

Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807026050/lh2401sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536807026050/lh2401Isup2.hkl |
CCDC reference: 654904
Two solutions were made up: imipramine hydrochloride (0.95 g, 0.03 mol) in 50 ml of water and picric acid (1.1 g, 0.03 mol) in 50 ml of water. The solutions were mixed and stirred for few minutes. The resulting salt was filtered off and dried over P2O5. Red-orange chunks of (I) were recrystallized from methylethylketone (m.p.: 415 K).
The displacement ellipsoids for C7 and C8 are elongated, suggesting disorder, but no convincing models could be developed to describe this. A very similar situation was seen in imipramine hydrochloride (Post et al., 1975).
The N-bound hydrogen atom was located in a difference map and its position was freely refined with Uiso(H) = 1.2Ueq(N). The C-bound hydrogen atoms were geometrically placed (C—H = 0.93–0.98 Å) and refined as riding with Uiso(H) = 1.2Ueq(carrier). The methyl groups were allowed to rotate, but not to tip, to best fit the electron density.
Imipramine, C19H20N2, a tricyclic molecule containing two tertiary amine moieties, inhibits the re-uptake of serotonin more effectively than most secondary amine tricyclics, meaning that it blocks the re-uptake of the neurotransmitters serotonin and noradrenaline almost equally. It has been widely used to treat depression and neurosis for the past 50 years and is still under intensive study (Zanoveli et al., 2007).
Here we describe the title compound, (I), (Fig. 1), C19H25N2·C6H2N3O7, a molecular salt of imipramine and picric acid.
Compound (I) formally arises via proton transfer from the phenol group of the picric acid to the tertiary N atom of the imipramine side chain. The resulting cation and anion interact via a bifurcated N—H···(O,O) hydrogen bond (Table 1). One of the acceptor oxygen atoms is the deprotonated phenolic O atom, and the other is part of a nitro group.
The dihedral angle between the aromatic rings in the cation is 56.13 (6)°. The conformation of the seven-membered ring in (I) is uncertain because of probable disorder of the bridging methylene C6 and C7 species. The bond angle sum at N1 of 351.0° is ambiguous with respect to the hybridization of this nitrogen atom (nominal values for sp2 and sp3 hybridization = 360 and 328°, respectively). The N1—C15—C16—C17 and C15—C16—C17—N2 conformations in the side chain in (I) are both gauche [torsion angles = 53.8 (2) and 57.8 (2)°, respectively].
In the crystal of (I), π-π stacking is evident. The C20—C25 aromatic ring (centroid = Cg1) of the anion interacts with a symmetry related partner [Cg1···Cg1i = 3.6805 (12) Å, i = 1 - x, 1 - y, 1 - z) and also with the C1—C6 ring (centroid = Cg2) of the cation [Cg1···Cg2 = 3.7726 (14) Å].
The structure of imipramine hydrochloride, (II), was determined by Post et al. (1975). They also found unresolvable disorder for the bridging methylene groups in the seven-membered rings of the two unique cations. The dihedral angles between the aromatic rings in the cations in (II) were calculated to be 49.7° and 57° (standard uncertainties not stated). One cation in (II) has a gauche-gauche conformation in its side chain, the other a gauche-trans conformation.
For the crystal structure of impramine hydrochloride, see: Post et al. (1975). For recent background on the neurochemistry of imapramine, see: Zanoveli et al. (2007).
Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
C19H25N2+·C6H2N3O7− | Z = 2 |
Mr = 509.52 | F(000) = 536 |
Triclinic, P1 | Dx = 1.369 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 10.5204 (10) Å | Cell parameters from 2120 reflections |
b = 10.6661 (10) Å | θ = 4.4–25.7° |
c = 11.7603 (11) Å | µ = 0.10 mm−1 |
α = 77.292 (1)° | T = 295 K |
β = 73.862 (1)° | Chunk, red-orange |
γ = 84.590 (1)° | 0.40 × 0.30 × 0.30 mm |
V = 1235.8 (2) Å3 |
Bruker SMART 1000 CCD diffractometer | 2818 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.021 |
Graphite monochromator | θmax = 26.0°, θmin = 4.3° |
ω scans | h = −12→12 |
7898 measured reflections | k = −13→13 |
4674 independent reflections | l = −14→13 |
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)] = 0.049 | Hydrogen site location: difmap (N-H) and geom (C-H) |
wR(F2) = 0.127 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.95 | w = 1/[σ2(Fo2) + (0.0649P)2] where P = (Fo2 + 2Fc2)/3 |
4674 reflections | (Δ/σ)max < 0.001 |
339 parameters | Δρmax = 0.17 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
C19H25N2+·C6H2N3O7− | γ = 84.590 (1)° |
Mr = 509.52 | V = 1235.8 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 10.5204 (10) Å | Mo Kα radiation |
b = 10.6661 (10) Å | µ = 0.10 mm−1 |
c = 11.7603 (11) Å | T = 295 K |
α = 77.292 (1)° | 0.40 × 0.30 × 0.30 mm |
β = 73.862 (1)° |
Bruker SMART 1000 CCD diffractometer | 2818 reflections with I > 2σ(I) |
7898 measured reflections | Rint = 0.021 |
4674 independent reflections |
R[F2 > 2σ(F2)] = 0.049 | 0 restraints |
wR(F2) = 0.127 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.95 | Δρmax = 0.17 e Å−3 |
4674 reflections | Δρmin = −0.19 e Å−3 |
339 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 | ||
C1 | 0.19775 (18) | 0.83478 (18) | 0.27495 (19) | 0.0455 (5) | |
C2 | 0.1915 (2) | 0.9091 (2) | 0.1636 (2) | 0.0557 (6) | |
H2 | 0.2345 | 0.9867 | 0.1359 | 0.067* | |
C3 | 0.1235 (2) | 0.8713 (3) | 0.0929 (2) | 0.0760 (8) | |
H3 | 0.1214 | 0.9228 | 0.0185 | 0.091* | |
C4 | 0.0589 (2) | 0.7578 (3) | 0.1327 (3) | 0.0913 (10) | |
H4 | 0.0126 | 0.7314 | 0.0858 | 0.110* | |
C5 | 0.0636 (2) | 0.6838 (3) | 0.2424 (3) | 0.0819 (9) | |
H5 | 0.0189 | 0.6072 | 0.2689 | 0.098* | |
C6 | 0.1323 (2) | 0.7176 (2) | 0.3168 (2) | 0.0613 (6) | |
C7 | 0.1284 (3) | 0.6248 (2) | 0.4349 (3) | 0.0854 (9) | |
H7A | 0.1469 | 0.5390 | 0.4178 | 0.102* | |
H7B | 0.0385 | 0.6265 | 0.4859 | 0.102* | |
C8 | 0.2204 (3) | 0.6445 (2) | 0.5079 (2) | 0.0761 (8) | |
H8A | 0.2139 | 0.5735 | 0.5766 | 0.091* | |
H8B | 0.3111 | 0.6461 | 0.4582 | 0.091* | |
C9 | 0.1852 (2) | 0.7681 (2) | 0.5516 (2) | 0.0595 (6) | |
C10 | 0.1256 (3) | 0.7721 (3) | 0.6715 (2) | 0.0825 (8) | |
H10 | 0.1110 | 0.6958 | 0.7287 | 0.099* | |
C11 | 0.0875 (3) | 0.8877 (3) | 0.7073 (2) | 0.0803 (8) | |
H11 | 0.0475 | 0.8890 | 0.7883 | 0.096* | |
C12 | 0.1085 (2) | 0.9995 (2) | 0.6245 (2) | 0.0612 (6) | |
H12 | 0.0831 | 1.0774 | 0.6489 | 0.073* | |
C13 | 0.16742 (19) | 0.99837 (19) | 0.50393 (19) | 0.0475 (5) | |
H13 | 0.1811 | 1.0754 | 0.4475 | 0.057* | |
C14 | 0.20606 (18) | 0.88278 (18) | 0.46723 (18) | 0.0426 (5) | |
C15 | 0.36804 (18) | 0.97595 (17) | 0.27865 (17) | 0.0409 (5) | |
H15A | 0.3221 | 1.0591 | 0.2668 | 0.049* | |
H15B | 0.4122 | 0.9577 | 0.1996 | 0.049* | |
C16 | 0.47105 (18) | 0.98213 (17) | 0.34556 (18) | 0.0444 (5) | |
H16A | 0.5360 | 1.0440 | 0.2952 | 0.053* | |
H16B | 0.4278 | 1.0140 | 0.4185 | 0.053* | |
C17 | 0.54306 (19) | 0.85605 (19) | 0.38034 (17) | 0.0471 (5) | |
H17A | 0.6065 | 0.8710 | 0.4216 | 0.056* | |
H17B | 0.4793 | 0.7969 | 0.4373 | 0.056* | |
C18 | 0.6879 (2) | 0.6759 (2) | 0.3248 (2) | 0.0674 (7) | |
H18A | 0.6273 | 0.6209 | 0.3884 | 0.101* | |
H18B | 0.7551 | 0.7003 | 0.3559 | 0.101* | |
H18C | 0.7284 | 0.6309 | 0.2608 | 0.101* | |
C19 | 0.7051 (2) | 0.8795 (2) | 0.17754 (19) | 0.0585 (6) | |
H19A | 0.6545 | 0.9491 | 0.1421 | 0.088* | |
H19B | 0.7523 | 0.8320 | 0.1172 | 0.088* | |
H19C | 0.7670 | 0.9132 | 0.2086 | 0.088* | |
N1 | 0.27124 (15) | 0.87742 (13) | 0.34391 (14) | 0.0404 (4) | |
N2 | 0.61469 (17) | 0.79317 (14) | 0.27744 (15) | 0.0444 (4) | |
H1 | 0.555 (2) | 0.7628 (18) | 0.2485 (18) | 0.053* | |
C20 | 0.41881 (19) | 0.57369 (17) | 0.17240 (18) | 0.0422 (5) | |
C21 | 0.3622 (2) | 0.44759 (17) | 0.21547 (17) | 0.0447 (5) | |
C22 | 0.2846 (2) | 0.39896 (18) | 0.16199 (18) | 0.0471 (5) | |
H22 | 0.2469 | 0.3195 | 0.1971 | 0.057* | |
C23 | 0.26218 (19) | 0.46791 (18) | 0.05557 (18) | 0.0447 (5) | |
C24 | 0.31935 (19) | 0.58543 (18) | 0.00231 (17) | 0.0443 (5) | |
H24 | 0.3059 | 0.6306 | −0.0709 | 0.053* | |
C25 | 0.39595 (18) | 0.63523 (16) | 0.05766 (17) | 0.0406 (4) | |
N3 | 0.3867 (2) | 0.36765 (17) | 0.32566 (18) | 0.0648 (5) | |
N4 | 0.18039 (18) | 0.4167 (2) | −0.00232 (19) | 0.0618 (5) | |
N5 | 0.45440 (18) | 0.75804 (16) | −0.00482 (17) | 0.0538 (5) | |
O1 | 0.47543 (16) | 0.62008 (13) | 0.23215 (14) | 0.0649 (4) | |
O2 | 0.2998 (2) | 0.29774 (18) | 0.39253 (17) | 0.0990 (7) | |
O3 | 0.4926 (2) | 0.3707 (2) | 0.3451 (2) | 0.1137 (8) | |
O4 | 0.13910 (18) | 0.30810 (18) | 0.04328 (17) | 0.0885 (6) | |
O5 | 0.15606 (18) | 0.48256 (19) | −0.09388 (17) | 0.0863 (6) | |
O6 | 0.52913 (19) | 0.80446 (16) | 0.03556 (17) | 0.0852 (6) | |
O7 | 0.4274 (2) | 0.81032 (16) | −0.09792 (17) | 0.0897 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0343 (11) | 0.0464 (11) | 0.0570 (14) | −0.0002 (9) | −0.0054 (10) | −0.0225 (10) |
C2 | 0.0436 (12) | 0.0712 (14) | 0.0598 (15) | 0.0016 (10) | −0.0185 (11) | −0.0241 (12) |
C3 | 0.0506 (15) | 0.117 (2) | 0.0771 (18) | 0.0103 (15) | −0.0275 (14) | −0.0464 (16) |
C4 | 0.0429 (15) | 0.138 (3) | 0.122 (3) | 0.0032 (16) | −0.0239 (17) | −0.087 (2) |
C5 | 0.0435 (14) | 0.0834 (18) | 0.128 (3) | −0.0160 (13) | 0.0009 (16) | −0.0647 (19) |
C6 | 0.0419 (12) | 0.0521 (13) | 0.0879 (18) | −0.0065 (10) | 0.0039 (12) | −0.0348 (13) |
C7 | 0.0818 (19) | 0.0418 (13) | 0.110 (2) | −0.0195 (12) | 0.0233 (17) | −0.0223 (14) |
C8 | 0.0834 (18) | 0.0413 (13) | 0.0789 (18) | 0.0003 (12) | 0.0023 (16) | 0.0076 (12) |
C9 | 0.0602 (14) | 0.0513 (13) | 0.0524 (15) | 0.0020 (10) | −0.0015 (12) | 0.0012 (10) |
C10 | 0.090 (2) | 0.0821 (19) | 0.0527 (17) | −0.0011 (15) | −0.0016 (15) | 0.0109 (14) |
C11 | 0.0763 (18) | 0.105 (2) | 0.0515 (16) | 0.0011 (16) | −0.0019 (14) | −0.0205 (16) |
C12 | 0.0508 (13) | 0.0760 (16) | 0.0637 (17) | 0.0054 (12) | −0.0131 (12) | −0.0346 (13) |
C13 | 0.0428 (12) | 0.0480 (11) | 0.0548 (14) | 0.0029 (9) | −0.0160 (11) | −0.0148 (10) |
C14 | 0.0387 (11) | 0.0449 (11) | 0.0413 (12) | 0.0015 (8) | −0.0086 (9) | −0.0066 (9) |
C15 | 0.0438 (11) | 0.0377 (10) | 0.0406 (11) | −0.0035 (8) | −0.0121 (9) | −0.0047 (8) |
C16 | 0.0472 (12) | 0.0440 (11) | 0.0439 (12) | −0.0050 (9) | −0.0115 (10) | −0.0122 (9) |
C17 | 0.0488 (12) | 0.0575 (12) | 0.0373 (12) | −0.0015 (10) | −0.0148 (10) | −0.0104 (9) |
C18 | 0.0751 (16) | 0.0605 (14) | 0.0795 (18) | 0.0191 (12) | −0.0425 (15) | −0.0218 (12) |
C19 | 0.0501 (13) | 0.0732 (15) | 0.0520 (14) | −0.0097 (11) | −0.0062 (11) | −0.0185 (11) |
N1 | 0.0435 (9) | 0.0365 (8) | 0.0400 (10) | −0.0080 (7) | −0.0083 (8) | −0.0065 (7) |
N2 | 0.0483 (10) | 0.0426 (9) | 0.0504 (11) | 0.0004 (8) | −0.0235 (9) | −0.0136 (8) |
C20 | 0.0453 (11) | 0.0380 (10) | 0.0457 (12) | −0.0003 (8) | −0.0128 (10) | −0.0133 (9) |
C21 | 0.0580 (13) | 0.0396 (10) | 0.0365 (11) | −0.0012 (9) | −0.0129 (10) | −0.0073 (8) |
C22 | 0.0574 (13) | 0.0390 (10) | 0.0447 (13) | −0.0085 (9) | −0.0090 (10) | −0.0110 (9) |
C23 | 0.0468 (12) | 0.0507 (11) | 0.0404 (12) | −0.0071 (9) | −0.0102 (10) | −0.0168 (9) |
C24 | 0.0477 (12) | 0.0493 (11) | 0.0344 (11) | 0.0047 (9) | −0.0098 (10) | −0.0092 (9) |
C25 | 0.0441 (11) | 0.0334 (10) | 0.0418 (12) | −0.0023 (8) | −0.0072 (9) | −0.0069 (8) |
N3 | 0.0959 (16) | 0.0504 (11) | 0.0547 (13) | −0.0132 (11) | −0.0340 (12) | −0.0017 (9) |
N4 | 0.0588 (12) | 0.0745 (13) | 0.0596 (13) | −0.0115 (10) | −0.0158 (11) | −0.0253 (11) |
N5 | 0.0604 (12) | 0.0436 (10) | 0.0505 (12) | −0.0037 (8) | −0.0067 (10) | −0.0047 (9) |
O1 | 0.0853 (11) | 0.0562 (9) | 0.0676 (10) | −0.0135 (8) | −0.0376 (9) | −0.0155 (7) |
O2 | 0.1468 (18) | 0.0813 (12) | 0.0686 (12) | −0.0507 (13) | −0.0436 (13) | 0.0244 (10) |
O3 | 0.1231 (17) | 0.1125 (16) | 0.1131 (17) | −0.0232 (13) | −0.0787 (15) | 0.0300 (13) |
O4 | 0.1012 (14) | 0.0870 (13) | 0.0932 (14) | −0.0402 (11) | −0.0334 (12) | −0.0256 (10) |
O5 | 0.0975 (14) | 0.1118 (14) | 0.0655 (12) | −0.0157 (11) | −0.0453 (11) | −0.0157 (10) |
O6 | 0.1030 (14) | 0.0667 (11) | 0.0918 (14) | −0.0421 (10) | −0.0330 (12) | −0.0026 (9) |
O7 | 0.1236 (16) | 0.0688 (11) | 0.0703 (13) | −0.0279 (10) | −0.0366 (12) | 0.0238 (9) |
C1—C2 | 1.389 (3) | C16—C17 | 1.512 (3) |
C1—C6 | 1.408 (3) | C16—H16A | 0.9700 |
C1—N1 | 1.428 (2) | C16—H16B | 0.9700 |
C2—C3 | 1.377 (3) | C17—N2 | 1.496 (2) |
C2—H2 | 0.9300 | C17—H17A | 0.9700 |
C3—C4 | 1.370 (4) | C17—H17B | 0.9700 |
C3—H3 | 0.9300 | C18—N2 | 1.489 (2) |
C4—C5 | 1.367 (4) | C18—H18A | 0.9600 |
C4—H4 | 0.9300 | C18—H18B | 0.9600 |
C5—C6 | 1.398 (3) | C18—H18C | 0.9600 |
C5—H5 | 0.9300 | C19—N2 | 1.483 (3) |
C6—C7 | 1.511 (4) | C19—H19A | 0.9600 |
C7—C8 | 1.516 (4) | C19—H19B | 0.9600 |
C7—H7A | 0.9700 | C19—H19C | 0.9600 |
C7—H7B | 0.9700 | N2—H1 | 0.90 (2) |
C8—C9 | 1.496 (3) | C20—O1 | 1.239 (2) |
C8—H8A | 0.9700 | C20—C25 | 1.439 (3) |
C8—H8B | 0.9700 | C20—C21 | 1.451 (2) |
C9—C10 | 1.383 (3) | C21—C22 | 1.356 (2) |
C9—C14 | 1.388 (3) | C21—N3 | 1.460 (2) |
C10—C11 | 1.378 (4) | C22—C23 | 1.375 (3) |
C10—H10 | 0.9300 | C22—H22 | 0.9300 |
C11—C12 | 1.356 (3) | C23—C24 | 1.383 (3) |
C11—H11 | 0.9300 | C23—N4 | 1.442 (2) |
C12—C13 | 1.383 (3) | C24—C25 | 1.371 (2) |
C12—H12 | 0.9300 | C24—H24 | 0.9300 |
C13—C14 | 1.383 (3) | C25—N5 | 1.453 (2) |
C13—H13 | 0.9300 | N3—O3 | 1.203 (2) |
C14—N1 | 1.433 (2) | N3—O2 | 1.217 (2) |
C15—N1 | 1.464 (2) | N4—O5 | 1.227 (2) |
C15—C16 | 1.519 (2) | N4—O4 | 1.229 (2) |
C15—H15A | 0.9700 | N5—O7 | 1.210 (2) |
C15—H15B | 0.9700 | N5—O6 | 1.214 (2) |
C2—C1—C6 | 118.95 (19) | C17—C16—H16B | 108.4 |
C2—C1—N1 | 119.71 (17) | C15—C16—H16B | 108.4 |
C6—C1—N1 | 121.34 (19) | H16A—C16—H16B | 107.5 |
C3—C2—C1 | 121.9 (2) | N2—C17—C16 | 115.19 (15) |
C3—C2—H2 | 119.0 | N2—C17—H17A | 108.5 |
C1—C2—H2 | 119.0 | C16—C17—H17A | 108.5 |
C4—C3—C2 | 119.8 (3) | N2—C17—H17B | 108.5 |
C4—C3—H3 | 120.1 | C16—C17—H17B | 108.5 |
C2—C3—H3 | 120.1 | H17A—C17—H17B | 107.5 |
C5—C4—C3 | 119.0 (2) | N2—C18—H18A | 109.5 |
C5—C4—H4 | 120.5 | N2—C18—H18B | 109.5 |
C3—C4—H4 | 120.5 | H18A—C18—H18B | 109.5 |
C4—C5—C6 | 123.3 (2) | N2—C18—H18C | 109.5 |
C4—C5—H5 | 118.3 | H18A—C18—H18C | 109.5 |
C6—C5—H5 | 118.3 | H18B—C18—H18C | 109.5 |
C5—C6—C1 | 117.1 (2) | N2—C19—H19A | 109.5 |
C5—C6—C7 | 116.7 (2) | N2—C19—H19B | 109.5 |
C1—C6—C7 | 126.2 (2) | H19A—C19—H19B | 109.5 |
C6—C7—C8 | 118.57 (19) | N2—C19—H19C | 109.5 |
C6—C7—H7A | 107.7 | H19A—C19—H19C | 109.5 |
C8—C7—H7A | 107.7 | H19B—C19—H19C | 109.5 |
C6—C7—H7B | 107.7 | C1—N1—C14 | 117.96 (15) |
C8—C7—H7B | 107.7 | C1—N1—C15 | 116.68 (15) |
H7A—C7—H7B | 107.1 | C14—N1—C15 | 116.36 (14) |
C9—C8—C7 | 110.5 (2) | C19—N2—C18 | 110.88 (17) |
C9—C8—H8A | 109.5 | C19—N2—C17 | 113.60 (15) |
C7—C8—H8A | 109.5 | C18—N2—C17 | 108.74 (16) |
C9—C8—H8B | 109.5 | C19—N2—H1 | 109.5 (13) |
C7—C8—H8B | 109.5 | C18—N2—H1 | 104.2 (12) |
H8A—C8—H8B | 108.1 | C17—N2—H1 | 109.5 (13) |
C10—C9—C14 | 118.9 (2) | O1—C20—C25 | 126.36 (17) |
C10—C9—C8 | 122.5 (2) | O1—C20—C21 | 122.04 (18) |
C14—C9—C8 | 118.5 (2) | C25—C20—C21 | 111.57 (16) |
C11—C10—C9 | 120.9 (2) | C22—C21—C20 | 124.55 (18) |
C11—C10—H10 | 119.5 | C22—C21—N3 | 117.02 (17) |
C9—C10—H10 | 119.5 | C20—C21—N3 | 118.42 (17) |
C12—C11—C10 | 119.9 (2) | C21—C22—C23 | 119.55 (18) |
C12—C11—H11 | 120.0 | C21—C22—H22 | 120.2 |
C10—C11—H11 | 120.0 | C23—C22—H22 | 120.2 |
C11—C12—C13 | 120.4 (2) | C22—C23—C24 | 120.44 (17) |
C11—C12—H12 | 119.8 | C22—C23—N4 | 119.96 (18) |
C13—C12—H12 | 119.8 | C24—C23—N4 | 119.59 (18) |
C12—C13—C14 | 120.0 (2) | C25—C24—C23 | 119.82 (18) |
C12—C13—H13 | 120.0 | C25—C24—H24 | 120.1 |
C14—C13—H13 | 120.0 | C23—C24—H24 | 120.1 |
C13—C14—C9 | 119.83 (19) | C24—C25—C20 | 123.72 (17) |
C13—C14—N1 | 121.85 (17) | C24—C25—N5 | 116.59 (17) |
C9—C14—N1 | 118.30 (17) | C20—C25—N5 | 119.68 (16) |
N1—C15—C16 | 112.33 (15) | O3—N3—O2 | 122.7 (2) |
N1—C15—H15A | 109.1 | O3—N3—C21 | 119.0 (2) |
C16—C15—H15A | 109.1 | O2—N3—C21 | 118.3 (2) |
N1—C15—H15B | 109.1 | O5—N4—O4 | 123.49 (19) |
C16—C15—H15B | 109.1 | O5—N4—C23 | 118.9 (2) |
H15A—C15—H15B | 107.9 | O4—N4—C23 | 117.6 (2) |
C17—C16—C15 | 115.34 (15) | O7—N5—O6 | 121.92 (18) |
C17—C16—H16A | 108.4 | O7—N5—C25 | 117.90 (18) |
C15—C16—H16A | 108.4 | O6—N5—C25 | 120.17 (18) |
C6—C1—C2—C3 | −0.1 (3) | C13—C14—N1—C15 | 38.7 (2) |
N1—C1—C2—C3 | 179.10 (18) | C9—C14—N1—C15 | −139.54 (18) |
C1—C2—C3—C4 | 0.4 (3) | C16—C15—N1—C1 | −160.55 (15) |
C2—C3—C4—C5 | −0.1 (4) | C16—C15—N1—C14 | 52.9 (2) |
C3—C4—C5—C6 | −0.5 (4) | C16—C17—N2—C19 | 52.0 (2) |
C4—C5—C6—C1 | 0.7 (3) | C16—C17—N2—C18 | 176.04 (17) |
C4—C5—C6—C7 | −179.6 (2) | O1—C20—C21—C22 | 171.0 (2) |
C2—C1—C6—C5 | −0.4 (3) | C25—C20—C21—C22 | −6.9 (3) |
N1—C1—C6—C5 | −179.61 (18) | O1—C20—C21—N3 | −7.3 (3) |
C2—C1—C6—C7 | 180.0 (2) | C25—C20—C21—N3 | 174.70 (18) |
N1—C1—C6—C7 | 0.7 (3) | C20—C21—C22—C23 | 4.0 (3) |
C5—C6—C7—C8 | 169.2 (2) | N3—C21—C22—C23 | −177.59 (18) |
C1—C6—C7—C8 | −11.1 (3) | C21—C22—C23—C24 | 0.8 (3) |
C6—C7—C8—C9 | 65.1 (3) | C21—C22—C23—N4 | 179.67 (18) |
C7—C8—C9—C10 | 108.0 (3) | C22—C23—C24—C25 | −1.8 (3) |
C7—C8—C9—C14 | −68.1 (3) | N4—C23—C24—C25 | 179.26 (17) |
C14—C9—C10—C11 | −0.1 (4) | C23—C24—C25—C20 | −1.8 (3) |
C8—C9—C10—C11 | −176.2 (3) | C23—C24—C25—N5 | 179.00 (17) |
C9—C10—C11—C12 | 0.0 (4) | O1—C20—C25—C24 | −172.09 (19) |
C10—C11—C12—C13 | 0.3 (4) | C21—C20—C25—C24 | 5.8 (3) |
C11—C12—C13—C14 | −0.4 (3) | O1—C20—C25—N5 | 7.1 (3) |
C12—C13—C14—C9 | 0.2 (3) | C21—C20—C25—N5 | −175.09 (16) |
C12—C13—C14—N1 | −177.97 (17) | C22—C21—N3—O3 | 145.3 (2) |
C10—C9—C14—C13 | 0.0 (3) | C20—C21—N3—O3 | −36.2 (3) |
C8—C9—C14—C13 | 176.3 (2) | C22—C21—N3—O2 | −32.7 (3) |
C10—C9—C14—N1 | 178.3 (2) | C20—C21—N3—O2 | 145.8 (2) |
C8—C9—C14—N1 | −5.5 (3) | C22—C23—N4—O5 | 176.3 (2) |
N1—C15—C16—C17 | 53.8 (2) | C24—C23—N4—O5 | −4.8 (3) |
C15—C16—C17—N2 | 57.8 (2) | C22—C23—N4—O4 | −4.0 (3) |
C2—C1—N1—C14 | 127.93 (19) | C24—C23—N4—O4 | 174.97 (19) |
C6—C1—N1—C14 | −52.8 (2) | C24—C25—N5—O7 | 3.0 (3) |
C2—C1—N1—C15 | −18.1 (2) | C20—C25—N5—O7 | −176.15 (19) |
C6—C1—N1—C15 | 161.15 (17) | C24—C25—N5—O6 | −175.99 (19) |
C13—C14—N1—C1 | −107.4 (2) | C20—C25—N5—O6 | 4.8 (3) |
C9—C14—N1—C1 | 74.3 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H1···O1 | 0.90 (2) | 1.88 (2) | 2.686 (2) | 148.2 (17) |
N2—H1···O6 | 0.90 (2) | 2.53 (2) | 3.189 (2) | 130.0 (16) |
Experimental details
Crystal data | |
Chemical formula | C19H25N2+·C6H2N3O7− |
Mr | 509.52 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 295 |
a, b, c (Å) | 10.5204 (10), 10.6661 (10), 11.7603 (11) |
α, β, γ (°) | 77.292 (1), 73.862 (1), 84.590 (1) |
V (Å3) | 1235.8 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.40 × 0.30 × 0.30 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7898, 4674, 2818 |
Rint | 0.021 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.049, 0.127, 0.95 |
No. of reflections | 4674 |
No. of parameters | 339 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.17, −0.19 |
Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H1···O1 | 0.90 (2) | 1.88 (2) | 2.686 (2) | 148.2 (17) |
N2—H1···O6 | 0.90 (2) | 2.53 (2) | 3.189 (2) | 130.0 (16) |
Imipramine, C19H20N2, a tricyclic molecule containing two tertiary amine moieties, inhibits the re-uptake of serotonin more effectively than most secondary amine tricyclics, meaning that it blocks the re-uptake of the neurotransmitters serotonin and noradrenaline almost equally. It has been widely used to treat depression and neurosis for the past 50 years and is still under intensive study (Zanoveli et al., 2007).
Here we describe the title compound, (I), (Fig. 1), C19H25N2·C6H2N3O7, a molecular salt of imipramine and picric acid.
Compound (I) formally arises via proton transfer from the phenol group of the picric acid to the tertiary N atom of the imipramine side chain. The resulting cation and anion interact via a bifurcated N—H···(O,O) hydrogen bond (Table 1). One of the acceptor oxygen atoms is the deprotonated phenolic O atom, and the other is part of a nitro group.
The dihedral angle between the aromatic rings in the cation is 56.13 (6)°. The conformation of the seven-membered ring in (I) is uncertain because of probable disorder of the bridging methylene C6 and C7 species. The bond angle sum at N1 of 351.0° is ambiguous with respect to the hybridization of this nitrogen atom (nominal values for sp2 and sp3 hybridization = 360 and 328°, respectively). The N1—C15—C16—C17 and C15—C16—C17—N2 conformations in the side chain in (I) are both gauche [torsion angles = 53.8 (2) and 57.8 (2)°, respectively].
In the crystal of (I), π-π stacking is evident. The C20—C25 aromatic ring (centroid = Cg1) of the anion interacts with a symmetry related partner [Cg1···Cg1i = 3.6805 (12) Å, i = 1 - x, 1 - y, 1 - z) and also with the C1—C6 ring (centroid = Cg2) of the cation [Cg1···Cg2 = 3.7726 (14) Å].
The structure of imipramine hydrochloride, (II), was determined by Post et al. (1975). They also found unresolvable disorder for the bridging methylene groups in the seven-membered rings of the two unique cations. The dihedral angles between the aromatic rings in the cations in (II) were calculated to be 49.7° and 57° (standard uncertainties not stated). One cation in (II) has a gauche-gauche conformation in its side chain, the other a gauche-trans conformation.