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

Journal logoIUCrDATA
ISSN: 2414-3146

cis-Bromido­bis­­(ethyl­ene-1,2-di­amine)(2-methyl­propan-1-amine)­cobalt(III) dibromide

CROSSMARK_Color_square_no_text.svg

aDepartment of Chemistry, BWDA Arts and Science College, Tindivanam 604 304, India, bDepartment of Chemistry, Pondicherry University, Pondicherry 605 014, India, cP. G. & Research Department of Physics, A. A. Govt. Arts College, Villupuram, India, and dDepartment of Physics, Thiruvalluvar University College of Arts and Science, Thiruvennainallur 607 203, India
*Correspondence e-mail: e.govindan84@gmail.com

Edited by H. Stoeckli-Evans, University of Neuchâtel, Switzerland (Received 22 August 2018; accepted 12 September 2018; online 21 September 2018)

In the title compound, [CoBr(C2H8N2)2(C4H11N)]Br2, the cobalt(III) ion has a distorted octa­hedral coordination environment and is ligated by three N atoms and a bromine ion in the equatorial plane, and by two N atoms occupying the axial positions. In the crystal, the complex cation and the two Br counter-anions are linked by N—H⋯Br hydrogen bonds, forming a supra­molecular framework.

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

Structure description

In recent years, considerable effort has been dedicated to the design and synthesis of supra­molecular architectures of coordination complexes (Lehn, 1995[Lehn, J. M. (1995). Supramolecular Chemistry. Concepts and Perspectives. Weinheim: VCH.]; Khlobystov et al., 2001[Khlobystov, A. N., Blake, A. J., Champness, N. R., Lemenovskii, D. A., Majouga, A. G., Zyk, N. V. & Schröder, M. (2001). Coord. Chem. Rev. 222, 155-192.]). The primary reason for the inter­est in such complexes is their new and versatile topologies and potential applications in functional materials (Desiraju, 1995[Desiraju, G. R. (1995). Angew. Chem. Int. Ed. Engl. 34, 2311-2327.]; Seo et al., 2000[Seo, J. S., Whang, D., Lee, H., Jun, S. I., Oh, J., Jeon, Y. J. & Kim, K. (2000). Nature, 404, 982-986.]). The inter­action of transition metal polyamine complexes of cobalt(III) with DNA has received considerable attention in recent years. Using mixed-ligand complexes, it is possible to systematically vary parameters of inter­est by changing the properties of the inter­acting units either by the use of suitable substituents or by simply changing the nature of the ancillary ligand. In addition, cobalt(III) complexes have sustained a high level of attention because of their relevance in various redox processes in biological systems and their anti­tumor, anthelmintic, anti­parasitic, anti­biotic and anti­microbial activities, as well as their multiple applications in the fields of medicine and drug delivery (Chang et al., 2010[Chang, E. L., Simmers, C. & Andrew Knight, D. (2010). Pharmaceuticals, 3, 1711-1728.]). Against this background and to ascertain the mol­ecular structure and configuration of the title compound, the crystal structure determination has been carried out.

The mol­ecular structure of the title compound is shown in Fig. 1[link]. It is composed of a cobalt(III) complex with the metal atom being coordinated by two ethyl­ene-1,2-di­amine (en) and one 2-methyl­propan-1-amine ligands, and a Br ion. The metal cation has a distorted hexa­gonal coordination sphere, being ligated to three N atoms, N2 and N3 of two en ligands and atom N5 of the 3-methyl­butan-1-amine ligand, and a bromine atom (Br1) in the equatorial plane. The remaining en N atoms, N1 and N4, occupy the axial positions. This arrangement is very similar to that observed for cis-chlorido­(ethyl­amine)bis(ethyl­ene-1,2-di­amine)­cobalt(III) dichloride (Maheshwaran et al., 2013[Maheshwaran, V., Thiruselvam, V., Manjunathan, M., Anbalagan, K. & Ponnuswamy, M. N. G. (2013). Acta Cryst. E69, m170-m171.]). In the title complex cation, the Co—Nen bond lengths vary from 1.950 (4) to 1.963 (4) Å, while the Co—N5 bond length involving the 2-methyl­propan-1-amine ligand is 1.998 (4) Å and the Co1—Br1 bond length is 2.4019 (11) Å. These bond lengths are comparable to the values reported in the literature for similar compounds (Lee et al., 2007[Lee, D. N., Lee, E. Y., Kim, C., Kim, S.-J. & Kim, Y. (2007). Acta Cryst. E63, m1949-m1950.]; Ramesh et al., 2008[Ramesh, P., SubbiahPandi, A., Jothi, P., Revathi, C. & Dayalan, A. (2008). Acta Cryst. E64, m300-m301.]; Anbalagan et al., 2009[Anbalagan, K., Tamilselvan, M., Nirmala, S. & Sudha, L. (2009). Acta Cryst. E65, m836-m837.]; Ravichandran et al., 2009[Ravichandran, K., Ramesh, P., Tamilselvan, M., Anbalagan, K. & Ponnuswamy, M. N. (2009). Acta Cryst. E65, m1174-m1175.]). Both five-membered chelate rings, which are cis to each other, have twisted conformations on the C—C (C1—C2 and C3—C4) bonds and their mean planes are inclined to each other by 79.4 (3)°.

[Figure 1]
Figure 1
The mol­ecular structure of the title complex, with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

In the crystal, the cations and anions are linked by a number of N—H⋯Br hydrogen bonds forming a supra­molecular framework (Table 1[link], Fig. 2[link]), with small cavities as shown in Fig. 3[link]. No residual electron density was observed in these regions in the final difference-Fourier map.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1NA⋯Br1i 0.89 2.68 3.458 (5) 147
N1—H1NB⋯Br3i 0.89 2.50 3.348 (5) 159
N2—H2NA⋯Br2ii 0.89 2.57 3.430 (5) 164
N2—H2NB⋯Br2 0.89 2.60 3.436 (4) 158
N3—H3NA⋯Br2ii 0.89 2.54 3.380 (5) 158
N3—H3NB⋯Br3i 0.89 2.76 3.493 (4) 141
N4—H4NA⋯Br3iii 0.89 2.56 3.430 (4) 166
N4—H4NB⋯Br2 0.89 2.69 3.521 (5) 157
N5—H5NB⋯Br3iii 0.89 2.88 3.506 (4) 129
N5—H5NA⋯Br3iv 0.89 2.67 3.509 (5) 159
C3—H3A⋯Br3iv 0.97 2.88 3.647 (6) 137
C6—H6⋯Br3iv 0.98 3.09 3.875 (8) 138
Symmetry codes: (i) -x, -y+1, -z+1; (ii) -x, -y+1, -z; (iii) -x+1, -y+1, -z+1; (iv) x, y+1, z.
[Figure 2]
Figure 2
The crystal packing of the title compound, viewed along the a axis, showing the N—H⋯Br hydrogen bonds (see Table 1[link]) as dashed lines. Only the N-bound H atoms have been included.
[Figure 3]
Figure 3
The crystal packing of the title compound, viewed along the a axis, showing the small voids (yellow regions) in the supra­molecular framework (Mercury; Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]), and the N—H⋯Br hydrogen bonds (see Table 1[link]) as dashed lines.

Synthesis and crystallization

A suspension of 2 g of trans-[CoIII(ethyl­ene-1,2-di­amine)2Br2]Br was made into a paste using 3–4 drops of water. To this solid mass, ca 2 ml of 2-methyl­propan-1-amine was added drop wise over 20 min and mixed well. Grinding was continued until the colour becomes 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 ethanol then dissolved in 5–10 ml of water and pre-heated to 343 K. It was allowed to crystallize using hot acidified water (yield 0.85 g). The crystals were filtered, washed with ethanol and dried under vacuum. X-ray quality crystals were obtained by repeated recrystallization from hot acidified distilled water giving finally pink plate-like crystals.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula [CoBr(C2H8N2)2(C4H11N)]Br2
Mr 492.00
Crystal system, space group Triclinic, P[\overline{1}]
Temperature (K) 293
a, b, c (Å) 7.3567 (7), 11.6172 (19), 11.7805 (15)
α, β, γ (°) 112.084 (13), 99.118 (9), 99.431 (10)
V3) 893.3 (2)
Z 2
Radiation type Mo Kα
μ (mm−1) 7.66
Crystal size (mm) 0.23 × 0.17 × 0.11
 
Data collection
Diffractometer Bruker SMART APEXII area-detector
Absorption correction Multi-scan (SADABS; Bruker, 2008[Bruker (2008). APEX, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.165, 0.361
No. of measured, independent and observed [I > 2σ(I)] reflections 6158, 3318, 1911
Rint 0.052
(sin θ/λ)max−1) 0.606
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.079, 0.83
No. of reflections 3318
No. of parameters 156
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.90, −0.63
Computer programs: APEX2 and SAINT (Bruker, 2008[Bruker (2008). APEX, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 and SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Structural data


Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

cis-Bromidobis(ethylene-1,2-diamine)(2-methylpropan-1-amine)cobalt(III) dibromide top
Crystal data top
[CoBr(C2H8N2)2(C4H11N)]Br2Z = 2
Mr = 492.00F(000) = 484
Triclinic, P1Dx = 1.829 Mg m3
a = 7.3567 (7) ÅMo Kα radiation, λ = 0.71073 Å
b = 11.6172 (19) ÅCell parameters from 4095 reflections
c = 11.7805 (15) Åθ = 2.9–29.3°
α = 112.084 (13)°µ = 7.66 mm1
β = 99.118 (9)°T = 293 K
γ = 99.431 (10)°Plate, pink
V = 893.3 (2) Å30.23 × 0.17 × 0.11 mm
Data collection top
Bruker SMART APEXII area-detector
diffractometer
1911 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.052
ω and φ scansθmax = 25.5°, θmin = 2.9°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 78
Tmin = 0.165, Tmax = 0.361k = 1411
6158 measured reflectionsl = 1413
3318 independent 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) = 0.079H-atom parameters constrained
S = 0.83 w = 1/[σ2(Fo2) + (0.0329P)2]
where P = (Fo2 + 2Fc2)/3
3318 reflections(Δ/σ)max < 0.001
156 parametersΔρmax = 0.90 e Å3
0 restraintsΔρmin = 0.63 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.23622 (8)0.50309 (7)0.39902 (6)0.0407 (2)
Co10.11284 (9)0.65284 (7)0.33292 (7)0.0240 (2)
N10.1140 (5)0.6266 (4)0.3951 (4)0.0275 (12)
H1NA0.0928060.5927870.4508510.033*
H1NB0.1406720.7016050.4338250.033*
N20.0369 (5)0.5104 (4)0.1749 (4)0.0267 (12)
H2NA0.0765250.5406100.1187480.032*
H2NB0.0350860.4576550.1431800.032*
N30.0362 (6)0.7809 (4)0.2775 (4)0.0318 (13)
H3NA0.0685900.7440830.2152460.038*
H3NB0.0105530.8420210.3412750.038*
N40.3228 (6)0.6700 (5)0.2517 (4)0.0288 (12)
H4NA0.4296480.7158280.3102940.035*
H4NB0.3391740.5929550.2075800.035*
N50.2648 (6)0.7926 (4)0.4973 (4)0.0310 (12)
H5NB0.3798760.7783850.5109580.037*
H5NA0.2790420.8655950.4875530.037*
C10.2779 (7)0.5397 (6)0.2890 (6)0.0389 (18)
H1A0.3357250.5872130.2473900.047*
H1B0.3728930.4994180.3198850.047*
C20.2015 (7)0.4402 (6)0.1987 (5)0.0331 (16)
H2A0.1631590.3832880.2354380.040*
H2B0.2973450.3896240.1206740.040*
C30.1892 (8)0.8384 (6)0.2331 (6)0.0356 (16)
H3A0.2818270.9074670.3039330.043*
H3B0.1372640.8725860.1751500.043*
C40.2801 (8)0.7335 (6)0.1679 (6)0.0325 (15)
H4A0.1945940.6725530.0885080.039*
H4B0.3959170.7688600.1503960.039*
C50.1973 (8)0.8142 (7)0.6138 (5)0.0442 (18)
H5A0.1623520.7330480.6202830.053*
H5B0.0846790.8469840.6084940.053*
C60.3486 (11)0.9092 (7)0.7335 (6)0.060 (2)
H60.3967260.9860630.7206470.071*
C70.2505 (13)0.9469 (9)0.8421 (7)0.100 (3)
H7A0.2186700.8756200.8639660.150*
H7B0.1367960.9705290.8168890.150*
H7C0.3342501.0181260.9139150.150*
C80.5128 (10)0.8535 (8)0.7599 (7)0.081 (3)
H8A0.6017730.9138260.8365270.121*
H8B0.5742380.8353170.6912550.121*
H8C0.4670660.7757590.7687340.121*
Br20.26843 (8)0.36505 (7)0.01047 (6)0.0434 (2)
Br30.27866 (8)0.10929 (6)0.53790 (6)0.0379 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0363 (4)0.0475 (5)0.0489 (5)0.0158 (3)0.0119 (3)0.0285 (4)
Co10.0204 (4)0.0230 (5)0.0245 (5)0.0014 (4)0.0038 (3)0.0079 (4)
N10.031 (3)0.030 (3)0.021 (3)0.007 (2)0.005 (2)0.011 (3)
N20.024 (3)0.022 (3)0.033 (3)0.008 (2)0.007 (2)0.010 (2)
N30.032 (3)0.030 (3)0.023 (3)0.002 (2)0.009 (2)0.002 (3)
N40.021 (2)0.030 (3)0.029 (3)0.005 (2)0.003 (2)0.007 (3)
N50.030 (3)0.030 (3)0.029 (3)0.002 (2)0.001 (2)0.011 (3)
C10.019 (3)0.047 (5)0.040 (4)0.001 (3)0.002 (3)0.011 (4)
C20.023 (3)0.025 (4)0.039 (4)0.005 (3)0.002 (3)0.007 (3)
C30.040 (4)0.032 (4)0.033 (4)0.001 (3)0.006 (3)0.016 (3)
C40.029 (3)0.032 (4)0.034 (4)0.007 (3)0.014 (3)0.015 (3)
C50.051 (4)0.051 (5)0.022 (4)0.008 (4)0.006 (3)0.009 (4)
C60.082 (6)0.045 (5)0.033 (4)0.003 (4)0.003 (4)0.011 (4)
C70.156 (9)0.089 (8)0.032 (5)0.029 (7)0.017 (5)0.002 (5)
C80.066 (5)0.095 (7)0.063 (6)0.030 (5)0.019 (4)0.046 (6)
Br20.0378 (4)0.0469 (5)0.0378 (4)0.0144 (3)0.0014 (3)0.0107 (4)
Br30.0280 (3)0.0276 (4)0.0471 (4)0.0035 (3)0.0077 (3)0.0055 (4)
Geometric parameters (Å, º) top
Br1—Co12.4019 (11)C1—H1A0.9700
Co1—N11.950 (4)C1—H1B0.9700
Co1—N31.962 (5)C2—H2A0.9700
Co1—N41.962 (4)C2—H2B0.9700
Co1—N21.963 (4)C3—C41.500 (8)
Co1—N51.998 (4)C3—H3A0.9700
N1—C11.486 (6)C3—H3B0.9700
N1—H1NA0.8900C4—H4A0.9700
N1—H1NB0.8900C4—H4B0.9700
N2—C21.472 (6)C5—C61.541 (9)
N2—H2NA0.8900C5—H5A0.9700
N2—H2NB0.8900C5—H5B0.9700
N3—C31.479 (7)C6—C81.505 (9)
N3—H3NA0.8900C6—C71.525 (10)
N3—H3NB0.8900C6—H60.9800
N4—C41.464 (7)C7—H7A0.9600
N4—H4NA0.8900C7—H7B0.9600
N4—H4NB0.8900C7—H7C0.9600
N5—C51.480 (7)C8—H8A0.9600
N5—H5NB0.8900C8—H8B0.9600
N5—H5NA0.8900C8—H8C0.9600
C1—C21.503 (7)
N1—Co1—N393.07 (18)C2—C1—H1A110.4
N1—Co1—N4173.73 (18)N1—C1—H1B110.4
N3—Co1—N484.75 (19)C2—C1—H1B110.4
N1—Co1—N284.76 (18)H1A—C1—H1B108.6
N3—Co1—N292.30 (19)N2—C2—C1106.4 (5)
N4—Co1—N289.44 (18)N2—C2—H2A110.5
N1—Co1—N594.20 (18)C1—C2—H2A110.5
N3—Co1—N589.98 (19)N2—C2—H2B110.5
N4—Co1—N591.69 (18)C1—C2—H2B110.5
N2—Co1—N5177.5 (2)H2A—C2—H2B108.6
N1—Co1—Br192.15 (14)N3—C3—C4106.7 (5)
N3—Co1—Br1174.59 (13)N3—C3—H3A110.4
N4—Co1—Br190.21 (14)C4—C3—H3A110.4
N2—Co1—Br189.62 (13)N3—C3—H3B110.4
N5—Co1—Br188.19 (14)C4—C3—H3B110.4
C1—N1—Co1110.5 (3)H3A—C3—H3B108.6
C1—N1—H1NA109.6N4—C4—C3107.6 (5)
Co1—N1—H1NA109.6N4—C4—H4A110.2
C1—N1—H1NB109.6C3—C4—H4A110.2
Co1—N1—H1NB109.6N4—C4—H4B110.2
H1NA—N1—H1NB108.1C3—C4—H4B110.2
C2—N2—Co1109.8 (3)H4A—C4—H4B108.5
C2—N2—H2NA109.7N5—C5—C6112.4 (5)
Co1—N2—H2NA109.7N5—C5—H5A109.1
C2—N2—H2NB109.7C6—C5—H5A109.1
Co1—N2—H2NB109.7N5—C5—H5B109.1
H2NA—N2—H2NB108.2C6—C5—H5B109.1
C3—N3—Co1110.5 (3)H5A—C5—H5B107.9
C3—N3—H3NA109.6C8—C6—C7112.3 (7)
Co1—N3—H3NA109.6C8—C6—C5111.7 (6)
C3—N3—H3NB109.6C7—C6—C5107.5 (6)
Co1—N3—H3NB109.6C8—C6—H6108.4
H3NA—N3—H3NB108.1C7—C6—H6108.4
C4—N4—Co1109.6 (3)C5—C6—H6108.4
C4—N4—H4NA109.7C6—C7—H7A109.5
Co1—N4—H4NA109.7C6—C7—H7B109.5
C4—N4—H4NB109.7H7A—C7—H7B109.5
Co1—N4—H4NB109.7C6—C7—H7C109.5
H4NA—N4—H4NB108.2H7A—C7—H7C109.5
C5—N5—Co1120.2 (4)H7B—C7—H7C109.5
C5—N5—H5NB107.3C6—C8—H8A109.5
Co1—N5—H5NB107.3C6—C8—H8B109.5
C5—N5—H5NA107.3H8A—C8—H8B109.5
Co1—N5—H5NA107.3C6—C8—H8C109.5
H5NB—N5—H5NA106.9H8A—C8—H8C109.5
N1—C1—C2106.7 (4)H8B—C8—H8C109.5
N1—C1—H1A110.4
Co1—N1—C1—C237.1 (6)N3—C3—C4—N449.4 (6)
Co1—N2—C2—C141.1 (5)Co1—N5—C5—C6170.0 (5)
N1—C1—C2—N250.2 (6)N5—C5—C6—C869.0 (8)
Co1—N3—C3—C436.3 (5)N5—C5—C6—C7167.4 (6)
Co1—N4—C4—C340.1 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1NA···Br1i0.892.683.458 (5)147
N1—H1NB···Br3i0.892.503.348 (5)159
N2—H2NA···Br2ii0.892.573.430 (5)164
N2—H2NB···Br20.892.603.436 (4)158
N3—H3NA···Br2ii0.892.543.380 (5)158
N3—H3NB···Br3i0.892.763.493 (4)141
N4—H4NA···Br3iii0.892.563.430 (4)166
N4—H4NB···Br20.892.693.521 (5)157
N5—H5NB···Br3iii0.892.883.506 (4)129
N5—H5NA···Br3iv0.892.673.509 (5)159
C3—H3A···Br3iv0.972.883.647 (6)137
C6—H6···Br3iv0.983.093.875 (8)138
Symmetry codes: (i) x, y+1, z+1; (ii) x, y+1, z; (iii) x+1, y+1, z+1; (iv) x, y+1, z.
 

Acknowledgements

The authors thank the Department of Chemistry, Pondicherry University, for the data collection.

Funding information

EG and MM gratefully acknowledge the DST–SERB for a young scientist start-up research grant (YSS/2014/000561) and DST–FIST for providing NMR facilities to the department.

References

First citationAnbalagan, K., Tamilselvan, M., Nirmala, S. & Sudha, L. (2009). Acta Cryst. E65, m836–m837.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationBruker (2008). APEX, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChang, E. L., Simmers, C. & Andrew Knight, D. (2010). Pharmaceuticals, 3, 1711-1728.  CrossRef CAS Google Scholar
First citationDesiraju, G. R. (1995). Angew. Chem. Int. Ed. Engl. 34, 2311–2327.  CrossRef CAS Web of Science Google Scholar
First citationKhlobystov, A. N., Blake, A. J., Champness, N. R., Lemenovskii, D. A., Majouga, A. G., Zyk, N. V. & Schröder, M. (2001). Coord. Chem. Rev. 222, 155–192.  Web of Science CrossRef CAS Google Scholar
First citationLee, D. N., Lee, E. Y., Kim, C., Kim, S.-J. & Kim, Y. (2007). Acta Cryst. E63, m1949–m1950.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationLehn, J. M. (1995). Supramolecular Chemistry. Concepts and Perspectives. Weinheim: VCH.  Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationMaheshwaran, V., Thiruselvam, V., Manjunathan, M., Anbalagan, K. & Ponnuswamy, M. N. G. (2013). Acta Cryst. E69, m170–m171.  CrossRef IUCr Journals Google Scholar
First citationRamesh, P., SubbiahPandi, A., Jothi, P., Revathi, C. & Dayalan, A. (2008). Acta Cryst. E64, m300–m301.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationRavichandran, K., Ramesh, P., Tamilselvan, M., Anbalagan, K. & Ponnuswamy, M. N. (2009). Acta Cryst. E65, m1174–m1175.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationSeo, J. S., Whang, D., Lee, H., Jun, S. I., Oh, J., Jeon, Y. J. & Kim, K. (2000). Nature, 404, 982–986.  CSD CrossRef PubMed 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. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  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 logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds