Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106001545/jz1772sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270106001545/jz1772Isup2.hkl |
CCDC reference: 299650
The title compound was synthesized according to the method reported by the Sureshan & Bhattacharya (1999). A mixture of methyl salicylate (12.20 g, 0.1 mol) and diethylenetriamine (5.16 g, 0.05 mol) were stirred at 322 K for 12 h. The mass was then crystallized from methanol to afford a colorless solid (m.p. 424–425 K, yield 77%). Crystals of (1) suitable for single-crystal X-ray diffraction were grown by slow evaporation of methanol and water (1:1).
All C-bonded H atoms were positioned geometrically and refined as riding [with C—H = 0.93–0.97 Å and Uiso(H) = 1.2Ueq(C)]. The H atoms attached to the hydroxy O atom and to the N atoms were located in a difference map and refined freely with an isotropic model.
Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.
C18H21N3O4 | F(000) = 728 |
Mr = 343.38 | Dx = 1.291 Mg m−3 |
Monoclinic, P21/c | Melting point = 423–424 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 10.775 (2) Å | Cell parameters from 2404 reflections |
b = 11.668 (2) Å | θ = 2.6–24.3° |
c = 14.290 (3) Å | µ = 0.09 mm−1 |
β = 100.572 (3)° | T = 294 K |
V = 1766.1 (6) Å3 | Block, colorless |
Z = 4 | 0.30 × 0.28 × 0.12 mm |
Bruker SMART 1000 CCD area-detector diffractometer | 3616 independent reflections |
Radiation source: fine-focus sealed tube | 2100 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
ϕ and ω scans | θmax = 26.4°, θmin = 1.9° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −13→13 |
Tmin = 0.972, Tmax = 0.992 | k = −14→13 |
9668 measured reflections | l = −12→17 |
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)] = 0.041 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.118 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0557P)2 + 0.2173P] where P = (Fo2 + 2Fc2)/3 |
3616 reflections | (Δ/σ)max < 0.001 |
246 parameters | Δρmax = 0.14 e Å−3 |
0 restraints | Δρmin = −0.16 e Å−3 |
C18H21N3O4 | V = 1766.1 (6) Å3 |
Mr = 343.38 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.775 (2) Å | µ = 0.09 mm−1 |
b = 11.668 (2) Å | T = 294 K |
c = 14.290 (3) Å | 0.30 × 0.28 × 0.12 mm |
β = 100.572 (3)° |
Bruker SMART 1000 CCD area-detector diffractometer | 3616 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2100 reflections with I > 2σ(I) |
Tmin = 0.972, Tmax = 0.992 | Rint = 0.036 |
9668 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.118 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 0.14 e Å−3 |
