Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100015535/os1128sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270100015535/os1128Isup2.hkl |
CCDC reference: 158279
Compound (I) was prepared from a mixture of salicylaldehyde (1.16 g, 9.50 mmol) and 4-aminophenazone (1.93 g, 9.50 mmol) in boiling methanol (100 ml). The precipitate was filtered. The residue was dissolved in CHCl3—MeOH (3:1) and set aside for crystallization (yield 2.58 g, 88%; m.p. 474 K).
Data collection: MolEN (Fair, 1990); cell refinement: MolEN; data reduction: MolEN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: MolEN.
Fig. 1. An ORTEPII (Johnson, 1976) drawing of (I) with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. |
C18H17N3O2 | F(000) = 648 |
Mr = 307.35 | Dx = 1.320 Mg m−3 |
Monoclinic, P21/n | Cu Kα radiation, λ = 1.54180 Å |
a = 7.595 (1) Å | Cell parameters from 25 reflections |
b = 7.498 (1) Å | θ = 20–43° |
c = 27.277 (2) Å | µ = 0.71 mm−1 |
β = 95.332 (7)° | T = 293 K |
V = 1546.6 (3) Å3 | Rod, yellow |
Z = 4 | 0.30 × 0.20 × 0.15 mm |
Enraf-Nonius CAD-4 diffractometer | Rint = 0.033 |
Radiation source: fine-focus sealed tube | θmax = 74.2°, θmin = 3.3° |
Graphite monochromator | h = 0→9 |
ω/2θ scans | k = 0→9 |
3226 measured reflections | l = −33→33 |
3079 independent reflections | 3 standard reflections every 120 min |
2463 reflections with I > 2σ(I) | intensity decay: 1% |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.066 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.180 | w = 1/[σ2Fo2 + (0.1629P)2 + 0.3199P] where P = (Fo2 + 2Fc2)/3 |
S = 0.80 | (Δ/σ)max < 0.001 |
3079 reflections | Δρmax = 0.29 e Å−3 |
231 parameters | Δρmin = −0.31 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0068 (12) |
C18H17N3O2 | V = 1546.6 (3) Å3 |
Mr = 307.35 | Z = 4 |
Monoclinic, P21/n | Cu Kα radiation |
a = 7.595 (1) Å | µ = 0.71 mm−1 |
b = 7.498 (1) Å | T = 293 K |
c = 27.277 (2) Å | 0.30 × 0.20 × 0.15 mm |
β = 95.332 (7)° |
Enraf-Nonius CAD-4 diffractometer | Rint = 0.033 |
3226 measured reflections | 3 standard reflections every 120 min |
3079 independent reflections | intensity decay: 1% |
2463 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.066 | 0 restraints |
wR(F2) = 0.180 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.80 | Δρmax = 0.29 e Å−3 |
3079 reflections | Δρmin = −0.31 e Å−3 |
231 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 | ||
H1 | 0.793 (3) | 0.211 (3) | −0.0155 (10) | 0.080 (7)* | |
N2 | 0.5451 (2) | 0.28689 (18) | 0.15230 (5) | 0.0480 (4) | |
C1 | 0.8432 (2) | 0.3767 (3) | −0.06089 (6) | 0.0549 (4) | |
C2 | 0.9142 (3) | 0.4188 (3) | −0.10447 (7) | 0.0680 (6) | |
H21 | 0.9474 | 0.3278 | −0.1249 | 0.079 (7)* | |
C6 | 0.7934 (2) | 0.5140 (2) | −0.03010 (6) | 0.0471 (4) | |
C3 | 0.9362 (3) | 0.5940 (4) | −0.11783 (7) | 0.0701 (6) | |
