Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101008459/sk1456sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101008459/sk1456Isup2.hkl |
CCDC reference: 170209
The title compound was synthesized according to the method described by Goldberg & Nimerovsky (1907). Green crystals of (I) suitable for X-ray investigation were grown from ethyl alcohol.
No constraints were applied for H atoms; the mean Car—H distance was 0.965 Å and the refined O—H distance was 1.08 (4) Å. C—H bond lengths were in the range 0.92–1.02 Å and their s.u.s did not exceed 0.03 Å.
Data collection: Kuma KM-4 Software (Kuma Diffraction, 1989); cell refinement: Kuma KM-4 Software; data reduction: Kuma KM-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
C19H15NO2 | Z = 2 |
Mr = 289.32 | F(000) = 304 |
Triclinic, P1 | Dx = 1.282 Mg m−3 |
a = 9.145 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.427 (2) Å | Cell parameters from 50 reflections |
c = 9.889 (2) Å | θ = 6–13° |
α = 85.19 (3)° | µ = 0.08 mm−1 |
β = 82.64 (3)° | T = 293 K |
γ = 62.45 (3)° | Plate, green |
V = 749.3 (3) Å3 | 0.5 × 0.3 × 0.3 mm |
Kuma KM-4 diffractometer | Rint = 0.036 |
Radiation source: fine-focus sealed tube | θmax = 30.1°, θmin = 2.1° |
Graphite monochromator | h = −11→11 |
θ/2θ scans | k = −12→12 |
4376 measured reflections | l = −13→0 |
4175 independent reflections | 3 standard reflections every 200 reflections |
1581 reflections with I > 2σ(I) | intensity decay: 22% |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.151 | All H-atom parameters refined |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0699P)2] where P = (Fo2 + 2Fc2)/3 |
4175 reflections | (Δ/σ)max < 0.001 |
259 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
C19H15NO2 | γ = 62.45 (3)° |
Mr = 289.32 | V = 749.3 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.145 (2) Å | Mo Kα radiation |
b = 9.427 (2) Å | µ = 0.08 mm−1 |
c = 9.889 (2) Å | T = 293 K |
α = 85.19 (3)° | 0.5 × 0.3 × 0.3 mm |
β = 82.64 (3)° |
Kuma KM-4 diffractometer | Rint = 0.036 |
4376 measured reflections | 3 standard reflections every 200 reflections |
4175 independent reflections | intensity decay: 22% |
1581 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.151 | All H-atom parameters refined |
S = 1.00 | Δρmax = 0.18 e Å−3 |
4175 reflections | Δρmin = −0.23 e Å−3 |
259 parameters |