3616 reflections | Δρmin = −0.16 e Å−3 |
246 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 | 0.25783 (17) | 0.84938 (17) | 0.16143 (12) | 0.0922 (6) | |
H1 | 0.163 (3) | 0.859 (2) | 0.1689 (19) | 0.124 (10)* | |
O2 | 0.02119 (13) | 0.86542 (12) | 0.13935 (10) | 0.0640 (4) | |
O3 | 0.05542 (12) | 0.59885 (11) | 0.09812 (10) | 0.0569 (4) | |
O4 | 0.15778 (11) | 0.26527 (11) | 0.19007 (8) | 0.0492 (3) | |
N1 | −0.10065 (14) | 0.82938 (13) | −0.00209 (12) | 0.0469 (4) | |
H1A | −0.1077 (18) | 0.8082 (17) | −0.0617 (15) | 0.059 (6)* | |
N2 | −0.16556 (14) | 0.66339 (13) | 0.14445 (11) | 0.0397 (4) | |
H2A | −0.1651 (19) | 0.7140 (19) | 0.2045 (16) | 0.078 (7)* | |
H2B | −0.082 (2) | 0.6550 (16) | 0.1283 (13) | 0.065 (6)* | |
N3 | −0.01223 (13) | 0.42939 (14) | 0.14451 (11) | 0.0427 (4) | |
H3 | 0.0162 (19) | 0.3600 (16) | 0.1635 (14) | 0.061 (6)* | |
C1 | 0.2439 (2) | 0.85329 (18) | 0.06505 (16) | 0.0624 (6) | |
C2 | 0.3509 (2) | 0.8554 (2) | 0.0255 (2) | 0.0845 (8) | |
H2 | 0.4301 | 0.8542 | 0.0647 | 0.101* | |
C3 | 0.3415 (3) | 0.8591 (2) | −0.0718 (2) | 0.0858 (8) | |
H3A | 0.4145 | 0.8604 | −0.0979 | 0.103* | |
C4 | 0.2256 (3) | 0.86092 (19) | −0.13090 (18) | 0.0728 (7) | |
H4A | 0.2196 | 0.8634 | −0.1966 | 0.087* | |
C5 | 0.1186 (2) | 0.85910 (16) | −0.09136 (14) | 0.0550 (5) | |
H5 | 0.0400 | 0.8613 | −0.1311 | 0.066* | |
C6 | 0.12491 (17) | 0.85403 (14) | 0.00666 (13) | 0.0451 (5) | |
C7 | 0.01179 (18) | 0.84974 (14) | 0.05174 (14) | 0.0459 (5) | |
C8 | −0.21575 (17) | 0.83078 (16) | 0.03666 (14) | 0.0528 (5) | |
H8A | −0.2829 | 0.8634 | −0.0103 | 0.063* | |
H8B | −0.2036 | 0.8803 | 0.0921 | 0.063* | |
C9 | −0.25665 (16) | 0.71342 (16) | 0.06488 (13) | 0.0465 (5) | |
H9A | −0.3386 | 0.7197 | 0.0834 | 0.056* | |
H9B | −0.2653 | 0.6626 | 0.0104 | 0.056* | |
C10 | −0.19657 (17) | 0.54503 (16) | 0.17194 (13) | 0.0491 (5) | |
H10A | −0.2876 | 0.5372 | 0.1635 | 0.059* | |
H10B | −0.1621 | 0.5335 | 0.2389 | 0.059* | |
C11 | −0.14582 (15) | 0.45342 (15) | 0.11464 (13) | 0.0453 (5) | |
H11A | −0.1928 | 0.3833 | 0.1188 | 0.054* | |
H11B | −0.1608 | 0.4767 | 0.0484 | 0.054* | |
C12 | 0.07869 (15) | 0.50023 (16) | 0.12951 (11) | 0.0389 (4) | |
C13 | 0.21071 (15) | 0.45751 (15) | 0.15188 (11) | 0.0399 (4) | |
C14 | 0.30507 (17) | 0.53558 (18) | 0.14225 (14) | 0.0570 (5) | |
H14 | 0.2827 | 0.6099 | 0.1226 | 0.068* | |
C15 | 0.43006 (19) | 0.5058 (2) | 0.16096 (18) | 0.0814 (7) | |
H15 | 0.4919 | 0.5592 | 0.1541 | 0.098* | |
C16 | 0.4628 (2) | 0.3956 (2) | 0.19008 (18) | 0.0827 (8) | |