H31 | 0.9833 | 0.6203 | −0.1473 | 0.076 (7)* | |
C13 | 0.5347 (2) | 0.3386 (2) | 0.20201 (6) | 0.0468 (4) | |
C4 | 0.8887 (3) | 0.7312 (3) | −0.08782 (7) | 0.0659 (5) | |
H41 | 0.9047 | 0.8495 | −0.0967 | 0.071 (6)* | |
C8 | 0.6428 (2) | 0.2796 (2) | 0.07716 (6) | 0.0442 (4) | |
C5 | 0.8175 (3) | 0.6898 (3) | −0.04459 (6) | 0.0570 (5) | |
H51 | 0.7845 | 0.7818 | −0.0245 | 0.083 (7)* | |
C9 | 0.5966 (2) | 0.3992 (2) | 0.11537 (5) | 0.0440 (4) | |
C7 | 0.7229 (2) | 0.4781 (2) | 0.01688 (6) | 0.0473 (4) | |
H71 | 0.6917 | 0.5727 | 0.0363 | 0.048 (5)* | |
N3 | 0.5780 (2) | 0.10839 (18) | 0.14065 (5) | 0.0486 (4) | |
C11 | 0.6569 (4) | −0.0603 (3) | 0.06713 (8) | 0.0671 (6) | |
H111 | 0.7257 | −0.1400 | 0.0888 | 0.120 (11)* | |
H112 | 0.7194 | −0.0353 | 0.0389 | 0.142 (13)* | |
H113 | 0.5453 | −0.1146 | 0.0567 | 0.160 (15)* | |
C12 | 0.4574 (3) | −0.0266 (2) | 0.15751 (7) | 0.0605 (5) | |
H121 | 0.5008 | −0.1434 | 0.1507 | 0.093 (8)* | |
H122 | 0.3419 | −0.0110 | 0.1405 | 0.114 (10)* | |
H123 | 0.4505 | −0.0137 | 0.1923 | 0.080 (7)* | |
C10 | 0.6266 (2) | 0.1089 (2) | 0.09357 (6) | 0.0481 (4) | |
C14 | 0.4297 (2) | 0.4838 (2) | 0.21162 (7) | 0.0520 (4) | |
H141 | 0.3677 | 0.5456 | 0.1860 | 0.065 (6)* | |
O1 | 0.8262 (2) | 0.20324 (19) | −0.04885 (5) | 0.0733 (5) | |
C15 | 0.4187 (3) | 0.5352 (3) | 0.26009 (7) | 0.0626 (5) | |
H151 | 0.3490 | 0.6324 | 0.2669 | 0.082 (7)* | |
O2 | 0.60176 (19) | 0.56281 (16) | 0.11860 (4) | 0.0579 (4) | |
C16 | 0.5099 (3) | 0.4438 (3) | 0.29837 (7) | 0.0653 (5) | |
H161 | 0.5013 | 0.4796 | 0.3307 | 0.074 (7)* | |
N1 | 0.70351 (19) | 0.31696 (18) | 0.03167 (5) | 0.0462 (3) | |
C17 | 0.6137 (3) | 0.2996 (3) | 0.28866 (7) | 0.0613 (5) | |
H171 | 0.6741 | 0.2374 | 0.3145 | 0.068 (6)* | |
C18 | 0.6281 (2) | 0.2473 (3) | 0.24063 (6) | 0.0529 (4) | |
H181 | 0.6999 | 0.1513 | 0.2341 | 0.065 (6)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N2 | 0.0676 (8) | 0.0362 (7) | 0.0418 (7) | 0.0019 (6) | 0.0137 (6) | 0.0009 (5) |
C1 | 0.0630 (10) | 0.0592 (11) | 0.0428 (8) | 0.0003 (8) | 0.0067 (7) | −0.0065 (7) |
C2 | 0.0722 (12) | 0.0892 (15) | 0.0440 (9) | 0.0020 (11) | 0.0128 (8) | −0.0116 (10) |
C6 | 0.0522 (8) | 0.0530 (9) | 0.0365 (8) | 0.0029 (7) | 0.0066 (6) | 0.0004 (6) |
C3 | 0.0648 (11) | 0.1057 (19) | 0.0412 (9) | −0.0053 (11) | 0.0120 (8) | 0.0100 (10) |
C13 | 0.0542 (8) | 0.0457 (8) | 0.0426 (8) | −0.0014 (7) | 0.0149 (6) | 0.0003 (6) |
C4 | 0.0666 (11) | 0.0770 (14) | 0.0545 (10) | −0.0012 (10) | 0.0085 (8) | 0.0206 (9) |
C8 | 0.0541 (8) | 0.0398 (8) | 0.0396 (7) | 0.0003 (6) | 0.0089 (6) | −0.0003 (6) |
C5 | 0.0662 (10) | 0.0577 (11) | 0.0482 (9) | 0.0042 (8) | 0.0105 (8) | 0.0074 (8) |
C9 | 0.0560 (8) | 0.0371 (8) | 0.0402 (7) | 0.0004 (6) | 0.0107 (6) | 0.0012 (5) |
C7 | 0.0584 (9) | 0.0444 (8) | 0.0399 (8) | 0.0033 (7) | 0.0095 (6) | −0.0005 (6) |
N3 | 0.0674 (8) | 0.0340 (7) | 0.0459 (7) | −0.0011 (6) | 0.0136 (6) | 0.0013 (5) |
C11 | 0.1047 (16) | 0.0409 (9) | 0.0582 (11) | −0.0003 (10) | 0.0201 (11) | −0.0045 (8) |
C12 | 0.0730 (12) | 0.0446 (10) | 0.0662 (12) | −0.0077 (8) | 0.0193 (9) | 0.0056 (8) |
C10 | 0.0604 (9) | 0.0401 (9) | 0.0448 (8) | −0.0007 (7) | 0.0097 (7) | −0.0005 (6) |
C14 | 0.0583 (9) | 0.0482 (9) | 0.0513 (9) | 0.0038 (7) | 0.0140 (7) | 0.0011 (7) |
O1 | 0.1062 (12) | 0.0572 (9) | 0.0596 (8) | 0.0011 (7) | 0.0242 (8) | −0.0135 (6) |
C15 | 0.0717 (11) | 0.0579 (11) | 0.0619 (11) | 0.0011 (9) | 0.0256 (9) | −0.0072 (8) |
O2 | 0.0862 (9) | 0.0362 (6) | 0.0542 (7) | −0.0002 (5) | 0.0217 (6) | −0.0003 (5) |
C16 | 0.0820 (13) | 0.0726 (13) | 0.0444 (9) | −0.0043 (10) | 0.0219 (8) | −0.0056 (8) |
N1 | 0.0567 (7) | 0.0436 (7) | 0.0391 (7) | −0.0011 (6) | 0.0079 (5) | −0.0014 (5) |
C17 | 0.0701 (11) | 0.0710 (12) | 0.0440 (9) | −0.0010 (9) | 0.0122 (8) | 0.0057 (8) |
C18 | 0.0599 (9) | 0.0531 (10) | 0.0475 (9) | 0.0060 (8) | 0.0139 (7) | 0.0030 (7) |
N2—C9 | 1.3963 (19) | C7—N1 | 1.287 (2) |
N2—N3 | 1.4034 (18) | C7—H71 | 0.9300 |
N2—C13 | 1.4194 (19) | N3—C10 | 1.369 (2) |
C1—O1 | 1.351 (2) | N3—C12 | 1.468 (2) |
C1—C2 | 1.387 (3) | C11—C10 | 1.487 (2) |
C1—C6 | 1.403 (2) | C11—H111 | 0.9600 |
C2—C3 | 1.378 (4) | C11—H112 | 0.9600 |
C2—H21 | 0.9300 | C11—H113 | 0.9600 |
C6—C5 | 1.392 (2) | C12—H121 | 0.9600 |
C6—C7 | 1.459 (2) | C12—H122 | 0.9600 |
C3—C4 | 1.383 (3) | C12—H123 | 0.9600 |
C3—H31 | 0.9300 | C14—C15 | 1.387 (3) |
C13—C14 | 1.389 (2) | C14—H141 | 0.9300 |
C13—C18 | 1.393 (2) | O1—H1 | 0.97 (3) |
C4—C5 | 1.378 (2) | C15—C16 | 1.380 (3) |
C4—H41 | 0.9300 | C15—H151 | 0.9300 |
C8—C10 | 1.366 (2) | C16—C17 | 1.378 (3) |
C8—N1 | 1.3916 (19) | C16—H161 | 0.9300 |
C8—C9 | 1.443 (2) | C17—C18 | 1.382 (2) |
C5—H51 | 0.9300 | C17—H171 | 0.9300 |
C9—O2 | 1.230 (2) | C18—H181 | 0.9300 |
C9—N2—N3 | 110.14 (12) | C10—N3—C12 | 121.76 (14) |
C9—N2—C13 | 124.66 (13) | N2—N3—C12 | 117.22 (14) |
N3—N2—C13 | 120.23 (13) | C10—C11—H111 | 109.5 |
O1—C1—C2 | 118.77 (17) | C10—C11—H112 | 109.5 |
O1—C1—C6 | 121.60 (16) | H111—C11—H112 | 109.5 |
C2—C1—C6 | 119.62 (19) | C10—C11—H113 | 109.5 |
C3—C2—C1 | 120.7 (2) | H111—C11—H113 | 109.5 |
C3—C2—H21 | 119.7 | H112—C11—H113 | 109.5 |
C1—C2—H21 | 119.7 | N3—C12—H121 | 109.5 |
C5—C6—C1 | 118.35 (16) | N3—C12—H122 | 109.5 |
C5—C6—C7 | 119.50 (15) | H121—C12—H122 | 109.5 |
C1—C6—C7 | 122.12 (16) | N3—C12—H123 | 109.5 |
C2—C3—C4 | 120.55 (17) | H121—C12—H123 | 109.5 |
C2—C3—H31 | 119.7 | H122—C12—H123 | 109.5 |
C4—C3—H31 | 119.7 | C8—C10—N3 | 110.51 (13) |
C14—C13—C18 | 120.21 (15) | C8—C10—C11 | 128.15 (15) |
C14—C13—N2 | 118.55 (15) | N3—C10—C11 | 121.34 (14) |
C18—C13—N2 | 121.23 (15) | C15—C14—C13 | 118.93 (17) |
C5—C4—C3 | 118.9 (2) | C15—C14—H141 | 120.5 |
