Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102020371/ob1090sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102020371/ob1090Isup2.hkl |
CCDC reference: 201281
3-Formylsalicylic acid (H2fsa) was prepared according to Duff & Bills (1932). The Schiff base was obtained by mixing H2fsa (0.332 g, 2 mmol) and histamine base (0.223 g, 2 mmol) in absolute alcohol and refluxing for one hour under a nitrogen atmosphere (Andruh et al., 1993; Simmons et al., 1980). A yellow coloration occurred. After keeping for three days, yellow crystals were obtained and were collected by filtration and dried. Single crystals of (I) suitable for X-ray diffraction analysis were grown by slow evaporation from water over a period of a few weeks at room temperature.
All the H atoms were located in difference Fourier maps and were refined isotropically. The C—H, N—-H and O–H bond-length ranges are 0.90 (3)–1.01 (3), 0.89 (3)–1.01 (3) and 0.76 (4)–0.90 (3) Å, respectively.
Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990).
C13H13N3O3·H2O | F(000) = 584 |
Mr = 277.28 | Dx = 1.466 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 12.4975 (13) Å | Cell parameters from 2247 reflections |
b = 7.7837 (8) Å | θ = 3.1–28.3° |
c = 13.1320 (14) Å | µ = 0.11 mm−1 |
β = 100.402 (2)° | T = 293 K |
V = 1256.4 (2) Å3 | Block, colorless |
Z = 4 | 0.46 × 0.20 × 0.12 mm |
Siemens SMART CCD area-detector diffractometer | 3103 independent reflections |
Radiation source: fine-focus sealed tube | 2079 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
Detector resolution: 8.33 pixels mm-1 | θmax = 28.3°, θmin = 3.1° |
ω scans | h = −13→16 |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | k = −10→10 |
Tmin = 0.890, Tmax = 0.987 | l = −17→14 |
7773 measured reflections |
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)] = 0.061 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.157 | All H-atom parameters refined |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0779P)2 + 0.2851P] where P = (Fo2 + 2Fc2)/3 |
3103 reflections | (Δ/σ)max < 0.001 |
241 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.33 e Å−3 |
C13H13N3O3·H2O | V = 1256.4 (2) Å3 |
Mr = 277.28 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.4975 (13) Å | µ = 0.11 mm−1 |
b = 7.7837 (8) Å | T = 293 K |
c = 13.1320 (14) Å | 0.46 × 0.20 × 0.12 mm |
β = 100.402 (2)° |
Siemens SMART CCD area-detector diffractometer | 3103 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | 2079 reflections with I > 2σ(I) |
Tmin = 0.890, Tmax = 0.987 | Rint = 0.033 |
7773 measured reflections |
R[F2 > 2σ(F2)] = 0.061 | 0 restraints |
wR(F2) = 0.157 | All H-atom parameters refined |
S = 1.06 | Δρmax = 0.24 e Å−3 |
3103 reflections | Δρmin = −0.33 e Å−3 |
241 parameters |
Experimental. The data collection covered over a hemisphere of reciprocal space by a combination of three sets of exposures; each set had a different ϕ angle (0, 88 and 180°) for the crystal and each exposure of 10 s covered 0.3° in ω. The crystal-to-detector distance was 5 cm and the detector swing angle was -35°. Crystal decay was monitored by repeating fifty initial frames at the end of data collection and analysing the intensity of duplicate reflections, and was found to be negligible. |
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 | 0.93279 (12) | 0.6045 (2) | 0.34104 (12) | 0.0352 (4) | |
O2 | 0.82881 (15) | 0.4185 (2) | 0.23902 (12) | 0.0435 (5) | |
O3 | 0.91086 (12) | 0.6418 (2) | 0.52625 (12) | 0.0317 (4) | |
N1 | 0.62560 (14) | 0.6850 (3) | 0.73583 (14) | 0.0349 (5) | |
N2 | 0.65075 (16) | 0.5955 (3) | 0.89898 (15) | 0.0351 (5) | |
N3 | 0.88358 (15) | 0.4389 (2) | 0.74014 (14) | 0.0289 (4) | |
C1 | 0.78058 (17) | 0.4898 (3) | 0.40114 (16) | 0.0264 (5) | |
C2 | 0.68120 (19) | 0.4037 (3) | 0.38035 (19) | 0.0352 (5) | |
C3 | 0.6205 (2) | 0.3763 (3) | 0.4562 (2) | 0.0412 (6) | |
C4 | 0.65955 (19) | 0.4320 (3) | 0.55612 (19) | 0.0348 (5) | |
C5 | 0.75756 (16) | 0.5191 (3) | 0.58080 (15) | 0.0247 (4) | |
C6 | 0.81687 (16) | 0.5523 (2) | 0.50215 (16) | 0.0232 (4) | |
C7 | 0.80430 (17) | 0.5757 (3) | 0.69027 (16) | 0.0259 (5) | |
C8 | 0.72481 (16) | 0.6012 (3) | 0.76115 (16) | 0.0261 (5) | |
C9 | 0.5852 (2) | 0.6760 (4) | 0.82177 (19) | 0.0407 (6) | |
C10 | 0.74131 (17) | 0.5480 (3) | 0.86124 (16) | 0.0276 (5) | |
C11 | 0.8404 (2) | 0.4619 (3) | 0.91854 (18) | 0.0337 (5) | |
C12 | 0.92870 (19) | 0.4689 (3) | 0.85262 (18) | 0.0350 (6) | |
H12B | 0.982 (2) | 0.383 (3) | 0.878 (2) | 0.049 (8)* | |
C13 | 0.85108 (18) | 0.5048 (3) | 0.32037 (17) | 0.0294 (5) | |
O1W | 0.63168 (19) | 0.5278 (3) | 1.10306 (15) | 0.0500 (5) | |
H7 | 0.8487 (17) | 0.672 (3) | 0.6868 (16) | 0.023 (5)* | |
H3 | 0.555 (2) | 0.321 (4) | 0.442 (2) | 0.051 (8)* | |
H9 | 0.518 (2) | 0.718 (3) | 0.8289 (19) | 0.039 (7)* | |
H2 | 0.6560 (19) | 0.366 (3) | 0.313 (2) | 0.038 (7)* | |
H4 | 0.621 (2) | 0.412 (4) | 0.607 (2) | 0.050 (8)* | |
H2W1 | 0.621 (3) | 0.615 (4) | 1.144 (3) | 0.069 (11)* | |
H1W1 | 0.683 (3) | 0.490 (4) | 1.135 (3) | 0.069 (12)* | |
H11B | 0.8239 (19) | 0.340 (3) | 0.9380 (18) | 0.037 (6)* | |
H103 | 0.932 (2) | 0.642 (4) | 0.464 (2) | 0.058 (9)* | |
H11A | 0.859 (2) | 0.521 (3) | 0.979 (2) | 0.038 (7)* | |
H12A | 0.964 (2) | 0.581 (4) | 0.855 (2) | 0.051 (8)* | |
H3B | 0.8499 (19) | 0.338 (3) | 0.7333 (18) | 0.032 (6)* | |
H3A | 0.950 (2) | 0.429 (3) | 0.706 (2) | 0.053 (8)* | |
H2A | 0.6431 (19) | 0.574 (3) | 0.966 (2) | 0.037 (7)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0330 (9) | 0.0410 (9) | 0.0345 (9) | 0.0028 (7) | 0.0138 (7) | 0.0047 (7) |
O2 | 0.0560 (11) | 0.0494 (11) | 0.0266 (9) | 0.0078 (8) | 0.0115 (8) | −0.0069 (8) |
O3 | 0.0295 (8) | 0.0397 (9) | 0.0271 (9) | −0.0092 (7) | 0.0079 (7) | −0.0028 (7) |
N1 | 0.0288 (10) | 0.0466 (11) | 0.0299 (10) | 0.0059 (9) | 0.0063 (8) | 0.0010 (9) |
N2 | 0.0377 (11) | 0.0456 (12) | 0.0254 (10) | −0.0026 (9) | 0.0146 (9) | −0.0021 (9) |
N3 | 0.0260 (10) | 0.0311 (10) | 0.0300 (10) | 0.0013 (8) | 0.0060 (8) | −0.0005 (8) |
C1 | 0.0291 (11) | 0.0264 (10) | 0.0240 (11) | 0.0041 (9) | 0.0052 (8) | 0.0020 (8) |
C2 | 0.0357 (13) | 0.0416 (13) | 0.0262 (12) | −0.0006 (10) | 0.0000 (10) | −0.0063 (10) |
C3 | 0.0289 (12) | 0.0506 (15) | 0.0426 (14) | −0.0119 (11) | 0.0027 (10) | −0.0080 (12) |
C4 | 0.0309 (12) | 0.0434 (14) | 0.0312 (13) | −0.0079 (10) | 0.0090 (10) | −0.0016 (10) |
C5 | 0.0268 (10) | 0.0268 (10) | 0.0209 (10) | 0.0007 (8) | 0.0057 (8) | 0.0000 (8) |
C6 | 0.0230 (10) | 0.0203 (9) | 0.0262 (11) | 0.0017 (8) | 0.0040 (8) | 0.0015 (8) |
C7 | 0.0241 (10) | 0.0306 (11) | 0.0236 (11) | −0.0028 (9) | 0.0060 (8) | 0.0007 (8) |
C8 | 0.0249 (10) | 0.0309 (11) | 0.0226 (10) | −0.0022 (9) | 0.0046 (8) | −0.0007 (8) |
C9 | 0.0300 (12) | 0.0561 (16) | 0.0385 (14) | 0.0033 (12) | 0.0126 (10) | −0.0088 (12) |
C10 | 0.0298 (11) | 0.0299 (11) | 0.0240 (11) | −0.0055 (9) | 0.0075 (8) | −0.0043 (9) |
C11 | 0.0430 (13) | 0.0343 (12) | 0.0227 (12) | −0.0007 (10) | 0.0031 (10) | −0.0017 (10) |
C12 | 0.0336 (13) | 0.0381 (13) | 0.0301 (13) | 0.0018 (11) | −0.0025 (10) | −0.0007 (10) |
C13 | 0.0335 (12) | 0.0308 (11) | 0.0244 (11) | 0.0137 (9) | 0.0062 (9) | 0.0063 (9) |
O1W | 0.0578 (14) | 0.0628 (14) | 0.0292 (10) | 0.0048 (11) | 0.0074 (9) | −0.0044 (10) |
O1—C13 | 1.273 (3) | C3—C4 | 1.385 (3) |
O2—C13 | 1.250 (3) | C3—H3 | 0.91 (3) |
O3—C6 | 1.353 (2) | C4—C5 | 1.386 (3) |
O3—H103 | 0.90 (3) | C4—H4 | 0.90 (3) |
N1—C9 | 1.319 (3) | C5—C6 | 1.400 (3) |
N1—C8 | 1.387 (3) | C5—C7 | 1.516 (3) |
N2—C9 | 1.339 (3) | C7—C8 | 1.492 (3) |
N2—C10 | 1.366 (3) | C7—H7 | 0.94 (2) |
N2—H2A | 0.92 (3) | C8—C10 | 1.358 (3) |
N3—C12 | 1.501 (3) | C9—H9 | 0.92 (2) |
N3—C7 | 1.520 (3) | C10—C11 | 1.488 (3) |
N3—H3B | 0.89 (3) | C11—C12 | 1.521 (3) |
N3—H3A | 1.01 (3) | C11—H11B | 1.01 (3) |
C1—C2 | 1.394 (3) | C11—H11A | 0.91 (3) |
C1—C6 | 1.409 (3) | C12—H12B | 0.96 (3) |
C1—C13 | 1.501 (3) | C12—H12A | 0.97 (3) |
C2—C3 | 1.373 (3) | O1W—H2W1 | 0.89 (4) |
C2—H2 | 0.93 (3) | O1W—H1W1 | 0.76 (4) |
C6—O3—H103 | 100.2 (19) | C8—C7—N3 | 106.26 (17) |
C9—N1—C8 | 103.54 (19) | C5—C7—N3 | 108.30 (17) |
C9—N2—C10 | 106.60 (19) | C8—C7—H7 | 112.9 (13) |
C9—N2—H2A | 131.0 (15) | C5—C7—H7 | 108.5 (13) |
C10—N2—H2A | 122.4 (15) | N3—C7—H7 | 103.6 (13) |
C12—N3—C7 | 114.49 (17) | C10—C8—N1 | 110.38 (19) |
C12—N3—H3B | 109.0 (15) | C10—C8—C7 | 124.16 (19) |
C7—N3—H3B | 108.4 (15) | N1—C8—C7 | 125.45 (18) |
C12—N3—H3A | 104.7 (15) | N1—C9—N2 | 113.3 (2) |
C7—N3—H3A | 112.6 (16) | N1—C9—H9 | 124.4 (16) |
H3B—N3—H3A | 107 (2) | N2—C9—H9 | 122.3 (16) |
C2—C1—C6 | 118.3 (2) | C8—C10—N2 | 106.14 (19) |
C2—C1—C13 | 121.0 (2) | C8—C10—C11 | 126.4 (2) |
C6—C1—C13 | 120.54 (19) | N2—C10—C11 | 127.4 (2) |
C3—C2—C1 | 121.5 (2) | C10—C11—C12 | 108.61 (19) |
C3—C2—H2 | 120.1 (15) | C10—C11—H11B | 111.1 (13) |
C1—C2—H2 | 118.5 (15) | C12—C11—H11B | 112.3 (13) |
C2—C3—C4 | 119.5 (2) | C10—C11—H11A | 105.5 (15) |
C2—C3—H3 | 121.0 (18) | C12—C11—H11A | 112.8 (16) |
C4—C3—H3 | 119.5 (18) | H11B—C11—H11A | 106 (2) |
C3—C4—C5 | 121.3 (2) | N3—C12—C11 | 111.84 (19) |
C3—C4—H4 | 120.2 (18) | N3—C12—H12B | 110.2 (16) |
C5—C4—H4 | 118.5 (18) | C11—C12—H12B | 107.9 (16) |
C4—C5—C6 | 118.76 (19) | N3—C12—H12A | 105.3 (16) |
C4—C5—C7 | 122.47 (19) | C11—C12—H12A | 112.1 (16) |
C6—C5—C7 | 118.75 (18) | H12B—C12—H12A | 110 (2) |
O3—C6—C5 | 118.40 (18) | O2—C13—O1 | 123.8 (2) |
O3—C6—C1 | 121.10 (19) | O2—C13—C1 | 119.6 (2) |
C5—C6—C1 | 120.48 (19) | O1—C13—C1 | 116.59 (19) |
C8—C7—C5 | 116.37 (17) | H2W1—O1W—H1W1 | 99 (3) |
C6—C1—C2—C3 | −1.4 (3) | C9—N1—C8—C7 | −179.7 (2) |
C13—C1—C2—C3 | 174.3 (2) | C5—C7—C8—C10 | 137.3 (2) |
C1—C2—C3—C4 | −1.3 (4) | N3—C7—C8—C10 | 16.7 (3) |
C2—C3—C4—C5 | 1.7 (4) | C5—C7—C8—N1 | −44.3 (3) |
C3—C4—C5—C6 | 0.8 (3) | N3—C7—C8—N1 | −164.9 (2) |
C3—C4—C5—C7 | −177.7 (2) | C8—N1—C9—N2 | 0.6 (3) |
C4—C5—C6—O3 | 178.07 (19) | C10—N2—C9—N1 | 0.2 (3) |
C7—C5—C6—O3 | −3.4 (3) | N1—C8—C10—N2 | 1.2 (2) |
C4—C5—C6—C1 | −3.6 (3) | C7—C8—C10—N2 | 179.87 (19) |
C7—C5—C6—C1 | 174.90 (18) | N1—C8—C10—C11 | −176.6 (2) |
C2—C1—C6—O3 | −177.79 (19) | C7—C8—C10—C11 | 2.1 (3) |
C13—C1—C6—O3 | 6.4 (3) | C9—N2—C10—C8 | −0.8 (2) |
C2—C1—C6—C5 | 3.9 (3) | C9—N2—C10—C11 | 176.9 (2) |
C13—C1—C6—C5 | −171.82 (17) | C8—C10—C11—C12 | 9.3 (3) |
C4—C5—C7—C8 | −24.6 (3) | N2—C10—C11—C12 | −168.0 (2) |
C6—C5—C7—C8 | 156.96 (18) | C7—N3—C12—C11 | 64.2 (3) |
C4—C5—C7—N3 | 95.0 (2) | C10—C11—C12—N3 | −39.7 (3) |
C6—C5—C7—N3 | −83.5 (2) | C2—C1—C13—O2 | −10.6 (3) |
C12—N3—C7—C8 | −48.7 (2) | C6—C1—C13—O2 | 165.04 (19) |
C12—N3—C7—C5 | −174.44 (18) | C2—C1—C13—O1 | 170.82 (19) |
C9—N1—C8—C10 | −1.1 (3) | C6—C1—C13—O1 | −13.5 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1W | 0.92 (3) | 1.87 (3) | 2.783 (3) | 178 (2) |
N3—H3A···O1i | 1.02 (3) | 1.71 (3) | 2.720 (2) | 174 (2) |
N3—H3B···O2ii | 0.89 (2) | 2.02 (2) | 2.864 (2) | 159 (2) |
O1W—H1W1···O2iii | 0.76 (4) | 2.14 (4) | 2.897 (3) | 171 (3) |
O1W—H2W1···N1iv | 0.89 (3) | 1.96 (3) | 2.844 (3) | 170 (4) |
O3—H103···O1 | 0.90 (3) | 1.64 (3) | 2.513 (2) | 161 (3) |
C12—H12A···O1iv | 0.98 (3) | 2.48 (3) | 3.325 (3) | 145 (2) |
C12—H12B···O3v | 0.96 (2) | 2.51 (2) | 3.447 (3) | 166 (2) |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x, −y+1/2, z+1/2; (iii) x, y, z+1; (iv) x, −y+3/2, z+1/2; (v) −x+2, y−1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C13H13N3O3·H2O |
Mr | 277.28 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 12.4975 (13), 7.7837 (8), 13.1320 (14) |
β (°) | 100.402 (2) |
V (Å3) | 1256.4 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.46 × 0.20 × 0.12 |
Data collection | |
Diffractometer | Siemens SMART CCD area-detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.890, 0.987 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7773, 3103, 2079 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.666 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.061, 0.157, 1.06 |
No. of reflections | 3103 |
No. of parameters | 241 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.24, −0.33 |
Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SAINT, SHELXTL (Sheldrick, 1997), SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990).
O1—C13 | 1.273 (3) | N2—C10 | 1.366 (3) |
O2—C13 | 1.250 (3) | N3—C12 | 1.501 (3) |
O3—C6 | 1.353 (2) | N3—C7 | 1.520 (3) |
N1—C9 | 1.319 (3) | C10—C11 | 1.488 (3) |
N1—C8 | 1.387 (3) | C11—C12 | 1.521 (3) |
N2—C9 | 1.339 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1W | 0.92 (3) | 1.87 (3) | 2.783 (3) | 178 (2) |
N3—H3A···O1i | 1.02 (3) | 1.71 (3) | 2.720 (2) | 174 (2) |
N3—H3B···O2ii | 0.89 (2) | 2.02 (2) | 2.864 (2) | 159 (2) |
O1W—H1W1···O2iii | 0.76 (4) | 2.14 (4) | 2.897 (3) | 171 (3) |
O1W—H2W1···N1iv | 0.89 (3) | 1.96 (3) | 2.844 (3) | 170 (4) |
O3—H103···O1 | 0.90 (3) | 1.64 (3) | 2.513 (2) | 161 (3) |
C12—H12A···O1iv | 0.98 (3) | 2.48 (3) | 3.325 (3) | 145 (2) |
C12—H12B···O3v | 0.96 (2) | 2.51 (2) | 3.447 (3) | 166 (2) |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x, −y+1/2, z+1/2; (iii) x, y, z+1; (iv) x, −y+3/2, z+1/2; (v) −x+2, y−1/2, −z+3/2. |
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Several synthetic approaches for discrete polynuclear complexes have been proposed. One involves compartmental organic ligands which are able to hold one or more metal ions (Tuna et al., 1999). The development of new bridging binuclear ligands promote efficient magnetic interactions between coordinated paramagnetic transition metal ions in the metal complexes with varying dn configurations. Complexes containing two or more adjacent metal centres offer an added chemical dimension over those containing a single metal. The metals not only act independently but can also act in a co-operative manner, leading to chemistry that differs appreciably from that displayed by their single metal counterparts. The Schiff bases derived from 3-formylsalicylic acid and 2,6-diformyl-4-methylphenol can act as bridging binuclear ligands (Tanaka et al., 1974). We have initiated (Nayar & Kurup, 2002) the synthesis of binuclear ligands derived from 3-formylsalicylic acid, which are useful for the preparation of hetero- and homo-binuclear complexes. The crystal structure determination of the title compound, (I), was undertaken with a view to obtaining a clear understanding about the coordination site geometry of the expected ligand.
The structure of (I) is in the form of a monohydrated zwitterion, in which the positive and negative charges are localized on tetrahydropyridinium atom N3 and benzoate atom O1, respectively (Fig. 1). This is also confirmed by the geometric parameters (Table 1) and the unambiguous location and refinement of all H atoms in the structure. All bond lengths and angles have normal values (Allen et al., 1987).
The zwitterion is composed of three rings, viz the tetrahydropyridinium ring (C7/C8/C10–C12/N3), the imidazoline ring (C8–C10/N1/N2) and the benzoate aromatic ring (C1–C6). The tetrahydropyridinium ring adopts an envelop conformation, with atom C12 displaced by 0.279 (3) Å from the N3/C7/C8/C10/C11 plane. This plane is nearly coplanar with the imidazoline plane [dihedral angle of 5.5 (1)°]. The relative configuration of the attached benzoate aromatic ring with respect to the tetrahydropyridinium ring is conditioned by the sp3 hybridized C7 atom [average angle subtended at the C7 atom is 110.3°]. The dihedral angle between the mean plane of the tetrahydropyridinium and benzoate aromatic rings is 56.4 (1)°. The plane of the carboxylate group (O1/O2/C13/C1) is slightly twisted about the C—C bond with respect to its aromatic ring, by 14.0 (1)°. This relatively small twist angle is due to atom O1 being hydrogen bonded to the hydroxy group (O3—H103···O1), forming a six-membered O1—C13—C1—C6—O3—H103 ring (details in Table 2).
Within the asymmetric unit (Fig. 1), the water molecule is linked to the zwitterion and acts as a hydrogen-bond acceptor via the N2—H2···O1W hydrogen bond. In the crystal packing, the water molecule acts as a hydrogen-bond donor to the zwitterion via an O1W—H1W1···O2iii hydrogen bond [symmetry code: (iii) x, y, 1 + z]. Therefore, the water molecule plays an important role as a bridge between the zwitterions; in this manner, a C22(12) chain (Bernstein et al., 1995) is generated running along the c direction. Both N+—H bonds also play important roles in the crystal packing; N3—H3B forms an N3—H3B···O2ii hydrogen bond to carboxylate atom O2 at (2 - x, 1 - y, 1 - z) interconnecting two adjacent molecular chains into ribbons. The ribbons, as shown in Fig. 2, are comprised of R22(16) and R66(24) ring patterns of hydrogen bonds which are centered at (n, 1/2, 1/2+n) and (n, 1/2, n), respectively (n = zero or integer). The ribbons are stacked one above another along the b direction (Fig. 3); the ribbons are interconnected by two hydrogen bonds, viz. N3—H3A···O1i, formed from another N+—H bond of the zwitterion to carboxylate atom O1 at (x, 1/2 - y, 1/2 - z), and O1W—H2W1···N1iv, formed from the water molecule to zwitterion at (x, 3/2 - y, 1/2 + z).
In the packing, across the center of symmetry, the C···π distance for the C11—H11B···πbenzoate is 3.776 (2) Å, while the distance between the centroids of the aromatic rings of the imidazoline and benzoate is 3.882 (4) Å. These rather long distances indicate the weak interactions of C—H···π and aromaticπ–π interactions.
Fig. 1 shows the enantiomorph of the zwitterion having an S chiral center at C7, implying that the condensation reaction of the achiral 3-formylsalicylic acid and histamine base gives a chiral C atom at the additional ring. However, the centrosymmetric space group indicates the racemic crystal.