H16 | 0.5475 | 0.3747 | 0.2032 | 0.099* | |
C17 | 0.37225 (19) | 0.3160 (2) | 0.20002 (15) | 0.0662 (6) | |
H17 | 0.3969 | 0.2421 | 0.2195 | 0.079* | |
C18 | 0.24289 (16) | 0.34399 (17) | 0.18141 (12) | 0.0438 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0663 (11) | 0.1393 (17) | 0.0633 (11) | −0.0066 (10) | −0.0079 (8) | −0.0143 (10) |
O2 | 0.0648 (9) | 0.0805 (11) | 0.0468 (9) | −0.0026 (7) | 0.0106 (7) | −0.0176 (7) |
O3 | 0.0458 (8) | 0.0445 (8) | 0.0865 (10) | 0.0056 (6) | 0.0282 (7) | 0.0124 (7) |
O4 | 0.0521 (8) | 0.0528 (8) | 0.0426 (7) | 0.0059 (6) | 0.0087 (6) | 0.0099 (6) |
N1 | 0.0511 (10) | 0.0471 (10) | 0.0427 (10) | 0.0035 (7) | 0.0089 (8) | −0.0001 (8) |
N2 | 0.0341 (8) | 0.0437 (9) | 0.0423 (9) | 0.0020 (7) | 0.0095 (7) | −0.0043 (7) |
N3 | 0.0344 (8) | 0.0415 (10) | 0.0521 (10) | 0.0023 (7) | 0.0077 (7) | 0.0061 (7) |
C1 | 0.0561 (13) | 0.0621 (14) | 0.0680 (16) | −0.0025 (11) | 0.0090 (11) | −0.0066 (11) |
C2 | 0.0543 (15) | 0.095 (2) | 0.105 (2) | −0.0018 (13) | 0.0162 (14) | −0.0007 (16) |
C3 | 0.0698 (18) | 0.0760 (18) | 0.124 (3) | 0.0013 (13) | 0.0495 (17) | 0.0047 (16) |
C4 | 0.0892 (19) | 0.0607 (15) | 0.0786 (17) | −0.0010 (12) | 0.0420 (15) | 0.0115 (12) |
C5 | 0.0661 (14) | 0.0449 (12) | 0.0564 (13) | −0.0039 (9) | 0.0175 (10) | 0.0060 (9) |
C6 | 0.0511 (11) | 0.0339 (10) | 0.0510 (12) | −0.0026 (8) | 0.0112 (9) | −0.0018 (8) |
C7 | 0.0588 (13) | 0.0326 (10) | 0.0455 (12) | 0.0014 (9) | 0.0077 (9) | −0.0034 (8) |
C8 | 0.0495 (11) | 0.0517 (13) | 0.0575 (13) | 0.0116 (9) | 0.0105 (9) | 0.0016 (9) |
C9 | 0.0386 (10) | 0.0550 (12) | 0.0457 (11) | 0.0044 (9) | 0.0073 (8) | −0.0044 (9) |
C10 | 0.0432 (11) | 0.0484 (12) | 0.0603 (13) | −0.0016 (9) | 0.0212 (9) | 0.0034 (9) |
C11 | 0.0348 (10) | 0.0423 (11) | 0.0584 (12) | −0.0021 (8) | 0.0071 (8) | −0.0004 (9) |
C12 | 0.0378 (10) | 0.0441 (11) | 0.0364 (10) | 0.0016 (8) | 0.0109 (8) | −0.0029 (8) |
C13 | 0.0347 (9) | 0.0498 (11) | 0.0349 (10) | 0.0005 (8) | 0.0058 (7) | −0.0052 (8) |
C14 | 0.0422 (11) | 0.0572 (13) | 0.0724 (14) | −0.0050 (9) | 0.0127 (10) | −0.0080 (11) |
C15 | 0.0379 (13) | 0.0871 (19) | 0.118 (2) | −0.0088 (12) | 0.0108 (13) | −0.0024 (16) |
C16 | 0.0316 (12) | 0.115 (2) | 0.099 (2) | 0.0061 (13) | 0.0038 (12) | 0.0110 (16) |
C17 | 0.0505 (13) | 0.0823 (17) | 0.0628 (14) | 0.0187 (12) | 0.0029 (10) | 0.0148 (12) |
C18 | 0.0399 (10) | 0.0610 (13) | 0.0295 (10) | 0.0049 (9) | 0.0041 (8) | 0.0024 (8) |
O1—C1 | 1.359 (3) | C5—H5 | 0.9300 |
O1—H1 | 1.05 (3) | C6—C7 | 1.480 (3) |
O2—C7 | 1.251 (2) | C8—C9 | 1.516 (3) |
O3—C12 | 1.244 (2) | C8—H8A | 0.9700 |
O4—C18 | 1.320 (2) | C8—H8B | 0.9700 |
N1—C7 | 1.332 (2) | C9—H9A | 0.9700 |
N1—C8 | 1.448 (2) | C9—H9B | 0.9700 |
N1—H1A | 0.88 (2) | C10—C11 | 1.509 (2) |
N2—C9 | 1.479 (2) | C10—H10A | 0.9700 |
N2—C10 | 1.490 (2) | C10—H10B | 0.9700 |
N2—H2A | 1.04 (2) | C11—H11A | 0.9700 |
N2—H2B | 0.97 (2) | C11—H11B | 0.9700 |
N3—C12 | 1.329 (2) | C12—C13 | 1.486 (2) |
N3—C11 | 1.452 (2) | C13—C14 | 1.391 (2) |
N3—H3 | 0.890 (19) | C13—C18 | 1.414 (3) |
C1—C2 | 1.375 (3) | C14—C15 | 1.369 (3) |
C1—C6 | 1.395 (3) | C14—H14 | 0.9300 |
C2—C3 | 1.377 (3) | C15—C16 | 1.378 (3) |
C2—H2 | 0.9300 | C15—H15 | 0.9300 |
C3—C4 | 1.373 (3) | C16—C17 | 1.372 (3) |
C3—H3A | 0.9300 | C16—H16 | 0.9300 |
C4—C5 | 1.374 (3) | C17—C18 | 1.409 (3) |
C4—H4A | 0.9300 | C17—H17 | 0.9300 |
C5—C6 | 1.391 (3) | ||
C1—O1—H1 | 99.8 (15) | N2—C9—C8 | 112.14 (14) |
C7—N1—C8 | 121.96 (17) | N2—C9—H9A | 109.2 |
C7—N1—H1A | 121.2 (13) | C8—C9—H9A | 109.2 |
C8—N1—H1A | 116.6 (13) | N2—C9—H9B | 109.2 |
C9—N2—C10 | 114.78 (14) | C8—C9—H9B | 109.2 |
C9—N2—H2A | 108.2 (11) | H9A—C9—H9B | 107.9 |
C10—N2—H2A | 106.0 (11) | N2—C10—C11 | 113.10 (15) |
C9—N2—H2B | 111.7 (11) | N2—C10—H10A | 109.0 |
C10—N2—H2B | 103.3 (11) | C11—C10—H10A | 109.0 |
H2A—N2—H2B | 112.8 (16) | N2—C10—H10B | 109.0 |
C12—N3—C11 | 123.58 (16) | C11—C10—H10B | 109.0 |
C12—N3—H3 | 113.1 (13) | H10A—C10—H10B | 107.8 |
C11—N3—H3 | 122.2 (13) | N3—C11—C10 | 114.57 (15) |
O1—C1—C2 | 118.2 (2) | N3—C11—H11A | 108.6 |
O1—C1—C6 | 121.7 (2) | C10—C11—H11A | 108.6 |
C2—C1—C6 | 120.1 (2) | N3—C11—H11B | 108.6 |
C1—C2—C3 | 120.3 (2) | C10—C11—H11B | 108.6 |
C1—C2—H2 | 119.9 | H11A—C11—H11B | 107.6 |
C3—C2—H2 | 119.9 | O3—C12—N3 | 121.85 (16) |
C4—C3—C2 | 120.8 (2) | O3—C12—C13 | 120.64 (16) |
C4—C3—H3A | 119.6 | N3—C12—C13 | 117.50 (17) |
C2—C3—H3A | 119.6 | C14—C13—C18 | 119.97 (16) |
C3—C4—C5 | 119.0 (2) | C14—C13—C12 | 116.58 (17) |
C3—C4—H4A | 120.5 | C18—C13—C12 | 123.45 (16) |
C5—C4—H4A | 120.5 | C15—C14—C13 | 121.7 (2) |
C4—C5—C6 | 121.7 (2) | C15—C14—H14 | 119.1 |
C4—C5—H5 | 119.2 | C13—C14—H14 | 119.1 |
C6—C5—H5 | 119.2 | C14—C15—C16 | 118.9 (2) |
C5—C6—C1 | 118.16 (19) | C14—C15—H15 | 120.5 |
C5—C6—C7 | 123.22 (18) | C16—C15—H15 | 120.5 |
C1—C6—C7 | 118.62 (18) | C17—C16—C15 | 121.0 (2) |
O2—C7—N1 | 120.14 (18) | C17—C16—H16 | 119.5 |
O2—C7—C6 | 120.58 (17) | C15—C16—H16 | 119.5 |
N1—C7—C6 | 119.28 (17) | C16—C17—C18 | 121.4 (2) |
N1—C8—C9 | 113.76 (15) | C16—C17—H17 | 119.3 |
N1—C8—H8A | 108.8 | C18—C17—H17 | 119.3 |
C9—C8—H8A | 108.8 | O4—C18—C17 | 120.11 (18) |
N1—C8—H8B | 108.8 | O4—C18—C13 | 122.92 (15) |
C9—C8—H8B | 108.8 | C17—C18—C13 | 116.96 (18) |
H8A—C8—H8B | 107.7 | ||
O1—C1—C2—C3 | 179.9 (2) | C9—N2—C10—C11 | 86.81 (19) |
C6—C1—C2—C3 | 0.5 (4) | C12—N3—C11—C10 | −72.2 (2) |
C1—C2—C3—C4 | 0.1 (4) | N2—C10—C11—N3 | 78.6 (2) |
C2—C3—C4—C5 | 0.1 (4) | C11—N3—C12—O3 | 8.4 (3) |
C3—C4—C5—C6 | −0.8 (3) | C11—N3—C12—C13 | −171.72 (15) |
C4—C5—C6—C1 | 1.4 (3) | O3—C12—C13—C14 | 4.4 (2) |
C4—C5—C6—C7 | −178.82 (17) | N3—C12—C13—C14 | −175.49 (16) |
O1—C1—C6—C5 | 179.47 (19) | O3—C12—C13—C18 | −175.45 (16) |
C2—C1—C6—C5 | −1.2 (3) | N3—C12—C13—C18 | 4.7 (2) |
O1—C1—C6—C7 | −0.4 (3) | C18—C13—C14—C15 | −0.2 (3) |
C2—C1—C6—C7 | 178.97 (19) | C12—C13—C14—C15 | 179.97 (19) |
C8—N1—C7—O2 | 3.5 (3) | C13—C14—C15—C16 | 0.0 (4) |
C8—N1—C7—C6 | −176.30 (15) | C14—C15—C16—C17 | 0.3 (4) |
C5—C6—C7—O2 | −167.40 (17) | C15—C16—C17—C18 | −0.3 (4) |
C1—C6—C7—O2 | 12.4 (3) | C16—C17—C18—O4 | 178.9 (2) |
C5—C6—C7—N1 | 12.3 (3) | C16—C17—C18—C13 | 0.1 (3) |
C1—C6—C7—N1 | −167.84 (17) | C14—C13—C18—O4 | −178.60 (16) |
C7—N1—C8—C9 | −95.3 (2) | C12—C13—C18—O4 | 1.2 (3) |
C10—N2—C9—C8 | −176.63 (14) | C14—C13—C18—C17 | 0.1 (2) |
N1—C8—C9—N2 | 65.1 (2) | C12—C13—C18—C17 | 179.96 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O4i | 0.88 (2) | 2.01 (2) | 2.865 (2) | 165.7 (18) |
N2—H2A···O4ii | 1.04 (2) | 1.61 (2) | 2.6342 (19) | 167.0 (19) |
N2—H2B···O3 | 0.97 (2) | 1.75 (2) | 2.6933 (19) | 163.7 (17) |
N2—H2B···O2 | 0.97 (2) | 2.689 (19) | 3.109 (2) | 106.5 (13) |
N3—H3···O4 | 0.890 (19) | 1.87 (2) | 2.6475 (19) | 145.4 (18) |
O1—H1···O2 | 1.05 (3) | 1.51 (3) | 2.518 (2) | 158 (2) |
C5—H5···O4i | 0.93 | 2.60 | 3.380 (3) | 141 |
C11—H11B···O3i | 0.97 | 2.71 | 3.413 (2) | 130 |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C18H21N3O4 |
Mr | 343.38 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 294 |
a, b, c (Å) | 10.775 (2), 11.668 (2), 14.290 (3) |
β (°) | 100.572 (3) |
V (Å3) | 1766.1 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.30 × 0.28 × 0.12 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.972, 0.992 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9668, 3616, 2100 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.625 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.118, 1.00 |
No. of reflections | 3616 |
No. of parameters | 246 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.14, −0.16 |
Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997), SHELXTL.
O2—C7 | 1.251 (2) | N2—C9 | 1.479 (2) |
O3—C12 | 1.244 (2) | N2—C10 | 1.490 (2) |
N1—C8 | 1.448 (2) | N3—C11 | 1.452 (2) |
C7—N1—C8 | 121.96 (17) | C12—N3—C11 | 123.58 (16) |
C9—N2—C10 | 114.78 (14) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O4i | 0.88 (2) | 2.01 (2) | 2.865 (2) | 165.7 (18) |
N2—H2A···O4ii | 1.04 (2) | 1.61 (2) | 2.6342 (19) | 167.0 (19) |
N2—H2B···O3 | 0.97 (2) | 1.75 (2) | 2.6933 (19) | 163.7 (17) |
N2—H2B···O2 | 0.97 (2) | 2.689 (19) | 3.109 (2) | 106.5 (13) |
N3—H3···O4 | 0.890 (19) | 1.87 (2) | 2.6475 (19) | 145.4 (18) |
O1—H1···O2 | 1.05 (3) | 1.51 (3) | 2.518 (2) | 158 (2) |
C5—H5···O4i | 0.93 | 2.60 | 3.380 (3) | 141 |
C11—H11B···O3i | 0.97 | 2.71 | 3.413 (2) | 130 |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x, y+1/2, −z+1/2. |
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There is considerable interest in complexes that are capable of mimicking the active sites of metalloproteins (Cao et al., 2004; Tolman & Spencer, 2001; Xing & DeRose, 2001). Generally, these model complexes are obtained from bulky multidentate ligands in order to construct an environment similar to that found in the proteins. 1,5-Bis(2-hydroxybenzamido)-3-azapentane, bhap, is a potentially pentadentate coordinating ligand containing N and O donor atoms, and has been synthesized in order to study its coordination behavior with several transition metal ions (e.g. Zn2+, Cu2+ and Co2+, which are most the abundant and important metals in biology; Lipscomb & Sträter, 1996). In previous reports, this compound exhibited different chelating modes in the formation of mononuclear or binuclear complexes with copper(II) (Sureshan & Bhattacharya, 1999) and iron(III) ions (Dash & Rath, 2004; Rath et al., 2005 or 2002). However, to the best of our knowledge, there are no published data related to the crystal structure of either bhap or its complexes mentioned above.
It is commonly accepted that the aliphatic amino group acts as a comparatively strong base, whereas the phenol group, as an acid, can be deprotonated in a polar medium. Recently, it was reported that some 5,5'-derivativates of 3-diethylaminomethyl-2,2'-biphenol exist as zwitterions in the crystalline state (Ng et al., 2002; Bartoszak-Adamska et al., 2000; Brzezinski et al., 1998, 1995). The reason for the formation of the zwitterions, confirmed by experimental and theoretical methods, is that the –CH2N(C2H5)2 group, as a relatively strong base, causes the deprotonation of the nearby phenol group and thereby builds a short intramolecular hydrogen bond involving a six-membered ring. Other zwitterionic species, such as the salicylideneimine Schiff bases (Mondal et al., 2002; Hazell et al., 1997), were also formed as the result of an intramolecular proton transfer. These results prompted us to look into the structure of the bhap molecule, which also bears both aliphatic amine and phenol groups. Here we present the crystal structure of the title compound, (I), which is the zwitterion of bhap obtained by recrystallization from methanol/water.
The structure of compound (I) (Fig. 1) is composed of a 2-hydroxybenzamido and a 2-aminocarbonylphenolate moieties linked by a protonated 3-azapentandiyl chain. The zwitterionic nature is confirmed by the location and free refinement of the relevant H atoms. The two pendant moieties attached to the terminals of the C—C—N—C—C backbone adopt a cis conformation, as shown by the N1—C8—C9—N2 [65.1?(2)°] and N2—C10—C11—N3 torsion angles [78.6?(2)°]. Similar to the previously studied 5,5'-derivativates of 3-diethylaminomethyl-2,2'-biphenol, (I) exists as a zwitterion, with an H atom from one phenol hydroxy group having been transferred to the 3-azapentandiyl N atom. The C8—C9—N2—C10—C11 backbone does not adopt a normal anti staggered conformation as some polymethylene carbon chains do (Wang et al., 2004, 2005); the C10—N2—C9—C8 and C9—N2—C10—C11torsion angles are −176.63?(14) and 86.81?(19)°, and atom C11 deviates from the C10/N2/C9/C8 plane by 1.4242?(9) Å. The protonated N2 atom exhibits tetrahedral sp3 hybridization, whereas the two amide N atoms display planar sp2 hybridization. As can be see from Table 1, the N1—C8 and N3—C11 bond distances are shorter than the N2—C9 and N2—C10 bonds as a result of the p-π conjugation. The planarity of the benzamido group is well documented (Halfpenny & Small, 1980; Palmer et al., 1995). In our case, the 2-hydroxybenzamido moiety is also planar, with atoms O2 and N1 deviating 0.2131?(6) and −0.2611?(6) Å from the plane defined by C1–C7/O1. The 2-aminocarbonylphenolate moiety is also planar, with a mean derivation of 0.0267?(5) Å. The two phenyl rings subtend a dihedral angle of 73.4?(6)°. The O1—C1—C6 [121.7?(2)°] and O4—C18—C13 [122.92 ?(15)°] angles are slightly larger than the ideal angle of 120° for sp2 hybridization. The bond lengths in the two phenyl groups show significant differences at the O substitution sites. The negative charge of atom O4 is partly transferred to the benzene ring, lengthening the C13—C18 and C18—C17 bonds to 1.414 (3) and 1.409 (3) Å, respectively. The extensive delocalization of the negative charge also causes C18—O4 [1.320 (2) Å] to be slightly shorter than C1—O1 [1.359 (3) Å].
All H atoms bonded to O or N atoms are involved in hydrogen bonds. Within the intramolecular hydrogen-bonding system (Fig. 1 and Table 2), atom O2 atom acts as a double (bifurcated) hydrogen-bond acceptor towards the N2+/H2B group and the hydroxy O1/H1 group, forming seven- and six-membered rings, respectively. The former hydrogen bond is comparatively weak because it forms the longer branch of an asymmetric three-centre system (see below). Whereas atom O2 lies in a position close to the hydroxy group, carbonyl atom O3 of the 2-aminocarbonylphenolate moiety is located opposite to the negatively charged O4 atom, with C1—C6—C7—O2 and O3—C12—C13—C18 torsion angles of 12.4 (3) and −175.45 (16)°, respectively. Such an arrangement allows carbonyl atom O3, like atom O2, to act as a hydrogen-bond acceptor towards the same N2+/H2B H atom, thus forming a three-centre hydrogen-bond system and a second seven-membered ring. The final intramolecular hydrogen bond involves the phenolate O4− atom, which acts as acceptor towards the N3/H3 group, forming a six-membered ring.
The crystal packing is characterized by two intermolecular hydrogen bonds, which lead to a supramolecular network pattern. As shown in Fig. 2, the zwitterions are dimerized head-to-tail through three pairs of N1—H1A···O4, C5—H5···O4 and C11—H11B···O3 hydrogen-bond interactions. These centrosymmetric dimers are joined by the N2+—H2A···O4 interactions into a two-dimensional network parallel to the crystallographic bc plane.