C5—C4—H41 | 120.5 | C13—C14—H141 | 120.5 |
C3—C4—H41 | 120.5 | C1—O1—H1 | 102.1 (15) |
C10—C8—N1 | 121.89 (14) | C16—C15—C14 | 120.89 (18) |
C10—C8—C9 | 108.09 (14) | C16—C15—H151 | 119.6 |
N1—C8—C9 | 129.95 (14) | C14—C15—H151 | 119.6 |
C4—C5—C6 | 121.91 (18) | C17—C16—C15 | 119.96 (17) |
C4—C5—H51 | 119.0 | C17—C16—H161 | 120.0 |
C6—C5—H51 | 119.0 | C15—C16—H161 | 120.0 |
O2—C9—N2 | 123.99 (14) | C7—N1—C8 | 121.70 (14) |
O2—C9—C8 | 131.53 (14) | C16—C17—C18 | 120.16 (18) |
N2—C9—C8 | 104.45 (13) | C16—C17—H171 | 119.9 |
N1—C7—C6 | 120.71 (15) | C18—C17—H171 | 119.9 |
N1—C7—H71 | 119.6 | C17—C18—C13 | 119.84 (17) |
C6—C7—H71 | 119.6 | C17—C18—H181 | 120.1 |
C10—N3—N2 | 106.21 (12) | C13—C18—H181 | 120.1 |
O1—C1—C2—C3 | −179.12 (19) | C1—C6—C7—N1 | −0.2 (3) |
C6—C1—C2—C3 | −0.1 (3) | C9—N2—N3—C10 | −8.16 (18) |
O1—C1—C6—C5 | 179.00 (17) | C13—N2—N3—C10 | −164.32 (15) |
C2—C1—C6—C5 | 0.0 (3) | C9—N2—N3—C12 | −148.16 (15) |
O1—C1—C6—C7 | 0.9 (3) | C13—N2—N3—C12 | 55.7 (2) |
C2—C1—C6—C7 | −178.13 (17) | N1—C8—C10—N3 | 175.22 (14) |
C1—C2—C3—C4 | 0.4 (3) | C9—C8—C10—N3 | −1.9 (2) |
C9—N2—C13—C14 | 56.0 (2) | N1—C8—C10—C11 | −4.0 (3) |
N3—N2—C13—C14 | −151.52 (16) | C9—C8—C10—C11 | 178.95 (19) |
C9—N2—C13—C18 | −123.67 (19) | N2—N3—C10—C8 | 6.1 (2) |
N3—N2—C13—C18 | 28.9 (2) | C12—N3—C10—C8 | 143.83 (16) |
C2—C3—C4—C5 | −0.7 (3) | N2—N3—C10—C11 | −174.68 (17) |
C3—C4—C5—C6 | 0.6 (3) | C12—N3—C10—C11 | −36.9 (3) |
C1—C6—C5—C4 | −0.2 (3) | C18—C13—C14—C15 | −0.4 (3) |
C7—C6—C5—C4 | 177.91 (17) | N2—C13—C14—C15 | 179.97 (16) |
N3—N2—C9—O2 | −171.33 (16) | C13—C14—C15—C16 | −0.2 (3) |
C13—N2—C9—O2 | −16.5 (3) | C14—C15—C16—C17 | 0.1 (3) |
N3—N2—C9—C8 | 6.92 (17) | C6—C7—N1—C8 | 177.55 (14) |
C13—N2—C9—C8 | 161.79 (15) | C10—C8—N1—C7 | −178.20 (16) |
C10—C8—C9—O2 | 174.94 (18) | C9—C8—N1—C7 | −1.8 (3) |
N1—C8—C9—O2 | −1.8 (3) | C15—C16—C17—C18 | 0.6 (3) |
C10—C8—C9—N2 | −3.12 (18) | C16—C17—C18—C13 | −1.2 (3) |
N1—C8—C9—N2 | −179.89 (16) | C14—C13—C18—C17 | 1.1 (3) |
C5—C6—C7—N1 | −178.27 (16) | N2—C13—C18—C17 | −179.30 (16) |
Experimental details
Crystal data | |
Chemical formula | C18H17N3O2 |
Mr | 307.35 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 7.595 (1), 7.498 (1), 27.277 (2) |
β (°) | 95.332 (7) |
V (Å3) | 1546.6 (3) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 0.71 |
Crystal size (mm) | 0.30 × 0.20 × 0.15 |
Data collection | |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3226, 3079, 2463 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.624 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.066, 0.180, 0.80 |
No. of reflections | 3079 |
No. of parameters | 231 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.29, −0.31 |
Computer programs: MolEN (Fair, 1990), MolEN, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976).
N2—C9 | 1.3963 (19) | C8—N1 | 1.3916 (19) |
N2—N3 | 1.4034 (18) | C8—C9 | 1.443 (2) |
N2—C13 | 1.4194 (19) | C9—O2 | 1.230 (2) |
C1—O1 | 1.351 (2) | C7—N1 | 1.287 (2) |
C6—C7 | 1.459 (2) | N3—C10 | 1.369 (2) |
C8—C10 | 1.366 (2) | O1—H1 | 0.97 (3) |
C9—N2—N3 | 110.14 (12) | N2—C9—C8 | 104.45 (13) |
C9—N2—C13 | 124.66 (13) | N1—C7—C6 | 120.71 (15) |
O1—C1—C6 | 121.60 (16) | C10—N3—N2 | 106.21 (12) |
C1—C6—C7 | 122.12 (16) | N2—N3—C12 | 117.22 (14) |
C10—C8—N1 | 121.89 (14) | C8—C10—N3 | 110.51 (13) |
C10—C8—C9 | 108.09 (14) | C8—C10—C11 | 128.15 (15) |
N1—C8—C9 | 129.95 (14) | C1—O1—H1 | 102.1 (15) |
O2—C9—C8 | 131.53 (14) | C7—N1—C8 | 121.70 (14) |
O1—C1—C6—C7 | 0.9 (3) | N2—N3—C10—C11 | −174.68 (17) |
C13—N2—N3—C10 | −164.32 (15) | C12—N3—C10—C11 | −36.9 (3) |
C9—N2—N3—C12 | −148.16 (15) | C6—C7—N1—C8 | 177.55 (14) |
C13—N2—N3—C12 | 55.7 (2) |
2-Hydroxy Schiff base ligands and their transition-metal complexes derived from the reactions of hydroxyaldehyde derivatives with various amines have been extensively studied (Hökelek, Akduran et al., 2000; Hökelek, Işıklan & Kılıç, 2000; Hökelek, Kılıç et al., 2000; Hökelek et al., 1995a,b; Yıldız et al., 1998; Gavranić et al., 1996) and a number of them have been used as models for biological systems (Chen & Martell, 1987; Pyrz et al., 1985; Costamagna et al., 1992). The Schiff base ligand of salicylaldehyde with 4-amino-1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one (4-aminophenazone, 4-AAP) has been prepared and various transition-metal complexes of this ligand have been synthesized (Nair & Prabhakaran, 1998; Barton et al., 1987). 4-Aminophenazone and its derivatives are very important compounds in pharmacology and biochemistry (El-Naggar et al., 1981; Lenarcik et al., 1980). They are especially used as anti-inflammatory drugs (Lodzinska et al., 1989).
Aldimine Schiff base ligands are of interest mainly due to the existence of O—H···N and O···H—N types of intramolecular hydrogen bonds and tautomerism between phenol-imine and keto-amine forms (Yıldız et al., 1998; Costamagna et al., 1992; Salman et al., 1991). In these types of ligands, short hydrogen bonds are observed between the 2-hydroxy group and the imine N atom. In some instances, the H atom from the phenol group is completely transferred to the imine N (Hökelek, Akduran et al., 2000; Kaitner & Pavlovic, 1996; Gavranić et al., 1996).
In the solid state, salicylaldimine and naphthaldimine ligands tend to form the N···H—O and N—H···O types of hydrogen bonding, respectively (Hökelek, Işıklan & Kılıç, 2000; Hökelek, Kılıç et al., 2000). In solution, both forms have been observed. Tautomerism in Schiff base ligands is very important for distinguishing their photochromic (Barbara et al., 1980; Hadjoudis, 1981; Higelin & Sixl, 1983; Dürr, 1989; Dürr & Bouas-Laurent, 1990) and thermochromic (Cohen et al., 1964; Moustakali et al., 1978) characteristics.
Although the oxomolybdenum(V) and dioxomolybdenum(VI) complexes of the title compound, (I), have been reported (Nair & Prabhakaran, 1998), the free Schiff base ligand, (I), has not been studied crystallographically. The present structure determination of (I) was undertaken in order to determine the type of hydrogen bonding and to compare the results obtained with those reported previously. The crystallographic atom-numbering of (I) is different from that in the IUPAC name; the latter is not suitable, due to the duplicate C2 atom labels in the salicylidene and phenazone parts. \sch
The molecule of (I) (Fig. 1) contains the bulky 4-aminophenazone-N substituent. It includes a short intramolecular O—H···N hydrogen bond [O1—H1 0.97 (3), H1···N1 1.71 (3) and N1···O1 2.607 (3) Å, and O—H···N 153 (2)°], which means that the ligand is in the phenol-imine form, as in 1,8-di(N-2-oxyphenylsalicylidene)-3,6-dioxaoctane [O—H 1.154 (3), H···N 1.488 (3) and O···N 2.578 (3) Å; Yıldız et al., 1998] and 1,5-di(N-2-oxyphenylsalicylidene)-3-oxapentane [O1—H1 0.864 (4), H1···N1 1.865 (3) and N1···O1 2.587 (4), and O5—H5 1.056 (3), H5···N2 1.603 (4) and N2···O5 2.542 (4) Å; Hökelek, Akduran et al., 2000]. The 1H NMR data for (I) illustrate that the phenol-imine form dominates in CDCl3 solution (δCH = 9.63 and δOH = 13.33 p.p.m., both singlets), supporting the location of the H atom on the O atom.
The C=N imine bond distance and the C—N—C bond angle in (I) [1.287 (3) Å and 121.7 (1)°, respectively] can be compared with the values of 1.270 (3) Å and 123.5 (2)° in 1,8-di(N-2-oxyphenylsalicylidene)-3,6-dioxaoctane (Yıldız et al., 1998), and 1.288 (4) Å and 121.3 (3)°, and 1.277 (4) Å and 124.3 (3)°, in 1,5-di(N-2-oxyphenylsalicylidene)-3-oxapentane (Hökelek, Akduran et al., 2000).
As expected, rings A (C1—C6) and D (C13—C18) are planar, while rings B (N1/H1/O1/C1/C6/C7) and C (N2/N3/C10/C8/C9) are not, with maximum deviations of 0.023 (1) and 0.040 (2) Å from the best least squares planes, respectively. The dihedral angles between the best planes of the rings are A/C 5.7 (6), A/D 131.6 (1), B/C 4.3 (7), B/D 132.8 (1) and C/D 136.4 (1)°. The ΦCN torsion angle (C6—C7—N1—C8) is 177.6 (1)°, which shows that the conformation about the C7—N1 bond is anti (1E). The ΦCN (C11—C10—N3—C12) and ΦNN (C13—N2—N3—C12) torsion angles are -36.9 (3) and 55.7 (2)°, respectively, showing that the conformations about C10—N3 and N2—N3 are gauche. The sums of the bond angles about atoms N2 and N3 are 355.0 (1) and 345.2 (1)°, respectively. In the five-membered ring the puckering parameter, i.e. the angle between the best planes (N3/C8/C9/C10 and N2/N3/C9), is 7.1(1.5)°. The displacements of atoms C12 and C13 from the best plane of the five-membered ring are 0.710 (5) and -0.324 (4)°, respectively, showing that the methyl group bonded to N3 and the phenyl group are on opposite sides of ring C.
The close contact H123(C12)···H181(C18) [2.45 Å query] may cause steric hindrance between the methyl and phenyl groups.