Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807032643/hb2472sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807032643/hb2472Isup2.hkl |
CCDC reference: 657735
2-(Indol-3-yl)ethylamine (3.2 g, 19.9 mmol) and 2-hydroxy-5-methylacetophenone (3.0 g, 19.9 mmol) were heated in ethanol (50 ml) for 2 h. The solution was filtered; slow evaporation of the solvent yielded faint yellow blocks of (I).
All hydrogen atoms were located in difference Fourier maps, and were refined with distance restraints C—H = 1.00±0.01 Å and N–H = 0.88±0.01 Å. Their Uiso values were freely refined.
Some Schiff bases that are formed from a primary amine and a substituted salicylaldehyde (or 2-hydroxyacetophenone) exist in a zwitterionic form as the phenolic hydrogen is transferred to the imino group. Among the (indol-3-yl)ethyl-2-amine derivatives that have been synthesized, the crystal structures of only two have been reported: 2-[2-(1H-Indol-3-yl)ethyliminomethy]phenol (1H-indole-3-ethylenesalicylaldimine exists as a neutral compound (Rodriguez et al.,1987) whereas 2-[2-(1H-indol-3-yl)ethylminomethyl]-6-methoxyphenol is zwitterionic (Zarza et al., 1988). The title compound, (I), (Fig. 1) exists in the latter form; two zwitterions are linked by an Nindole–H···O hydrogen bond (Table 1) into a dimer.
See Rodriguez et al. (1987) for the crystal structure of neutral 2-[2-(1H-indol-3-yl)ethyliminomethy]phenol (1H-indole-3-ethylenesalicylaldimine) and Zarza et al. (1988) for the crystal structure of zwitterionic 2-[2-(1H-indol-3-yl)ethylminomethyl]-6-methoxyphenol.
Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2007).
C19H20N2O | F(000) = 624 |
Mr = 292.37 | Dx = 1.275 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 7004 reflections |
a = 13.5170 (2) Å | θ = 2.7–31.3° |
b = 8.5778 (1) Å | µ = 0.08 mm−1 |
c = 14.4551 (2) Å | T = 173 K |
β = 114.619 (1)° | Block, pale yellow |
V = 1523.66 (4) Å3 | 0.35 × 0.26 × 0.21 mm |
Z = 4 |
Bruker APEXII CCD area-detector diffractometer | 3516 reflections with I > 2σ(I) |
Radiation source: medium-focus sealed tube | Rint = 0.036 |
Graphite monochromator | θmax = 30.0°, θmin = 1.7° |
φ and ω scans | h = −19→18 |
23521 measured reflections | k = −12→11 |
4406 independent reflections | l = −20→20 |
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)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.126 | All H-atom parameters refined |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0734P)2 + 0.3723P] where P = (Fo2 + 2Fc2)/3 |
4406 reflections | (Δ/σ)max = 0.001 |
279 parameters | Δρmax = 0.41 e Å−3 |
19 restraints | Δρmin = −0.23 e Å−3 |
C19H20N2O | V = 1523.66 (4) Å3 |
Mr = 292.37 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 13.5170 (2) Å | µ = 0.08 mm−1 |
b = 8.5778 (1) Å | T = 173 K |
c = 14.4551 (2) Å | 0.35 × 0.26 × 0.21 mm |
β = 114.619 (1)° |
Bruker APEXII CCD area-detector diffractometer | 3516 reflections with I > 2σ(I) |
23521 measured reflections | Rint = 0.036 |
4406 independent reflections |
R[F2 > 2σ(F2)] = 0.042 | 19 restraints |
wR(F2) = 0.126 | All H-atom parameters refined |
S = 1.01 | Δρmax = 0.41 e Å−3 |
4406 reflections | Δρmin = −0.23 e Å−3 |
279 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.33096 (6) | 0.49058 (9) | 0.57718 (6) | 0.02106 (18) | |
N1 | 0.23306 (7) | 0.23687 (10) | 0.53951 (7) | 0.01704 (19) | |
N2 | 0.49741 (8) | 0.32926 (11) | 0.42664 (8) | 0.0209 (2) | |
C1 | 0.25791 (9) | 0.54412 (12) | 0.60614 (8) | 0.0171 (2) | |
C2 | 0.26495 (9) | 0.69894 (12) | 0.64407 (9) | 0.0205 (2) | |
C3 | 0.18869 (9) | 0.75560 (13) | 0.67537 (9) | 0.0217 (2) | |
C4 | 0.10061 (9) | 0.66421 (13) | 0.67272 (8) | 0.0207 (2) | |
C5 | 0.09244 (9) | 0.51336 (13) | 0.63649 (8) | 0.0187 (2) | |
C6 | 0.16864 (8) | 0.45039 (12) | 0.60263 (8) | 0.0162 (2) | |
C7 | 0.01783 (11) | 0.73171 (16) | 0.70630 (10) | 0.0289 (3) | |
C8 | 0.15994 (8) | 0.28929 (12) | 0.56854 (8) | 0.0156 (2) | |
C9 | 0.07030 (9) | 0.18642 (13) | 0.56894 (9) | 0.0208 (2) | |
C10 | 0.24093 (9) | 0.07834 (12) | 0.50569 (9) | 0.0202 (2) | |
C11 | 0.35855 (9) | 0.04142 (13) | 0.52407 (9) | 0.0199 (2) | |
C12 | 0.47967 (9) | 0.25886 (13) | 0.50420 (9) | 0.0199 (2) | |
C13 | 0.40163 (9) | 0.14509 (12) | 0.46586 (8) | 0.0176 (2) | |
C14 | 0.36938 (9) | 0.14302 (12) | 0.35741 (9) | 0.0179 (2) | |
C15 | 0.29601 (10) | 0.05272 (14) | 0.27707 (9) | 0.0245 (2) | |
C16 | 0.28554 (10) | 0.08129 (17) | 0.17906 (10) | 0.0288 (3) | |
C17 | 0.34742 (10) | 0.19798 (16) | 0.15950 (10) | 0.0280 (3) | |
C18 | 0.42114 (10) | 0.28781 (14) | 0.23730 (10) | 0.0238 (2) | |
C19 | 0.43160 (9) | 0.25923 (12) | 0.33626 (9) | 0.0188 (2) | |
H1N | 0.2810 (13) | 0.3128 (17) | 0.5431 (15) | 0.050 (5)* | |
H2N | 0.5501 (11) | 0.3947 (16) | 0.4316 (12) | 0.034 (4)* | |
H2 | 0.3273 (10) | 0.7633 (16) | 0.6463 (12) | 0.031 (4)* | |
H3 | 0.1963 (13) | 0.8649 (11) | 0.7016 (11) | 0.030 (4)* | |
H5 | 0.0309 (9) | 0.4469 (15) | 0.6345 (11) | 0.025 (4)* | |
H7A | −0.0255 (14) | 0.8188 (18) | 0.6613 (13) | 0.056 (6)* | |
H7C | 0.0516 (13) | 0.7826 (19) | 0.7746 (9) | 0.041 (5)* | |
H7B | −0.0326 (14) | 0.6505 (19) | 0.7118 (15) | 0.059 (6)* | |
H9A | 0.0684 (16) | 0.0850 (15) | 0.5364 (14) | 0.058 (6)* | |
H9B | 0.0804 (15) | 0.168 (2) | 0.6398 (8) | 0.050 (5)* | |
H9C | −0.0012 (9) | 0.2380 (18) | 0.5348 (11) | 0.037 (4)* | |
H10A | 0.2141 (12) | 0.0024 (15) | 0.5416 (11) | 0.030 (4)* | |
H10B | 0.1942 (10) | 0.0725 (16) | 0.4313 (7) | 0.019 (3)* | |
H11A | 0.3595 (11) | −0.0698 (11) | 0.5031 (11) | 0.024 (4)* | |
H11B | 0.4061 (10) | 0.0464 (17) | 0.5990 (7) | 0.023 (4)* | |
H12 | 0.5225 (11) | 0.2920 (18) | 0.5761 (7) | 0.028 (4)* | |
H15 | 0.2513 (11) | −0.0278 (14) | 0.2920 (11) | 0.027 (4)* | |
H16 | 0.2377 (15) | 0.019 (2) | 0.1234 (14) | 0.042 (5)* | |
H17 | 0.3362 (13) | 0.2144 (19) | 0.0881 (8) | 0.036 (4)* | |
H18 | 0.4634 (11) | 0.3714 (14) | 0.2233 (11) | 0.028 (4)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0195 (4) | 0.0183 (4) | 0.0292 (4) | −0.0025 (3) | 0.0139 (3) | 0.0005 (3) |
N1 | 0.0173 (4) | 0.0148 (4) | 0.0217 (5) | −0.0016 (3) | 0.0108 (4) | 0.0008 (3) |
N2 | 0.0194 (4) | 0.0180 (4) | 0.0297 (5) | −0.0038 (3) | 0.0145 (4) | −0.0009 (4) |
C1 | 0.0174 (5) | 0.0168 (5) | 0.0157 (5) | −0.0003 (4) | 0.0054 (4) | 0.0030 (4) |
C2 | 0.0211 (5) | 0.0168 (5) | 0.0207 (5) | −0.0025 (4) | 0.0059 (4) | 0.0002 (4) |
C3 | 0.0238 (6) | 0.0188 (5) | 0.0170 (5) | 0.0015 (4) | 0.0029 (4) | −0.0017 (4) |
C4 | 0.0198 (5) | 0.0239 (5) | 0.0155 (5) | 0.0040 (4) | 0.0045 (4) | −0.0018 (4) |
C5 | 0.0166 (5) | 0.0215 (5) | 0.0173 (5) | 0.0001 (4) | 0.0064 (4) | −0.0012 (4) |
C6 | 0.0159 (5) | 0.0168 (4) | 0.0154 (5) | −0.0003 (4) | 0.0060 (4) | 0.0005 (4) |
C7 | 0.0262 (6) | 0.0339 (6) | 0.0265 (6) | 0.0061 (5) | 0.0108 (5) | −0.0076 (5) |
C8 | 0.0149 (5) | 0.0177 (5) | 0.0143 (5) | −0.0015 (3) | 0.0061 (4) | 0.0007 (4) |
C9 | 0.0189 (5) | 0.0214 (5) | 0.0262 (6) | −0.0056 (4) | 0.0133 (5) | −0.0043 (4) |
C10 | 0.0209 (5) | 0.0152 (5) | 0.0294 (6) | −0.0022 (4) | 0.0155 (5) | −0.0013 (4) |
C11 | 0.0204 (5) | 0.0172 (5) | 0.0265 (6) | 0.0019 (4) | 0.0142 (5) | 0.0033 (4) |
C12 | 0.0181 (5) | 0.0191 (5) | 0.0249 (6) | 0.0001 (4) | 0.0114 (4) | −0.0012 (4) |
C13 | 0.0161 (5) | 0.0162 (4) | 0.0232 (5) | 0.0008 (4) | 0.0110 (4) | 0.0004 (4) |
C14 | 0.0160 (5) | 0.0172 (5) | 0.0234 (5) | 0.0008 (4) | 0.0110 (4) | 0.0008 (4) |
C15 | 0.0206 (5) | 0.0267 (6) | 0.0281 (6) | −0.0033 (4) | 0.0120 (5) | −0.0040 (5) |
C16 | 0.0236 (6) | 0.0374 (7) | 0.0249 (6) | 0.0004 (5) | 0.0095 (5) | −0.0059 (5) |
C17 | 0.0274 (6) | 0.0370 (7) | 0.0239 (6) | 0.0099 (5) | 0.0148 (5) | 0.0036 (5) |
C18 | 0.0231 (5) | 0.0252 (5) | 0.0300 (6) | 0.0061 (4) | 0.0179 (5) | 0.0065 (5) |
C19 | 0.0165 (5) | 0.0172 (5) | 0.0261 (6) | 0.0023 (4) | 0.0122 (4) | 0.0018 (4) |
O1—C1 | 1.3059 (13) | C9—H9A | 0.984 (9) |
N1—C8 | 1.3041 (13) | C9—H9B | 0.989 (9) |
N1—C10 | 1.4638 (14) | C9—H9C | 0.988 (9) |
N1—H1N | 0.905 (9) | C10—C11 | 1.5319 (15) |
N2—C19 | 1.3750 (15) | C10—H10A | 0.991 (9) |
N2—C12 | 1.3795 (15) | C10—H10B | 0.995 (8) |
N2—H2N | 0.886 (9) | C11—C13 | 1.4986 (14) |
C1—C2 | 1.4247 (15) | C11—H11A | 1.003 (9) |
C1—C6 | 1.4332 (14) | C11—H11B | 1.004 (8) |
C2—C3 | 1.3755 (16) | C12—C13 | 1.3730 (15) |
C2—H2 | 0.997 (9) | C12—H12 | 0.998 (9) |
