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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 70| Part 4| April 2014| Pages o483-o484

N′-[(E)-(3-Fluoro­pyridin-2-yl)methyl­­idene]pyridine-3-carbohydrazide dihydrate

aDepartment of Chemical Ocenography, Cochin University of Science and Technology, Lakeside Campus, Kochi 682 016, India, bDepartment of Chemistry, Faculty of Science, Eastern University, Sri Lanka, Chenkalady, Sri Lanka, and cDepartment of Applied Chemistry, Cochin University of Science and Technology, Kochi 682 022, India
*Correspondence e-mail: eesans@yahoo.com

(Received 5 March 2014; accepted 19 March 2014; online 26 March 2014)

The organic molecule in the title dihydrate, C12H9FN4O·2H2O, exists in the E conformation with respect to the azo­methane C=N double bond. The mol­ecule is approximately planar, with a maximum deviation of 0.117 (1) Å for the carbonyl O atom from the mean plane of the mol­ecule. Both pyridine rings are essentially coplanar with the central C(=O)N2C unit [dihedral angles = 1.99 (7) and 5.71 (8)°], exhibiting a significant difference in dihedral angles from its benzohydrazide analogue. The crystal packing features N—H⋯O, O—H⋯N and O—H⋯O hydrogen-bond inter­actions, which lead to the formation of a chain along the c-axis direction through one of the water mol­ecules present, and these chains are stacked one over the other by means of ππ inter­actions [with centroid–centroid distances of 3.7099 (10) and 3.6322 (10) Å] between the aromatic rings in neighbouring anti­parallel mol­ecules, building a three-dimensional supra­molecular network.

Related literature

For the biological activity of carbohydrazide derivatives, see: Sreeja et al. (2004[Sreeja, P. B., Kurup, M. R. P., Kishore, A. & Jasmin, C. (2004). Polyhedron, 23, 575-581.]); Havanur et al. (2010[Havanur, V. C., Badiger, D. S., Ligade, S. G. & Gudasi, K. B. (2010). Pharma Chem. 2, 390-404.]); Despaigne et al. (2010[Despaigne, A. A. R., Vieira, L. F., Mendes, I. C., da Costa, F. B., Speziali, N. L. & Beraldo, H. (2010). J. Braz. Chem. Soc. 21, 1247-1257.]). For the synthesis of related compounds, see: Kuriakose et al. (2007[Kuriakose, M., Kurup, M. R. P. & Suresh, E. (2007). Polyhedron, 26, 2713-2718.]). For a related structure, see Nair et al. (2012[Nair, Y., Sithambaresan, M. & Kurup, M. R. P. (2012). Acta Cryst. E68, o2709.]).

[Scheme 1]

Experimental

Crystal data
  • C12H9FN4O·2H2O

  • Mr = 280.26

  • Monoclinic, P 21 /c

  • a = 7.3023 (7) Å

  • b = 14.4031 (17) Å

  • c = 12.6422 (13) Å

  • β = 94.842 (3)°

  • V = 1324.9 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 296 K

  • 0.41 × 0.21 × 0.20 mm

Data collection
  • Bruker Kappa APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2004[Bruker (2004). APEX2, SADABS, SAINT and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.963, Tmax = 0.969

  • 9779 measured reflections

  • 3237 independent reflections

  • 2339 reflections with I > 2σ(I)

  • Rint = 0.030

Refinement
  • R[F2 > 2σ(F2)] = 0.048

  • wR(F2) = 0.149

  • S = 1.04

  • 3237 reflections

  • 202 parameters

  • 7 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.29 e Å−3

  • Δρmin = −0.20 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N3—H3′⋯O1S 0.88 (1) 2.04 (1) 2.8821 (19) 160 (2)
O1S—H1A⋯N4i 0.87 (1) 2.09 (1) 2.946 (2) 170 (3)
O2S—H2A⋯N1i 0.87 (1) 2.10 (1) 2.965 (2) 177 (2)
O2S—H2B⋯O1i 0.86 (1) 1.97 (1) 2.816 (2) 172 (2)
Symmetry code: (i) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2004[Bruker (2004). APEX2, SADABS, SAINT and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: APEX2 and SAINT (Bruker, 2004[Bruker (2004). APEX2, SADABS, SAINT and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT and XPREP (Bruker, 2004[Bruker (2004). APEX2, SADABS, SAINT and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and DIAMOND (Brandenburg, 2010[Brandenburg, K. (2010). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

