (11) | C8—N—C9 | 124.41 (11) |
| | | |
O—C1—C2—C3 | −176.71 (14) | C2—C3—C8—N | 1.99 (14) |
N—C1—C2—C3 | 3.88 (14) | N—C9—C10—C11 | −122.02 (14) |
O—C1—C2—Cl2 | −54.26 (18) | N—C9—C10—C15 | 59.29 (17) |
N—C1—C2—Cl2 | 126.33 (10) | C15—C10—C11—C12 | −0.3 (2) |
O—C1—C2—Cl1 | 64.35 (17) | C9—C10—C11—C12 | −178.97 (13) |
N—C1—C2—Cl1 | −115.06 (11) | C10—C11—C12—C13 | 0.7 (2) |
C1—C2—C3—C4 | 178.48 (14) | C11—C12—C13—C14 | −0.3 (2) |
Cl2—C2—C3—C4 | 59.00 (18) | C12—C13—C14—C15 | −0.4 (2) |
Cl1—C2—C3—C4 | −65.44 (17) | C13—C14—C15—C10 | 0.8 (2) |
C1—C2—C3—C8 | −3.51 (14) | C11—C10—C15—C14 | −0.4 (2) |
Cl2—C2—C3—C8 | −122.99 (10) | C9—C10—C15—C14 | 178.28 (12) |
Cl1—C2—C3—C8 | 112.57 (11) | O—C1—N—C8 | 177.71 (14) |
C8—C3—C4—C5 | 0.0 (2) | C2—C1—N—C8 | −2.90 (15) |
C2—C3—C4—C5 | 177.77 (14) | O—C1—N—C9 | −3.7 (2) |
C3—C4—C5—C6 | −0.5 (2) | C2—C1—N—C9 | 175.65 (11) |
C4—C5—C6—C7 | 0.7 (2) | C7—C8—N—C1 | −179.33 (13) |
C5—C6—C7—C8 | −0.5 (2) | C3—C8—N—C1 | 0.67 (15) |
C6—C7—C8—C3 | 0.00 (19) | C7—C8—N—C9 | 2.1 (2) |
C6—C7—C8—N | 180.00 (12) | C3—C8—N—C9 | −177.86 (12) |
C4—C3—C8—C7 | 0.3 (2) | C10—C9—N—C1 | −107.55 (15) |
C2—C3—C8—C7 | −178.01 (12) | C10—C9—N—C8 | 70.82 (17) |
C4—C3—C8—N | −179.75 (12) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11···Oi | 0.95 | 2.64 | 3.325 (2) | 129 |
C9—H9B···Cgii | 0.99 | 2.93 | 3.660 (2) | 132 |
C6—H6···Cl2iii | 0.95 | 2.98 | 3.4461 (15) | 112 |
C13—H13···Cl1iv | 0.95 | 3.01 | 3.4815 (18) | 112 |
Symmetry codes: (i) −x+2, y+1/2, −z+1/2; (ii) x, −y−1/2, z−3/2; (iii) −x+1, y+1/2, −z+1/2; (iv) −x+2, y+1/2, −z+3/2. |
Experimental details
Crystal data |
Chemical formula | C15H11Cl2NO |
Mr | 292.15 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 10.4847 (13), 14.4641 (18), 9.2203 (11) |
β (°) | 107.244 (2) |
V (Å3) | 1335.4 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.48 |
Crystal size (mm) | 0.48 × 0.30 × 0.26 |
|
Data collection |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8835, 3213, 2603 |
Rint | 0.028 |
(sin θ/λ)max (Å−1) | 0.661 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.088, 1.05 |
No. of reflections | 3213 |
No. of parameters | 172 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.33, −0.35 |
Selected geometric parameters (Å, º) topC1—O | 1.2107 (17) | C2—C3 | 1.4945 (19) |
C1—N | 1.3637 (18) | C3—C8 | 1.3966 (18) |
C1—C2 | 1.5555 (19) | C8—N | 1.4109 (17) |
| | | |
N—C1—C2 | 106.23 (11) | C3—C8—N | 110.30 (11) |
C3—C2—C1 | 103.98 (11) | C1—N—C8 | 111.85 (11) |
C8—C3—C2 | 107.49 (11) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11···Oi | 0.95 | 2.64 | 3.325 (2) | 129 |
C9—H9B···Cgii | 0.99 | 2.93 | 3.660 (2) | 132 |
C6—H6···Cl2iii | 0.95 | 2.98 | 3.4461 (15) | 112 |
C13—H13···Cl1iv | 0.95 | 3.01 | 3.4815 (18) | 112 |
Symmetry codes: (i) −x+2, y+1/2, −z+1/2; (ii) x, −y−1/2, z−3/2; (iii) −x+1, y+1/2, −z+1/2; (iv) −x+2, y+1/2, −z+3/2. |
Comparison of selected bond lengths and
angles (Å, °) for compound (II), KUNMUB and QASXEO topStructure/Refcode | N—C1 | C8—N—C1 | N—C1—C2 |
(II) | 1.364 (2) | 111.8 (1) | 106.2 (1) |
KUNMUBa | 1.339 (5) | 112.8 (3) | 106.1 (3) |
QASXEOb | 1.37 | 114 | 105 |
aZukerman-Schpector et al. (1993);
bMeketa et al. (2005); |
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Oxindoles occur commonly as subunits of biologically active compounds. For example compound 1 has been found to be a potential inhibitor of the kinase insert domain-containing receptor (KDR), alternatively referred to as VEGFR-2, a receptor for vascular endothelial growth factors (Bouérat et al., 2005). In essence, this compound is believed to function as a key regulator of angiogenesis.
As part of our research programme, we have been interested in the synthesis of substituted heterocycles, such as carbazoles (de Koning et al., 2003; Pelly et al., 2005; Pathak et al., 2006) and fused indole systems (de Koning et al., 2004). During the course of our work on the synthesis of potential kinase inhibitors (Fabbro et al., 2002; Geyer et al., 2005; Noble et al., 2005), we had reason to synthesize the simple oxindole derivative 2 from N-benzyl isatin 3, where the carbonyl at the 3-position of isatin is replaced by two Cl atoms. The structure of the product, (II), was confirmed by single-crystal X-ray crystallography (Fig. 1).
The bond lengths and angles for (II) were found to be typical for compounds of this type. Bond lengths and angles for the nitrogen-containing ring of the indol-2-one system are given in Table 1. A search of the Cambridge Structural Database (CSD; Version 5.27; Allen, 2002) for indol-2-one compounds with dichloro substitution on C2 (or IUPAC position 3; Fig. 1) yielded only two structures, viz. 3,3-dichloro-1H-indol-2(3H)-one, (IV) (CSD refcode KUNMUB; Zukerman-Schpector et al., 1993), and 1,3,3,5-tetrachloro-1,3-dihydroindol-2-one, (V) (QASXEO; Meketa et al., 2005). Comparison of the bond angles around the N-containing five-membered ring indicates that the N—C1 bond length as well as the C8—N—C1 and N—C1—C2 angles are most affected by the atom type bonded to the N atom (Table 3). Comparing geometric parameters around the rest of the five-membered ring for all three structures leads to differences of less than 0.01 Å and 1° for the bond lengths and angles, respectively.
The title compound is capable of rotation around the C9—N and C9—C10 bonds (Fig. 1). The conformation adopted by the molecule is one in which the indol-2-one system is rotated such that it is almost perpendicular [82.03 (3)°] to the phenyl ring (Fig. 2). This conformation allows for a simultaneous C—H···π and π–π interaction between molecules related by the c-glide plane. The C—H···π interaction occurs between the C9/H9B group and the C10–C15 ring (centroid Cg) of a neighbouring molecule (Table 2 and Fig. 2).
The π–π interaction occurs between the ring defined by N, C1, C2, C3 and C8 (the five-membered ring of the indol-2-one system) and the ring defined by C3–C8 (the six-membered ring of the indol-2-one system) of a neighbouring molecule (Fig. 2). In this interaction, the two rings are slipped by 30.2° relative to their ring perpendiculars (the average interplanar distance being 3.484 Å), with the ring centroid to ring centroid distance being 4.0329 (9) Å. Admittedly, the five-membered ring of the indol-2-one system is only partly aromatic, but a significant part of the ring (O, C1 and N) is involved in conjugation with the aromatic six-membered ring as shown by the bond lengths between these atoms (Table 1). The π–π interaction is therefore really between these atoms and those of the neighbouring ring. and if this were taken into account the centroid to centroid distance would be even shorter. A consequence of the C—H···π and π–π interactions is the creation of stacks of molecules running down the c axis (Fig. 3).
Finally, acting between the stacks of molecules just described are C—H···O and C—H···Cl interactions (Table 2 and Fig. 4).