C3—C4 | 1.4127 (16) | C13—C14 | 1.4418 (16) |
C3—H3 | 1.001 (9) | C14—C15 | 1.4045 (16) |
C4—C5 | 1.3830 (15) | C14—C19 | 1.4173 (14) |
C4—C7 | 1.5085 (16) | C15—C16 | 1.3856 (18) |
C5—C6 | 1.4185 (14) | C15—H15 | 0.999 (9) |
C5—H5 | 0.998 (8) | C16—C17 | 1.4066 (19) |
C6—C8 | 1.4553 (14) | C16—H16 | 0.959 (19) |
C7—H7A | 1.003 (9) | C17—C18 | 1.3848 (19) |
C7—H7C | 0.999 (9) | C17—H17 | 0.989 (9) |
C7—H7B | 1.001 (9) | C18—C19 | 1.3992 (16) |
C8—C9 | 1.5009 (14) | C18—H18 | 0.989 (9) |
C8—N1—C10 | 126.73 (9) | H9B—C9—H9C | 105.9 (14) |
C8—N1—H1N | 110.7 (12) | N1—C10—C11 | 110.41 (9) |
C10—N1—H1N | 122.5 (12) | N1—C10—H10A | 110.0 (9) |
C19—N2—C12 | 108.56 (9) | C11—C10—H10A | 110.7 (9) |
C19—N2—H2N | 122.2 (10) | N1—C10—H10B | 107.8 (8) |
C12—N2—H2N | 128.2 (11) | C11—C10—H10B | 108.8 (8) |
O1—C1—C2 | 120.86 (10) | H10A—C10—H10B | 109.1 (12) |
O1—C1—C6 | 121.95 (9) | C13—C11—C10 | 113.45 (9) |
C2—C1—C6 | 117.18 (10) | C13—C11—H11A | 109.7 (8) |
C3—C2—C1 | 121.13 (10) | C10—C11—H11A | 106.7 (8) |
C3—C2—H2 | 122.2 (9) | C13—C11—H11B | 110.9 (8) |
C1—C2—H2 | 116.7 (9) | C10—C11—H11B | 109.3 (8) |
C2—C3—C4 | 122.25 (10) | H11A—C11—H11B | 106.5 (12) |
C2—C3—H3 | 118.9 (9) | C13—C12—N2 | 110.34 (10) |
C4—C3—H3 | 118.9 (9) | C13—C12—H12 | 129.6 (9) |
C5—C4—C3 | 117.57 (10) | N2—C12—H12 | 120.0 (9) |
C5—C4—C7 | 121.88 (11) | C12—C13—C14 | 106.32 (9) |
C3—C4—C7 | 120.53 (10) | C12—C13—C11 | 127.45 (10) |
C4—C5—C6 | 122.15 (10) | C14—C13—C11 | 126.22 (10) |
C4—C5—H5 | 118.6 (8) | C15—C14—C19 | 119.18 (10) |
C6—C5—H5 | 119.2 (8) | C15—C14—C13 | 134.06 (10) |
C5—C6—C1 | 119.72 (10) | C19—C14—C13 | 106.74 (9) |
C5—C6—C8 | 120.70 (9) | C16—C15—C14 | 118.95 (11) |
C1—C6—C8 | 119.53 (9) | C16—C15—H15 | 122.0 (9) |
C4—C7—H7A | 112.8 (11) | C14—C15—H15 | 119.0 (9) |
C4—C7—H7C | 113.0 (10) | C15—C16—C17 | 121.02 (12) |
H7A—C7—H7C | 102.6 (15) | C15—C16—H16 | 120.3 (10) |
C4—C7—H7B | 112.3 (12) | C17—C16—H16 | 118.6 (10) |
H7A—C7—H7B | 109.7 (16) | C18—C17—C16 | 121.31 (11) |
H7C—C7—H7B | 105.8 (15) | C18—C17—H17 | 120.9 (10) |
N1—C8—C6 | 118.11 (9) | C16—C17—H17 | 117.8 (10) |
N1—C8—C9 | 121.33 (9) | C17—C18—C19 | 117.69 (11) |
C6—C8—C9 | 120.56 (9) | C17—C18—H18 | 121.3 (9) |
C8—C9—H9A | 112.2 (11) | C19—C18—H18 | 121.0 (9) |
C8—C9—H9B | 109.7 (11) | N2—C19—C18 | 130.14 (10) |
H9A—C9—H9B | 108.4 (15) | N2—C19—C14 | 108.02 (10) |
C8—C9—H9C | 111.0 (10) | C18—C19—C14 | 121.84 (11) |
H9A—C9—H9C | 109.4 (15) | ||
O1—C1—C2—C3 | −179.52 (10) | N2—C12—C13—C14 | 0.69 (12) |
C6—C1—C2—C3 | −0.33 (16) | N2—C12—C13—C11 | −179.97 (10) |
C1—C2—C3—C4 | 0.63 (17) | C10—C11—C13—C12 | 109.95 (13) |
C2—C3—C4—C5 | −0.39 (17) | C10—C11—C13—C14 | −70.83 (14) |
C2—C3—C4—C7 | −179.08 (11) | C12—C13—C14—C15 | 178.40 (12) |
C3—C4—C5—C6 | −0.14 (16) | C11—C13—C14—C15 | −1.0 (2) |
C7—C4—C5—C6 | 178.53 (11) | C12—C13—C14—C19 | −0.10 (12) |
C4—C5—C6—C1 | 0.41 (16) | C11—C13—C14—C19 | −179.45 (10) |
C4—C5—C6—C8 | 177.68 (10) | C19—C14—C15—C16 | −0.83 (17) |
O1—C1—C6—C5 | 179.00 (9) | C13—C14—C15—C16 | −179.19 (12) |
C2—C1—C6—C5 | −0.17 (15) | C14—C15—C16—C17 | 0.36 (19) |
O1—C1—C6—C8 | 1.71 (16) | C15—C16—C17—C18 | 0.27 (19) |
C2—C1—C6—C8 | −177.47 (9) | C16—C17—C18—C19 | −0.38 (18) |
C10—N1—C8—C6 | 178.04 (10) | C12—N2—C19—C18 | −179.07 (11) |
C10—N1—C8—C9 | −0.81 (17) | C12—N2—C19—C14 | 0.95 (12) |
C5—C6—C8—N1 | −179.09 (10) | C17—C18—C19—N2 | 179.90 (11) |
C1—C6—C8—N1 | −1.83 (15) | C17—C18—C19—C14 | −0.12 (16) |
C5—C6—C8—C9 | −0.23 (15) | C15—C14—C19—N2 | −179.29 (10) |
C1—C6—C8—C9 | 177.03 (10) | C13—C14—C19—N2 | −0.52 (12) |
C8—N1—C10—C11 | −154.48 (10) | C15—C14—C19—C18 | 0.73 (16) |
N1—C10—C11—C13 | −62.04 (13) | C13—C14—C19—C18 | 179.49 (10) |
C19—N2—C12—C13 | −1.04 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O1 | 0.90 (1) | 1.66 (1) | 2.487 (1) | 151 (2) |
N2—H2N···O1i | 0.89 (1) | 1.93 (1) | 2.807 (1) | 168 (2) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C19H20N2O |
Mr | 292.37 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 173 |
a, b, c (Å) | 13.5170 (2), 8.5778 (1), 14.4551 (2) |
β (°) | 114.619 (1) |
V (Å3) | 1523.66 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.35 × 0.26 × 0.21 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 23521, 4406, 3516 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.703 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.126, 1.01 |
No. of reflections | 4406 |
No. of parameters | 279 |
No. of restraints | 19 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.41, −0.23 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), X-SEED (Barbour, 2001), publCIF (Westrip, 2007).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O1 | 0.90 (1) | 1.66 (1) | 2.487 (1) | 151 (2) |
N2—H2N···O1i | 0.89 (1) | 1.93 (1) | 2.807 (1) | 168 (2) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Some Schiff bases that are formed from a primary amine and a substituted salicylaldehyde (or 2-hydroxyacetophenone) exist in a zwitterionic form as the phenolic hydrogen is transferred to the imino group. Among the (indol-3-yl)ethyl-2-amine derivatives that have been synthesized, the crystal structures of only two have been reported: 2-[2-(1H-Indol-3-yl)ethyliminomethy]phenol (1H-indole-3-ethylenesalicylaldimine exists as a neutral compound (Rodriguez et al.,1987) whereas 2-[2-(1H-indol-3-yl)ethylminomethyl]-6-methoxyphenol is zwitterionic (Zarza et al., 1988). The title compound, (I), (Fig. 1) exists in the latter form; two zwitterions are linked by an Nindole–H···O hydrogen bond (Table 1) into a dimer.