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

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ISSN: 2414-3146

(E)-2-(3,5-Di­meth­­oxy­benzyl­­idene)indan-1-one

aSchool of Science and Technology, H-3209, Georgia Gwinnett College, 1000 University Center Lane, Lawrenceville, GA 30043, USA, and bNorth Carolina State University, Molecular Education, Technology, and Research Innovation Center, 2620 Yarbrough Dr., Raleigh, NC 27695, USA
*Correspondence e-mail: jsloop@ggc.edu

Edited by M. Bolte, Goethe-Universität Frankfurt, Germany (Received 2 June 2020; accepted 4 June 2020; online 12 June 2020)

The title chalcone, C18H16O3, was prepared by a solventless base-promoted Claisen–Schmidt condensation and, upon recrystallization from ethanol, obtained in 56% yield. The dihedral angle between the indanone ring system and the benzene ring is 2.54 (4) ° and the C atoms of the methoxy groups deviate from the benzene ring by 0.087 (1) and 0.114 (1) Å. In the crystal, π-stacking is the predominant inter­molecular force, with the mol­ecules stacking into columns running parallel to the b axis of the unit cell.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

The chalcone family of compounds possess an aromatic α,β-unsaturated ketone functionality and can readily be formed by base-promoted condensation–dehydrations of an aromatic aldehyde and an aromatic ketone. They are important pharmacophore scaffolds and can possess anti-inflammatory, anti-fungal, anti-cancer, and anti-malarial biological activities (Singh et al., 2015[Singh, A., Fatima, K., Singh, A., Behl, A., Mintoo, M., Hasanain, M., Ashraf, R., Luqman, S., Shanker, K., Mondhe, D., Sarkar, J., Chanda, D. & Negi, A. S. (2015). Eur. J. Pharm. Sci. 76, 57-67.], 2014[Singh, P., Anand, A. & Kumar, V. (2014). Eur. J. Med. Chem. 85, 758-777.]; Berthelette et al., 1997[Berthelette, C., McCooye, C., Leblanc, Y., Trimble, L. A. & Tsou, N. N. (1997). J. Org. Chem. 62, 4339-4342.]). Additionally, the aromatic groups can be functionalized so as to produce other biological effects. The indanone family of compounds are biologically active compounds that are involved in steroid hormone biosynthesis and arachidonic acid metabolism pathways (Berthelette et al., 1997[Berthelette, C., McCooye, C., Leblanc, Y., Trimble, L. A. & Tsou, N. N. (1997). J. Org. Chem. 62, 4339-4342.]). In addition, indanone derivatives serve as scaffolds for a variety of heterocycles (Sloop et al., 2002[Sloop, J., Bumgardner, C. & Loehle, W. D. (2002). J. Fluor. Chem. 118, 135-147.], 2012[Sloop, J., Boyle, P., Fountain, A. W., Gomez, C., Jackson, J., Pearman, W., Schmidt, R. & Weyand, J. (2012). Appl. Sci. 2, 61-99.]).

The combination of these two potential pharmacophores using greener and more efficient synthesis pathways en route to a series of highly functionalized indanone-based chalcones is now being studied by our research group. The solvent-free Claisen–Schmidt reaction undertaken in Fig. 1[link] minimizes reaction toxicity, limits waste production and enables easier product isolation in many cases.

[Figure 1]
Figure 1
Green synthesis scheme for indanone-based chalcones

In the title mol­ecule (Fig. 2[link]), the dihedral angle between the indanone ring system and the benzene ring is 2.54 (4) ° and the C`7 and C18 atoms of the methoxy groups deviate from the benzene ring by 0.087 (1) and 0.114 (1) Å, respectively. No unusual bond lengths or angles are noted after a routine Mogul geometry check (Bruno et al., 2004[Bruno, I. J., Cole, J. C., Kessler, M., Luo, J., Motherwell, W. D. S., Purkis, L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133-2144.]).

[Figure 2]
Figure 2
Displacement ellipsoid plot of 1b. Ellipsoids are drawn at the 50% probability level.

The predominant supra­molecular feature of this structure (Fig. 3[link]) are slipped stacking inter­actions. This consists of ring-over-atom pairings between the indanone ring and the 3-position of the di­meth­oxy­phenyl ring of a neighboring mol­ecule and generates a relatively close contact of 2.7 Å for the methyl­ene H atoms of the indanone ring to the adjacent mol­ecule.

[Figure 3]
Figure 3
Packing diagram of 1b viewed along the b axis.

Structurally characterized 1b is consistent with known structures of similar indaneones. A search of the Cambridge Structural Database (Version 5.41, update of November 2019; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) gave 35 hits with a similar core structure. A defined three-dimensional parameter search on the distance between the carbonyl O atom and the phenyl ring gave a clear indication of the stereochemistry of the double bond. The title compound adopts the more common E isomer – along with 33 of the other structures published – indicated by an O—C distances 4.2 to 4.5 Å. Only two examples of Z isomers (O—C of 3.2 to 3.4 Å) exist [POWZUX (Zhou et al., 2009[Zhou, Y.-X., Wang, J.-Q., Du, R.-J., Tang, J.-G. & Guo, C. (2009). Acta Cryst. E65, o1936.]) and HAVLAR (Mori & Maeda, 1994[Mori, Y. & Maeda, K. (1994). Acta Cryst. B50, 106-112.])]. The latter has seven structure determinations as part of a light-driven solid-state isomerization study (Harada et al., 2009[Harada, J., Harakawa, M., Sugiyama, S. & Ogawa, K. (2009). CrystEngComm, 11, 1235-1239.]).

Synthesis and crystallization

A 25 mL beaker equipped with a stir bar was charged with 3,5-di­meth­oxy­benzaldehyde (0.50 g, 3.0 mmol) and warmed to 60°C. To the liquified aldehyde was added 1-indanone (0.40 g, 3.0 mmol) and solid NaOH (0.20 g, 3.8 mmol). The reaction mixture was stirred for 30 minutes at 60°C. The resulting reaction mixture was neutralized with 4 mL of 1 M HCl, the resulting residue was washed with several 1 mL aliquots of distilled water and the crude product (0.80 g, 95% yield) isolated via vacuum filtration. Recrystallization from 95% ethanol solution via slow evaporation afforded the target chalcone, (E)-2-(3,5-di­meth­oxy­benzyl­iden­yl)-1-indanone (1b) as colorless needles, (0.47 g, 56% yield). Melting range: 174–175°C. IR, 1H and 13C NMR spectroscopy and single-crystal X-ray analysis (see supporting information) confirmed the product identity.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1[link].

Table 1
Experimental details

Crystal data
Chemical formula C18H16O3
Mr 280.31
Crystal system, space group Monoclinic, P21/c
Temperature (K) 100
a, b, c (Å) 7.7611 (4), 7.2894 (4), 24.0331 (13)
β (°) 93.5573 (12)
V3) 1357.02 (13)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.09
Crystal size (mm) 0.39 × 0.12 × 0.05
 
Data collection
Diffractometer Bruker-Nonius X8 Kappa APEXII
Absorption correction Multi-scan (SADABS; Krause et al., 2015[Krause, L., Herbst-Irmer, R., Sheldrick, G. M. & Stalke, D. (2015). J. Appl. Cryst. 48, 3-10.])
Tmin, Tmax 0.95, 0.99
No. of measured, independent and observed [I > 2σ(I)] reflections 30838, 5231, 4087
Rint 0.040
(sin θ/λ)max−1) 0.772
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.123, 1.02
No. of reflections 5231
No. of parameters 192
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.61, −0.24
Computer programs: Instrument Service, APEX3 and SAINT (Bruker, 2017[Bruker (2017). Instrument Service, APEX3 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2016/6 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]), Mercury (Macrae et al., 2020[Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226-235.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Structural data


Computing details top

Data collection: Instrument Service (Bruker, 2017); cell refinement: APEX3 (Bruker, 2017); data reduction: SAINT (Bruker, 2017); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016/6 (Sheldrick, 2015b); molecular graphics: Mercury (Macrae et al., 2020); software used to prepare material for publication: publCIF (Westrip, 2010).

(E)-2-(3,5-Dimethoxybenzylidene)indan-1-one top
Crystal data top
C18H16O3F(000) = 592
Mr = 280.31Dx = 1.372 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 7.7611 (4) ÅCell parameters from 242 reflections
b = 7.2894 (4) Åθ = 3.0–33.1°
c = 24.0331 (13) ŵ = 0.09 mm1
β = 93.5573 (12)°T = 100 K
V = 1357.02 (13) Å3Needle, colourless
Z = 40.39 × 0.12 × 0.05 mm
Data collection top
Bruker-Nonius X8 Kappa APEXII
diffractometer
5231 independent reflections
Radiation source: fine-focus sealed tube4087 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
Detector resolution: 8.3333 pixels mm-1θmax = 33.3°, θmin = 2.6°
phi and ω scansh = 1111
Absorption correction: multi-scan
(SADABS; Krause et al., 2015)
k = 1111
Tmin = 0.95, Tmax = 0.99l = 3737
30838 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)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.123H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0695P)2 + 0.2851P]
where P = (Fo2 + 2Fc2)/3
5231 reflections(Δ/σ)max = 0.001
192 parametersΔρmax = 0.61 e Å3
0 restraintsΔρmin = 0.24 e Å3
Special details top

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. All hydrogen atoms were seen in the difference map of later refinements, but were placed at calculated positions and refined using a riding model, setting isotropic displacement parameters to 1.2 or 1.5 times that of the parent atom for ring H atoms and methyl groups respectively.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.47855 (9)0.17474 (11)0.33135 (3)0.01698 (15)
O21.03362 (8)0.10918 (10)0.58143 (3)0.01475 (14)
O30.48827 (9)0.32457 (10)0.64602 (3)0.01472 (14)
C10.37431 (12)0.23058 (12)0.36368 (4)0.01126 (16)
C20.40164 (11)0.24728 (12)0.42550 (4)0.01007 (15)
C30.23699 (11)0.31671 (12)0.44870 (4)0.01069 (16)
H3A0.1911090.2271180.4749810.013*
H3B0.2561990.4354890.4680750.013*
C40.11611 (11)0.33843 (12)0.39744 (4)0.01048 (16)
C50.19615 (12)0.29325 (12)0.34906 (4)0.01129 (16)
C60.11094 (12)0.30860 (13)0.29642 (4)0.01457 (18)
H60.1680190.2799790.2636760.017*
C70.05951 (13)0.36685 (14)0.29328 (4)0.01710 (19)
H70.1203290.3789440.2579350.021*
C80.14259 (12)0.40795 (13)0.34182 (4)0.01618 (18)
H80.2603250.4444220.3390620.019*
C90.05538 (12)0.39621 (12)0.39403 (4)0.01333 (17)
H90.1116640.4270020.4267560.016*
C100.55633 (12)0.20333 (12)0.44993 (4)0.01049 (16)
H100.637980.1608680.4250330.013*
C110.62038 (11)0.20978 (12)0.50842 (4)0.00944 (15)
C120.79305 (11)0.15891 (12)0.52012 (4)0.01034 (15)
H120.861790.1229650.4906260.012*
C130.86425 (11)0.16081 (12)0.57468 (4)0.01032 (15)
C140.76564 (11)0.21385 (12)0.61855 (4)0.01067 (16)
H140.8139480.2146730.6558480.013*
C150.59412 (11)0.26573 (12)0.60630 (4)0.01004 (15)
C160.52038 (11)0.26358 (12)0.55215 (4)0.01045 (15)
H160.403180.2982910.5448340.013*
C171.10933 (12)0.09692 (13)0.63704 (4)0.01411 (17)
H17A1.2290610.0548950.6360910.021*
H17B1.0437170.0095640.6583840.021*
H17C1.1071520.2178810.6547760.021*
C180.54517 (13)0.30032 (15)0.70314 (4)0.01596 (18)
H18A0.571730.1706040.7101080.024*
H18B0.4538870.3394850.7269210.024*
H18C0.6489750.3742240.7116130.024*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0152 (3)0.0258 (4)0.0101 (3)0.0022 (3)0.0025 (2)0.0029 (3)
O20.0093 (3)0.0234 (3)0.0114 (3)0.0048 (2)0.0004 (2)0.0017 (2)
O30.0125 (3)0.0249 (4)0.0069 (3)0.0053 (3)0.0018 (2)0.0017 (2)
C10.0120 (4)0.0128 (4)0.0089 (4)0.0009 (3)0.0004 (3)0.0003 (3)
C20.0117 (4)0.0111 (4)0.0074 (3)0.0006 (3)0.0009 (3)0.0002 (3)
C30.0112 (4)0.0120 (4)0.0090 (3)0.0004 (3)0.0015 (3)0.0008 (3)
C40.0108 (4)0.0096 (3)0.0110 (4)0.0010 (3)0.0002 (3)0.0002 (3)
C50.0119 (4)0.0119 (4)0.0099 (4)0.0007 (3)0.0007 (3)0.0004 (3)
C60.0155 (4)0.0170 (4)0.0109 (4)0.0010 (3)0.0017 (3)0.0006 (3)
C70.0164 (4)0.0177 (4)0.0165 (4)0.0009 (3)0.0053 (3)0.0025 (3)
C80.0121 (4)0.0142 (4)0.0218 (5)0.0007 (3)0.0021 (3)0.0023 (3)
C90.0116 (4)0.0126 (4)0.0159 (4)0.0006 (3)0.0012 (3)0.0014 (3)
C100.0117 (4)0.0116 (4)0.0083 (3)0.0002 (3)0.0012 (3)0.0007 (3)
C110.0100 (4)0.0097 (3)0.0086 (3)0.0002 (3)0.0006 (3)0.0004 (3)
C120.0110 (4)0.0116 (4)0.0086 (3)0.0012 (3)0.0016 (3)0.0005 (3)
C130.0089 (4)0.0112 (4)0.0109 (4)0.0009 (3)0.0007 (3)0.0002 (3)
C140.0103 (4)0.0125 (4)0.0092 (4)0.0011 (3)0.0004 (3)0.0005 (3)
C150.0101 (4)0.0121 (4)0.0080 (4)0.0006 (3)0.0017 (3)0.0010 (3)
C160.0094 (4)0.0127 (4)0.0093 (4)0.0011 (3)0.0003 (3)0.0004 (3)
C170.0123 (4)0.0165 (4)0.0132 (4)0.0014 (3)0.0025 (3)0.0011 (3)
C180.0172 (4)0.0238 (5)0.0071 (4)0.0020 (3)0.0022 (3)0.0007 (3)
Geometric parameters (Å, º) top
O1—C11.2255 (11)C8—H80.95
O2—C131.3673 (11)C9—H90.95
O2—C171.4289 (11)C10—C111.4623 (12)
O3—C151.3665 (11)C10—H100.95
O3—C181.4267 (11)C11—C161.4006 (12)
C1—C51.4777 (13)C11—C121.4020 (12)
C1—C21.4929 (12)C12—C131.3912 (12)
C2—C101.3421 (12)C12—H120.95
C2—C31.5127 (13)C13—C141.3952 (12)
C3—C41.5098 (13)C14—C151.3975 (12)
C3—H3A0.99C14—H140.95
C3—H3B0.99C15—C161.3890 (12)
C4—C51.3913 (12)C16—H160.95
C4—C91.3935 (12)C17—H17A0.98
C5—C61.3951 (12)C17—H17B0.98
C6—C71.3869 (14)C17—H17C0.98
C6—H60.95C18—H18A0.98
C7—C81.3999 (15)C18—H18B0.98
C7—H70.95C18—H18C0.98
C8—C91.3908 (13)
C13—O2—C17117.69 (7)C2—C10—H10114.6
C15—O3—C18118.00 (7)C11—C10—H10114.6
O1—C1—C5126.64 (8)C16—C11—C12119.40 (8)
O1—C1—C2126.83 (8)C16—C11—C10123.99 (8)
C5—C1—C2106.53 (7)C12—C11—C10116.61 (8)
C10—C2—C1118.94 (8)C13—C12—C11120.34 (8)
C10—C2—C3132.21 (8)C13—C12—H12119.8
C1—C2—C3108.84 (7)C11—C12—H12119.8
C4—C3—C2103.34 (7)O2—C13—C12115.58 (8)
C4—C3—H3A111.1O2—C13—C14123.71 (8)
C2—C3—H3A111.1C12—C13—C14120.70 (8)
C4—C3—H3B111.1C13—C14—C15118.42 (8)
C2—C3—H3B111.1C13—C14—H14120.8
H3A—C3—H3B109.1C15—C14—H14120.8
C5—C4—C9119.79 (8)O3—C15—C16115.30 (8)
C5—C4—C3111.71 (8)O3—C15—C14122.96 (8)
C9—C4—C3128.50 (8)C16—C15—C14121.73 (8)
C4—C5—C6121.84 (8)C15—C16—C11119.40 (8)
C4—C5—C1109.53 (8)C15—C16—H16120.3
C6—C5—C1128.63 (8)C11—C16—H16120.3
C7—C6—C5118.09 (9)O2—C17—H17A109.5
C7—C6—H6121.0O2—C17—H17B109.5
C5—C6—H6121.0H17A—C17—H17B109.5
C6—C7—C8120.48 (9)O2—C17—H17C109.5
C6—C7—H7119.8H17A—C17—H17C109.5
C8—C7—H7119.8H17B—C17—H17C109.5
C9—C8—C7121.00 (9)O3—C18—H18A109.5
C9—C8—H8119.5O3—C18—H18B109.5
C7—C8—H8119.5H18A—C18—H18B109.5
C8—C9—C4118.77 (9)O3—C18—H18C109.5
C8—C9—H9120.6H18A—C18—H18C109.5
C4—C9—H9120.6H18B—C18—H18C109.5
C2—C10—C11130.87 (8)
O1—C1—C2—C102.20 (14)C3—C4—C9—C8179.35 (9)
C5—C1—C2—C10178.24 (8)C1—C2—C10—C11178.55 (9)
O1—C1—C2—C3178.27 (9)C3—C2—C10—C110.85 (17)
C5—C1—C2—C31.28 (9)C2—C10—C11—C161.67 (15)
C10—C2—C3—C4179.41 (10)C2—C10—C11—C12178.08 (9)
C1—C2—C3—C40.03 (9)C16—C11—C12—C130.36 (13)
C2—C3—C4—C51.36 (9)C10—C11—C12—C13179.87 (8)
C2—C3—C4—C9179.02 (9)C17—O2—C13—C12175.86 (8)
C9—C4—C5—C61.74 (14)C17—O2—C13—C144.54 (13)
C3—C4—C5—C6177.92 (8)C11—C12—C13—O2179.86 (8)
C9—C4—C5—C1178.10 (8)C11—C12—C13—C140.25 (13)
C3—C4—C5—C12.24 (10)O2—C13—C14—C15179.29 (8)
O1—C1—C5—C4177.40 (9)C12—C13—C14—C150.29 (13)
C2—C1—C5—C42.16 (10)C18—O3—C15—C16169.35 (8)
O1—C1—C5—C62.42 (16)C18—O3—C15—C1411.69 (13)
C2—C1—C5—C6178.02 (9)C13—C14—C15—O3178.18 (8)
C4—C5—C6—C71.47 (14)C13—C14—C15—C160.72 (13)
C1—C5—C6—C7178.33 (9)O3—C15—C16—C11178.37 (8)
C5—C6—C7—C80.26 (14)C14—C15—C16—C110.61 (13)
C6—C7—C8—C91.73 (15)C12—C11—C16—C150.06 (13)
C7—C8—C9—C41.46 (14)C10—C11—C16—C15179.69 (8)
C5—C4—C9—C80.24 (13)
 

Acknowledgements

All X-ray crystallography measurements were made in the Mol­ecular Education, Technology, and Research Innovation Center (METRIC) at North Carolina State University.

Funding information

Funding for this research was provided by: GGC STEC 4500 Research Fund.

References

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