Geometry. Mean-plane data from final SHELXL refinement run:- # Plane C-COO Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 8.347 (0.006) x + 2.764 (0.011) y - 2.626 (0.009) z = 4.181 (0.011) * -0.0141 (0.0016) C19 * 0.0047 (0.0005) O1 * 0.0054 (0.0006) O2 * 0.0041 (0.0005) C2 Rms deviation of fitted atoms = 0.0082 # Plane N-ringA-COO 7.241 (0.006) x + 0.759 (0.008) y - 4.172 (0.008) z = 1.522 (0.010) Angle to previous plane (with approximate e.s.d.) = 14.61 (0.11) * -0.0144 (0.0013) C1 * 0.0191 (0.0012) C2 * -0.0079 (0.0013) C3 * -0.0084 (0.0015) C4 * 0.0133 (0.0016) C5 * -0.0017 (0.0015) C6 - 0.1002 (0.0027) N1 0.9638 (0.0036) C7 - 1.2698 (0.0034) C13 0.1417 (0.0029) C19 - 0.0644 (0.0036) O1 0.4642 (0.0033) O2 Rms deviation of fitted atoms = 0.0122 #Plane N—C(ringA)-C(ringB)-C(ringC) - 1.570 (0.009) x - 4.710 (0.009) y + 8.119 (0.007) z = 4.977 (0.010) Angle to previous plane (with approximate e.s.d.) = 64.45 (0.08) * 0.0056 (0.0004) C1 * 0.0060 (0.0005) C7 * 0.0060 (0.0005) C13 * -0.0176 (0.0013) N1 Rms deviation of fitted atoms = 0.0102 # Plane N-ringB 3.480 (0.008) x - 0.072 (0.009) y + 9.261 (0.006) z = 9.423 (0.007) Angle to previous plane (with approximate e.s.d.) = 35.78 (0.08) * 0.0048 (0.0014) C7 * -0.0067 (0.0014) C8 * 0.0012 (0.0016) C9 * 0.0064 (0.0018) C10 * -0.0083 (0.0019) C11 * 0.0027 (0.0017) C12 0.0429 (0.0027) N1 - 0.5939 (0.0036) C13 0.8231 (0.0036) C1 Rms deviation of fitted atoms = 0.0056 # Plane N-ringC - 2.316 (0.008) x - 7.982 (0.007) y + 4.441 (0.010) z = 1.361 (0.010) Angle to the plane C1 C7 C13 N1 (with approximate e.s.d.) = 29.21 (0.13) * -0.0025 (0.0015) C13 * -0.0046 (0.0019) C14 * 0.0064 (0.0020) C15 * -0.0010 (0.0018) C16 * -0.0061 (0.0017) C17 * 0.0078 (0.0015) C18 - 0.0306 (0.0029) N1 0.5601 (0.0039) C7 - 0.6249 (0.0036) C1 Rms deviation of fitted atoms = 0.0053 |
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 | ||
N1 | 0.63854 (17) | 0.08359 (17) | 0.78280 (15) | 0.0410 (4) | |
O1 | 0.5227 (2) | 0.56345 (18) | 0.66037 (18) | 0.0820 (6) | |
H1 | 0.491 (4) | 0.592 (4) | 0.557 (4) | 0.147 (13)* | |
O2 | 0.57696 (19) | 0.32822 (17) | 0.58513 (14) | 0.0645 (4) | |
C1 | 0.6798 (2) | 0.1847 (2) | 0.85232 (17) | 0.0386 (4) | |
C2 | 0.6426 (2) | 0.3415 (2) | 0.80817 (17) | 0.0379 (4) | |
C3 | 0.6757 (2) | 0.4351 (2) | 0.8892 (2) | 0.0458 (5) | |
H3A | 0.652 (3) | 0.540 (3) | 0.852 (2) | 0.063 (6)* | |
C4 | 0.7500 (2) | 0.3745 (3) | 1.0073 (2) | 0.0520 (5) | |
H4A | 0.774 (2) | 0.439 (2) | 1.059 (2) | 0.053 (6)* | |
C5 | 0.7922 (3) | 0.2184 (3) | 1.0469 (2) | 0.0588 (6) | |
H5A | 0.844 (3) | 0.176 (3) | 1.130 (2) | 0.075 (7)* | |
C7 | 0.7691 (2) | −0.0585 (2) | 0.72853 (17) | 0.0397 (4) | |
C6 | 0.7559 (3) | 0.1254 (3) | 0.9706 (2) | 0.0544 (6) | |
H6A | 0.778 (3) | 0.022 (3) | 0.996 (2) | 0.064 (7)* | |
C8 | 0.9161 (2) | −0.0609 (3) | 0.6720 (2) | 0.0482 (5) | |
