Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S2053229615016083/qs3049sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S2053229615016083/qs3049Isup2.hkl | |
Chemical Markup Language (CML) file https://doi.org/10.1107/S2053229615016083/qs3049Isup3.cml |
CCDC reference: 1052230
Coumarin (2H-1-benzopyran-2-one, cis-o-coumarinic acid lactone or coumarinic anhydride) consists of an aromatic ring fused to a condensed lactone ring. Because of its biochemical properties, coumarin has been used in clinical medicine (Egan et al., 1990; Thornes et al., 1989; Cox et al., 1989; Dexeus et al., 1990; Marshall et al., 1994).
Coumarin is a naturally occurring compound, being present in a wide variety of plants and microorganisms and in some animal species. The metabolism, toxicity and results of tests for carcinogenicity have recently been reviewed with respect to the safety for humans of coumarin present in foodstuffs and for fragrances used in cosmetic products (Lake, 1999). In many studies, coumarin has been reported to reduce the incidence of tumours produced by genotoxic carcinogens (Tseng, 1991).
In general, active pharmaceutical ingredients (APIs) are capable of existing in polymorphic forms and hence may show distinguishable physicochemical properties, bioavailabilities and therapeutic effects due to the different arrangement of the molecules in the crystal structure. Therefore, identifying and controlling the polymorphic properties of this class of compound are of crucial importance in medicinal chemistry (Arshad et al., 2014). In fact, slight variations in the crystallization process, such as changes in temperature, solvent, additives and concentration, can lead to different packings and the formation of different crystal structures or polymorphs (Munshi et al., 2004). Thus, the identification of new polymorphs of coumarin derivatives, like 3-acetyl-4-hydroxycoumarin, is an interesting target for organic chemists. Various strategies for manipulating their synthesis through changes in acylation, bromination, metallation or Claisen–Schmidt condensation could result in more polymorphs (Abdou, 2014).
The present investigation is a continuation of our broad focus on the synthesis, biological evaluation and structural study of coumarin derivatives as Schiff bases (Rohlíček et al., 2013), aminocoumarins (Brahmia et al., 2013) or chalcones (Mechi et al., 2009; Afef et al., 2011) in order to understand the geometric features and underlying intermolecular interactions which govern the assembly of the molecules in the crystalline lattice. In this paper, we report the crystal structure of a new polymorph, hereafter polymorph II, of 3-acetyl-4-hydroxycoumarin, (I) (see Scheme 1), and compare it with the structure of the originally reported polymorph, hereafter polymorph I (Lyssenko & Antipin, 2001).
All the chemicals were available commercially and used without further purification. All the solvents were dried using standard methods before use. Phosphorus oxychloride (5.6 ml) was added to a solution of 4-hydroxychromen-2-one (3 g, 1.86 mmol) in acetic acid (16 ml). The mixture was heated under reflux for 30 min. After cooling, the precipitate was collected and recrystallized from ethanol at low temperature in a salt–melted ice bath to give 3-acetyl-4-hydroxychromen-2-one, (I), as light-yellow prism crystals (yield 2.7 g, 90%; m.p. 408-410 K). It should be noted that the recrystallization of 3-acetyl-4-hydroxycoumarin at room temperature led systematically to polymorph I as yellow needle-shaped crystals (m.p. 405–407 K). The synthetic procedure used to prepare polymorph II of (I) is shown in Scheme 1.
Crystal data, data collection and structure refinement details (for model 1a) are summarized in Table 1. First, the O4—H hydrogen atom was located in a difference map and refined isotropically with full occupancy and no restraints. When the H atom was removed, two distinct peaks were evident in the electron-density difference map. Two other models with a split H atom were investigated (see Fig. 1). In the first split model, denoted model 2b, two hydroxy H atoms were allowed to refine with an occupancy of 0.5, using a rotating-group refinement. In the second split model, denoted model 2c, these hydroxy H atoms were refined with restraints on the O—H bond lengths (O—H = 0.82 Å for O3—H93 and O4—H94) and with occupancies of 0.4 and 0.6. Refinement assuming split model 2b yielded residuals of wR(F2) = 0.1971 and R(F) = 0.0555; for split model 2c, the residuals were wR(F2) = 0.1955 and R(F) = 0.0554. Split-model 2c seems to be the more reliable. The remaining H atoms were placed at idealized positions and allowed to ride on their parent atoms, with C—H = 0.93 (aromatic) or 0.96 Å (CH3), and with Uiso(H) = 1.2Ueq(C). We refer to both model 1a and split-model 2c in the discussion that follows.
An attempt to recrystallize freshly synthesized 3-acetyl-4-hydroxycoumarin, (I), from ethanol in an ice–salt bath unexpectedly produced light-yellow prism-shaped crystals suitable for X-ray diffraction. Fig. 2 shows two models of the crystal structure of this new polymorph, hereafter polymorph II, i.e. with the H atom located in difference maps and refined isotropically with no restraints (model 1a) or the more reliable split-atom model (model 2c).
A detailed discussion of the geometric analysis of polymorph I from X-ray single-crystal diffraction data collected at room temperature and at different temperatures has already been reported in the literature (Lyssenko & Antipin, 2001; Traven et al., 2000). Both polymorphs crystallize in the monoclinic system with different unit-cell parameters, i.e. a = 10.3193 (9) Å, b = 5.1605 (5) Å, c = 17.071 (1)Å and β = 99.337 (2)° for polymorph I; see Table 1 for the corresponding parameters for polymorph II. In all discussions herein, we refer to the room-temperature structure determination of polymorph I at 300 K (Lyssenko & Antipin, 2001).
In polymorphs I and II, the molecules have very similar geometries and exhibit strong intramolecular hydrogen bonding of the O—H···O type between the hydroxy group and the ketonic O atom [O···O = 2.4263 (13) Å in polymorph II and 2.442 (1) Å in polymorph I; Tables 2 and 3]. The H···O3 distance of 1.32 (2) Å, considering model 1a for polymorph II, is decreased compared with its value in polymorph I [1.45 (3) Å]. In fact, the O—H distance [1.02 (3) Å] in polymorph I is shorter than that in model 1a of polymorph II [1.11 (2) Å], owing to a shift of the hydroxy H atom towards the ketonic O atom. The O4—H···O3 angle of 169 (2)° in polymorph II is larger than that found for polymorph I [161 (2)°]. It should be noted that the C10—O3, C10—C8, C8—C7 and C7—O4 bond lengths [1.2534 (15), 1.4459 (17), 1.3995 (15) and 1.2957 (13) Å, respectively, for split-model 2c of polymorph II; Table 2] are only slightly different compared with the corresponding values observed for polymorph I [1.255 (1), 1.449 (2), 1.396 (2) and 1.304 (2) Å, respectively]; the C9—O2 bond length of 1.2019 (15) Å for split-model 2c of polymorph II is similar to, and possibly shorter than, that found in polymorph I at room temperature [1.203 (2) Å; Lyssenko & Antipin, 2001]. The bond lengths within the O4—C7═ C8—C10═O3 keto–enol fragment in polymorph II are indicative of substantial electron-density stabilization, which is manifested in the elongation of the formal C7═C8 and C10═O3 double bonds and the shortening of the C7—O4 and C8—C10 single bonds, compared with the `ideal' values for C—O, C═ O, C—C and C═C bonds (Gilli et al., 1989). Broadly speaking, the increase in π-delocalization of the O—C═C—C═OH fragment appears to be linearly related to the decrease in the O···O contact distance (intramolecular hydrogen bond).
In polymorph II using split-model 2c, the acetyl group is nearly coplanar with the fused ring plane, with torsion angles C7—C8—C10—C11 = -177.38 (11)°, C9—C8—C10—C11 = 0.94 (19)°, O2—-C9—-C8—C10 = -1.4 (2)° and C7—C8—C9—O2 = 179.74 (13)°. The C8—C7 bond length of 1.3995 (15) Å is representative of sp2 C═C double-bond character and is slightly elongated from the C═C double bond found at the same position in other compounds, for example, 1.375 (8) Å for the coumarin derivative 3-(2,2-dibromoacetyl)-4-hydroxy-2H-chromen-2-one (Brahmia et al., 2015), and slightly shorter than the corresponding distance found in the structure of polymorph I, i.e. 1.4035 (15) Å. The O2═ C9 bond length of 1.2019 (15) Å and the bond angles of 114.81 (11), 127.59 (13) and 117.60 (10)° at the C9 atom (Table 2) confirm the C═O bond character. The shorter O2═C9 bond length is probably due to the delocalized electrons in the lactone system. Table 2 recapitulates and summarizes the principal bond lengths and angles in polymorphs I and II (model 1a and split-model 2c) according to X-ray diffraction data at room temperature.
Fig. 3 shows that the packing in the crystalline lattice of polymorph II is mainly through C—H···O interactions, which link molecules into zigzag chains extended in the [100] direction, and a π–π interaction, with an acceptable separation distance, providing additional stability to the dimers and holding the chains in the crystallographic [010] direction. Lyssenko & Antipin (2001) have shown that, in the crystal packing of polymorph I, the molecules are linked into dimers through bifurcated C—H···O contacts, viz. C4—H4···O1' and C4—H4···O2' [C4···O1' = 3.523 (1) Å, H4···O1' = 2.51 Å and C4—H4··· O1' = 157°; C4···O2' = 3.404 (1) Å, H4···O2' = 2.44 Å and C4—H4···O2' = 149°; The prime denotes which symmetry operation?]. The dimers, in turn, are linked into layers through analogous contacts between the H atoms of the methyl group and the O3 atom of the keto–enol fragment [C11—-H11···O3''; C11···O3'' = 3.535 (1) Å, H11···O3'' = 2.47 Å and C11—H11···O3'' = 177°; The double prime denotes which symmetry operation?]. However, in polymorph II, we found that the molecules are linked into layers through analogous contacts between the H atoms of the methyl group and the O4 atom of the hydroxy group, viz. C11—H11···O4ii and C4—H4···O2i (Table 3). In addition to the above-mentioned contacts, the dimers in polymorph I are linked by π–π interactions between the keto–enol hydrogen-bonded rings parallel to one another, with a separation of 3.280 Å between their centres (Lyssenko & Antipin, 2001), while in polymorph II, π–π interactions are observed between the lactone rings (α-pyrone rings), with a Cg1···Cg1i separation of 3.670 (5) Å [Cg1 is the centroid of the O1/C5–C9 ring [OK?]; symmetry code: (i) -x + 1, -y - 1, -z + 1]. The observed stacking arrangement can be considered as a balance between van der Waals dispersion and repulsion interactions, and electrostatic interactions between the two α-pyrone rings of opposed polarity resulting from the opposed orientation. It can be said that the subsequent verification of subtle differences in the intermolecular interactions is due to delocalization of the hydroxy H atom between the hydroxy O atom and the ketone O atom in polymorph II. This result also correlates with the difference in the melting points of the two crystals, viz. 408–410 K for polymorph I and 405–407 K for polymorph II.
We have compared the crystal structures of two polymorphs of 3-acetyl-4-hydroxy-2H-chromen-2-one which pack differently in their crystal structures. In addition, there is more delocalization in polymorph II versus polymorph I, leading to almost identical C—O bond lengths for formally C—OH and C═O bonds, resulting in a molecule with an H atom shared between two O-atom centres.
Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).
C11H8O4 | Z = 4 |
Mr = 204.17 | F(000) = 424 |
Monoclinic, P21/n | Dx = 1.481 Mg m−3 |
Hall symbol: -P 2 y n | Mo Kα radiation, λ = 0.71073 Å |
a = 7.3340 (1) Å | µ = 0.11 mm−1 |
b = 9.9110 (1) Å | T = 298 K |
c = 12.6800 (2) Å | Prism, yellow |
β = 96.649 (1)° | 0.40 × 0.30 × 0.20 mm |
V = 915.48 (2) Å3 |
Bruker SMART?? CCD area-detector diffractometer | 2153 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.021 |
Graphite monochromator | θmax = 35.5°, θmin = 2.6° |
φ and ω scans | h = −11→10 |
12216 measured reflections | k = −16→15 |
4084 independent reflections | l = −18→20 |
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)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.199 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.1018P)2 + 0.041P] where P = (Fo2 + 2Fc2)/3 |
4084 reflections | (Δ/σ)max < 0.001 |
140 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C11H8O4 | V = 915.48 (2) Å3 |
Mr = 204.17 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.3340 (1) Å | µ = 0.11 mm−1 |
b = 9.9110 (1) Å | T = 298 K |
c = 12.6800 (2) Å | 0.40 × 0.30 × 0.20 mm |
β = 96.649 (1)° |
Bruker SMART?? CCD area-detector diffractometer | 2153 reflections with I > 2σ(I) |
12216 measured reflections | Rint = 0.021 |
4084 independent reflections |
R[F2 > 2σ(F2)] = 0.056 | 0 restraints |
wR(F2) = 0.199 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.33 e Å−3 |
4084 reflections | Δρmin = −0.24 e Å−3 |
140 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 | ||
O4 | 0.79610 (14) | −0.14012 (9) | 0.64919 (6) | 0.0553 (3) | |
C8 | 0.69322 (14) | −0.13504 (11) | 0.46616 (8) | 0.0385 (2) | |
O3 | 0.68053 (16) | −0.34053 (10) | 0.55390 (8) | 0.0632 (3) | |
C7 | 0.76572 (15) | −0.07321 (11) | 0.56104 (8) | 0.0385 (2) | |
C6 | 0.81042 (14) | 0.06839 (11) | 0.56420 (8) | 0.0387 (2) | |
C5 | 0.78099 (16) | 0.14036 (12) | 0.47033 (9) | 0.0434 (3) | |
C9 | 0.66511 (17) | −0.05560 (13) | 0.36977 (9) | 0.0473 (3) | |
C1 | 0.88262 (18) | 0.13521 (13) | 0.65727 (10) | 0.0502 (3) | |
H1 | 0.9035 | 0.0881 | 0.7209 | 0.060* | |
C4 | 0.8210 (2) | 0.27721 (15) | 0.46668 (12) | 0.0602 (4) | |
H4 | 0.8010 | 0.3251 | 0.4033 | 0.072* | |
O2 | 0.60509 (16) | −0.09320 (12) | 0.28242 (7) | 0.0740 (3) | |
C11 | 0.5836 (2) | −0.35630 (15) | 0.37174 (12) | 0.0647 (4) | |
H11A | 0.5672 | −0.4488 | 0.3910 | 0.097* | |
H11B | 0.6703 | −0.3513 | 0.3207 | 0.097* | |
H11C | 0.4681 | −0.3196 | 0.3415 | 0.097* | |
C10 | 0.65335 (17) | −0.27786 (13) | 0.46759 (10) | 0.0482 (3) | |
C3 | 0.8913 (2) | 0.34009 (14) | 0.55981 (14) | 0.0647 (4) | |
H3 | 0.9183 | 0.4317 | 0.5588 | 0.078* | |
C2 | 0.9223 (2) | 0.27032 (15) | 0.65409 (12) | 0.0595 (4) | |
H2 | 0.9702 | 0.3148 | 0.7157 | 0.071* | |
O1 | 0.71054 (13) | 0.08011 (10) | 0.37678 (7) | 0.0543 (3) | |
H | 0.754 (3) | −0.238 (2) | 0.6105 (17) | 0.114 (7)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O4 | 0.0777 (6) | 0.0544 (5) | 0.0325 (4) | −0.0051 (4) | 0.0006 (4) | 0.0086 (3) |
C8 | 0.0379 (5) | 0.0443 (6) | 0.0329 (5) | 0.0010 (4) | 0.0025 (4) | 0.0021 (4) |
O3 | 0.0820 (7) | 0.0478 (5) | 0.0587 (6) | −0.0102 (5) | 0.0027 (5) | 0.0094 (4) |
C7 | 0.0400 (5) | 0.0448 (6) | 0.0311 (4) | 0.0026 (4) | 0.0054 (4) | 0.0041 (4) |
C6 | 0.0383 (5) | 0.0412 (5) | 0.0375 (5) | 0.0027 (4) | 0.0083 (4) | −0.0003 (4) |
C5 | 0.0434 (6) | 0.0449 (6) | 0.0428 (5) | 0.0053 (4) | 0.0081 (4) | 0.0051 (4) |
C9 | 0.0490 (6) | 0.0568 (7) | 0.0349 (5) | 0.0032 (5) | 0.0003 (4) | 0.0037 (5) |
C1 | 0.0530 (7) | 0.0563 (7) | 0.0423 (6) | −0.0017 (5) | 0.0095 (5) | −0.0069 (5) |
C4 | 0.0672 (8) | 0.0480 (7) | 0.0675 (8) | 0.0062 (6) | 0.0175 (7) | 0.0138 (6) |
O2 | 0.0970 (8) | 0.0855 (8) | 0.0348 (5) | −0.0016 (6) | −0.0123 (5) | 0.0001 (4) |
C11 | 0.0671 (9) | 0.0618 (9) | 0.0633 (9) | −0.0132 (7) | −0.0001 (7) | −0.0146 (7) |
C10 | 0.0437 (6) | 0.0510 (7) | 0.0495 (6) | −0.0018 (5) | 0.0038 (5) | −0.0034 (5) |
C3 | 0.0677 (9) | 0.0410 (6) | 0.0898 (11) | −0.0035 (6) | 0.0282 (8) | −0.0072 (7) |
C2 | 0.0608 (8) | 0.0560 (7) | 0.0648 (8) | −0.0071 (6) | 0.0201 (6) | −0.0187 (6) |
O1 | 0.0671 (6) | 0.0552 (5) | 0.0391 (4) | 0.0030 (4) | −0.0001 (4) | 0.0127 (4) |
O4—C7 | 1.2965 (13) | C9—O1 | 1.3861 (16) |
O4—H | 1.11 (2) | C1—C2 | 1.3719 (19) |
C8—C7 | 1.3992 (15) | C1—H1 | 0.9300 |
C8—C10 | 1.4460 (17) | C4—C3 | 1.381 (2) |
C8—C9 | 1.4483 (15) | C4—H4 | 0.9300 |
O3—C10 | 1.2540 (15) | C11—C10 | 1.4830 (18) |
O3—H | 1.32 (2) | C11—H11A | 0.9600 |
C7—C6 | 1.4407 (16) | C11—H11B | 0.9600 |
C6—C5 | 1.3830 (15) | C11—H11C | 0.9600 |
C6—C1 | 1.4025 (16) | C3—C2 | 1.377 (2) |
C5—O1 | 1.3743 (14) | C3—H3 | 0.9300 |
C5—C4 | 1.3895 (19) | C2—H2 | 0.9300 |
C9—O2 | 1.2028 (14) | ||
C7—O4—H | 93.1 (11) | C3—C4—C5 | 118.12 (13) |
C7—C8—C10 | 118.37 (10) | C3—C4—H4 | 120.9 |
C7—C8—C9 | 119.36 (10) | C5—C4—H4 | 120.9 |
C10—C8—C9 | 122.25 (10) | C10—C11—H11A | 109.5 |
C10—O3—H | 96.1 (9) | C10—C11—H11B | 109.5 |
O4—C7—C8 | 121.84 (10) | H11A—C11—H11B | 109.5 |
O4—C7—C6 | 117.29 (10) | C10—C11—H11C | 109.5 |
C8—C7—C6 | 120.87 (9) | H11A—C11—H11C | 109.5 |
C5—C6—C1 | 119.12 (11) | H11B—C11—H11C | 109.5 |
C5—C6—C7 | 117.79 (10) | O3—C10—C8 | 118.94 (11) |
C1—C6—C7 | 123.08 (10) | O3—C10—C11 | 117.42 (12) |
O1—C5—C6 | 121.62 (11) | C8—C10—C11 | 123.64 (11) |
O1—C5—C4 | 117.07 (11) | C2—C3—C4 | 121.56 (13) |
C6—C5—C4 | 121.31 (12) | C2—C3—H3 | 119.2 |
O2—C9—O1 | 114.79 (11) | C4—C3—H3 | 119.2 |
O2—C9—C8 | 127.58 (13) | C1—C2—C3 | 120.10 (13) |
O1—C9—C8 | 117.63 (10) | C1—C2—H2 | 120.0 |
C2—C1—C6 | 119.79 (13) | C3—C2—H2 | 120.0 |
C2—C1—H1 | 120.1 | C5—O1—C9 | 122.72 (9) |
C6—C1—H1 | 120.1 | ||
C10—C8—C7—O4 | −0.56 (17) | C5—C6—C1—C2 | 0.21 (18) |
C9—C8—C7—O4 | −178.97 (10) | C7—C6—C1—C2 | 179.84 (11) |
C10—C8—C7—C6 | 179.18 (10) | O1—C5—C4—C3 | 179.76 (11) |
C9—C8—C7—C6 | 0.77 (16) | C6—C5—C4—C3 | −0.05 (19) |
O4—C7—C6—C5 | 179.11 (10) | C7—C8—C10—O3 | 1.79 (17) |
C8—C7—C6—C5 | −0.64 (15) | C9—C8—C10—O3 | −179.85 (11) |
O4—C7—C6—C1 | −0.52 (17) | C7—C8—C10—C11 | −177.38 (11) |
C8—C7—C6—C1 | 179.73 (10) | C9—C8—C10—C11 | 0.97 (19) |
C1—C6—C5—O1 | −179.99 (10) | C5—C4—C3—C2 | 0.3 (2) |
C7—C6—C5—O1 | 0.37 (16) | C6—C1—C2—C3 | 0.01 (19) |
C1—C6—C5—C4 | −0.19 (17) | C4—C3—C2—C1 | −0.3 (2) |
C7—C6—C5—C4 | −179.84 (11) | C6—C5—O1—C9 | −0.25 (17) |
C7—C8—C9—O2 | 179.77 (12) | C4—C5—O1—C9 | 179.95 (11) |
C10—C8—C9—O2 | 1.4 (2) | O2—C9—O1—C5 | −179.98 (11) |
C7—C8—C9—O1 | −0.62 (16) | C8—C9—O1—C5 | 0.37 (17) |
C10—C8—C9—O1 | −178.96 (10) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H···O3 | 1.11 (2) | 1.32 (2) | 2.4263 (13) | 169 (2) |
C4—H4···O2i | 0.93 | 2.65 | 3.510 (2) | 153 |
C11—H11C···O4ii | 0.96 | 2.64 | 3.320 (2) | 128 |
Symmetry codes: (i) −x+3/2, y+1/2, −z+1/2; (ii) x−1/2, −y−1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C11H8O4 |
Mr | 204.17 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 298 |
a, b, c (Å) | 7.3340 (1), 9.9110 (1), 12.6800 (2) |
β (°) | 96.649 (1) |
V (Å3) | 915.48 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.40 × 0.30 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART?? CCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12216, 4084, 2153 |
Rint | 0.021 |
(sin θ/λ)max (Å−1) | 0.818 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.199, 1.05 |
No. of reflections | 4084 |
No. of parameters | 140 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.33, −0.24 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), WinGX (Farrugia, 2012).
Parameter | Polymorph I | Polymorph II (model 1a) | Polymorph II (model 2c) |
O4—O3 | 2.442 (1) | 2.4263 (13) | 2.4309 (14) |
O4—C7 | 1.304 (2) | 1.2965 (13) | 1.2957 (13) |
O4—H | 1.02 (3) | 1.11 (2) | 0.829 (18) |
C8—C7 | 1.396 (2) | 1.3992 (15) | 1.3995 (15) |
C8—C10 | 1.45 (3) | 1.4460 (17) | 1.4459 (17) |
C8—C9 | 1.452 (2) | 1.4483 (15) | 1.4485 (15) |
O3—C10 | 1.255 (1) | 1.2540 (15) | 1.2534 (15) |
O3—H | 1.45 (3) | 1.32 (2) | 0.862 (19) |
C7—C6 | 1.442 (2) | 1.4407 (16) | 1.4407 (16) |
C9—O2 | 1.203 (2) | 1.2028 (14) | 1.2019 (15) |
C9—O1 | 1.381 (2) | 1.3861 (16) | 1.3864 (17) |
C11—C10 | 1.485 (2) | 1.4830 (18) | 1.4830 (18) |
O1—C5 | 1.365 (1) | 1.3743 (14) | 1.3742 (15) |
O4—H—O3 | 161 (2) | 169 (2) | 167 (3) |
C7—O4—H | 99 (1) | 93.1 (11) | 96 (2) |
C10—O3—H | 99.7 (9) | 96.1 (9) | 101 (3) |
O3—C10—C8 | 118.9 (1) | 118.94 (11) | 119.06 (11) |
O3—C10—C11 | 118.2 (1) | 117.42 (12) | 117.32 (12) |
C7—C8—C10 | 118.7 (1) | 118.37 (10) | 118.36 (10) |
O4—C7—C8 | 122.1 (1) | 122.84 (10) | 121.94 (10) |
O1—C9—C8 | 117.5 (1) | 117.63 (10) | 117.60 (10) |
C9—O1—C5 | 122.7 (1) | 122.72 (9) | 122.74 (9) |
O2—C9—O1 | 115.2 (1) | 114.79 (11) | 114.81 (11) |
O2—C9—C8 | 127.3 (1) | 127.58 (13) | 127.59 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H···O3 | 1.11 (2) | 1.32 (2) | 2.4263 (13) | 169 (2) |
C4—H4···O2i | 0.93 | 2.65 | 3.510 (2) | 153.1 |
C11—H11C···O4ii | 0.96 | 2.64 | 3.320 (2) | 127.9 |
Symmetry codes: (i) −x+3/2, y+1/2, −z+1/2; (ii) x−1/2, −y−1/2, z−1/2. |
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