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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

rac-2-Bromo-3-eth­­oxy-1,3-bis­­(4-meth­oxy­phen­yl)propan-1-one

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and bDepartment of Studies in Chemistry, Mangalore University, Mangalagangotri, Mangalore 574 199, India
*Correspondence e-mail: hkfun@usm.my

(Received 17 November 2008; accepted 21 November 2008; online 3 December 2008)

In the racemic (S,S/R,R) title compound, C19H21BrO4, the two benzene rings are almost coplanar to each other, forming a dihedral angle of 3.58 (10)°. The crystal packing is strengthened by inter­molecular Br—O [2.9800 (16) Å] short contacts, which link the molecules into infinite one-dimensional chains along [001].

Related literature

For the pharmacological applications of chalcones, see: Di Carlo et al. (1999[Di Carlo, G., Mascolo, N., Izzo, A. A. & Capasso, F. (1999). Life Sci. 65, 337-353.]); Dimmock et al. (1999[Dimmock, J. R., Elias, D. W., Beazely, M. A. & Kandepu, N. M. (1999). Curr. Med. Chem. 6, 1125-1149.]); Go et al. (2005[Go, M. L., Wu, X. & Liu, X. L. (2005). Curr. Med. Chem. 12, 483-499.]); Kalluraya et al. (1994[Kalluraya, B., De Souza, A. & Holla, B. S. (1994). Indian J. Chem. Sect. B, 33, 1017-1022.]); Rai et al. (2007[Rai, N. S., Kalluraya, B. & Lingappa, B. (2007). Synth. Commun. 37, 2267-2273.]). 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
  • C19H21BrO4

  • Mr = 393.27

  • Monoclinic, P 21 /c

  • a = 12.2734 (10) Å

  • b = 15.3432 (12) Å

  • c = 10.4381 (8) Å

  • β = 114.399 (4)°

  • V = 1790.1 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 2.31 mm−1

  • T = 100.0 (1) K

  • 0.55 × 0.38 × 0.19 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.351, Tmax = 0.644

  • 22919 measured reflections

  • 5229 independent reflections

  • 4345 reflections with I > 2σ(I)

  • Rint = 0.045

Refinement
  • R[F2 > 2σ(F2)] = 0.036

  • wR(F2) = 0.103

  • S = 1.09

  • 5229 reflections

  • 219 parameters

  • H-atom parameters constrained

  • Δρmax = 1.15 e Å−3

  • Δρmin = −1.21 e Å−3

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

Chalcones, one of the major classes of natural products with widespread distribution in fruits, vegetables, spices, tea and soy based foodstuff, have recently been the subject of great interest for their interesting pharmacological activities (Di Carlo et al., 1999). Chalcones and its derivatives have been reported to possess many useful properties including anti-inflammatory, antimicrobial, antifungal, antioxidant, cytotoxic, antitumor and anticancer activities (Dimmock et al., 1999; Go et al., 2005). Monobromo chalcones are used in the formation of many heterocyclic compounds having multiple applications (Kalluraya et al., 1994; Rai et al., 2007). Due to these varied applications, we have synthesized a new α-bromo chalcone and report its crystal structure.

Bond lengths and angles in (I) (Fig. 1) are found to have normal values (Allen et al., 1987). There are two chiral centres C7 and C8 in the molecular structure therefore the centrosymmetic crystal is a racemate. The dihedral angle formed by the phenyl (C1—C6; C10—C15) rings is 3.58 (10)°, indicating that they are almost coplanar to each other.

The crystal packing is strengthened by intermolecular Br···Oi=2.9800 (16)Å [symmetry code: X,1/2-Y,-1/2+Z] short contact. In the crystal packing, the molecules are linked into infinite one-dimensional chains along the [001] direction (Fig 2).

Related literature top

For the pharmacological applications of chalcones, see: Di Carlo et al. (1999); Dimmock et al. (1999); Go et al. (2005); Kalluraya et al. (1994); Rai et al. (2007). For bond-length data, see: Allen et al. (1987).

