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The title compound, C15H18FN4O3+·I−, forms ionic crystals consisting of protonated enoxacin cations, C15H18FN4O3+, and I− anions. The naphthyridine system of the cation is essentially planar, whereas the piperazine ring has a chair conformation; the enoxacin is protonated at the unsubstituted N atom of the piperazine ring. The carboxyl OH group forms an intramolecular hydrogen bond with the carbonyl O atom of the naphthyridine system, thus forming a six-membered pseudo-ring. The crystal packing is stabilized by π–π stacking of the naphthyridine rings and intermolecular hydrogen bonding involving the piperazine N—H group, the carboxyl group of the cation and the I− anion, linking the residues of the structure into infinite chains running along the diagonal of the ac plane.
Supporting information
CCDC reference: 242344
Key indicators
- Single-crystal X-ray study
- T = 193 K
- Mean (C-C) = 0.005 Å
- R factor = 0.042
- wR factor = 0.078
- Data-to-parameter ratio = 16.5
checkCIF/PLATON results
No syntax errors found
No errors found in this datablock
Data collection: CrsytalClear (Rigaku, 1999); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku and Rigaku/MSC, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Siemens, 1994); software used to prepare material for publication: SHELXTL.
Crystal data top
C15H18FN4O3+·I− | Z = 2 |
Mr = 448.23 | F(000) = 444 |
Triclinic, P1 | Dx = 1.789 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71070 Å |
a = 6.9831 (17) Å | Cell parameters from 3760 reflections |
b = 10.235 (3) Å | θ = 3.2–27.5° |
c = 11.931 (3) Å | µ = 1.96 mm−1 |
α = 82.783 (11)° | T = 193 K |
β = 79.961 (11)° | Irregular, light yellow |
γ = 85.934 (12)° | 0.20 × 0.11 × 0.07 mm |
V = 832.0 (4) Å3 | |
Data collection top
Rigaku Mercury CCD diffractometer | 3753 independent reflections |
Radiation source: fine-focus sealed tube | 3401 reflections with I > 2σ(I)' |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 7.31 pixels mm-1 | θmax = 27.5°, θmin = 3.2° |
ω scans | h = −7→9 |
Absorption correction: multi-scan (Jacobson, 1998) | k = −13→13 |
Tmin = 0.696, Tmax = 0.875 | l = −15→14 |
9442 measured reflections | |
Refinement top
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)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.078 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.18 | w = 1/[σ2(Fo2) + (0.0167P)2 + 1.7702P] where P = (Fo2 + 2Fc2)/3 |
3753 reflections | (Δ/σ)max < 0.001 |
227 parameters | Δρmax = 0.55 e Å−3 |
0 restraints | Δρmin = −0.64 e Å−3 |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
I1 | 0.70806 (4) | 0.55328 (3) | 0.77263 (2) | 0.02814 (9) | |
F1 | 0.6576 (3) | 0.9896 (3) | 0.77860 (19) | 0.0351 (6) | |
O1 | 0.9380 (4) | 0.9109 (3) | 0.3722 (2) | 0.0274 (6) | |
O2 | 0.9727 (4) | 0.8435 (3) | 0.1801 (2) | 0.0333 (7) | |
H2 | 0.9938 | 0.8720 | 0.2396 | 0.050* | |
O3 | 0.7482 (5) | 0.7337 (4) | 0.1287 (3) | 0.0478 (9) | |
N1 | 0.4069 (4) | 0.7437 (3) | 0.4558 (3) | 0.0187 (6) | |
N2 | 0.3579 (4) | 0.8095 (3) | 0.6379 (2) | 0.0181 (6) | |
N3 | 0.2833 (5) | 0.8713 (3) | 0.8195 (3) | 0.0263 (7) | |
N4 | 0.1901 (6) | 0.6841 (4) | 1.0144 (3) | 0.0296 (8) | |
C2 | 0.5152 (5) | 0.7386 (4) | 0.3518 (3) | 0.0212 (8) | |
H1 | 0.4663 | 0.6948 | 0.2979 | 0.025* | |
C3 | 0.6934 (5) | 0.7937 (4) | 0.3192 (3) | 0.0202 (8) | |
C4 | 0.7735 (5) | 0.8584 (3) | 0.3988 (3) | 0.0195 (7) | |
C9 | 0.6575 (5) | 0.8610 (3) | 0.5101 (3) | 0.0184 (7) | |
C8 | 0.4758 (5) | 0.8058 (3) | 0.5377 (3) | 0.0176 (7) | |
C5 | 0.7180 (5) | 0.9236 (4) | 0.5959 (3) | 0.0215 (8) | |
H6 | 0.8401 | 0.9633 | 0.5825 | 0.026* | |
C6 | 0.5979 (6) | 0.9257 (4) | 0.6976 (3) | 0.0226 (8) | |
C7 | 0.4142 (5) | 0.8677 (3) | 0.7204 (3) | 0.0192 (7) | |
C1 | 0.8033 (6) | 0.7866 (4) | 0.2020 (3) | 0.0300 (9) | |
C10 | 0.2179 (5) | 0.6787 (4) | 0.4870 (3) | 0.0225 (8) | |
H10A | 0.1672 | 0.6687 | 0.4163 | 0.027* | |
H10B | 0.1226 | 0.7356 | 0.5330 | 0.027* | |
C11 | 0.2374 (6) | 0.5451 (4) | 0.5547 (3) | 0.0261 (9) | |
H11A | 0.3096 | 0.4831 | 0.5045 | 0.039* | |
H11B | 0.1076 | 0.5131 | 0.5857 | 0.039* | |
H11C | 0.3076 | 0.5522 | 0.6178 | 0.039* | |
C12 | 0.1057 (6) | 0.7981 (4) | 0.8363 (4) | 0.0311 (10) | |
H12A | 0.0722 | 0.7867 | 0.7609 | 0.037* | |
H12B | −0.0038 | 0.8484 | 0.8787 | 0.037* | |
C13 | 0.1354 (6) | 0.6649 (4) | 0.9025 (3) | 0.0296 (9) | |
H13A | 0.0140 | 0.6167 | 0.9156 | 0.036* | |
H13B | 0.2398 | 0.6123 | 0.8583 | 0.036* | |
C14 | 0.3639 (6) | 0.7647 (4) | 1.0016 (4) | 0.0322 (10) | |
H14A | 0.4805 | 0.7163 | 0.9640 | 0.039* | |
H14B | 0.3870 | 0.7810 | 1.0781 | 0.039* | |
C15 | 0.3303 (7) | 0.8943 (4) | 0.9304 (3) | 0.0324 (10) | |
H15A | 0.2218 | 0.9463 | 0.9718 | 0.039* | |
H15B | 0.4487 | 0.9455 | 0.9178 | 0.039* | |
H4A | 0.091 (9) | 0.725 (6) | 1.060 (5) | 0.067 (18)* | |
H4B | 0.212 (7) | 0.614 (5) | 1.056 (4) | 0.038 (14)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
I1 | 0.03270 (15) | 0.02672 (14) | 0.02515 (14) | 0.00166 (10) | −0.00684 (10) | −0.00252 (10) |
F1 | 0.0350 (14) | 0.0513 (16) | 0.0232 (12) | −0.0159 (12) | −0.0041 (10) | −0.0146 (11) |
O1 | 0.0217 (14) | 0.0316 (15) | 0.0257 (14) | −0.0063 (11) | 0.0033 (11) | 0.0014 (12) |
O2 | 0.0341 (17) | 0.0388 (18) | 0.0227 (15) | −0.0037 (13) | 0.0083 (13) | −0.0048 (13) |
O3 | 0.050 (2) | 0.072 (3) | 0.0233 (16) | −0.0148 (18) | 0.0045 (15) | −0.0189 (16) |
N1 | 0.0200 (16) | 0.0184 (15) | 0.0179 (15) | −0.0019 (12) | −0.0022 (12) | −0.0032 (12) |
N2 | 0.0195 (15) | 0.0184 (15) | 0.0153 (15) | −0.0020 (12) | −0.0006 (12) | −0.0002 (12) |
N3 | 0.0263 (18) | 0.0333 (19) | 0.0187 (16) | −0.0029 (14) | 0.0001 (14) | −0.0046 (14) |
N4 | 0.033 (2) | 0.030 (2) | 0.0210 (18) | 0.0032 (16) | −0.0001 (16) | 0.0056 (16) |
C2 | 0.028 (2) | 0.0204 (18) | 0.0150 (17) | 0.0034 (15) | −0.0034 (15) | −0.0019 (15) |
C3 | 0.0229 (19) | 0.0189 (18) | 0.0172 (18) | 0.0000 (15) | −0.0004 (15) | −0.0003 (15) |
C4 | 0.0179 (18) | 0.0167 (17) | 0.0210 (18) | 0.0017 (14) | 0.0003 (15) | 0.0020 (15) |
C9 | 0.0202 (18) | 0.0155 (17) | 0.0174 (17) | 0.0002 (14) | −0.0008 (14) | 0.0020 (14) |
C8 | 0.0215 (18) | 0.0128 (16) | 0.0176 (17) | 0.0011 (14) | −0.0047 (15) | 0.0026 (14) |
C5 | 0.0219 (19) | 0.0200 (18) | 0.0214 (19) | −0.0041 (15) | −0.0027 (15) | 0.0026 (15) |
C6 | 0.027 (2) | 0.0215 (19) | 0.0200 (18) | −0.0028 (15) | −0.0041 (16) | −0.0024 (15) |
C7 | 0.0226 (19) | 0.0153 (17) | 0.0182 (18) | 0.0006 (14) | −0.0030 (15) | 0.0023 (14) |
C1 | 0.033 (2) | 0.031 (2) | 0.022 (2) | 0.0030 (18) | 0.0012 (18) | −0.0001 (18) |
C10 | 0.0171 (18) | 0.028 (2) | 0.0231 (19) | −0.0049 (15) | −0.0014 (15) | −0.0062 (16) |
C11 | 0.026 (2) | 0.026 (2) | 0.025 (2) | −0.0079 (16) | 0.0001 (17) | −0.0011 (17) |
C12 | 0.020 (2) | 0.048 (3) | 0.023 (2) | −0.0005 (18) | 0.0017 (16) | 0.0004 (19) |
C13 | 0.025 (2) | 0.039 (2) | 0.025 (2) | −0.0061 (18) | −0.0011 (17) | −0.0042 (18) |
C14 | 0.032 (2) | 0.044 (3) | 0.021 (2) | −0.0043 (19) | −0.0025 (17) | −0.0049 (19) |
C15 | 0.039 (2) | 0.041 (3) | 0.0182 (19) | −0.011 (2) | 0.0024 (18) | −0.0115 (18) |
Geometric parameters (Å, º) top
C1—C3 | 1.480 (5) | N3—C12 | 1.466 (5) |
C2—C3 | 1.376 (5) | N3—C15 | 1.467 (5) |
C3—C4 | 1.432 (5) | N4—C13 | 1.490 (5) |
C4—C9 | 1.432 (5) | N4—C14 | 1.491 (6) |
C5—C6 | 1.351 (5) | N4—H4A | 0.91 (6) |
C5—C9 | 1.411 (5) | N4—H4B | 0.84 (5) |
C6—C7 | 1.420 (5) | C2—H1 | 0.9500 |
C8—C9 | 1.395 (5) | C5—H6 | 0.9500 |
C10—C11 | 1.509 (5) | C10—H10A | 0.9900 |
C12—C13 | 1.507 (6) | C10—H10B | 0.9900 |
C14—C15 | 1.510 (6) | C11—H11A | 0.9800 |
F1—C6 | 1.369 (4) | C11—H11B | 0.9800 |
O1—C4 | 1.275 (4) | C11—H11C | 0.9800 |
O2—C1 | 1.326 (5) | C12—H12A | 0.9900 |
O2—H2 | 0.8400 | C12—H12B | 0.9900 |
O3—C1 | 1.214 (5) | C13—H13A | 0.9900 |
N1—C2 | 1.340 (5) | C13—H13B | 0.9900 |
N1—C8 | 1.398 (5) | C14—H14A | 0.9900 |
N1—C10 | 1.488 (5) | C14—H14B | 0.9900 |
N2—C8 | 1.331 (5) | C15—H15A | 0.9900 |
N2—C7 | 1.339 (5) | C15—H15B | 0.9900 |
N3—C7 | 1.365 (5) | | |
| | | |
C1—O2—H2 | 109.5 | O3—C1—C3 | 124.6 (4) |
C2—N1—C8 | 119.8 (3) | O2—C1—C3 | 115.1 (4) |
C2—N1—C10 | 120.8 (3) | N1—C10—C11 | 112.1 (3) |
C8—N1—C10 | 119.4 (3) | N1—C10—H10A | 109.2 |
C8—N2—C7 | 119.4 (3) | C11—C10—H10A | 109.2 |
C7—N3—C12 | 119.7 (3) | N1—C10—H10B | 109.2 |
C7—N3—C15 | 125.3 (3) | C11—C10—H10B | 109.2 |
C12—N3—C15 | 110.4 (3) | H10A—C10—H10B | 107.9 |
C13—N4—C14 | 113.0 (3) | C10—C11—H11A | 109.5 |
C13—N4—H4A | 112 (4) | C10—C11—H11B | 109.5 |
C14—N4—H4A | 107 (4) | H11A—C11—H11B | 109.5 |
C13—N4—H4B | 115 (3) | C10—C11—H11C | 109.5 |
C14—N4—H4B | 107 (3) | H11A—C11—H11C | 109.5 |
H4A—N4—H4B | 103 (5) | H11B—C11—H11C | 109.5 |
N1—C2—C3 | 123.4 (3) | N3—C12—C13 | 110.1 (3) |
N1—C2—H1 | 118.3 | N3—C12—H12A | 109.6 |
C3—C2—H1 | 118.3 | C13—C12—H12A | 109.6 |
C2—C3—C4 | 119.9 (3) | N3—C12—H12B | 109.6 |
C2—C3—C1 | 120.4 (3) | C13—C12—H12B | 109.6 |
C4—C3—C1 | 119.7 (3) | H12A—C12—H12B | 108.2 |
O1—C4—C3 | 122.0 (3) | N4—C13—C12 | 108.8 (3) |
O1—C4—C9 | 122.0 (3) | N4—C13—H13A | 109.9 |
C3—C4—C9 | 116.0 (3) | C12—C13—H13A | 109.9 |
C8—C9—C5 | 116.7 (3) | N4—C13—H13B | 109.9 |
C8—C9—C4 | 121.6 (3) | C12—C13—H13B | 109.9 |
C5—C9—C4 | 121.7 (3) | H13A—C13—H13B | 108.3 |
N2—C8—C9 | 124.5 (3) | N4—C14—C15 | 109.5 (3) |
N2—C8—N1 | 116.2 (3) | N4—C14—H14A | 109.8 |
C9—C8—N1 | 119.3 (3) | C15—C14—H14A | 109.8 |
C6—C5—C9 | 118.3 (3) | N4—C14—H14B | 109.8 |
C6—C5—H6 | 120.9 | C15—C14—H14B | 109.8 |
C9—C5—H6 | 120.9 | H14A—C14—H14B | 108.2 |
C5—C6—F1 | 117.3 (3) | N3—C15—C14 | 110.3 (3) |
C5—C6—C7 | 122.3 (3) | N3—C15—H15A | 109.6 |
F1—C6—C7 | 120.4 (3) | C14—C15—H15A | 109.6 |
N2—C7—N3 | 116.2 (3) | N3—C15—H15B | 109.6 |
N2—C7—C6 | 118.8 (3) | C14—C15—H15B | 109.6 |
N3—C7—C6 | 125.0 (3) | H15A—C15—H15B | 108.1 |
O3—C1—O2 | 120.3 (4) | | |
| | | |
C8—N1—C2—C3 | −1.0 (5) | C9—C5—C6—C7 | −0.2 (6) |
C10—N1—C2—C3 | −178.2 (3) | C8—N2—C7—N3 | 178.1 (3) |
N1—C2—C3—C4 | 1.2 (5) | C8—N2—C7—C6 | 1.0 (5) |
N1—C2—C3—C1 | −178.8 (3) | C12—N3—C7—N2 | 8.2 (5) |
C2—C3—C4—O1 | −179.9 (3) | C15—N3—C7—N2 | 161.6 (4) |
C1—C3—C4—O1 | 0.1 (5) | C12—N3—C7—C6 | −174.9 (3) |
C2—C3—C4—C9 | −0.1 (5) | C15—N3—C7—C6 | −21.5 (6) |
C1—C3—C4—C9 | 179.9 (3) | C5—C6—C7—N2 | −0.4 (5) |
O1—C4—C9—C8 | 178.6 (3) | F1—C6—C7—N2 | 178.0 (3) |
C3—C4—C9—C8 | −1.3 (5) | C5—C6—C7—N3 | −177.2 (4) |
O1—C4—C9—C5 | 1.0 (5) | F1—C6—C7—N3 | 1.2 (6) |
C3—C4—C9—C5 | −178.9 (3) | C2—C3—C1—O3 | −0.3 (6) |
C7—N2—C8—C9 | −1.1 (5) | C4—C3—C1—O3 | 179.8 (4) |
C7—N2—C8—N1 | −179.9 (3) | C2—C3—C1—O2 | 179.7 (3) |
C5—C9—C8—N2 | 0.5 (5) | C4—C3—C1—O2 | −0.3 (5) |
C4—C9—C8—N2 | −177.2 (3) | C2—N1—C10—C11 | 98.1 (4) |
C5—C9—C8—N1 | 179.3 (3) | C8—N1—C10—C11 | −79.1 (4) |
C4—C9—C8—N1 | 1.5 (5) | C7—N3—C12—C13 | 95.2 (4) |
C2—N1—C8—N2 | 178.4 (3) | C15—N3—C12—C13 | −61.9 (4) |
C10—N1—C8—N2 | −4.3 (5) | C14—N4—C13—C12 | −55.4 (5) |
C2—N1—C8—C9 | −0.4 (5) | N3—C12—C13—N4 | 58.0 (4) |
C10—N1—C8—C9 | 176.9 (3) | C13—N4—C14—C15 | 54.5 (5) |
C8—C9—C5—C6 | 0.1 (5) | C7—N3—C15—C14 | −94.9 (5) |
C4—C9—C5—C6 | 177.8 (3) | C12—N3—C15—C14 | 60.6 (4) |
C9—C5—C6—F1 | −178.6 (3) | N4—C14—C15—N3 | −55.8 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O1 | 0.84 | 1.65 | 2.442 (4) | 156 |
N4—H4B···I1i | 0.84 (5) | 2.61 (5) | 3.421 (4) | 163 (4) |
N4—H4A···O2ii | 0.91 (6) | 2.02 (6) | 2.880 (5) | 156 (5) |
N4—H4A···O3ii | 0.91 (6) | 2.39 (6) | 3.182 (5) | 145 (5) |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) x−1, y, z+1. |
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