H8A | 0.927 (2) | 0.039 (2) | 0.669 (2) | 0.057 (6)* | |
C9 | 1.0470 (3) | −0.2005 (3) | 0.6226 (2) | 0.0620 (6) | |
H9A | 1.145 (3) | −0.194 (3) | 0.585 (3) | 0.082 (8)* | |
C10 | 1.0324 (3) | −0.3397 (3) | 0.6276 (3) | 0.0726 (7) | |
H10A | 1.126 (3) | −0.440 (3) | 0.587 (3) | 0.103 (9)* | |
C11 | 0.8856 (4) | −0.3374 (3) | 0.6812 (3) | 0.0757 (8) | |
H11A | 0.873 (3) | −0.436 (3) | 0.684 (3) | 0.100 (9)* | |
C12 | 0.7555 (3) | −0.1997 (3) | 0.7323 (2) | 0.0592 (6) | |
H12A | 0.652 (3) | −0.195 (3) | 0.773 (2) | 0.074 (7)* | |
C13 | 0.4697 (2) | 0.1263 (2) | 0.77782 (17) | 0.0405 (4) | |
C14 | 0.4170 (3) | 0.0826 (4) | 0.6713 (2) | 0.0718 (7) | |
H14A | 0.500 (3) | 0.025 (3) | 0.602 (3) | 0.088 (8)* | |
C15 | 0.2517 (3) | 0.1263 (4) | 0.6662 (3) | 0.0783 (8) | |
H15A | 0.221 (3) | 0.090 (3) | 0.595 (3) | 0.105 (9)* | |
C16 | 0.1356 (3) | 0.2164 (3) | 0.7659 (3) | 0.0648 (6) | |
H16A | 0.020 (3) | 0.242 (3) | 0.763 (2) | 0.080 (8)* | |
C17 | 0.1858 (3) | 0.2614 (3) | 0.8718 (3) | 0.0626 (6) | |
H17A | 0.097 (3) | 0.323 (3) | 0.948 (2) | 0.075 (7)* | |
C18 | 0.3517 (2) | 0.2156 (2) | 0.8792 (2) | 0.0494 (5) | |
H18A | 0.389 (3) | 0.242 (3) | 0.956 (2) | 0.070 (7)* | |
C19 | 0.5761 (2) | 0.4098 (2) | 0.67586 (19) | 0.0438 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0389 (9) | 0.0385 (8) | 0.0443 (9) | −0.0145 (7) | −0.0111 (7) | −0.0028 (7) |
O1 | 0.1277 (15) | 0.0444 (9) | 0.0619 (11) | −0.0251 (9) | −0.0364 (10) | 0.0136 (7) |
O2 | 0.0905 (12) | 0.0547 (9) | 0.0440 (8) | −0.0279 (8) | −0.0203 (7) | 0.0092 (7) |
C1 | 0.0370 (9) | 0.0363 (10) | 0.0404 (9) | −0.0138 (8) | −0.0094 (7) | 0.0004 (7) |
C2 | 0.0326 (9) | 0.0403 (10) | 0.0386 (9) | −0.0149 (8) | −0.0059 (7) | 0.0034 (8) |
C3 | 0.0442 (11) | 0.0388 (11) | 0.0545 (12) | −0.0193 (9) | −0.0027 (9) | −0.0033 (9) |
C4 | 0.0482 (12) | 0.0538 (13) | 0.0567 (12) | −0.0223 (10) | −0.0114 (9) | −0.0123 (10) |
C5 | 0.0632 (14) | 0.0581 (14) | 0.0532 (13) | −0.0208 (11) | −0.0284 (11) | 0.0001 (10) |
C7 | 0.0443 (11) | 0.0387 (10) | 0.0336 (9) | −0.0154 (8) | −0.0113 (8) | 0.0018 (7) |
C6 | 0.0681 (14) | 0.0422 (12) | 0.0523 (12) | −0.0209 (10) | −0.0267 (10) | 0.0074 (9) |
C8 | 0.0476 (12) | 0.0505 (12) | 0.0456 (11) | −0.0203 (10) | −0.0108 (9) | 0.0001 (9) |
C9 | 0.0460 (13) | 0.0723 (17) | 0.0559 (13) | −0.0158 (12) | −0.0056 (10) | −0.0089 (12) |
C10 | 0.0681 (17) | 0.0513 (15) | 0.0730 (17) | −0.0047 (13) | −0.0049 (13) | −0.0126 (12) |
C11 | 0.093 (2) | 0.0415 (13) | 0.0843 (18) | −0.0269 (14) | 0.0085 (15) | −0.0116 (12) |
C12 | 0.0678 (15) | 0.0468 (13) | 0.0632 (14) | −0.0287 (11) | 0.0059 (11) | −0.0064 (10) |
C13 | 0.0428 (10) | 0.0432 (10) | 0.0368 (9) | −0.0200 (8) | −0.0111 (8) | 0.0051 (8) |
C14 | 0.0525 (14) | 0.113 (2) | 0.0486 (13) | −0.0338 (14) | −0.0063 (11) | −0.0203 (13) |
C15 | 0.0613 (16) | 0.119 (2) | 0.0623 (16) | −0.0433 (16) | −0.0222 (13) | −0.0060 (15) |
C16 | 0.0466 (14) | 0.0656 (15) | 0.0845 (17) | −0.0269 (12) | −0.0177 (12) | 0.0100 (13) |
C17 | 0.0474 (13) | 0.0511 (13) | 0.0893 (18) | −0.0233 (10) | 0.0036 (12) | −0.0119 (12) |
C18 | 0.0529 (13) | 0.0420 (11) | 0.0567 (13) | −0.0244 (9) | −0.0025 (10) | −0.0069 (9) |
C19 | 0.0431 (10) | 0.0406 (11) | 0.0415 (10) | −0.0148 (8) | −0.0046 (8) | 0.0045 (8) |
N1—C1 | 1.426 (2) | C8—H8A | 0.99 (2) |
N1—C7 | 1.409 (2) | C9—C10 | 1.376 (4) |
N1—C13 | 1.411 (2) | C9—H9A | 0.95 (3) |
O1—C19 | 1.299 (2) | C10—C11 | 1.369 (4) |
O1—H1 | 1.08 (4) | C10—H10A | 1.00 (3) |
O2—C19 | 1.227 (2) | C11—C12 | 1.372 (3) |
C1—C6 | 1.379 (2) | C11—H11A | 0.98 (3) |
C1—C2 | 1.398 (2) | C12—H12A | 0.96 (2) |
C2—C3 | 1.393 (3) | C13—C14 | 1.378 (3) |
C2—C19 | 1.482 (2) | C13—C18 | 1.379 (3) |
C3—C4 | 1.373 (3) | C14—C15 | 1.377 (3) |
C3—H3A | 0.96 (2) | C14—H14A | 0.94 (3) |
C4—C5 | 1.373 (3) | C15—C16 | 1.363 (4) |
C4—H4A | 0.94 (2) | C15—H15A | 0.93 (3) |
C5—C6 | 1.375 (3) | C16—C17 | 1.366 (3) |
C5—H5A | 0.96 (2) | C16—H16A | 0.97 (2) |
C7—C8 | 1.378 (3) | C17—C18 | 1.382 (3) |
C7—C12 | 1.391 (3) | C17—H17A | 1.02 (2) |
C6—H6A | 0.92 (2) | C18—H18A | 0.97 (2) |
C8—C9 | 1.380 (3) | ||
C1—N1—C7 | 118.01 (14) | C11—C10—C9 | 119.0 (2) |
C1—N1—C13 | 118.60 (14) | C11—C10—H10A | 120.8 (17) |
C7—N1—C13 | 123.31 (15) | C9—C10—H10A | 120.0 (17) |
C19—O1—H1 | 105.8 (16) | C10—C11—C12 | 121.0 (3) |
C6—C1—C2 | 119.00 (18) | C10—C11—H11A | 119.7 (16) |
C6—C1—N1 | 117.93 (17) | C12—C11—H11A | 119.3 (16) |
C2—C1—N1 | 123.05 (15) | C11—C12—C7 | 120.5 (2) |
C3—C2—C1 | 118.68 (16) | C11—C12—H12A | 123.1 (14) |
C3—C2—C19 | 118.57 (17) | C7—C12—H12A | 116.4 (14) |
C1—C2—C19 | 122.69 (17) | C14—C13—C18 | 117.95 (19) |
C4—C3—C2 | 121.4 (2) | C14—C13—N1 | 121.39 (17) |
C4—C3—H3A | 123.3 (13) | C18—C13—N1 | 120.66 (17) |
C2—C3—H3A | 115.0 (13) | C15—C14—C13 | 121.1 (2) |
C3—C4—C5 | 119.4 (2) | C15—C14—H14A | 123.2 (15) |
C3—C4—H4A | 119.7 (12) | C13—C14—H14A | 115.7 (15) |
C5—C4—H4A | 120.8 (12) | C16—C15—C14 | 120.6 (2) |
C4—C5—C6 | 120.1 (2) | C16—C15—H15A | 120.4 (17) |
C4—C5—H5A | 119.6 (14) | C14—C15—H15A | 119.0 (17) |
C6—C5—H5A | 120.3 (14) | C15—C16—C17 | 119.0 (2) |
C8—C7—C12 | 118.23 (19) | C15—C16—H16A | 119.5 (15) |
C8—C7—N1 | 120.16 (17) | C17—C16—H16A | 121.4 (15) |
C12—C7—N1 | 121.60 (18) | C16—C17—C18 | 120.8 (2) |
C5—C6—C1 | 121.3 (2) | C16—C17—H17A | 117.6 (13) |
C5—C6—H6A | 122.2 (14) | C18—C17—H17A | 121.5 (13) |
C1—C6—H6A | 116.5 (14) | C13—C18—C17 | 120.5 (2) |
C7—C8—C9 | 120.8 (2) | C13—C18—H18A | 117.9 (13) |
C7—C8—H8A | 118.9 (11) | C17—C18—H18A | 121.6 (13) |
C9—C8—H8A | 120.3 (11) | O1—C19—C2 | 114.72 (18) |
C10—C9—C8 | 120.4 (2) | O2—C19—C2 | 123.23 (18) |
C10—C9—H9A | 122.8 (15) | O1—C19—O2 | 121.99 (18) |
C8—C9—H9A | 116.8 (15) | ||
C7—N1—C1—C6 | −64.0 (2) | C9—C10—C11—C12 | −1.5 (4) |
C13—N1—C1—C6 | 112.8 (2) | C10—C11—C12—C7 | 1.2 (4) |
C7—N1—C1—C2 | 117.85 (19) | C8—C7—C12—C11 | 0.1 (3) |
C6—C1—C2—C3 | −3.4 (3) | N1—C7—C12—C11 | −178.7 (2) |
N1—C1—C2—C3 | 174.76 (16) | C7—N1—C13—C14 | −31.8 (3) |
C6—C1—C2—C19 | 173.88 (18) | C1—N1—C13—C14 | 151.6 (2) |
N1—C1—C2—C19 | −8.0 (3) | C7—N1—C13—C18 | 149.18 (18) |
C1—C2—C3—C4 | 2.8 (3) | C1—N1—C13—C18 | −27.5 (2) |
C19—C2—C3—C4 | −174.55 (17) | C18—C13—C14—C15 | −0.1 (4) |
C2—C3—C4—C5 | −0.2 (3) | N1—C13—C14—C15 | −179.2 (2) |
C3—C4—C5—C6 | −1.8 (3) | C13—C14—C15—C16 | 1.0 (4) |
C13—N1—C7—C8 | 146.43 (17) | C14—C15—C16—C17 | −0.6 (4) |
C1—N1—C7—C8 | −36.9 (2) | C15—C16—C17—C18 | −0.6 (4) |
C13—N1—C7—C12 | −34.8 (3) | C14—C13—C18—C17 | −1.0 (3) |
C1—N1—C7—C12 | 141.88 (19) | N1—C13—C18—C17 | 178.00 (18) |
C4—C5—C6—C1 | 1.2 (3) | C16—C17—C18—C13 | 1.4 (3) |
C2—C1—C6—C5 | 1.5 (3) | C3—C2—C19—O2 | 163.56 (19) |
N1—C1—C6—C5 | −176.79 (19) | C1—C2—C19—O2 | −13.7 (3) |
C12—C7—C8—C9 | −1.0 (3) | C3—C2—C19—O1 | −13.6 (2) |
N1—C7—C8—C9 | 177.82 (17) | C1—C2—C19—O1 | 169.08 (18) |
C7—C8—C9—C10 | 0.7 (3) | C2—C1—N1—C13 | −65.3 (2) |
C8—C9—C10—C11 | 0.6 (4) | O2—C19—O1—H1 | −3 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O2i | 1.08 (4) | 1.59 (4) | 2.657 (3) | 168 (3) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C19H15NO2 |
Mr | 289.32 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 9.145 (2), 9.427 (2), 9.889 (2) |
α, β, γ (°) | 85.19 (3), 82.64 (3), 62.45 (3) |
V (Å3) | 749.3 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.5 × 0.3 × 0.3 |
Data collection | |
Diffractometer | Kuma KM-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4376, 4175, 1581 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.705 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.151, 1.00 |
No. of reflections | 4175 |
No. of parameters | 259 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.18, −0.23 |
Computer programs: Kuma KM-4 Software (Kuma Diffraction, 1989), Kuma KM-4 Software, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976), SHELXL97.
N1—C1 | 1.426 (2) | O1—C19 | 1.299 (2) |
N1—C7 | 1.409 (2) | O2—C19 | 1.227 (2) |
N1—C13 | 1.411 (2) | C2—C19 | 1.482 (2) |
C1—N1—C7 | 118.01 (14) | O1—C19—C2 | 114.72 (18) |
C1—N1—C13 | 118.60 (14) | O2—C19—C2 | 123.23 (18) |
C7—N1—C13 | 123.31 (15) | O1—C19—O2 | 121.99 (18) |
C19—O1—H1 | 105.8 (16) | ||
C1—N1—C7—C8 | −36.9 (2) | C2—C1—N1—C13 | −65.3 (2) |
C7—N1—C13—C14 | −31.8 (3) | O2—C19—O1—H1 | −3 (2) |
C1—C2—C19—O2 | −13.7 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O2i | 1.08 (4) | 1.59 (4) | 2.657 (3) | 168 (3) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Compound name | Space group | Z | Average N—C | Angle of inclinationb | Ref | ||
distancea | 1 | 2 | 3 | ||||
2-(N,N-Diphenylamino)benzoic acid | P1 | 2 | 1.415 (3) | 64.5 | 35.8 | 29.2 | (i) |
triphenylaminec | B11b | 16 | 1.418 | 39.7 | 41.4 | 49.4 | (ii) |
38.2 | 44.6 | 50.5 | |||||
40.3 | 41.5 | 48.0 | |||||
37.0 | 44.4 | 49.8 | |||||
Tri(4-methylphenyl)amined | P1 | 4 | 1.421 | 30.7 | 33.0 | 61.2 | (iii) |
31.3 | 36.7 | 58.2 | |||||
Tri(2-methoxyphenyl)amine | Pa3 | 8 | 1.422 | 44.4 | 44.4 | 44.4 | (iv) |
Tri(2,3,4,5,6-pentachlorophenyl)amine | A2/a | 4 | 1.421 | 50.1 | 50.1 | 54.6 | (v) |
Tri[4-(N-tert-butylamino-N-oxy)phenyl]amine | Cc | 4 | 1.421 | 29.8 | 34.2 | 57.2 | (vi) |
Notes: (a) average distance between the central N atom and the adjacent C atoms; (b) Angle between the average plane formed by the central N atom and the adjacent C atoms and the average plane formed by all C atoms of the benzene rings 1, 2 or 3; (c) sixteen molecules in the unit cell and four in the independent part of the unit cell; (d) four molecules in the unit cell and two in the independent part of the unit cell. References: (i) this work; (ii) Sobolev et al. (1985); (iii) Reynolds & Scaringe (1982); (iv) Müller & Bürgi (1989); (v) Hayes et al. (1980); (vi) Itoh et al. (1999). |
Triphenylamine is a unique aromatic amine in which three phenyl substituents are attached to the N atom. The large size of the substituents means that all three C—N—C angles are ca 120° and that the N atom and the three adjacent C atoms lie in a single plane (Sobolev et al., 1985). The phenyl substituents surround the N atom, taking up an irregular propeller-like shape (Table 1). For such a structure, one may expect that the lone electron pair of the N atom occupies the p orbital perpendicular to the plane formed by the four central atoms and conjugates with the phenyl moieties of the substituents. This lone electron pair is less available to the proton, so the proton affinity of triphenylamine is lower than that of the majority of aromatic or aliphatic amines (Ikuta & Kebarle, 1983). If the phenyl fragments are substituted, the distortion from the regular propeller structure depends on the size and character of the atoms or groups attached to them. However, the phenyl substituents in tri(2-methoxyphenyl)amine surround the N atom, taking up a regular propeller-like shape (Table 1). To our knowledge, the structures of more than ten compounds (some are listed in Table 1) originating from triphenylamine have been established so far and none of them contains a group able to participate in strong hydrogen-bonding interactions. The title compound, (I), which we synthesized contains a carboxy group and it was our intention to explore the extent to which the presence of this group affects the structural and physicochemical features of the crystalline phase. \sch
In the crystalline phase, a molecule of (I) is shaped like a distorted propeller (Fig. 1), since the phenyl substituents are unequally twisted relative to the plane formed by the N and the three neighbouring C atoms (Tables 1 and 2). Note that the C—N—C angles are almost equal (a total of 359.92°) and the N—C bonds spread almost symmetrically from the N atom (Table 2). This means that the N atom is sp2-hybridized and the lone electron pair occupies the p orbital perpendicular to the plane formed by the four central atoms. This lone electron pair is involved in conjugation with the π-aromatic systems of the benzene rings. As a result, the N—C bonds (mean 1.415 Å) are only ca 0.002 Å longer than in aromatic amines and ca 0.054 Å shorter than in aliphatic ones (International Tables for X-ray Crystallography, 1992, vol. C, pp. 685–706).
All the atoms making up the carboxy group lie in a plane that is twisted through an angle of 13.7° relative to the benzene ring (Table 2). The distance between the C atom of the benzene ring and the C atom of the carboxy group is typical for carboxylic acids (International Tables for X-ray Crystallography, 1992, vol. C, pp. 685–706). On the other hand, the O—C distances within this group are almost equal, which suggests that both O atoms are involved in strong hydrogen bonds. Indeed, the arrangement of molecules in the crystalline phase shows that the carboxy groups are bonded via a couple of hydrogen bonds (Fig. 2), whose geometry is the same as in the strong bonds (Table 3). The dimers of (I) formed as a result of hydrogen bonding are arranged in the crystal in columns held via dispersive interactions between the phenyl moieties. These unique structural features of (I) explain the ease of formation and the relatively high stability of its crystalline phase.