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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 64| Part 11| November 2008| Page o2205
doi:10.1107/S160053680803451X

2-[(4-Chloro­benz­yl)carbonyl­meth­yl]benzoic acid

Obaid-ur-Rahman Abid,a Ghulam Qadeer,a* Nasim Hasan Ramaa and Ales Ruzickab

aDepartment of Chemistry, Quaid-i-Azam Univeristy, Islamabad 45320, Pakistan, and bDepartment of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Nam. Cs. Legii' 565, 53210 Pardubice, Czech Republic
*Correspondence e-mail: qadeerqau@yahoo.com

(Received 20 October 2008; accepted 22 October 2008; online 25 October 2008)

The title compound, C16H13ClO3, is an important inter­mediate in the conversion of isocoumarin to 3,4-dihydro­isocoumarin. The two aromatic rings are oriented at a dihedral angle of 67.18 (3)°. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. There is also a C—H⋯π contact between the benzoic acid and 4-chloro­benzyl rings.

Related literature

For a related structure, see: Abid et al. (2006[Abid, O., Rama, N. H., Qadeer, G., Khan, G. S. & Lu, X.-M. (2006). Acta Cryst. E62, o2895-o2896.]). For general background, see: Barry (1964[Barry, R. D. (1964). Chem. Rev. 64, 239-241.]); Powers et al. (2002[Powers, J. C., Asgian, J. L., Ekici, D. & James, K. E. (2002). Chem. Rev. 102, 4639-4643.]); Rossi et al. (2003[Rossi, R., Carpita, A., Bellina, F., Stabile, P. & Mannina, L. (2003). Tetrahedron, 59, 2067-2081.]); Sturtz et al. (2002[Sturtz, G., Meepagala, K. & Wedge, D. (2002). J. Agric. Food Chem. 50, 6979-6984.]); Thomas & Jens (1999[Thomas, L. & Jens, B. (1999). J. Nat. Prod. 62, 1182-1187.]). For bond-length data, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]).

[Scheme 1]

Experimental

Crystal data

  • C16H13ClO3

  • Mr = 288.71

  • Monoclinic, P 21 /c

  • a = 5.5000 (4) Å

  • b = 13.2720 (6) Å

  • c = 18.8120 (7) Å

  • β = 94.371 (4)°

  • V = 1369.21 (13) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.28 mm−1

  • T = 150 (1) K

  • 0.29 × 0.19 × 0.16 mm
Data collection

  • Bruker–Nonius Kappa CCD area-detector diffractometer

  • Absorption correction: integration (Coppens, 1970[Coppens, P. (1970). Crystallographic Computing, edited by F. R. Ahmed, S. R. Hall & C. P. Huber, pp. 255-270. Copenhagen: Munksgaard.]) Tmin = 0.936, Tmax = 0.962

  • 10076 measured reflections

  • 3010 independent reflections

  • 2284 reflections with I > 2σ(I)

  • Rint = 0.048
Refinement

  • R[F2 > 2σ(F2)] = 0.050

  • wR(F2) = 0.118

  • S = 1.14

  • 3010 reflections

  • 181 parameters

  • H-atom parameters constrained

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.42 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O2—H2⋯O1i 0.82 1.81 2.626 (3) 176
C16—H16⋯Cg1ii 0.93 3.35 4.079 (3) 137
Symmetry codes: (i) -x, -y, -z+1; (ii) [-x+2, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]. Cg1 is the centroid of the C2–C7 ring.

Data collection: COLLECT (Hooft, 1998[Hooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: COLLECT and DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzimology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]); data reduction: COLLECT and DENZO; program(s) used to solve structure: SIR92 (Altomare et al., 1994[Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680803451X/hk2557sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680803451X/hk2557Isup2.hkl

checkCIF report


Comment top

The isocoumarin nucleus is an abundant structural motif in natural products (Barry, 1964). Many constituents of the steadily growing class of known isocoumarins exhibit valuable biological properties such as antifungal (Sturtz et al., 2002), antitumor or cytotoxic, anti-inflammatory, anti-allergic (Rossi et al., 2003) and enzyme inhibitory activity (Powers et al., 2002). Naturally occurring haloisocoumarins and their halogeno-3,4-dihydroisocoumarin derivatives are very rare. However, a few examples of naturally occurring chlorine containing isocoumarins are known (Thomas & Jens, 1999). In view of the importance of this class of compounds, the title compound, an intermediate during the conversion of isocoumarin to 3,4-dihydroisocoumarin, has been synthesized, and we report herein its crystal structure.

In the title compound (Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges, and comparable with the corresponding values in 3-(2-chlorobenzyl)isocoumarin (Abid et al., 2006). Rings A (C2-C7) and B (C11-C16) are, of course, planar and the dihedral angle between them is A/B = 67.18 (3)°. The intramolecular C-H···O hydrogen bonds (Table 1) result in the formation of nonplanar five- and six-membered rings C (O2/C1/C2/C7/H7) and D (O1/C1-C3/C8/H8B). Ring C adopts envelope conformation with C1 atom displaced by -0.108 (3) Å from the plane of the other ring atoms, while ring D has twisted conformation.

In the crystal structure, intermolecular O-H···O hydrogen bonds (Table 1) link the molecules into centrosymmetric dimers (Fig. 2), in which they may be effective in the stabilization of the structure. There also exist a C—H···π contact (Table 1) between the benzoic acid and 4-chlorobenzyl rings.

Related literature top

For a related structure, see: Abid et al. (2006). For general background, see: Barry (1964); Powers et al. (2002); Rossi et al. (2003); Sturtz et al. (2002); Thomas & Jens (1999). For bond-length data, see: Allen et al. (1987). Cg1 is the centroid of the C2–C7 ring.

Experimental top

A solution of 3-(4-chlorobenzyl)isocoumarin (2.0 g, 7 mmol) in ethanol (50 ml) and potassium hydroxide (100 ml, 5%) were refluxed for 4 h. Ethanol was removed from the reaction mixture by distillation. Ice cold water (20 ml) was added and the reaction mixture was acidified with hydrochloric acid. It was extracted with dichloromethane (3 × 20 ml), and then dried and evaporated to yield the crude solid, which was recrystallized from methanol (yield; 85%; m.p. 414-415 K).

Refinement top

H atoms were positioned geometrically, with O-H = 0.82 Å (for OH) and C-H = 0.93 and 0.97 Å for aromatic and methylene H, respectively, and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(C,O).

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); data reduction: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme.
[Figure 2] Fig. 2. A partial packing diagram. Hydrogen bonds are shown as dashed lines.
[Figure 3] Fig. 3. The formation of the title compound.
2-[(4-Chlorobenzyl)carbonylmethyl]benzoic acid top
Crystal data top
C16H13ClO3F(000) = 600
Mr = 288.71Dx = 1.401 Mg m−3
Monoclinic, P21/cMelting point: 414(1) K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 5.5000 (4) ÅCell parameters from 10141 reflections
b = 13.2720 (6) Åθ = 1–27.5°
c = 18.8120 (7) ŵ = 0.28 mm−1
β = 94.371 (4)°T = 150 K
V = 1369.21 (13) Å3Block, colorless
Z = 40.29 × 0.19 × 0.16 mm
Data collection top
Bruker–Nonius Kappa CCD area-detector
diffractometer		3010 independent reflections
Radiation source: fine-focus sealed tube2284 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 1.9°
ϕ and ω scansh = −6→7
Absorption correction: integration
(Coppens, 1970)		k = −17→15
Tmin = 0.936, Tmax = 0.962l = −21→24
10076 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.050Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.118H-atom parameters constrained
S = 1.14 w = 1/[σ2(Fo2) + (0.0291P)2 + 0.9198P]
where P = (Fo2 + 2Fc2)/3
3010 reflections(Δ/σ)max < 0.001
181 parametersΔρmax = 0.26 e Å−3
0 restraintsΔρmin = −0.42 e Å−3
Crystal data top
C16H13ClO3V = 1369.21 (13) Å3
Mr = 288.71Z = 4
Monoclinic, P21/cMo Kα radiation
a = 5.5000 (4) ŵ = 0.28 mm−1
b = 13.2720 (6) ÅT = 150 K
c = 18.8120 (7) Å0.29 × 0.19 × 0.16 mm
β = 94.371 (4)°
Data collection top
Bruker–Nonius Kappa CCD area-detector
diffractometer		3010 independent reflections
Absorption correction: integration
(Coppens, 1970)		2284 reflections with I > 2σ(I)
Tmin = 0.936, Tmax = 0.962Rint = 0.048
10076 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0500 restraints
wR(F2) = 0.118H-atom parameters constrained
S = 1.14Δρmax = 0.26 e Å−3
3010 reflectionsΔρmin = −0.42 e Å−3
181 parameters
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
xyzUiso*/Ueq
Cl10.56140 (14)0.35295 (5)0.41926 (4)0.0597 (2)
O10.1626 (3)−0.05908 (11)0.44337 (9)0.0445 (4)
O2−0.1720 (3)−0.11437 (12)0.48932 (9)0.0446 (4)
H2−0.1636−0.05930.50910.054*
O30.0425 (3)−0.11324 (13)0.27714 (9)0.0487 (4)
C10.0174 (4)−0.12684 (15)0.45249 (11)0.0312 (4)
C20.0445 (4)−0.23057 (15)0.42498 (10)0.0313 (4)
C30.2232 (4)−0.25579 (16)0.37852 (11)0.0338 (5)
C40.2425 (5)−0.35656 (18)0.35955 (13)0.0470 (6)
H40.3604−0.37530.32920.056*
C50.0930 (5)−0.42938 (18)0.38464 (15)0.0547 (7)
H50.1120−0.49630.37140.066*
C6−0.0840 (5)−0.40396 (18)0.42911 (14)0.0512 (6)
H6−0.1869−0.45290.44560.061*
C7−0.1076 (4)−0.30469 (17)0.44895 (12)0.0410 (5)
H7−0.2273−0.28690.47900.049*
C80.3863 (4)−0.18048 (17)0.34637 (12)0.0378 (5)
H8A0.5133−0.21650.32380.045*
H8B0.4648−0.14020.38450.045*
C90.2595 (4)−0.11086 (16)0.29233 (11)0.0354 (5)
C100.4211 (4)−0.03623 (19)0.25726 (13)0.0458 (6)
H10A0.5798−0.06650.25280.055*
H10B0.3504−0.02110.20960.055*
C110.4526 (4)0.06038 (17)0.29935 (11)0.0363 (5)
C120.6641 (4)0.07862 (19)0.34231 (13)0.0437 (6)
H120.78550.02970.34640.052*
C130.6968 (4)0.16829 (19)0.37871 (13)0.0459 (6)
H130.83960.18000.40720.055*
C140.5170 (4)0.23985 (16)0.37280 (11)0.0391 (5)
C150.3062 (4)0.22462 (18)0.33044 (13)0.0432 (5)
H150.18600.27400.32620.052*
C160.2761 (4)0.13451 (18)0.29391 (13)0.0430 (5)
H160.13340.12350.26520.052*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0813 (5)0.0436 (4)0.0545 (4)−0.0193 (3)0.0070 (3)−0.0008 (3)
O10.0533 (10)0.0334 (8)0.0491 (10)−0.0093 (7)0.0181 (8)−0.0123 (7)
O20.0431 (9)0.0377 (9)0.0549 (10)−0.0034 (7)0.0157 (8)−0.0169 (7)
O30.0400 (9)0.0498 (10)0.0547 (10)0.0010 (8)−0.0064 (7)0.0059 (8)
C10.0330 (11)0.0308 (10)0.0297 (10)0.0027 (9)0.0012 (8)−0.0025 (8)
C20.0362 (11)0.0269 (10)0.0300 (10)0.0030 (9)−0.0028 (8)−0.0027 (8)
C30.0365 (11)0.0342 (11)0.0297 (10)0.0071 (9)−0.0045 (8)−0.0057 (9)
C40.0560 (15)0.0397 (13)0.0446 (13)0.0147 (11)−0.0015 (11)−0.0126 (11)
C50.0716 (18)0.0266 (11)0.0633 (17)0.0077 (12)−0.0123 (14)−0.0102 (11)
C60.0652 (17)0.0299 (12)0.0567 (16)−0.0076 (12)−0.0075 (13)0.0017 (11)
C70.0470 (13)0.0343 (12)0.0409 (12)−0.0043 (10)−0.0009 (10)−0.0001 (9)
C80.0331 (11)0.0430 (12)0.0375 (11)0.0079 (10)0.0042 (9)−0.0073 (10)
C90.0386 (12)0.0345 (11)0.0334 (11)0.0041 (9)0.0046 (9)−0.0085 (9)
C100.0484 (14)0.0492 (14)0.0414 (13)0.0000 (11)0.0139 (10)−0.0019 (11)
C110.0353 (11)0.0410 (12)0.0337 (11)−0.0017 (9)0.0096 (9)0.0053 (9)
C120.0346 (12)0.0512 (14)0.0449 (13)0.0089 (10)0.0005 (10)0.0104 (11)
C130.0394 (13)0.0566 (15)0.0404 (12)−0.0076 (11)−0.0067 (10)0.0060 (11)
C140.0453 (13)0.0351 (11)0.0371 (12)−0.0104 (10)0.0052 (10)0.0075 (9)
C150.0388 (12)0.0393 (12)0.0515 (14)0.0029 (10)0.0025 (10)0.0069 (11)
C160.0324 (11)0.0496 (14)0.0463 (13)−0.0025 (10)−0.0024 (9)0.0028 (11)
Geometric parameters (Å, º) top
Cl1—C141.745 (2)C8—C91.505 (3)
O2—H20.8200C8—H8A0.9700
O3—C91.207 (3)C8—H8B0.9700
C1—O11.223 (2)C9—C101.515 (3)
C1—O21.305 (2)C10—H10A0.9700
C1—C21.482 (3)C10—H10B0.9701
C3—C41.390 (3)C11—C101.510 (3)
C3—C21.404 (3)C11—C121.386 (3)
C4—H40.9300C11—C161.381 (3)
C5—C41.376 (4)C12—H120.9300
C5—C61.373 (4)C13—C121.378 (4)
C5—H50.9300C13—C141.369 (3)
C6—H60.9299C13—H130.9300
C7—C21.389 (3)C15—C141.371 (3)
C7—C61.378 (3)C15—C161.383 (3)
C7—H70.9299C15—H150.9299
C8—C31.501 (3)C16—H160.9299
C1—O2—H2109.6O3—C9—C8122.9 (2)
O1—C1—O2122.49 (19)O3—C9—C10121.1 (2)
O1—C1—C2123.35 (18)C8—C9—C10116.01 (19)
O2—C1—C2114.13 (18)C11—C10—C9111.99 (18)
C7—C2—C3120.05 (19)C11—C10—H10A109.2
C7—C2—C1117.74 (19)C9—C10—H10A109.2
C3—C2—C1122.16 (18)C11—C10—H10B109.3
C4—C3—C2117.4 (2)C9—C10—H10B109.3
C4—C3—C8118.5 (2)H10A—C10—H10B107.9
C2—C3—C8124.08 (18)C16—C11—C12118.2 (2)
C5—C4—C3121.9 (2)C16—C11—C10120.9 (2)
C5—C4—H4119.1C12—C11—C10120.8 (2)
C3—C4—H4119.1C13—C12—C11120.8 (2)
C6—C5—C4120.4 (2)C13—C12—H12119.7
C6—C5—H5119.8C11—C12—H12119.5
C4—C5—H5119.7C14—C13—C12119.5 (2)
C5—C6—C7119.1 (2)C14—C13—H13120.2
C5—C6—H6120.6C12—C13—H13120.2
C7—C6—H6120.3C13—C14—C15121.2 (2)
C6—C7—C2121.2 (2)C13—C14—Cl1118.91 (18)
C6—C7—H7119.5C15—C14—Cl1119.86 (18)
C2—C7—H7119.3C14—C15—C16118.7 (2)
C3—C8—C9114.86 (18)C14—C15—H15120.7
C3—C8—H8A108.7C16—C15—H15120.6
C9—C8—H8A108.6C11—C16—C15121.5 (2)
C3—C8—H8B108.4C11—C16—H16119.3
C9—C8—H8B108.6C15—C16—H16119.2
H8A—C8—H8B107.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O1i0.821.812.626 (3)176
C7—H7···O20.932.322.669 (3)102
C8—H8B···O10.972.332.790 (3)108
C16—H16···Cg1ii0.933.354.079 (3)137
Symmetry codes: (i) −x, −y, −z+1; (ii) −x+2, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formulaC16H13ClO3
Mr288.71
Crystal system, space groupMonoclinic, P21/c
Temperature (K)150
a, b, c (Å)5.5000 (4), 13.2720 (6), 18.8120 (7)
β (°) 94.371 (4)
V (Å3)1369.21 (13)
Z4
Radiation typeMo Kα
µ (mm−1)0.28
Crystal size (mm)0.29 × 0.19 × 0.16
Data collection
DiffractometerBruker–Nonius Kappa CCD area-detector
diffractometer
Absorption correctionIntegration
(Coppens, 1970)
Tmin, Tmax0.936, 0.962
No. of measured, independent and
observed [I > 2σ(I)] reflections		10076, 3010, 2284
Rint0.048
(sin θ/λ)max (Å−1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.050, 0.118, 1.14
No. of reflections3010
No. of parameters181
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.26, −0.42

Computer programs: , COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O1i0.821.812.626 (3)176
C7—H7···O20.932.322.669 (3)102
C8—H8B···O10.972.332.790 (3)108
C16—H16···Cg1ii0.933.354.079 (3)137
Symmetry codes: (i) −x, −y, −z+1; (ii) −x+2, y+1/2, −z+1/2.
 

Acknowledgements

The authors gratefully acknowledge the financial support of the Ministry of Education of the Czech Republic (project No. VZ0021627501) and Higher Education Commission, Islam­a­bad, Pakistan.

References

First citationAbid, O., Rama, N. H., Qadeer, G., Khan, G. S. & Lu, X.-M. (2006). Acta Cryst. E62, o2895–o2896.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CrossRef Web of Science Google Scholar
 First citationAltomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.  CrossRef Web of Science IUCr Journals Google Scholar
 First citationBarry, R. D. (1964). Chem. Rev. 64, 239–241.  CrossRef Web of Science Google Scholar
 First citationCoppens, P. (1970). Crystallographic Computing, edited by F. R. Ahmed, S. R. Hall & C. P. Huber, pp. 255–270. Copenhagen: Munksgaard.  Google Scholar
 First citationHooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.  Google Scholar
 First citationOtwinowski, Z. & Minor, W. (1997). Methods in Enzimology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.  Google Scholar
 First citationPowers, J. C., Asgian, J. L., Ekici, D. & James, K. E. (2002). Chem. Rev. 102, 4639–4643.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationRossi, R., Carpita, A., Bellina, F., Stabile, P. & Mannina, L. (2003). Tetrahedron, 59, 2067–2081.  Web of Science CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSpek, A. L. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSturtz, G., Meepagala, K. & Wedge, D. (2002). J. Agric. Food Chem. 50, 6979–6984.  Google Scholar
 First citationThomas, L. & Jens, B. (1999). J. Nat. Prod. 62, 1182–1187.  Web of Science CrossRef PubMed Google Scholar

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ISSN: 2056-9890
Volume 64| Part 11| November 2008| Page o2205
doi:10.1107/S160053680803451X
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