Carbohydrazides have attracted much attention for their excellent biological properties. Moreover, carbohydrazides derived from 2-acetylpyridine are known to inhibit the proliferation of tumour cells to a greater extent compared to standard anticancer agents (Havanur et al., 2010; Sreeja et al., 2004). In addition, metal complexes with carbohydrazides exhibit antimicrobial, DNA-binding and cytotoxic activities. It has also been shown that these metal complexes can be potent inhibitors of cell growth and DNA synthesis (Despaigne et al., 2010). We report herein the crystal structure of the title compound, a new carbohydrazide.

This molecule adopts an E configuration (Fig. 1) with respect to the C6=N2 bond and it exists in the amido form with a C7=O1 bond length of 1.2211 (18) Å which is very close to the reported C=O bond length of similar structure of benzene analogue (Nair et al., 2012). The O1 and N2 atoms are in a Z configuration with respect to C7–N3 having a tortional angle of -0.6 (3)°. The molecule is almost planar with maximum deviation of 0.117 (1) Å for the atom O1 from the mean plane of the molecule (r.m.s. deviation, 0.0513). The pyridyl ring having F atom is essentially coplanar with the central C(=O)N2C unit (dihedral angle 5.71 (8)°), the other pyridyl ring exhibits a torsion angle of 1.99 (7)°.

Whilst one of the water molecules connects two adjacent molecules through two O–H···N and N–H···O H-bonding interactions with D···A distances of 2.946 (2) and 2.882 (1) Å respectively, the other water molecule forms two O–H···N and O–H···O H-bonds with D···A distances of 2.965 (2) and 2.816 (2) Å with the same molecule (Fig. 2, Table 1). One of the water molecules acts as both a hydrogen bond acceptor as well as a donor towards another carbohydrazide molecule while the other acts only as hydrogen bond donor. By means of these interactions the molecules are chained through one of the water molecules to form infinite chains parallel to the c axis of the unit cell (Fig. 3). These parallel chains are stacked one over the other by means of two ππ interactions between the two aromatic rings of the neighbouring anti parallel molecules (Fig. 4) with centeroid-centeroid distances of 3.7099 (10) and 3.6322 (10) Å. Fig. 5 shows the stacked packing of the molecules along a axis in the unit cell.

Related literature top

For the biological activity of carbohydrazide derivatives, see: Sreeja et al. (2004); Havanur et al. (2010); Despaigne et al. (2010). For the synthesis of related compounds, see: Kuriakose et al. (2007). For a related structure, see Nair et al. (2012).

Experimental top

The title compound was prepared by adapting a reported procedure (Kuriakose et al., 2007). A solution of 3-fluoropyridine-2-carbaldehyde (1.25 g,1 mmol) in ethanol (10 ml) was mixed with an ethanolic solution (10 ml) of pyridine-3-carbohydrazide (1.37 g,1 mmol). The mixture was boiled under reflux for 12 h after adding few drops of glacial acetic acid and then cooled to room temperature. Colorless needle shaped crystals, suitable for single-crystal analysis, were obtained after slow evaporation of the solution in air for a few days.

Refinement top

The atoms H3', H1A, H1B, H2A and H2B were located from a difference Fourier map and refined isotropically. The N3—H3' bond distance was restrained to 0.88±0.01 Å. The O—H distances of water were restrained to 0.86±0.01 Å and H···H distances to 1.36±0.02 Å. The remaining hydrogen atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C–H distances of 0.93 Å, and with isotropic displacement parameters 1.2 times that of the parent carbon atoms.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 and SAINT (Bruker, 2004); data reduction: SAINT and XPREP (Bruker, 2004); 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, 2010); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. ORTEP diagram of N'-[(E)-(3-fluoropyridin-2-yl)methylidene]pyridine-3-carbohydrazide dihydrate with 50% probability ellipsoids.
[Figure 2] Fig. 2. Hydrogen-bonding interactions showing the interconnection of the molecules via one of the water molecules in the lattice.
[Figure 3] Fig. 3. Hydrogen-bonding interactions showing the chain progressing along c axis.
[Figure 4] Fig. 4. Hydrogen-bonding and ππ interactions in the lattice.
[Figure 5] Fig. 5. Packing diagram showing the stacked packing arrangement of the molecules along a axis.
N'-[(E)-(3-Fluoropyridin-2-yl)methylidene]pyridine-3-carbohydrazide dihydrate top
Crystal data top
C12H9FN4O·2H2OF(000) = 584
Mr = 280.26Dx = 1.405 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 4225 reflections
a = 7.3023 (7) Åθ = 2.8–28.0°
b = 14.4031 (17) ŵ = 0.11 mm1
c = 12.6422 (13) ÅT = 296 K
β = 94.842 (3)°Needle, colorless
V = 1324.9 (2) Å30.41 × 0.21 × 0.20 mm
Z = 4
Data collection top
Bruker Kappa APEXII CCD
diffractometer
3237 independent reflections
Radiation source: fine-focus sealed tube2339 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.030
Detector resolution: 8.33 pixels mm-1θmax = 28.2°, θmin = 2.8°
ω and ϕ scanh = 99
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
k = 1719
Tmin = 0.963, Tmax = 0.969l = 1616
9779 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.048H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.149 w = 1/[σ2(Fo2) + (0.0712P)2 + 0.3471P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max < 0.001
3237 reflectionsΔρmax = 0.29 e Å3
202 parametersΔρmin = 0.20 e Å3
7 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.079 (6)
Crystal data top
C12H9FN4O·2H2OV = 1324.9 (2) Å3
Mr = 280.26Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.3023 (7) ŵ = 0.11 mm1
b = 14.4031 (17) ÅT = 296 K
c = 12.6422 (13) Å0.41 × 0.21 × 0.20 mm
β = 94.842 (3)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
3237 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
2339 reflections with I > 2σ(I)
Tmin = 0.963, Tmax = 0.969Rint = 0.030
9779 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0487 restraints
wR(F2) = 0.149H atoms treated by a mixture of independent and constrained refinement
S = 1.04Δρmax = 0.29 e Å3
3237 reflectionsΔρmin = 0.20 e Å3
202 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
O2S0.5863 (3)0.45901 (12)0.25212 (11)0.0835 (5)
F10.77433 (17)1.26247 (8)0.16447 (8)0.0683 (4)
O10.7242 (2)0.88186 (10)0.13894 (9)0.0770 (5)
O1S0.7875 (3)0.96417 (11)0.24957 (11)0.0792 (5)
N10.60794 (18)1.20176 (10)0.10083 (10)0.0470 (3)
C60.7337 (2)1.10213 (11)0.04205 (11)0.0427 (4)
H60.77101.09450.11370.051*
N20.73006 (18)1.03335 (9)0.02053 (10)0.0440 (3)
N40.8628 (2)0.62144 (10)0.03962 (11)0.0543 (4)
C10.5563 (2)1.28602 (13)0.13628 (13)0.0530 (4)
H10.50711.29150.20630.064*
C20.5718 (2)1.36560 (12)0.07482 (15)0.0548 (4)
H20.53311.42260.10310.066*
C30.6450 (3)1.35901 (12)0.02835 (14)0.0540 (4)
H30.65831.41090.07210.065*
C40.6980 (2)1.27194 (11)0.06413 (12)0.0455 (4)
C50.6785 (2)1.19411 (10)0.00027 (11)0.0396 (3)
N30.78095 (19)0.94872 (9)0.02199 (10)0.0435 (3)
C70.7743 (2)0.87503 (11)0.04464 (11)0.0452 (4)
C80.8311 (2)0.78321 (10)0.00146 (11)0.0396 (3)
C90.8966 (2)0.76657 (11)0.10573 (12)0.0475 (4)
H90.91010.81510.15430.057*
C100.9414 (2)0.67696 (12)0.13635 (13)0.0514 (4)
H100.98360.66380.20620.062*
C110.9223 (2)0.60731 (12)0.06144 (14)0.0530 (4)
H110.95280.54710.08280.064*
C120.8172 (2)0.70823 (12)0.06745 (12)0.0479 (4)
H120.77340.71910.13760.057*
H3'0.809 (3)0.9462 (13)0.0910 (8)0.057 (5)*
H2A0.597 (3)0.4119 (11)0.2949 (16)0.088 (8)*
H1A0.807 (4)0.9453 (19)0.3148 (10)0.110 (9)*
H2B0.623 (4)0.5053 (11)0.2904 (17)0.097 (9)*
H1B0.902 (2)0.962 (3)0.233 (3)0.19 (2)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O2S0.1384 (15)0.0589 (9)0.0478 (7)0.0012 (9)0.0228 (8)0.0033 (7)
F10.1063 (9)0.0553 (6)0.0417 (5)0.0069 (6)0.0038 (5)0.0027 (4)
O10.1404 (14)0.0510 (8)0.0373 (6)0.0225 (8)0.0057 (7)0.0003 (5)
O1S0.1276 (15)0.0674 (9)0.0409 (7)0.0091 (9)0.0028 (8)0.0039 (6)
N10.0501 (7)0.0474 (8)0.0426 (7)0.0026 (6)0.0009 (5)0.0049 (6)
C60.0482 (8)0.0418 (8)0.0377 (7)0.0021 (6)0.0007 (6)0.0040 (6)
N20.0547 (8)0.0379 (7)0.0393 (6)0.0069 (5)0.0033 (5)0.0047 (5)
N40.0634 (9)0.0430 (8)0.0545 (8)0.0091 (6)0.0071 (6)0.0092 (6)
C10.0532 (10)0.0578 (10)0.0474 (8)0.0067 (8)0.0002 (7)0.0133 (7)
C20.0565 (10)0.0453 (9)0.0638 (10)0.0106 (7)0.0123 (8)0.0164 (8)
C30.0659 (11)0.0395 (9)0.0584 (10)0.0046 (7)0.0159 (8)0.0007 (7)
C40.0525 (9)0.0449 (8)0.0397 (7)0.0033 (7)0.0069 (6)0.0023 (6)
C50.0403 (8)0.0389 (8)0.0400 (7)0.0023 (6)0.0061 (6)0.0042 (6)
N30.0568 (8)0.0372 (7)0.0360 (6)0.0067 (5)0.0011 (5)0.0033 (5)
C70.0582 (9)0.0418 (8)0.0359 (7)0.0072 (7)0.0060 (6)0.0005 (6)
C80.0404 (8)0.0397 (8)0.0390 (7)0.0041 (6)0.0048 (6)0.0008 (6)
C90.0596 (10)0.0420 (8)0.0406 (8)0.0068 (7)0.0021 (7)0.0035 (6)
C100.0610 (10)0.0500 (9)0.0419 (8)0.0113 (7)0.0033 (7)0.0036 (7)
C110.0577 (10)0.0408 (9)0.0589 (10)0.0112 (7)0.0036 (8)0.0016 (7)
C120.0540 (9)0.0465 (9)0.0417 (8)0.0070 (7)0.0041 (6)0.0045 (6)
Geometric parameters (Å, º) top
O2S—H2A0.866 (9)C2—C31.371 (2)
O2S—H2B0.855 (9)C2—H20.9300
F1—C41.3486 (18)C3—C41.377 (2)
O1—C71.2211 (18)C3—H30.9300
O1S—H1A0.869 (10)C4—C51.382 (2)
O1S—H1B0.881 (10)N3—C71.3534 (19)
N1—C11.337 (2)N3—H3'0.880 (9)
N1—C51.3417 (18)C7—C81.490 (2)
C6—N21.267 (2)C8—C91.385 (2)
C6—C51.470 (2)C8—C121.386 (2)
C6—H60.9300C9—C101.379 (2)
N2—N31.3707 (17)C9—H90.9300
N4—C111.330 (2)C10—C111.379 (2)
N4—C121.333 (2)C10—H100.9300
C1—C21.384 (3)C11—H110.9300
C1—H10.9300C12—H120.9300
H2A—O2S—H2B104.5 (17)C4—C5—C6120.63 (13)
H1A—O1S—H1B97.5 (19)C7—N3—N2117.32 (12)
C1—N1—C5117.95 (14)C7—N3—H3'125.3 (13)
N2—C6—C5119.32 (13)N2—N3—H3'117.3 (13)
N2—C6—H6120.3O1—C7—N3122.44 (14)
C5—C6—H6120.3O1—C7—C8120.26 (14)
C6—N2—N3117.37 (13)N3—C7—C8117.29 (13)
C11—N4—C12116.80 (14)C9—C8—C12117.69 (14)
N1—C1—C2123.80 (15)C9—C8—C7126.03 (13)
N1—C1—H1118.1C12—C8—C7116.28 (13)
C2—C1—H1118.1C10—C9—C8118.94 (14)
C3—C2—C1118.92 (15)C10—C9—H9120.5
C3—C2—H2120.5C8—C9—H9120.5
C1—C2—H2120.5C11—C10—C9118.72 (15)
C2—C3—C4116.87 (16)C11—C10—H10120.6
C2—C3—H3121.6C9—C10—H10120.6
C4—C3—H3121.6N4—C11—C10123.68 (15)
F1—C4—C3118.90 (15)N4—C11—H11118.2
F1—C4—C5118.79 (14)C10—C11—H11118.2
C3—C4—C5122.30 (15)N4—C12—C8124.16 (14)
N1—C5—C4120.16 (14)N4—C12—H12117.9
N1—C5—C6119.21 (13)C8—C12—H12117.9
C5—C6—N2—N3179.37 (13)N2—N3—C7—O10.6 (3)
C5—N1—C1—C20.1 (3)N2—N3—C7—C8179.54 (13)
N1—C1—C2—C30.4 (3)O1—C7—C8—C9177.57 (17)
C1—C2—C3—C40.3 (3)N3—C7—C8—C92.5 (2)
C2—C3—C4—F1178.65 (15)O1—C7—C8—C122.0 (2)
C2—C3—C4—C50.3 (3)N3—C7—C8—C12177.88 (14)
C1—N1—C5—C40.8 (2)C12—C8—C9—C101.2 (2)
C1—N1—C5—C6179.01 (14)C7—C8—C9—C10179.25 (15)
F1—C4—C5—N1178.09 (13)C8—C9—C10—C111.1 (3)
C3—C4—C5—N10.9 (2)C12—N4—C11—C101.1 (3)
F1—C4—C5—C62.1 (2)C9—C10—C11—N40.0 (3)
C3—C4—C5—C6178.89 (15)C11—N4—C12—C81.1 (3)
N2—C6—C5—N16.6 (2)C9—C8—C12—N40.0 (3)
N2—C6—C5—C4173.62 (15)C7—C8—C12—N4179.68 (16)
C6—N2—N3—C7179.03 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3···O1S0.88 (1)2.04 (1)2.8821 (19)160 (2)
O2S—H2A···N1i0.87 (1)2.10 (1)2.965 (2)177 (2)
O1S—H1A···N4i0.87 (1)2.09 (1)2.946 (2)170 (3)
O2S—H2B···O1i0.86 (1)1.97 (1)2.816 (2)172 (2)
Symmetry code: (i) x, y+3/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3'···O1S0.880 (9)2.041 (11)2.8821 (19)159.6 (17)
O2S—H2A···N1i0.866 (9)2.100 (10)2.965 (2)177 (2)
O1S—H1A···N4i0.869 (10)2.086 (11)2.946 (2)170 (3)
O2S—H2B···O1i0.855 (9)1.967 (10)2.816 (2)172 (2)
Symmetry code: (i) x, y+3/2, z+1/2.
 

Acknowledgements

The authors are thankful to Dr Shibu M. Eapen, SAIF, Cochin University of Science and Technology, for the single-crystal XRD measurements.

References

First citationBrandenburg, K. (2010). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBruker (2004). APEX2, SADABS, SAINT and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationDespaigne, A. A. R., Vieira, L. F., Mendes, I. C., da Costa, F. B., Speziali, N. L. & Beraldo, H. (2010). J. Braz. Chem. Soc. 21, 1247–1257.  Web of Science CSD CrossRef CAS Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationHavanur, V. C., Badiger, D. S., Ligade, S. G. & Gudasi, K. B. (2010). Pharma Chem. 2, 390–404.  CAS Google Scholar
First citationKuriakose, M., Kurup, M. R. P. & Suresh, E. (2007). Polyhedron, 26, 2713–2718.  Web of Science CSD CrossRef CAS Google Scholar
First citationNair, Y., Sithambaresan, M. & Kurup, M. R. P. (2012). Acta Cryst. E68, o2709.  CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSreeja, P. B., Kurup, M. R. P., Kishore, A. & Jasmin, C. (2004). Polyhedron, 23, 575–581.  Web of Science CSD CrossRef CAS Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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Volume 70| Part 4| April 2014| Pages o483-o484
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