Experimental top

1,3-Di(p-anisyl)-2,3-dibromopropane (0.01 mol) when treated with ethanol(25 mL) at room temperature in presence of triethyl amine (0.02 mol) resulted in the formation of the title compound involving a nucleophilic substitution reaction.

Refinement top

H atoms were positioned geometrically (C—H=0.93–0.98 Å) and refined using a riding model with, Uiso(H)=1.2Uequ(C) and 1.5Uequ(Cmethyl). A rotating group model was used for the methyl groups.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom numbering scheme.
[Figure 2] Fig. 2. The crystal packing of the title compound, viewed down the b axis, showing the linking of the molecules by Br—O short contacts into an infinite one-dimensional chain along the [0 0 1]-direction.
rac-2-Bromo-3-ethoxy-1,3-bis(4-methoxyphenyl)propan-1-one top
Crystal data top
C19H21BrO4F(000) = 808
Mr = 393.27Dx = 1.459 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 9847 reflections
a = 12.2734 (10) Åθ = 2.3–35.9°
b = 15.3432 (12) ŵ = 2.32 mm1
c = 10.4381 (8) ÅT = 100 K
β = 114.399 (4)°Block, colourless
V = 1790.1 (3) Å30.55 × 0.38 × 0.19 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
5229 independent reflections
Radiation source: fine-focus sealed tube4345 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
ϕ and ω scansθmax = 30.0°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 1717
Tmin = 0.351, Tmax = 0.644k = 2119
22919 measured reflectionsl = 1414
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)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.103H-atom parameters constrained
S = 1.09 w = 1/[σ2(Fo2) + (0.0572P)2 + 0.6245P]
where P = (Fo2 + 2Fc2)/3
5229 reflections(Δ/σ)max = 0.001
219 parametersΔρmax = 1.15 e Å3
0 restraintsΔρmin = 1.21 e Å3
Crystal data top
C19H21BrO4V = 1790.1 (3) Å3
Mr = 393.27Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.2734 (10) ŵ = 2.32 mm1
b = 15.3432 (12) ÅT = 100 K
c = 10.4381 (8) Å0.55 × 0.38 × 0.19 mm
β = 114.399 (4)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
5229 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
4345 reflections with I > 2σ(I)
Tmin = 0.351, Tmax = 0.644Rint = 0.046
22919 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0360 restraints
wR(F2) = 0.103H-atom parameters constrained
S = 1.09Δρmax = 1.15 e Å3
5229 reflectionsΔρmin = 1.21 e Å3
219 parameters
Special details top

Experimental. The data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
Br10.141463 (16)0.307078 (13)0.897910 (19)0.01800 (8)
O10.43693 (13)0.28784 (11)0.57932 (16)0.0269 (3)
O20.59815 (14)0.61005 (11)1.23343 (17)0.0280 (3)
O30.01580 (12)0.41258 (9)1.14119 (14)0.0178 (3)
O40.23341 (13)0.32415 (10)1.25655 (16)0.0242 (3)
C10.18733 (17)0.26157 (13)0.9281 (2)0.0188 (4)
H1A0.16360.22631.00750.023*
C20.29744 (18)0.24568 (14)0.8159 (2)0.0215 (4)
H2A0.34690.20130.82130.026*
C30.33187 (17)0.29711 (13)0.6964 (2)0.0198 (4)
C40.25693 (17)0.36403 (14)0.6904 (2)0.0196 (4)
H4A0.27960.39800.60970.024*
C50.14917 (17)0.38024 (13)0.8036 (2)0.0173 (4)
H5A0.10100.42590.79920.021*
C60.11204 (17)0.32845 (13)0.9248 (2)0.0156 (4)
C70.00122 (16)0.34564 (13)1.05432 (19)0.0153 (4)
H7A0.02540.29171.10930.018*
C80.10736 (16)0.38049 (13)1.03024 (19)0.0156 (4)
H8A0.09160.44040.99500.019*
C90.22347 (17)0.37698 (13)1.16527 (19)0.0168 (4)
C100.32249 (16)0.43701 (12)1.17987 (19)0.0156 (4)
C110.31634 (18)0.49576 (14)1.0753 (2)0.0207 (4)
H11A0.24870.49690.99060.025*
C120.40986 (19)0.55249 (15)1.0964 (2)0.0244 (4)
H12A0.40460.59171.02610.029*
C130.51188 (18)0.55101 (14)1.2228 (2)0.0214 (4)
C140.51982 (18)0.49233 (14)1.3275 (2)0.0215 (4)
H14A0.58770.49101.41190.026*
C150.42559 (17)0.43567 (13)1.3052 (2)0.0194 (4)
H15A0.43130.39611.37510.023*
C160.7050 (2)0.61116 (17)1.3607 (3)0.0305 (5)
H16A0.75930.65381.35320.046*
H16B0.74200.55471.37620.046*
H16C0.68550.62571.43820.046*
C170.52119 (18)0.22532 (17)0.5863 (2)0.0286 (5)
H17A0.59050.22450.49830.043*
H17B0.54440.24100.66050.043*
H17C0.48500.16860.60460.043*
C180.07984 (19)0.38291 (14)1.2207 (2)0.0210 (4)
H18A0.04990.32651.26230.025*
H18B0.16430.37731.16020.025*
C190.0613 (3)0.44917 (18)1.3337 (3)0.0375 (6)
H19A0.10250.43081.38980.056*
H19B0.09230.50451.29130.056*
H19C0.02260.45461.39230.056*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.01397 (11)0.02230 (13)0.01772 (11)0.00063 (7)0.00655 (8)0.00428 (7)
O10.0155 (7)0.0366 (9)0.0219 (8)0.0060 (6)0.0008 (6)0.0019 (6)
O20.0209 (7)0.0318 (9)0.0297 (8)0.0109 (7)0.0088 (6)0.0012 (7)
O30.0188 (6)0.0194 (7)0.0179 (6)0.0001 (5)0.0103 (5)0.0021 (5)
O40.0190 (7)0.0292 (8)0.0205 (7)0.0047 (6)0.0043 (6)0.0068 (6)
C10.0180 (9)0.0186 (10)0.0199 (9)0.0004 (7)0.0080 (7)0.0015 (7)
C20.0171 (9)0.0239 (11)0.0244 (10)0.0048 (8)0.0096 (8)0.0017 (8)
C30.0128 (8)0.0250 (11)0.0199 (9)0.0007 (7)0.0050 (7)0.0041 (7)
C40.0169 (8)0.0239 (10)0.0172 (9)0.0014 (8)0.0061 (7)0.0017 (7)
C50.0156 (8)0.0177 (9)0.0200 (9)0.0007 (7)0.0089 (7)0.0003 (7)
C60.0136 (8)0.0174 (9)0.0162 (8)0.0007 (7)0.0066 (7)0.0019 (7)
C70.0139 (8)0.0160 (9)0.0159 (8)0.0002 (7)0.0060 (7)0.0007 (7)
C80.0141 (8)0.0180 (9)0.0150 (8)0.0006 (7)0.0062 (7)0.0017 (7)
C90.0144 (8)0.0195 (10)0.0152 (8)0.0004 (7)0.0048 (7)0.0014 (7)
C100.0141 (8)0.0175 (9)0.0160 (8)0.0008 (7)0.0069 (7)0.0009 (7)
C110.0168 (9)0.0266 (11)0.0166 (9)0.0029 (8)0.0050 (7)0.0020 (7)
C120.0217 (10)0.0305 (12)0.0212 (10)0.0057 (9)0.0090 (8)0.0037 (8)
C130.0175 (9)0.0241 (11)0.0239 (10)0.0060 (8)0.0097 (8)0.0050 (8)
C140.0164 (9)0.0251 (11)0.0183 (9)0.0022 (8)0.0024 (7)0.0016 (7)
C150.0181 (9)0.0211 (10)0.0168 (9)0.0009 (8)0.0050 (7)0.0012 (7)
C160.0180 (10)0.0336 (13)0.0356 (12)0.0075 (9)0.0067 (9)0.0066 (10)
C170.0144 (9)0.0372 (13)0.0320 (12)0.0058 (9)0.0075 (9)0.0100 (10)
C180.0234 (10)0.0237 (10)0.0197 (9)0.0043 (8)0.0126 (8)0.0038 (7)
C190.0482 (15)0.0422 (15)0.0324 (13)0.0034 (12)0.0272 (12)0.0100 (11)
Geometric parameters (Å, º) top
Br1—C81.9569 (18)C9—C101.482 (3)
O1—C31.369 (2)C10—C111.393 (3)
O1—C171.434 (3)C10—C151.395 (3)
O2—C131.363 (2)C11—C121.384 (3)
O2—C161.431 (3)C11—H11A0.9300
O3—C181.433 (2)C12—C131.394 (3)
O3—C71.441 (2)C12—H12A0.9300
O4—C91.218 (2)C13—C141.388 (3)
C1—C61.391 (3)C14—C151.388 (3)
C1—C21.396 (3)C14—H14A0.9300
C1—H1A0.9300C15—H15A0.9300
C2—C31.387 (3)C16—H16A0.9600
C2—H2A0.9300C16—H16B0.9600
C3—C41.397 (3)C16—H16C0.9600
C4—C51.384 (3)C17—H17A0.9600
C4—H4A0.9300C17—H17B0.9600
C5—C61.401 (3)C17—H17C0.9600
C5—H5A0.9300C18—C191.502 (3)
C6—C71.509 (3)C18—H18A0.9700
C7—C81.522 (3)C18—H18B0.9700
C7—H7A0.9800C19—H19A0.9600
C8—C91.536 (3)C19—H19B0.9600
C8—H8A0.9800C19—H19C0.9600
Br1···O4i2.9800 (16)
C3—O1—C17117.21 (17)C12—C11—C10120.63 (19)
C13—O2—C16117.85 (18)C12—C11—H11A119.7
C18—O3—C7113.25 (15)C10—C11—H11A119.7
C6—C1—C2122.07 (18)C11—C12—C13120.13 (19)
C6—C1—H1A119.0C11—C12—H12A119.9
C2—C1—H1A119.0C13—C12—H12A119.9
C3—C2—C1119.00 (19)O2—C13—C14124.58 (19)
C3—C2—H2A120.5O2—C13—C12115.48 (19)
C1—C2—H2A120.5C14—C13—C12119.94 (19)
O1—C3—C2124.66 (19)C15—C14—C13119.47 (18)
O1—C3—C4115.54 (18)C15—C14—H14A120.3
C2—C3—C4119.81 (18)C13—C14—H14A120.3
C5—C4—C3120.56 (18)C14—C15—C10121.22 (18)
C5—C4—H4A119.7C14—C15—H15A119.4
C3—C4—H4A119.7C10—C15—H15A119.4
C4—C5—C6120.57 (18)O2—C16—H16A109.5
C4—C5—H5A119.7O2—C16—H16B109.5
C6—C5—H5A119.7H16A—C16—H16B109.5
C1—C6—C5117.97 (17)O2—C16—H16C109.5
C1—C6—C7118.85 (17)H16A—C16—H16C109.5
C5—C6—C7123.05 (17)H16B—C16—H16C109.5
O3—C7—C6111.65 (15)O1—C17—H17A109.5
O3—C7—C8102.12 (14)O1—C17—H17B109.5
C6—C7—C8116.62 (15)H17A—C17—H17B109.5
O3—C7—H7A108.7O1—C17—H17C109.5
C6—C7—H7A108.7H17A—C17—H17C109.5
C8—C7—H7A108.7H17B—C17—H17C109.5
C7—C8—C9111.65 (15)O3—C18—C19107.37 (18)
C7—C8—Br1111.20 (13)O3—C18—H18A110.2
C9—C8—Br1103.86 (12)C19—C18—H18A110.2
C7—C8—H8A110.0O3—C18—H18B110.2
C9—C8—H8A110.0C19—C18—H18B110.2
Br1—C8—H8A110.0H18A—C18—H18B108.5
O4—C9—C10121.35 (17)C18—C19—H19A109.5
O4—C9—C8119.74 (18)C18—C19—H19B109.5
C10—C9—C8118.89 (16)H19A—C19—H19B109.5
C11—C10—C15118.61 (18)C18—C19—H19C109.5
C11—C10—C9123.01 (17)H19A—C19—H19C109.5
C15—C10—C9118.36 (17)H19B—C19—H19C109.5
C6—C1—C2—C31.2 (3)C7—C8—C9—O425.2 (3)
C17—O1—C3—C25.5 (3)Br1—C8—C9—O494.68 (19)
C17—O1—C3—C4174.36 (19)C7—C8—C9—C10156.22 (17)
C1—C2—C3—O1179.59 (19)Br1—C8—C9—C1083.87 (18)
C1—C2—C3—C40.5 (3)O4—C9—C10—C11177.2 (2)
O1—C3—C4—C5179.04 (18)C8—C9—C10—C111.3 (3)
C2—C3—C4—C50.9 (3)O4—C9—C10—C154.0 (3)
C3—C4—C5—C61.6 (3)C8—C9—C10—C15177.47 (17)
C2—C1—C6—C50.5 (3)C15—C10—C11—C121.0 (3)
C2—C1—C6—C7175.54 (18)C9—C10—C11—C12177.7 (2)
C4—C5—C6—C10.9 (3)C10—C11—C12—C130.4 (3)
C4—C5—C6—C7176.77 (18)C16—O2—C13—C140.7 (3)
C18—O3—C7—C676.10 (19)C16—O2—C13—C12179.8 (2)
C18—O3—C7—C8158.56 (15)C11—C12—C13—O2179.4 (2)
C1—C6—C7—O394.3 (2)C11—C12—C13—C140.2 (3)
C5—C6—C7—O381.5 (2)O2—C13—C14—C15179.4 (2)
C1—C6—C7—C8148.80 (18)C12—C13—C14—C150.1 (3)
C5—C6—C7—C835.3 (3)C13—C14—C15—C100.5 (3)
O3—C7—C8—C970.12 (18)C11—C10—C15—C141.1 (3)
C6—C7—C8—C9167.90 (16)C9—C10—C15—C14177.72 (19)
O3—C7—C8—Br1174.39 (11)C7—O3—C18—C19164.38 (17)
C6—C7—C8—Br152.41 (19)
Symmetry code: (i) x, y+1/2, z1/2.

Experimental details

Crystal data
Chemical formulaC19H21BrO4
Mr393.27
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)12.2734 (10), 15.3432 (12), 10.4381 (8)
β (°) 114.399 (4)
V3)1790.1 (3)
Z4
Radiation typeMo Kα
µ (mm1)2.32
Crystal size (mm)0.55 × 0.38 × 0.19
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.351, 0.644
No. of measured, independent and
observed [I > 2σ(I)] reflections
22919, 5229, 4345
Rint0.046
(sin θ/λ)max1)0.703
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.103, 1.09
No. of reflections5229
No. of parameters219
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.15, 1.21

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

 

Footnotes

Permanent address: Department of Physics, Karunya University, Karunya Nagar, Coimbatore 641 114, India.

Acknowledgements

FHK and SRJ thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. SRJ thanks Universiti Sains Malaysia for a post–doctoral research fellowship. HKF also thank Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

References

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 citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationDi Carlo, G., Mascolo, N., Izzo, A. A. & Capasso, F. (1999). Life Sci. 65, 337–353.  Web of Science CrossRef PubMed CAS Google Scholar
First citationDimmock, J. R., Elias, D. W., Beazely, M. A. & Kandepu, N. M. (1999). Curr. Med. Chem. 6, 1125–1149.  Web of Science PubMed CAS Google Scholar
First citationGo, M. L., Wu, X. & Liu, X. L. (2005). Curr. Med. Chem. 12, 483–499.  CrossRef CAS Google Scholar
First citationKalluraya, B., De Souza, A. & Holla, B. S. (1994). Indian J. Chem. Sect. B, 33, 1017–1022.  Google Scholar
First citationRai, N. S., Kalluraya, B. & Lingappa, B. (2007). Synth. Commun. 37, 2267–2273.  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

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds