supplementary materials


hb7095 scheme

Acta Cryst. (2013). E69, o1143-o1144    [ doi:10.1107/S1600536813016838 ]

(2E)-1-(4-Bromophenyl)-3-[3-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one

R. Prasath, P. Bhavana, S. W. Ng and E. R. T. Tiekink

Abstract top

The pyrazole ring in the title compound, C25H19BrN2O2, is almost planar (r.m.s. deviation = 0.003 Å) and forms dihedral angles of 7.56 (13) and 56.48 (13)° with the N- and C-bound benzene rings, respectively. The prop-2-en-1-one residue has an E conformation about the C=C double bond [1.328 (4) Å] and is almost coplanar with the pyrazole ring [C-C-C-C torsion angle = -174.4 (3)°]. A twist between the prop-2-en-1-one unit and the terminal benzene ring is evident [C-C-C-C torsion angle = -15.4 (4)°]. In the crystal, molecules are consolidated into a three-dimensional architecture by C-H...O, C-H...[pi] and [pi]-[pi] [centroid-centroid separation = 3.7597 (16) Å] interactions.

Comment top

In addition to their being valuable intermediates in organic synthesis (Prasath & Bhavana, 2012), nitrogen-containing heterocyclic analogues, such as pyrazole chalcones, exhibit a variety of biological activities, e.g. anti-plasmodial, anti-microbial and anti-cancer activities (Prasath et al., 2013; Babasaheb et al., 2009). It was in this context that the title compound, (I), was investigated.

The molecular structure of (I), Fig. 1, comprises a planar (r.m.s. deviation = 0.003 Å) tri-substituted pyrazoyl ring. The N1- and C12-bound benzene rings form dihedral angles of 7.56 (13) and 56.48 (13)°, respectively, with the five-membered ring, and 60.88 (12)° with each other. The prop-2-en-1-one residue has an E-configuration about the C8C9 double bond [1.328 (4) Å], and is also co-planar with the five-membered ring as seen in the value of the C8—C9—C10—C11 torsion angle of -174.4 (3)°. This planarity does not extend to the terminal benzene ring as there is a twist manifested in the C2—C1—C7—C8 torsion angle of -15.4 (4)°. The observed conformation for (I) resembles closely that reported recently for the unsubstituted parent compound (Fun et al., 2011).

In the crystal packing, centrosymmetrically related molecules are connected via C—H···O interactions, Table 1, and these are connected into a three-dimensional architecture by ππ [between centrosymmetrically related bromobenzene rings; 3.7597 (16)° for symmetry operation 1 - x, 2 - y, 2 - z] and methyl-C—H···π(methoxybenzene ring) interactions, Fig. 2 and Table 1.

Related literature top

For background details and biological applications of pyrazole and chalcones, see: Babasaheb et al. (2009); Prasath & Bhavana (2012); Prasath et al. (2013). For the structure of the 4-methoxyphenyl pyrazole compound, see: Fun et al. (2011).

Experimental top

A mixture of 3-(4-methoxyphenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde (1.4 g, 0.005 M), 4-bromo acetophenone (1 g, 0.005 M) and KOH (0.5 g) in distilled ethanol (50 ml) was stirred for 12 h at room temperature. The resulting mixture was neutralized with dilute acetic acid. The resultant solid was filtered, dried and purified by column chromatography using 1:2 mixture of ethyl acetate and hexane. Re-crystallization was by slow evaporation of an acetone solution of (I) which yielded yellow needles. M.pt. 433–435 K. Yield: 80%.

Refinement top

The C-bound H atoms were geometrically placed (C—H = 0.95–0.98 Å) and refined as riding with Uiso(H) = 1.2–1.5Ueq(C).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2013); cell refinement: CrysAlis PRO (Agilent, 2013); data reduction: CrysAlis PRO (Agilent, 2013); 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) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing displacement ellipsoids at the 70% probability level.
[Figure 2] Fig. 2. A view in projection down the a axis of the unit-cell contents of (I). The C—H···O, C—H···π, and ππ interactions are shown as blue, purple and blue dashed lines, respectively.
(2E)-1-(4-Bromophenyl)-3-[3-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one top
Crystal data top
C25H19BrN2O2Z = 2
Mr = 459.33F(000) = 468
Triclinic, P1Dx = 1.511 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.3643 (3) ÅCell parameters from 2849 reflections
b = 10.6795 (5) Åθ = 3.0–27.5°
c = 13.1038 (6) ŵ = 2.06 mm1
α = 91.822 (4)°T = 100 K
β = 101.311 (4)°Prism, yellow
γ = 91.792 (3)°0.50 × 0.40 × 0.30 mm
V = 1009.31 (8) Å3
Data collection top
Agilent SuperNova Dual
diffractometer with an Atlas detector
4649 independent reflections
Radiation source: SuperNova (Mo) X-ray Source3875 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.038
Detector resolution: 10.4041 pixels mm-1θmax = 27.6°, θmin = 3.0°
ω scanh = 99
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2013)
k = 1313
Tmin = 0.921, Tmax = 1.000l = 1517
8736 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)] = 0.043Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.111H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.0485P)2 + 0.731P]
where P = (Fo2 + 2Fc2)/3
4649 reflections(Δ/σ)max = 0.001
271 parametersΔρmax = 0.47 e Å3
0 restraintsΔρmin = 0.55 e Å3
Crystal data top
C25H19BrN2O2γ = 91.792 (3)°
Mr = 459.33V = 1009.31 (8) Å3
Triclinic, P1Z = 2
a = 7.3643 (3) ÅMo Kα radiation
b = 10.6795 (5) ŵ = 2.06 mm1
c = 13.1038 (6) ÅT = 100 K
α = 91.822 (4)°0.50 × 0.40 × 0.30 mm
β = 101.311 (4)°
Data collection top
Agilent SuperNova Dual
diffractometer with an Atlas detector
4649 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2013)
3875 reflections with I > 2σ(I)
Tmin = 0.921, Tmax = 1.000Rint = 0.038
8736 measured reflectionsθmax = 27.6°
Refinement top
R[F2 > 2σ(F2)] = 0.043H-atom parameters constrained
wR(F2) = 0.111Δρmax = 0.47 e Å3
S = 1.04Δρmin = 0.55 e Å3
4649 reflectionsAbsolute structure: ?
271 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
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
Br10.11696 (4)1.12761 (3)0.86611 (2)0.03080 (12)
O10.6500 (3)0.61824 (19)0.97288 (15)0.0248 (4)
O20.6830 (2)0.98810 (16)0.42732 (14)0.0185 (4)
N11.2201 (3)0.58644 (19)0.65301 (17)0.0145 (4)
N21.3006 (3)0.51261 (19)0.73128 (16)0.0137 (4)
C10.5191 (4)0.7966 (2)0.8896 (2)0.0172 (5)
C20.5417 (4)0.8979 (3)0.8283 (2)0.0213 (6)
H20.63960.89920.79060.026*
C30.4235 (4)0.9967 (3)0.8216 (2)0.0227 (6)
H30.43911.06560.77960.027*
C40.2828 (4)0.9933 (3)0.8769 (2)0.0208 (6)
C50.2543 (4)0.8941 (3)0.9378 (2)0.0227 (6)
H50.15510.89310.97450.027*
C60.3751 (4)0.7954 (3)0.9440 (2)0.0205 (6)
H60.35870.72660.98590.025*
C70.6504 (4)0.6906 (2)0.9023 (2)0.0173 (5)
C80.7763 (4)0.6782 (2)0.8287 (2)0.0176 (5)
H80.74830.71740.76370.021*
C90.9287 (4)0.6129 (2)0.8514 (2)0.0164 (5)
H90.95150.57590.91740.020*
C101.0640 (3)0.5920 (2)0.7864 (2)0.0147 (5)
C111.2115 (4)0.5143 (2)0.8117 (2)0.0155 (5)
H111.24390.47030.87420.019*
C121.0770 (3)0.6352 (2)0.68607 (19)0.0130 (5)
C131.4631 (3)0.4466 (2)0.7208 (2)0.0142 (5)
C141.5469 (4)0.4699 (2)0.6376 (2)0.0162 (5)
H141.49930.53050.58890.019*
C151.7022 (4)0.4038 (2)0.6258 (2)0.0172 (5)
H151.75940.41830.56810.021*
C161.7731 (4)0.3171 (2)0.6979 (2)0.0198 (6)
H161.87910.27220.68990.024*
C171.6886 (4)0.2960 (3)0.7821 (2)0.0215 (6)
H171.73810.23700.83190.026*
C181.5322 (4)0.3604 (2)0.7942 (2)0.0186 (5)
H181.47410.34570.85160.022*
C190.9641 (3)0.7257 (2)0.62029 (19)0.0132 (5)
C200.9485 (3)0.8468 (2)0.6597 (2)0.0153 (5)
H201.00310.86780.73030.018*
C210.8557 (3)0.9374 (2)0.5987 (2)0.0153 (5)
H210.84581.01910.62740.018*
C220.7771 (3)0.9074 (2)0.4951 (2)0.0141 (5)
C230.7907 (4)0.7859 (2)0.4545 (2)0.0164 (5)
H230.73590.76480.38400.020*
C240.8836 (3)0.6967 (2)0.5167 (2)0.0154 (5)
H240.89250.61460.48840.019*
C250.6747 (4)1.1152 (2)0.4644 (2)0.0196 (6)
H25A0.60391.16360.40890.029*
H25B0.80061.15210.48510.029*
H25C0.61381.11660.52450.029*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.02570 (17)0.03300 (19)0.03209 (19)0.01428 (13)0.00041 (12)0.00323 (13)
O10.0285 (11)0.0290 (11)0.0198 (10)0.0076 (9)0.0099 (9)0.0081 (9)
O20.0181 (9)0.0157 (9)0.0203 (9)0.0013 (7)0.0009 (8)0.0053 (8)
N10.0168 (10)0.0125 (10)0.0143 (10)0.0032 (8)0.0026 (8)0.0040 (8)
N20.0139 (10)0.0133 (10)0.0140 (10)0.0025 (8)0.0023 (8)0.0037 (8)
C10.0174 (12)0.0205 (13)0.0129 (12)0.0009 (11)0.0018 (10)0.0020 (10)
C20.0200 (13)0.0246 (14)0.0206 (14)0.0025 (11)0.0065 (11)0.0015 (12)
C30.0259 (14)0.0216 (14)0.0209 (14)0.0038 (12)0.0042 (12)0.0041 (12)
C40.0177 (13)0.0239 (14)0.0185 (13)0.0078 (11)0.0025 (11)0.0043 (11)
C50.0157 (13)0.0336 (16)0.0189 (14)0.0042 (12)0.0043 (11)0.0035 (12)
C60.0212 (13)0.0268 (14)0.0147 (13)0.0023 (11)0.0054 (11)0.0038 (11)
C70.0172 (12)0.0200 (13)0.0144 (12)0.0010 (10)0.0025 (10)0.0003 (11)
C80.0195 (13)0.0189 (13)0.0149 (12)0.0006 (11)0.0044 (10)0.0007 (10)
C90.0192 (12)0.0180 (12)0.0124 (12)0.0009 (10)0.0034 (10)0.0039 (10)
C100.0141 (12)0.0149 (12)0.0151 (12)0.0014 (10)0.0024 (10)0.0015 (10)
C110.0170 (12)0.0155 (12)0.0144 (12)0.0003 (10)0.0032 (10)0.0037 (10)
C120.0111 (11)0.0113 (11)0.0157 (12)0.0011 (9)0.0013 (9)0.0006 (10)
C130.0139 (11)0.0136 (11)0.0144 (12)0.0025 (10)0.0009 (10)0.0011 (10)
C140.0189 (12)0.0140 (12)0.0160 (12)0.0025 (10)0.0040 (10)0.0016 (10)
C150.0174 (12)0.0195 (13)0.0158 (13)0.0001 (10)0.0060 (10)0.0008 (10)
C160.0172 (12)0.0191 (13)0.0244 (14)0.0043 (11)0.0067 (11)0.0013 (11)
C170.0231 (14)0.0217 (14)0.0210 (14)0.0090 (11)0.0053 (11)0.0090 (11)
C180.0190 (13)0.0186 (13)0.0200 (13)0.0036 (11)0.0064 (11)0.0073 (11)
C190.0109 (11)0.0152 (12)0.0142 (12)0.0009 (9)0.0034 (9)0.0035 (10)
C200.0155 (12)0.0185 (12)0.0116 (12)0.0004 (10)0.0018 (10)0.0013 (10)
C210.0145 (12)0.0126 (12)0.0190 (13)0.0006 (10)0.0046 (10)0.0011 (10)
C220.0088 (11)0.0157 (12)0.0185 (13)0.0015 (9)0.0038 (10)0.0059 (10)
C230.0176 (12)0.0162 (12)0.0139 (12)0.0009 (10)0.0001 (10)0.0002 (10)
C240.0165 (12)0.0124 (11)0.0172 (13)0.0013 (10)0.0032 (10)0.0002 (10)
C250.0181 (13)0.0154 (12)0.0255 (14)0.0025 (11)0.0037 (11)0.0076 (11)
Geometric parameters (Å, º) top
Br1—C41.903 (3)C11—H110.9500
O1—C71.224 (3)C12—C191.480 (3)
O2—C221.362 (3)C13—C141.379 (4)
O2—C251.434 (3)C13—C181.388 (4)
N1—C121.329 (3)C14—C151.394 (3)
N1—N21.366 (3)C14—H140.9500
N2—C111.347 (3)C15—C161.384 (4)
N2—C131.435 (3)C15—H150.9500
C1—C61.389 (4)C16—C171.389 (4)
C1—C21.393 (4)C16—H160.9500
C1—C71.504 (4)C17—C181.392 (4)
C2—C31.383 (4)C17—H170.9500
C2—H20.9500C18—H180.9500
C3—C41.376 (4)C19—C201.394 (3)
C3—H30.9500C19—C241.391 (3)
C4—C51.382 (4)C20—C211.385 (4)
C5—C61.394 (4)C20—H200.9500
C5—H50.9500C21—C221.391 (4)
C6—H60.9500C21—H210.9500
C7—C81.470 (4)C22—C231.400 (3)
C8—C91.328 (4)C23—C241.383 (4)
C8—H80.9500C23—H230.9500
C9—C101.450 (3)C24—H240.9500
C9—H90.9500C25—H25A0.9800
C10—C111.382 (3)C25—H25B0.9800
C10—C121.427 (3)C25—H25C0.9800
C22—O2—C25117.2 (2)C14—C13—N2119.2 (2)
C12—N1—N2105.0 (2)C18—C13—N2119.4 (2)
C11—N2—N1112.2 (2)C13—C14—C15119.4 (2)
C11—N2—C13128.4 (2)C13—C14—H14120.3
N1—N2—C13119.4 (2)C15—C14—H14120.3
C6—C1—C2119.1 (2)C16—C15—C14120.2 (2)
C6—C1—C7118.7 (2)C16—C15—H15119.9
C2—C1—C7122.1 (2)C14—C15—H15119.9
C3—C2—C1120.8 (3)C15—C16—C17119.7 (2)
C3—C2—H2119.6C15—C16—H16120.1
C1—C2—H2119.6C17—C16—H16120.1
C4—C3—C2118.7 (3)C16—C17—C18120.7 (3)
C4—C3—H3120.6C16—C17—H17119.7
C2—C3—H3120.6C18—C17—H17119.7
C3—C4—C5122.3 (2)C13—C18—C17118.6 (2)
C3—C4—Br1118.9 (2)C13—C18—H18120.7
C5—C4—Br1118.7 (2)C17—C18—H18120.7
C4—C5—C6118.2 (2)C20—C19—C24118.3 (2)
C4—C5—H5120.9C20—C19—C12119.7 (2)
C6—C5—H5120.9C24—C19—C12121.8 (2)
C1—C6—C5120.8 (3)C21—C20—C19121.8 (2)
C1—C6—H6119.6C21—C20—H20119.1
C5—C6—H6119.6C19—C20—H20119.1
O1—C7—C8122.2 (2)C20—C21—C22119.3 (2)
O1—C7—C1119.7 (2)C20—C21—H21120.3
C8—C7—C1118.1 (2)C22—C21—H21120.3
C9—C8—C7121.1 (2)O2—C22—C21124.8 (2)
C9—C8—H8119.4O2—C22—C23115.6 (2)
C7—C8—H8119.4C21—C22—C23119.6 (2)
C8—C9—C10127.1 (2)C24—C23—C22120.2 (2)
C8—C9—H9116.4C24—C23—H23119.9
C10—C9—H9116.4C22—C23—H23119.9
C11—C10—C12104.5 (2)C23—C24—C19120.8 (2)
C11—C10—C9123.8 (2)C23—C24—H24119.6
C12—C10—C9131.6 (2)C19—C24—H24119.6
N2—C11—C10107.2 (2)O2—C25—H25A109.5
N2—C11—H11126.4O2—C25—H25B109.5
C10—C11—H11126.4H25A—C25—H25B109.5
N1—C12—C10111.1 (2)O2—C25—H25C109.5
N1—C12—C19118.7 (2)H25A—C25—H25C109.5
C10—C12—C19130.2 (2)H25B—C25—H25C109.5
C14—C13—C18121.4 (2)
C12—N1—N2—C110.0 (3)C9—C10—C12—C196.5 (5)
C12—N1—N2—C13179.2 (2)C11—N2—C13—C14171.7 (2)
C6—C1—C2—C30.3 (4)N1—N2—C13—C147.3 (3)
C7—C1—C2—C3177.2 (2)C11—N2—C13—C188.5 (4)
C1—C2—C3—C40.2 (4)N1—N2—C13—C18172.5 (2)
C2—C3—C4—C50.8 (4)C18—C13—C14—C151.4 (4)
C2—C3—C4—Br1178.9 (2)N2—C13—C14—C15178.5 (2)
C3—C4—C5—C61.0 (4)C13—C14—C15—C161.1 (4)
Br1—C4—C5—C6179.1 (2)C14—C15—C16—C170.2 (4)
C2—C1—C6—C50.1 (4)C15—C16—C17—C180.6 (4)
C7—C1—C6—C5177.5 (2)C14—C13—C18—C170.6 (4)
C4—C5—C6—C10.5 (4)N2—C13—C18—C17179.2 (2)
C6—C1—C7—O113.0 (4)C16—C17—C18—C130.3 (4)
C2—C1—C7—O1164.4 (3)N1—C12—C19—C20120.3 (3)
C6—C1—C7—C8167.2 (2)C10—C12—C19—C2056.7 (4)
C2—C1—C7—C815.4 (4)N1—C12—C19—C2454.7 (3)
O1—C7—C8—C919.6 (4)C10—C12—C19—C24128.3 (3)
C1—C7—C8—C9160.2 (2)C24—C19—C20—C210.1 (4)
C7—C8—C9—C10179.5 (2)C12—C19—C20—C21175.2 (2)
C8—C9—C10—C11174.4 (3)C19—C20—C21—C220.6 (4)
C8—C9—C10—C121.9 (5)C25—O2—C22—C214.0 (4)
N1—N2—C11—C100.3 (3)C25—O2—C22—C23176.8 (2)
C13—N2—C11—C10179.4 (2)C20—C21—C22—O2179.9 (2)
C12—C10—C11—N20.5 (3)C20—C21—C22—C230.9 (4)
C9—C10—C11—N2176.7 (2)O2—C22—C23—C24179.9 (2)
N2—N1—C12—C100.3 (3)C21—C22—C23—C240.8 (4)
N2—N1—C12—C19177.2 (2)C22—C23—C24—C190.3 (4)
C11—C10—C12—N10.5 (3)C20—C19—C24—C230.1 (4)
C9—C10—C12—N1176.3 (3)C12—C19—C24—C23175.0 (2)
C11—C10—C12—C19176.6 (2)
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C1–C6 ring.
D—H···AD—HH···AD···AD—H···A
C11—H11···O1i0.952.253.198 (3)173
C25—H25B···Cg1ii0.982.613.478 (3)148
Symmetry codes: (i) x+2, y+1, z+2; (ii) x+2, y+2, z+1.

Experimental details

Crystal data
Chemical formulaC25H19BrN2O2
Mr459.33
Crystal system, space groupTriclinic, P1
Temperature (K)100
a, b, c (Å)7.3643 (3), 10.6795 (5), 13.1038 (6)
α, β, γ (°)91.822 (4), 101.311 (4), 91.792 (3)
V3)1009.31 (8)
Z2
Radiation typeMo Kα
µ (mm1)2.06
Crystal size (mm)0.50 × 0.40 × 0.30
Data collection
DiffractometerAgilent SuperNova Dual
diffractometer with an Atlas detector
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2013)
Tmin, Tmax0.921, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
8736, 4649, 3875
Rint0.038
(sin θ/λ)max1)0.651
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.111, 1.04
No. of reflections4649
No. of parameters271
No. of restraints0
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.47, 0.55

Computer programs: CrysAlis PRO (Agilent, 2013), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C1–C6 ring.
D—H···AD—HH···AD···AD—H···A
C11—H11···O1i0.952.253.198 (3)173
C25—H25B···Cg1ii0.982.613.478 (3)148
Symmetry codes: (i) x+2, y+1, z+2; (ii) x+2, y+2, z+1.
Acknowledgements top

PB and RP gratefully acknowledge the Council of Scientific and Industrial Research (CSIR), India, for research grant 02 (0076)/12/EMR-II and Senior Research Fellowship (09/919/(0014)/2012 EMR-I), respectively. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR-MOHE/SC/03).

references
References top

Agilent (2013). CrysAlis PRO. Agilent Technologies Inc., Santa Clara, CA, USA.

Babasaheb, P. B., Shrikant, S. G., Ragini, G. B., Nalini, M. G. & Chandrahasya, N. K. (2009). Bioorg. Med. Chem. 17, 8168–8173.

Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.

Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.

Fun, H.-K., Quah, C. K., Malladi, S., Hebbar, R. & Isloor, A. M. (2011). Acta Cryst. E67, o3105.

Prasath, R. & Bhavana, P. (2012). Heteroat. Chem. 23, 525–530.

Prasath, R., Bhavana, P., Ng, S. W. & Tiekink, E. R. T. (2013). J. Organomet. Chem. 726, 62–70.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.