PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2009 November 1; 65(Pt 11): m1458–m1459.
Published online 2009 October 28. doi:  10.1107/S1600536809043323
PMCID: PMC2971162

Chloridobis(ethane-1,2-diamine)(4-methyl­aniline)cobalt(III) dichloride monohydrate

Abstract

In the title compound, [CoCl(C2H8N2)2(C7H9N)]Cl2·H2O, the CoIII ion has a distorted octa­hedral coordination environment and is surrounded by four N atoms in an equatorial plane, with the other N and Cl atoms occupying the axial positions. The crystal packing is stabilized by N—H(...)O, N—H(...)Cl and O—H(...)Cl inter­actions.

Related literature

For the biological activity and potential applications of mixed ligand cobalt(III) complexes, see: Arslan et al. (2009 [triangle]); Delehanty et al. (2008 [triangle]); Sayed et al. (1992 [triangle]); Teicher et al. (1990 [triangle]). For Co—N and Co—Cl bond lengths in related complexes, see: Anbalagan et al. (2009 [triangle]); Lee et al. (2007 [triangle]); Ramesh et al. (2008 [triangle]); Ravichandran et al. (2009 [triangle]). For the preparation of dichloro­bis(1,2-diamino­ethane)cobalt(III) chloride, see: Bailer & Clapp (1945 [triangle]). For asymmetry parameters, see: Nardelli (1983 [triangle]). For puckering parameters, see: Cremer & Pople (1975 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-m1458-scheme1.jpg

Experimental

Crystal data

  • [CoCl(C2H8N2)2(C7H9N)]Cl2·H2O
  • M r = 410.66
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-m1458-efi1.jpg
  • a = 7.3796 (2) Å
  • b = 10.8367 (3) Å
  • c = 12.1789 (3) Å
  • α = 75.201 (1)°
  • β = 74.671 (2)°
  • γ = 78.862 (1)°
  • V = 899.86 (4) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 1.40 mm−1
  • T = 293 K
  • 0.20 × 0.20 × 0.15 mm

Data collection

  • Bruker Kappa APEXII CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2004 [triangle]) T min = 0.767, T max = 0.817
  • 27923 measured reflections
  • 8633 independent reflections
  • 6851 reflections with I > 2σ(I)
  • R int = 0.025

Refinement

  • R[F 2 > 2σ(F 2)] = 0.032
  • wR(F 2) = 0.091
  • S = 1.10
  • 8633 reflections
  • 239 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.50 e Å−3
  • Δρmin = −0.33 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: SAINT (Bruker, 2004 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809043323/bt5082sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809043323/bt5082Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

KR thanks Dr Babu Varghese, SAIF, IIT-Madras, India, for his help with the data collection, and the management of Kandaswami Kandar’s College, Velur, Namakkal, TN, India, for the encouragement to pursue the programme. KA records his sincere thanks to the Council of Scientific and Industrial Research, New Delhi, and the Department of Science and Technology-SERC, New Delhi, for financial support through major research projects.

supplementary crystallographic information

Comment

Mixed ligand cobalt(III) complexes find potential applications in the fields of antitumor, antibacterial, antimicrobial, radiosenzitation and cytotoxicity activities (Sayed et al., 1992; Teicher et al., 1990; Arslan et al., 2009; Delehanty et al., 2008). Cobalt is an essential and integral component of vitamin B12, therefore it is physiologically found in most tissues. Complexes of cobalt are useful for nutritional supplementation to provide cobalt in a form which effectively increases the bioavailability, for instance, vitamin B12 by microorganisms present in the gut. In addition, cobalt(III) complexes are known for electron transfer and ligand substitution reactions, which find applications in chemical and biological systems. Against this background and to ascertain the molecular conformation, the structure determination of the title compound has been carried out.

The ORTEP diagram of the title compound is shown in Fig.1. The coordination geometry around the CoIII ion can be described as a slightly distorted octahedral. The CoIII ion and the four N atoms almost lie in the same plane, whereas the other N and Cl atoms are approximately perpendicular to this plane. The Co—N and Co—Cl bond lengths are comparable with related complexes (Lee et al., 2007; Ramesh et al., 2008; Anbalagan et al., 2009; Ravichandran et al., 2009). One of the five membered rings in the molecule adopts an envelope conformation, whereas the other ring adopts a twist conformation with the puckering parameters (Cremer & Pople, 1975) and the asymmetry parameters (Nardelli, 1983) for the ring Co1/N1/C2/C3/N4 are: q2 = 0.430 (1) Å, [var phi]= 100.4 (1)° and Δ2(Co1)= 9.92 (9)°; and for the ring Co1/N5/C6/C7/N8 are: q2 = 0.428 (2) Å, [var phi]= 272.0 (2)° and Δ2(Co1)= 1.9 (1)°.

The crystal packing is controlled by N—H···O, N—H···Cl and O—H···Cl interactions.

Experimental

The complex was synthesized using dichlorobis(1,2-diamino ethane) cobalt(III) chloride by the reported method (Bailer & Clapp, 1945). A paste was prepared in a mortar with 2 g of trans-[CoIII(en)2Cl2]Cl crystals in 3–4 drops of deionized water. To the solid mass, about 2.5 g of 4-methyl aniline dissolved in ethanol was added in drops for 20 min. The grinding was continued for half an hour and the color was found to change from dull green to red. The reaction mixture was set aside until no further change was observed and the product was allowed to stand overnight. Finally, the solid was washed with 3–4 times using pure ethanol. The final complex was dissolved in 5–10 ml of deionized water pre-heated to 70°C. The cobalt(III) complex was recrystallized out on addition of few drops of hot conc. HCl and 2 ml of water and cooled. The crystals were filtered, washed with ethanol and dried over vacuum.

Refinement

Nitrogen and Oxygen H atoms were freely refined. Other H atoms were positioned geometrically (C—H = 0.93–0.97 Å) and allowed to ride on their parent atoms, with 1.5Ueq(C) for methyl H and 1.2 Ueq(C) for other H atoms.

Figures

Fig. 1.
Perspective view of the molecule showing the displacement ellipsoids at the 30% probability level.
Fig. 2.
The crystal packing of the molecules viewed down the a–axis. H atoms not involved in hydrogen bonding have been omitted for clarity.

Crystal data

[CoCl(C2H8N2)2(C7H9N)]Cl2·H2OZ = 2
Mr = 410.66F(000) = 428
Triclinic, P1Dx = 1.516 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.3796 (2) ÅCell parameters from 5716 reflections
b = 10.8367 (3) Åθ = 2.4–32.8°
c = 12.1789 (3) ŵ = 1.40 mm1
α = 75.201 (1)°T = 293 K
β = 74.671 (2)°Block, red
γ = 78.862 (1)°0.20 × 0.20 × 0.15 mm
V = 899.86 (4) Å3

Data collection

Bruker Kappa APEXII CCD diffractometer8633 independent reflections
Radiation source: fine-focus sealed tube6851 reflections with I > 2σ(I)
graphiteRint = 0.025
ω and [var phi] scansθmax = 37.6°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2004)h = −11→11
Tmin = 0.767, Tmax = 0.817k = −18→18
27923 measured reflectionsl = −20→20

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.032Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.091H atoms treated by a mixture of independent and constrained refinement
S = 1.10w = 1/[σ2(Fo2) + (0.0444P)2 + 0.0729P] where P = (Fo2 + 2Fc2)/3
8633 reflections(Δ/σ)max < 0.001
239 parametersΔρmax = 0.50 e Å3
0 restraintsΔρmin = −0.32 e Å3

Special details

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)

xyzUiso*/Ueq
Cl10.22560 (5)0.10374 (4)0.37990 (3)0.03929 (8)
Cl2−0.29764 (4)0.01499 (3)0.10024 (3)0.03307 (7)
Cl30.25518 (5)0.52141 (3)0.17368 (3)0.03977 (8)
Co10.11254 (2)0.140646 (14)0.218880 (12)0.02132 (4)
O1−0.30863 (18)0.39142 (13)0.09756 (12)0.0472 (3)
H1W−0.287 (3)0.415 (2)0.029 (2)0.061 (7)*
H2W−0.408 (4)0.424 (2)0.122 (2)0.061 (7)*
N10.32886 (14)0.23025 (10)0.13118 (9)0.02693 (18)
H1A0.319 (3)0.3017 (19)0.1556 (17)0.047 (5)*
H1B0.435 (2)0.1842 (16)0.1437 (14)0.031 (4)*
C20.33739 (18)0.26181 (12)0.00430 (11)0.0304 (2)
H2A0.40460.1897−0.03020.036*
H2B0.40310.3362−0.03370.036*
C30.13641 (18)0.29018 (12)−0.01003 (10)0.0305 (2)
H3A0.07610.37140.01090.037*
H3B0.13340.2954−0.09020.037*
N40.03717 (15)0.18257 (11)0.06885 (8)0.02559 (18)
H4A−0.075 (3)0.1988 (15)0.0745 (14)0.028 (4)*
H4B0.065 (2)0.1235 (17)0.0370 (15)0.033 (4)*
N50.25627 (16)−0.02271 (11)0.18526 (11)0.0299 (2)
H5A0.325 (3)−0.043 (2)0.2275 (18)0.051 (6)*
H5B0.319 (3)−0.0173 (19)0.1170 (18)0.045 (5)*
C60.1287 (2)−0.12166 (12)0.21421 (12)0.0336 (2)
H6A0.1999−0.20720.22700.040*
H6B0.0666−0.11250.15110.040*
C7−0.0154 (2)−0.10131 (13)0.32353 (13)0.0383 (3)
H7A−0.1160−0.15360.33920.046*
H7B0.0437−0.12510.38960.046*
N8−0.09254 (16)0.03689 (11)0.30385 (10)0.02891 (19)
H8A−0.146 (3)0.0534 (18)0.3710 (18)0.047 (5)*
H8B−0.177 (3)0.0465 (18)0.2693 (17)0.043 (5)*
N9−0.04520 (15)0.30641 (10)0.25264 (9)0.02624 (18)
H9A0.032 (3)0.3621 (19)0.2425 (17)0.045 (5)*
H9B−0.113 (2)0.3357 (15)0.2038 (14)0.028 (4)*
C10−0.17753 (17)0.31173 (11)0.36291 (10)0.0269 (2)
C11−0.35600 (19)0.27735 (14)0.38350 (12)0.0352 (3)
H11−0.38980.24790.32730.042*
C12−0.4850 (2)0.28674 (16)0.48792 (13)0.0411 (3)
H12−0.60440.26210.50170.049*
C13−0.4384 (2)0.33237 (14)0.57219 (11)0.0382 (3)
C14−0.2609 (2)0.36910 (13)0.54924 (11)0.0370 (3)
H14−0.22890.40180.60410.044*
C15−0.12911 (19)0.35829 (13)0.44591 (11)0.0320 (2)
H15−0.00930.38210.43240.038*
C16−0.5802 (3)0.34315 (19)0.68492 (14)0.0541 (4)
H16A−0.53680.39330.72500.081*
H16B−0.59370.25870.73300.081*
H16C−0.70050.38440.66860.081*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cl10.04434 (18)0.04594 (18)0.03245 (15)−0.00318 (14)−0.01775 (13)−0.00983 (13)
Cl20.02439 (13)0.03889 (16)0.03991 (15)−0.00327 (11)−0.00643 (11)−0.01715 (13)
Cl30.04419 (18)0.03590 (16)0.04088 (17)−0.01063 (13)−0.00336 (13)−0.01388 (13)
Co10.02056 (7)0.02343 (7)0.02069 (7)−0.00416 (5)−0.00377 (5)−0.00610 (5)
O10.0374 (6)0.0573 (7)0.0410 (6)0.0044 (5)−0.0122 (5)−0.0047 (5)
N10.0222 (4)0.0276 (5)0.0325 (5)−0.0052 (4)−0.0036 (4)−0.0106 (4)
C20.0274 (5)0.0302 (6)0.0301 (5)−0.0087 (4)0.0021 (4)−0.0057 (4)
C30.0310 (6)0.0320 (6)0.0246 (5)−0.0060 (5)−0.0022 (4)−0.0018 (4)
N40.0240 (4)0.0301 (5)0.0236 (4)−0.0064 (4)−0.0034 (3)−0.0075 (4)
N50.0272 (5)0.0278 (5)0.0347 (5)−0.0025 (4)−0.0055 (4)−0.0094 (4)
C60.0392 (7)0.0252 (5)0.0365 (6)−0.0066 (5)−0.0068 (5)−0.0068 (5)
C70.0456 (7)0.0292 (6)0.0343 (6)−0.0101 (5)−0.0008 (5)−0.0012 (5)
N80.0285 (5)0.0319 (5)0.0253 (4)−0.0084 (4)−0.0011 (4)−0.0064 (4)
N90.0258 (4)0.0286 (5)0.0235 (4)−0.0034 (4)−0.0022 (3)−0.0078 (4)
C100.0276 (5)0.0274 (5)0.0245 (5)−0.0015 (4)−0.0029 (4)−0.0081 (4)
C110.0319 (6)0.0441 (7)0.0317 (6)−0.0065 (5)−0.0021 (5)−0.0161 (5)
C120.0330 (6)0.0486 (8)0.0384 (7)−0.0093 (6)0.0045 (5)−0.0139 (6)
C130.0453 (8)0.0352 (7)0.0258 (5)0.0013 (6)0.0020 (5)−0.0075 (5)
C140.0499 (8)0.0350 (6)0.0262 (5)0.0001 (6)−0.0087 (5)−0.0111 (5)
C150.0355 (6)0.0333 (6)0.0295 (5)−0.0036 (5)−0.0085 (5)−0.0104 (5)
C160.0601 (10)0.0575 (10)0.0318 (7)0.0018 (8)0.0083 (7)−0.0135 (7)

Geometric parameters (Å, °)

Cl1—Co12.2444 (3)C6—H6B0.9700
Co1—N11.9493 (10)C7—N81.4777 (18)
Co1—N51.9600 (11)C7—H7A0.9700
Co1—N81.9648 (11)C7—H7B0.9700
Co1—N41.9673 (10)N8—H8A0.86 (2)
Co1—N92.0167 (10)N8—H8B0.82 (2)
O1—H1W0.79 (3)N9—C101.4439 (15)
O1—H2W0.77 (3)N9—H9A0.87 (2)
N1—C21.4818 (17)N9—H9B0.841 (17)
N1—H1A0.88 (2)C10—C111.3797 (18)
N1—H1B0.873 (17)C10—C151.3876 (16)
C2—C31.5027 (18)C11—C121.3866 (19)
C2—H2A0.9700C11—H110.9300
C2—H2B0.9700C12—C131.388 (2)
C3—N41.4849 (16)C12—H120.9300
C3—H3A0.9700C13—C141.379 (2)
C3—H3B0.9700C13—C161.506 (2)
N4—H4A0.801 (17)C14—C151.3883 (19)
N4—H4B0.797 (17)C14—H140.9300
N5—C61.4768 (17)C15—H150.9300
N5—H5A0.78 (2)C16—H16A0.9600
N5—H5B0.83 (2)C16—H16B0.9600
C6—C71.505 (2)C16—H16C0.9600
C6—H6A0.9700
N1—Co1—N590.39 (5)N5—C6—H6A110.4
N1—Co1—N8175.15 (5)C7—C6—H6A110.4
N5—Co1—N884.75 (5)N5—C6—H6B110.4
N1—Co1—N484.77 (4)C7—C6—H6B110.4
N5—Co1—N490.54 (5)H6A—C6—H6B108.6
N8—Co1—N495.17 (4)N8—C7—C6106.93 (11)
N1—Co1—N991.51 (4)N8—C7—H7A110.3
N5—Co1—N9177.58 (4)C6—C7—H7A110.3
N8—Co1—N993.34 (4)N8—C7—H7B110.3
N4—Co1—N988.15 (4)C6—C7—H7B110.3
N1—Co1—Cl189.09 (3)H7A—C7—H7B108.6
N5—Co1—Cl189.51 (4)C7—N8—Co1109.73 (9)
N8—Co1—Cl190.95 (4)C7—N8—H8A106.8 (13)
N4—Co1—Cl1173.86 (3)Co1—N8—H8A112.7 (13)
N9—Co1—Cl192.01 (3)C7—N8—H8B107.1 (13)
H1W—O1—H2W108 (2)Co1—N8—H8B113.5 (13)
C2—N1—Co1111.40 (7)H8A—N8—H8B106.6 (18)
C2—N1—H1A109.7 (13)C10—N9—Co1122.01 (8)
Co1—N1—H1A108.8 (13)C10—N9—H9A106.4 (13)
C2—N1—H1B108.9 (11)Co1—N9—H9A107.7 (13)
Co1—N1—H1B111.2 (11)C10—N9—H9B103.3 (11)
H1A—N1—H1B106.7 (17)Co1—N9—H9B109.0 (11)
N1—C2—C3107.07 (10)H9A—N9—H9B107.5 (16)
N1—C2—H2A110.3C11—C10—C15119.80 (11)
C3—C2—H2A110.3C11—C10—N9120.15 (11)
N1—C2—H2B110.3C15—C10—N9119.95 (11)
C3—C2—H2B110.3C10—C11—C12120.01 (12)
H2A—C2—H2B108.6C10—C11—H11120.0
N4—C3—C2106.54 (10)C12—C11—H11120.0
N4—C3—H3A110.4C11—C12—C13120.90 (14)
C2—C3—H3A110.4C11—C12—H12119.6
N4—C3—H3B110.4C13—C12—H12119.6
C2—C3—H3B110.4C14—C13—C12118.40 (12)
H3A—C3—H3B108.6C14—C13—C16121.16 (14)
C3—N4—Co1108.95 (7)C12—C13—C16120.43 (15)
C3—N4—H4A111.1 (12)C13—C14—C15121.37 (12)
Co1—N4—H4A113.9 (11)C13—C14—H14119.3
C3—N4—H4B107.5 (12)C15—C14—H14119.3
Co1—N4—H4B112.7 (12)C10—C15—C14119.49 (13)
H4A—N4—H4B102.4 (16)C10—C15—H15120.3
C6—N5—Co1110.44 (8)C14—C15—H15120.3
C6—N5—H5A108.2 (15)C13—C16—H16A109.5
Co1—N5—H5A104.6 (15)C13—C16—H16B109.5
C6—N5—H5B109.6 (13)H16A—C16—H16B109.5
Co1—N5—H5B114.2 (13)C13—C16—H16C109.5
H5A—N5—H5B110 (2)H16A—C16—H16C109.5
N5—C6—C7106.72 (11)H16B—C16—H16C109.5
N5—Co1—N1—C282.07 (9)N5—Co1—N8—C715.23 (9)
N8—Co1—N1—C281.1 (5)N4—Co1—N8—C7105.29 (9)
N4—Co1—N1—C2−8.43 (8)N9—Co1—N8—C7−166.27 (9)
N9—Co1—N1—C2−96.43 (8)Cl1—Co1—N8—C7−74.20 (9)
Cl1—Co1—N1—C2171.58 (8)N1—Co1—N9—C10−142.93 (9)
Co1—N1—C2—C333.98 (12)N5—Co1—N9—C1075.2 (11)
N1—C2—C3—N4−49.24 (13)N8—Co1—N9—C1037.28 (10)
C2—C3—N4—Co142.63 (11)N4—Co1—N9—C10132.35 (9)
N1—Co1—N4—C3−19.47 (8)Cl1—Co1—N9—C10−53.79 (9)
N5—Co1—N4—C3−109.82 (8)Co1—N9—C10—C11−81.78 (14)
N8—Co1—N4—C3165.40 (8)Co1—N9—C10—C15101.80 (12)
N9—Co1—N4—C372.21 (8)C15—C10—C11—C12−1.4 (2)
Cl1—Co1—N4—C3−19.4 (4)N9—C10—C11—C12−177.80 (13)
N1—Co1—N5—C6−166.79 (9)C10—C11—C12—C131.0 (2)
N8—Co1—N5—C613.13 (9)C11—C12—C13—C140.5 (2)
N4—Co1—N5—C6−82.01 (9)C11—C12—C13—C16179.51 (15)
N9—Co1—N5—C6−24.9 (12)C12—C13—C14—C15−1.5 (2)
Cl1—Co1—N5—C6104.13 (9)C16—C13—C14—C15179.43 (14)
Co1—N5—C6—C7−37.90 (13)C11—C10—C15—C140.34 (19)
N5—C6—C7—N850.01 (14)N9—C10—C15—C14176.77 (12)
C6—C7—N8—Co1−39.65 (13)C13—C14—C15—C101.1 (2)
N1—Co1—N8—C716.2 (6)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1B···Cl2i0.873 (17)2.465 (17)3.2553 (11)150.8 (14)
N4—H4B···Cl2ii0.797 (17)2.602 (18)3.3299 (11)152.5 (15)
O1—H1W···Cl3iii0.79 (3)2.34 (3)3.1339 (14)174 (2)
O1—H2W···Cl3iv0.77 (3)2.49 (3)3.2470 (14)170 (2)
N9—H9A···Cl30.87 (2)2.45 (2)3.3152 (11)168.9 (17)
N8—H8B···Cl20.82 (2)2.57 (2)3.3046 (12)150.8 (18)
N9—H9B···O10.841 (17)2.090 (17)2.9250 (16)172.1 (15)
N1—H1A···Cl30.88 (2)2.39 (2)3.2467 (11)163.5 (17)
N4—H4A···O10.801 (17)2.461 (17)3.0754 (17)134.3 (14)

Symmetry codes: (i) x+1, y, z; (ii) −x, −y, −z; (iii) −x, −y+1, −z; (iv) x−1, y, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5082).

References

  • Anbalagan, K., Tamilselvan, M., Nirmala, S. & Sudha, L. (2009). Acta Cryst. E65, m836–m837. [PMC free article] [PubMed]
  • Arslan, H., Duran, N., Borekci, G., Ozer, C. K. & Akbay, C. (2009). Molecules, 14, 519–527. [PubMed]
  • Bailer, J. C. & Clapp, L. B. (1945). J. Am. Chem. Soc.67, 171–175.
  • Bruker (2004). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc.97, 1354–1358.
  • Delehanty, J. B., Bongard, J. E., Thach, C. D., Knight, D. A., Hickeya, T. E. & Chang, E. L. (2008). Bioorg. Med. Chem.16, 830–837. [PubMed]
  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
  • Lee, D. N., Lee, E. Y., Kim, C., Kim, S.-J. & Kim, Y. (2007). Acta Cryst. E63, m1949–m1950.
  • Nardelli, M. (1983). Acta Cryst. C39, 1141–1142.
  • Ramesh, P., SubbiahPandi, A., Jothi, P., Revathi, C. & Dayalan, A. (2008). Acta Cryst. E64, m300–m301. [PMC free article] [PubMed]
  • Ravichandran, K., Ramesh, P., Tamilselvan, M., Anbalagan, K. & Ponnuswamy, M. N. (2009). Acta Cryst. E65, m1174–m1175. [PMC free article] [PubMed]
  • Sayed, G. H., Radwan, A., Mohamed, S. M., Shiba, S. A. & Kalil, M. (1992). Chin. J. Chem.10, 475–480.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]
  • Teicher, B. A., Abrams, M. J., Rosbe, K. W. & Herman, T. S. (1990). Cancer Res.50, 6971–6975. [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography