Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102014968/ta1382sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102014968/ta1382Isup2.hkl |
CCDC reference: 197331
Fleroxacin was kindly donated by Qingdao Pharmaceutical Factory. Fleroxacin (0.185 g, 0.5 mmol) was dissolved in distilled water (5 ml) and the pH was adjusted to 5 with dilute hydrochloric acid under heating. The mixture was sealed in a 20 ml stainless-steel reactor with a Teflon liner and heated at 373 K for 76 h. Yellow crystals of (I) were obtained (m.p. 553 K).
The organic H atoms were generated geometrically and allowed to ride on their parent atoms, with N—H = 0.91, O—H = 0.82 and C—H = 0.93–0.97 Å. Are these added distances correct? The water H atoms were located from difference maps and refined with isotropic displacement parameters, which can introduce high Uiso parameters for water H atoms. Therefore, the ratio of Ueq(max)/Ueq(min) is relatively high.
Data collection: SMART (Bruker, Year?); cell refinement: SMART; data reduction: SHELXTL (Sheldrick, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
C17H19F3N3O3+·Cl−·H2O | Dx = 1.550 Mg m−3 |
Mr = 423.82 | Melting point = 552–553 K |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 12.961 (8) Å | Cell parameters from 7320 reflections |
b = 7.979 (5) Å | θ = 1.6–25.0° |
c = 18.113 (11) Å | µ = 0.27 mm−1 |
β = 104.184 (10)° | T = 293 K |
V = 1816.1 (19) Å3 | Plate, light yellow |
Z = 4 | 0.30 × 0.25 × 0.20 mm |
F(000) = 880 |
Make Model CCD area-detector diffractometer | 3209 independent reflections |
Radiation source: fine-focus sealed tube | 2103 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
ϕ and ω scans | θmax = 25.0°, θmin = 1.6° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −15→14 |
Tmin = 0.923, Tmax = 0.948 | k = −9→6 |
7320 measured reflections | l = −19→21 |
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)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | w = 1/[σ2(Fo2) + (0.049P)2] where P = (Fo2 + 2Fc2)/3 |
3209 reflections | (Δ/σ)max = 0.006 |
263 parameters | Δρmax = 0.32 e Å−3 |
3 restraints | Δρmin = −0.22 e Å−3 |
C17H19F3N3O3+·Cl−·H2O | V = 1816.1 (19) Å3 |
Mr = 423.82 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.961 (8) Å | µ = 0.27 mm−1 |
b = 7.979 (5) Å | T = 293 K |
c = 18.113 (11) Å | 0.30 × 0.25 × 0.20 mm |
β = 104.184 (10)° |
Make Model CCD area-detector diffractometer | 3209 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2103 reflections with I > 2σ(I) |
Tmin = 0.923, Tmax = 0.948 | Rint = 0.032 |
7320 measured reflections |
R[F2 > 2σ(F2)] = 0.038 | 3 restraints |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.32 e Å−3 |
3209 reflections | Δρmin = −0.22 e Å−3 |
263 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 | ||
F1 | 0.30649 (10) | 0.42751 (16) | −0.03141 (7) | 0.0480 (4) | |
F2 | 0.20227 (9) | 0.08553 (15) | 0.14874 (7) | 0.0392 (3) | |
F3 | −0.06282 (11) | 0.33299 (18) | 0.19962 (8) | 0.0578 (4) | |
N1 | −0.01656 (13) | 0.1435 (2) | 0.07711 (9) | 0.0287 (4) | |
N2 | 0.36572 (14) | 0.2335 (2) | 0.09522 (10) | 0.0339 (5) | |
N3 | 0.58899 (14) | 0.2668 (2) | 0.15901 (10) | 0.0357 (5) | |
H3A | 0.6081 | 0.1576 | 0.1682 | 0.043* | |
C1 | −0.25737 (18) | 0.2444 (3) | −0.07653 (13) | 0.0362 (6) | |
C2 | −0.14409 (17) | 0.2377 (3) | −0.03491 (12) | 0.0306 (5) | |
C3 | −0.06400 (17) | 0.3163 (3) | −0.06467 (12) | 0.0317 (5) | |
C4 | 0.04459 (16) | 0.2960 (2) | −0.02017 (11) | 0.0279 (5) | |
C5 | 0.06800 (16) | 0.2083 (2) | 0.04974 (12) | 0.0264 (5) | |
C6 | −0.11704 (17) | 0.1594 (3) | 0.03428 (12) | 0.0307 (5) | |
H6 | −0.1716 | 0.1140 | 0.0531 | 0.037* | |
C7 | −0.00443 (18) | 0.0801 (3) | 0.15613 (12) | 0.0349 (5) | |
H7A | 0.0521 | −0.0027 | 0.1674 | 0.042* | |
H7B | −0.0699 | 0.0256 | 0.1598 | 0.042* | |
C8 | 0.02102 (19) | 0.2194 (3) | 0.21361 (13) | 0.0441 (6) | |
H8A | 0.0317 | 0.1741 | 0.2646 | 0.053* | |
H8B | 0.0860 | 0.2755 | 0.2099 | 0.053* | |
C9 | 0.17591 (17) | 0.1851 (2) | 0.08573 (11) | 0.0283 (5) | |
C10 | 0.25941 (16) | 0.2518 (2) | 0.05999 (12) | 0.0282 (5) | |
C11 | 0.22898 (17) | 0.3470 (3) | −0.00770 (12) | 0.0320 (5) | |
C12 | 0.12699 (17) | 0.3653 (3) | −0.04726 (12) | 0.0324 (5) | |
H12 | 0.1115 | 0.4245 | −0.0929 | 0.039* | |
C13 | 0.44228 (17) | 0.1808 (3) | 0.05222 (13) | 0.0354 (6) | |
H13A | 0.4110 | 0.1940 | −0.0019 | 0.042* | |
H13B | 0.4597 | 0.0634 | 0.0621 | 0.042* | |
C14 | 0.54216 (17) | 0.2852 (3) | 0.07522 (12) | 0.0372 (6) | |
H14A | 0.5932 | 0.2485 | 0.0474 | 0.045* | |
H14B | 0.5255 | 0.4019 | 0.0630 | 0.045* | |
C15 | 0.50829 (17) | 0.3076 (3) | 0.20329 (13) | 0.0386 (6) | |
H15A | 0.4920 | 0.4263 | 0.1984 | 0.046* | |
H15B | 0.5386 | 0.2841 | 0.2568 | 0.046* | |
C16 | 0.40651 (17) | 0.2090 (3) | 0.17677 (12) | 0.0377 (6) | |
H16A | 0.4201 | 0.0909 | 0.1877 | 0.045* | |
H16B | 0.3544 | 0.2468 | 0.2035 | 0.045* | |
C17 | 0.68666 (18) | 0.3709 (3) | 0.18475 (14) | 0.0481 (7) | |
H17A | 0.7372 | 0.3414 | 0.1560 | 0.072* | |
H17B | 0.7173 | 0.3511 | 0.2379 | 0.072* | |
H17C | 0.6684 | 0.4873 | 0.1769 | 0.072* | |
Cl | 0.71815 (6) | 0.94195 (9) | 0.16859 (5) | 0.0677 (3) | |
O1 | −0.27944 (12) | 0.3331 (2) | −0.14036 (9) | 0.0495 (5) | |
H1 | −0.2241 | 0.3702 | −0.1482 | 0.074* | |
O2 | −0.32762 (12) | 0.1736 (2) | −0.05476 (9) | 0.0494 (5) | |
O3 | −0.08495 (12) | 0.3971 (2) | −0.12663 (9) | 0.0475 (5) | |
O4 | −0.52917 (16) | 0.3095 (2) | −0.12869 (11) | 0.0608 (5) | |
H42 | −0.4610 (12) | 0.261 (3) | −0.104 (2) | 0.126 (14)* | |
H41 | −0.5883 (16) | 0.230 (3) | −0.138 (2) | 0.158 (18)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.0353 (8) | 0.0612 (9) | 0.0485 (9) | −0.0116 (6) | 0.0124 (6) | 0.0168 (7) |
F2 | 0.0330 (7) | 0.0490 (8) | 0.0354 (8) | 0.0010 (6) | 0.0078 (6) | 0.0150 (6) |
F3 | 0.0535 (10) | 0.0592 (10) | 0.0628 (10) | 0.0079 (7) | 0.0180 (8) | −0.0104 (7) |
N1 | 0.0275 (10) | 0.0311 (10) | 0.0282 (11) | −0.0044 (8) | 0.0085 (8) | −0.0006 (8) |
N2 | 0.0256 (10) | 0.0527 (12) | 0.0241 (10) | −0.0004 (9) | 0.0075 (8) | −0.0008 (8) |
N3 | 0.0291 (11) | 0.0408 (11) | 0.0364 (12) | −0.0020 (8) | 0.0063 (9) | 0.0039 (9) |
C1 | 0.0333 (14) | 0.0389 (14) | 0.0353 (15) | −0.0015 (11) | 0.0061 (11) | −0.0080 (11) |
C2 | 0.0293 (12) | 0.0318 (12) | 0.0296 (13) | −0.0005 (10) | 0.0050 (10) | −0.0046 (10) |
C3 | 0.0336 (13) | 0.0327 (12) | 0.0275 (13) | −0.0006 (10) | 0.0048 (10) | −0.0042 (10) |
C4 | 0.0299 (12) | 0.0284 (12) | 0.0249 (12) | −0.0009 (9) | 0.0057 (9) | −0.0018 (9) |
C5 | 0.0288 (12) | 0.0242 (11) | 0.0276 (12) | −0.0022 (9) | 0.0094 (9) | −0.0046 (9) |
C6 | 0.0279 (13) | 0.0312 (12) | 0.0345 (13) | −0.0037 (9) | 0.0105 (10) | −0.0058 (10) |
C7 | 0.0326 (13) | 0.0428 (14) | 0.0319 (13) | −0.0016 (10) | 0.0127 (10) | 0.0076 (10) |
C8 | 0.0401 (15) | 0.0616 (17) | 0.0310 (14) | 0.0041 (13) | 0.0092 (11) | 0.0031 (12) |
C9 | 0.0320 (13) | 0.0292 (12) | 0.0233 (12) | −0.0004 (9) | 0.0062 (9) | 0.0035 (9) |
C10 | 0.0290 (12) | 0.0282 (12) | 0.0269 (12) | −0.0025 (9) | 0.0058 (10) | −0.0040 (9) |
C11 | 0.0327 (13) | 0.0341 (13) | 0.0318 (13) | −0.0081 (10) | 0.0130 (10) | 0.0000 (10) |
C12 | 0.0349 (14) | 0.0368 (13) | 0.0248 (12) | −0.0022 (10) | 0.0059 (10) | 0.0036 (10) |
C13 | 0.0325 (13) | 0.0442 (14) | 0.0306 (13) | 0.0008 (10) | 0.0098 (10) | −0.0035 (10) |
C14 | 0.0313 (13) | 0.0505 (15) | 0.0317 (14) | −0.0003 (11) | 0.0112 (10) | 0.0024 (11) |
C15 | 0.0343 (13) | 0.0539 (15) | 0.0272 (13) | −0.0046 (11) | 0.0066 (10) | 0.0010 (11) |
C16 | 0.0333 (13) | 0.0512 (15) | 0.0292 (13) | −0.0028 (11) | 0.0091 (10) | 0.0043 (11) |
C17 | 0.0293 (14) | 0.0618 (17) | 0.0493 (16) | −0.0108 (12) | 0.0025 (11) | 0.0040 (13) |
Cl | 0.0456 (4) | 0.0556 (5) | 0.0988 (6) | 0.0038 (3) | 0.0116 (4) | 0.0026 (4) |
O1 | 0.0355 (10) | 0.0679 (12) | 0.0409 (11) | −0.0031 (9) | 0.0014 (8) | 0.0087 (9) |
O2 | 0.0295 (10) | 0.0636 (12) | 0.0533 (11) | −0.0059 (8) | 0.0069 (8) | 0.0027 (9) |
O3 | 0.0387 (10) | 0.0653 (12) | 0.0351 (10) | −0.0003 (8) | 0.0025 (8) | 0.0152 (8) |
O4 | 0.0493 (12) | 0.0639 (13) | 0.0685 (14) | 0.0028 (10) | 0.0131 (10) | 0.0075 (10) |
F1—C11 | 1.348 (2) | C7—H7A | 0.9700 |
F2—C9 | 1.364 (2) | C7—H7B | 0.9700 |
F3—C8 | 1.390 (3) | C8—H8A | 0.9700 |
N1—C6 | 1.349 (3) | C8—H8B | 0.9700 |
N1—C5 | 1.407 (3) | C9—C10 | 1.385 (3) |
N1—C7 | 1.490 (3) | C10—C11 | 1.414 (3) |
N2—C10 | 1.377 (3) | C11—C12 | 1.348 (3) |
N2—C16 | 1.455 (3) | C12—H12 | 0.9300 |
N2—C13 | 1.465 (3) | C13—C14 | 1.509 (3) |
N3—C17 | 1.490 (3) | C13—H13A | 0.9700 |
N3—C14 | 1.497 (3) | C13—H13B | 0.9700 |
N3—C15 | 1.501 (3) | C14—H14A | 0.9700 |
N3—H3A | 0.9100 | C14—H14B | 0.9700 |
C1—O2 | 1.216 (3) | C15—C16 | 1.509 (3) |
C1—O1 | 1.326 (3) | C15—H15A | 0.9700 |
C1—C2 | 1.478 (3) | C15—H15B | 0.9700 |
C2—C6 | 1.367 (3) | C16—H16A | 0.9700 |
C2—C3 | 1.427 (3) | C16—H16B | 0.9700 |
C3—O3 | 1.265 (3) | C17—H17A | 0.9600 |
C3—C4 | 1.449 (3) | C17—H17B | 0.9600 |
C4—C12 | 1.394 (3) | C17—H17C | 0.9600 |
C4—C5 | 1.413 (3) | O1—H1 | 0.8200 |
C5—C9 | 1.403 (3) | O4—H42 | 0.969 (10) |
C6—H6 | 0.9300 | O4—H41 | 0.980 (10) |
C7—C8 | 1.504 (3) | ||
C6—N1—C5 | 119.25 (18) | F2—C9—C5 | 118.85 (18) |
C6—N1—C7 | 116.37 (18) | C10—C9—C5 | 124.41 (19) |
C5—N1—C7 | 123.74 (17) | N2—C10—C9 | 125.38 (19) |
C10—N2—C16 | 123.92 (18) | N2—C10—C11 | 119.58 (19) |
C10—N2—C13 | 121.02 (18) | C9—C10—C11 | 115.04 (18) |
C16—N2—C13 | 112.10 (17) | F1—C11—C12 | 119.3 (2) |
C17—N3—C14 | 111.39 (17) | F1—C11—C10 | 117.45 (18) |
C17—N3—C15 | 111.20 (18) | C12—C11—C10 | 123.2 (2) |
C14—N3—C15 | 110.97 (17) | C11—C12—C4 | 120.4 (2) |
C17—N3—H3A | 107.7 | C11—C12—H12 | 119.8 |
C14—N3—H3A | 107.7 | C4—C12—H12 | 119.8 |
C15—N3—H3A | 107.7 | N2—C13—C14 | 109.99 (18) |
O2—C1—O1 | 120.8 (2) | N2—C13—H13A | 109.7 |
O2—C1—C2 | 123.1 (2) | C14—C13—H13A | 109.7 |
O1—C1—C2 | 116.1 (2) | N2—C13—H13B | 109.7 |
C6—C2—C3 | 120.0 (2) | C14—C13—H13B | 109.7 |
C6—C2—C1 | 118.9 (2) | H13A—C13—H13B | 108.2 |
C3—C2—C1 | 121.0 (2) | N3—C14—C13 | 109.45 (18) |
O3—C3—C2 | 122.8 (2) | N3—C14—H14A | 109.8 |
O3—C3—C4 | 121.2 (2) | C13—C14—H14A | 109.8 |
C2—C3—C4 | 115.96 (19) | N3—C14—H14B | 109.8 |
C12—C4—C5 | 119.80 (19) | C13—C14—H14B | 109.8 |
C12—C4—C3 | 118.88 (19) | H14A—C14—H14B | 108.2 |
C5—C4—C3 | 121.3 (2) | N3—C15—C16 | 112.71 (19) |
C9—C5—N1 | 124.17 (19) | N3—C15—H15A | 109.0 |
C9—C5—C4 | 116.90 (19) | C16—C15—H15A | 109.0 |
N1—C5—C4 | 118.86 (18) | N3—C15—H15B | 109.0 |
N1—C6—C2 | 124.4 (2) | C16—C15—H15B | 109.0 |
N1—C6—H6 | 117.8 | H15A—C15—H15B | 107.8 |
C2—C6—H6 | 117.8 | N2—C16—C15 | 108.96 (18) |
N1—C7—C8 | 111.55 (18) | N2—C16—H16A | 109.9 |
N1—C7—H7A | 109.3 | C15—C16—H16A | 109.9 |
C8—C7—H7A | 109.3 | N2—C16—H16B | 109.9 |
N1—C7—H7B | 109.3 | C15—C16—H16B | 109.9 |
C8—C7—H7B | 109.3 | H16A—C16—H16B | 108.3 |
H7A—C7—H7B | 108.0 | N3—C17—H17A | 109.5 |
F3—C8—C7 | 109.08 (18) | N3—C17—H17B | 109.5 |
F3—C8—H8A | 109.9 | H17A—C17—H17B | 109.5 |
C7—C8—H8A | 109.9 | N3—C17—H17C | 109.5 |
F3—C8—H8B | 109.9 | H17A—C17—H17C | 109.5 |
C7—C8—H8B | 109.9 | H17B—C17—H17C | 109.5 |
H8A—C8—H8B | 108.3 | C1—O1—H1 | 109.5 |
F2—C9—C10 | 116.70 (18) | H42—O4—H41 | 113.9 (15) |
O2—C1—C2—C6 | −5.2 (3) | N1—C5—C9—C10 | −178.45 (19) |
O1—C1—C2—C6 | 174.9 (2) | C4—C5—C9—C10 | 4.6 (3) |
O2—C1—C2—C3 | 177.0 (2) | C16—N2—C10—C9 | −28.1 (3) |
O1—C1—C2—C3 | −2.8 (3) | C13—N2—C10—C9 | 130.9 (2) |
C6—C2—C3—O3 | −176.7 (2) | C16—N2—C10—C11 | 151.1 (2) |
C1—C2—C3—O3 | 1.1 (3) | C13—N2—C10—C11 | −49.9 (3) |
C6—C2—C3—C4 | 4.4 (3) | F2—C9—C10—N2 | −4.0 (3) |
C1—C2—C3—C4 | −177.83 (19) | C5—C9—C10—N2 | 178.60 (19) |
O3—C3—C4—C12 | −0.9 (3) | F2—C9—C10—C11 | 176.79 (17) |
C2—C3—C4—C12 | 178.02 (19) | C5—C9—C10—C11 | −0.7 (3) |
O3—C3—C4—C5 | 178.87 (19) | N2—C10—C11—F1 | −5.3 (3) |
C2—C3—C4—C5 | −2.2 (3) | C9—C10—C11—F1 | 174.02 (18) |
C6—N1—C5—C9 | −173.59 (19) | N2—C10—C11—C12 | 177.3 (2) |
C7—N1—C5—C9 | 15.9 (3) | C9—C10—C11—C12 | −3.4 (3) |
C6—N1—C5—C4 | 3.3 (3) | F1—C11—C12—C4 | −174.13 (19) |
C7—N1—C5—C4 | −167.17 (18) | C10—C11—C12—C4 | 3.3 (3) |
C12—C4—C5—C9 | −4.7 (3) | C5—C4—C12—C11 | 1.0 (3) |
C3—C4—C5—C9 | 175.53 (18) | C3—C4—C12—C11 | −179.2 (2) |
C12—C4—C5—N1 | 178.18 (18) | C10—N2—C13—C14 | 136.7 (2) |
C3—C4—C5—N1 | −1.6 (3) | C16—N2—C13—C14 | −62.0 (2) |
C5—N1—C6—C2 | −1.1 (3) | C17—N3—C14—C13 | −178.69 (19) |
C7—N1—C6—C2 | 170.08 (19) | C15—N3—C14—C13 | −54.2 (2) |
C3—C2—C6—N1 | −3.0 (3) | N2—C13—C14—N3 | 58.3 (2) |
C1—C2—C6—N1 | 179.24 (19) | C17—N3—C15—C16 | 177.85 (18) |
C6—N1—C7—C8 | −102.7 (2) | C14—N3—C15—C16 | 53.3 (2) |
C5—N1—C7—C8 | 68.0 (3) | C10—N2—C16—C15 | −140.8 (2) |
N1—C7—C8—F3 | 62.1 (2) | C13—N2—C16—C15 | 58.6 (2) |
N1—C5—C9—F2 | 4.2 (3) | N3—C15—C16—N2 | −54.1 (3) |
C4—C5—C9—F2 | −172.79 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···Cli | 0.91 | 2.23 | 3.067 (3) | 152 |
O1—H1···O3 | 0.82 | 1.76 | 2.524 (3) | 154 |
O4—H42···O2 | 0.97 (2) | 1.87 (2) | 2.842 (3) | 178 (1) |
O4—H42···O1 | 0.97 (2) | 2.66 (2) | 3.300 (3) | 124 (1) |
O4—H41···Clii | 0.98 (2) | 2.13 (2) | 3.111 (3) | 176 (1) |
Symmetry codes: (i) x, y−1, z; (ii) −x, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | C17H19F3N3O3+·Cl−·H2O |
Mr | 423.82 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 12.961 (8), 7.979 (5), 18.113 (11) |
β (°) | 104.184 (10) |
V (Å3) | 1816.1 (19) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.27 |
Crystal size (mm) | 0.30 × 0.25 × 0.20 |
Data collection | |
Diffractometer | Make Model CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.923, 0.948 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7320, 3209, 2103 |
Rint | 0.032 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.100, 1.01 |
No. of reflections | 3209 |
No. of parameters | 263 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.32, −0.22 |
Computer programs: SMART (Bruker, Year?), SMART, SHELXTL (Sheldrick, 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL.
F1—C11 | 1.348 (2) | N2—C13 | 1.465 (3) |
F2—C9 | 1.364 (2) | N3—C17 | 1.490 (3) |
F3—C8 | 1.390 (3) | N3—C14 | 1.497 (3) |
N1—C6 | 1.349 (3) | N3—C15 | 1.501 (3) |
N1—C5 | 1.407 (3) | C1—O2 | 1.216 (3) |
N1—C7 | 1.490 (3) | C1—O1 | 1.326 (3) |
N2—C10 | 1.377 (3) | C3—O3 | 1.265 (3) |
N2—C16 | 1.455 (3) | ||
C6—N1—C5 | 119.25 (18) | C17—N3—C14 | 111.39 (17) |
C6—N1—C7 | 116.37 (18) | C17—N3—C15 | 111.20 (18) |
C5—N1—C7 | 123.74 (17) | C14—N3—C15 | 110.97 (17) |
C10—N2—C16 | 123.92 (18) | O2—C1—O1 | 120.8 (2) |
C10—N2—C13 | 121.02 (18) | O2—C1—C2 | 123.1 (2) |
C16—N2—C13 | 112.10 (17) | O1—C1—C2 | 116.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···Cli | 0.91 | 2.234 | 3.067 (3) | 152 |
O1—H1···O3 | 0.82 | 1.762 | 2.524 (3) | 154 |
O4—H42···O2 | 0.97 (2) | 1.87 (2) | 2.842 (3) | 178.11 (18) |
O4—H42···O1 | 0.97 (2) | 2.66 (2) | 3.300 (3) | 123.94 (18) |
O4—H41···Clii | 0.98 (2) | 2.13 (2) | 3.111 (3) | 175.55 (17) |
Symmetry codes: (i) x, y−1, z; (ii) −x, −y+1, −z. |
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The compound 6,8-difluoro-1-(2-fluoroethyl)-1,4-dihydro-7-(4-methyl-1-piperazinyl)-4-oxo- quinoline-3-carboxylic acid, the trivial name of which is fleroxacin, is one of the fluoroquinolone antibiotic drugs, and is certified as the best choice for curing infections caused by susceptible bacteria (Drakopoulos & Ioannou, 1997). It affords powerful broad-spectrum antisepsis, long effectiveness, few side effects and no interference with other antibiotics (Weidekamm et al., 1987). It has been widely used for the treatment of bacterial infections, such as those of the respiratory system, the urinary tract, skin, soft tissue, bones and joints, the gastro-intestinal tract and the central nervous system (Krisztina et al., 1990). The photolysis (>320 nm) of fleroxacin results in the loss of the fluorine substituent at C9 (Fig. 1) as fluoride (Martinez et al., 1997). Fleroxacin has the highest DNA photocleaving activity among the fluoroquinolones; DNA damage probably results from the generation of a carbene at C9 as a result of the photoinduced loss of atom F2 as fluoride upon UVA irradiation (Martinez & Chignell, 1998). Therefore, it is important to know the molecular structure of fleroxacin to investigate this reaction better. To this end, the title compound, (I), the hydrochloride hydrate of fleroxacin, has been prepared and its structure is reported here. \sch
The molecular structure of (I) is shown in Fig. 1. The quinoline and its substituents, except the piperazinium moiety and the fluoroethyl group attached to atom N1, are nearly coplanar, with a mean deviation of 0.052 (2) Å, while the quinoline itself is planar, with a mean deviation of 0.032 (2) Å. The piperazinium moiety is in a chair form.
There are three C—F bonds in (I). The C8—F3 bond is apparently longer than the C—F bonds to the quinoline, C11—F1 and C9—F2 (Table 1). This can be attributed to the conjugation of the electrons of atoms F1 and F2 with the quinoline. The C9—F2 bond is longer than C11—F1 and the photoinduced C—F breakage is easier for the former under UV irradiation (Zhang et al., 2000). In the molecule of (I), the nine C—N bonds can be divided into two groups, of which six, falling in the range 1.455 (3)–1.501 (3) Å, characterize C—N single bonds. The two shorter C—N bonds, C5—N1 [1.407 (3) Å] and C6—N1 [1.349 (3) Å], result from the delocalization of their electrons on the quinoline. Another shorter C—N bond, C10—N2 [1.377 (3) Å], arises from the conjugation of the lone pair of electrons on N2 with the quinoline. The bond angles at N1 and N2 are different (Table 1).
In (I), the fleroxacin is in a cationic form, with atom N3 of the piperazinium group being protonated. The C1—O2 and C1—O1 bond lengths (Table 1) of the carboxyl group agree with those found in N,N,N',N'',N''',N'''-triethylenetetraminehexacetic acid (Finnen & Pinkerton, 1997), N-(2-hydroxyethyl)ethylenediaminetriacetic acid (Kettmann et al., 1993) and some derivatives or complexes of betaine (Ilczyszyn, Barnes et al., 1995; Ilczyszyn, Lis & Ratajczak, 1995; Ratajczak et al., 1994), and show that the carboxyl group is in the acid form. The C3—O3 bond length is intermediate between that expected for single and double bonds. The intramolecular hydrogen bond between atoms O1 and O3 (Table 2) may account for this phenomenon.
There are four intermolecular hydrogen bonds in the crystal of (I) (Table 2). The water molecule, as a hydrogen donor, is hydrogen-bonded to the Cl- anion, as well as to the two O atoms of the carboxyl group, forming a three-centre hydrogen bond. In addition, the Cl- anion is also hydrogen-bonded to the protonated N atom of the fleroxacin. Although F is the most electronegative element in (I), no hydrogen bonds were observed around F atoms. The quinoline rings are oriented to give alternate π-π stacking interactions of 3.375 (3) and 3.392 (3) Å (Fig. 2).