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Acta Crystallogr Sect E Struct Rep Online. 2009 October 1; 65(Pt 10): m1171.
Published online 2009 September 5. doi:  10.1107/S1600536809034965
PMCID: PMC2970167

Bis(1-carbamimidoyl-2-ethyl­isourea)copper(II) bis­(perchlorate)

Abstract

The title complex, [Cu(C4H10N4O)2](ClO4)2 or [Cu(L 1e)2](ClO4)2, where L 1e is 1-carbamimidoyl-2-ethyl­isourea, was obtained from the ethano­lysis reaction of 2-cyano­guanidine and copper(II) perchlorate hexa­hydrate in a 2:1 molar ratio. The two bidentate L 1e ligands are coordinated to the CuII center through N-donor atoms, leading to the CuN4 chromophore. The CuII environment is slightly distorted square-planar, with a dihedral angle of 5.17 (6)° between the two six-membered chelate rings. One of the ClO4 anions is disordered over two positions in a 0.6:0.4 ratio.

Related literature

For general reviews of 2-alkyl-1-carbamimidoyl­isourea ligand systems, see Hubberstey et al. (2000 [triangle]); Singh et al. (2005 [triangle]). For a previous study of copper(II) complexes containing the 1-carbamimidoyl-2-ethyl­isourea ligand in a 1:1 molar ratio, see Begley et al. (1986 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-m1171-scheme1.jpg

Experimental

Crystal data

  • [Cu(C4H10N4O)2](ClO4)2
  • M r = 522.76
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-m1171-efi1.jpg
  • a = 10.6928 (7) Å
  • b = 13.8061 (9) Å
  • c = 13.5977 (9) Å
  • β = 102.657 (1)°
  • V = 1958.6 (2) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 1.46 mm−1
  • T = 150 K
  • 0.42 × 0.15 × 0.10 mm

Data collection

  • Bruker SMART APEX CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.846, T max = 1.000
  • 16840 measured reflections
  • 4516 independent reflections
  • 3738 reflections with I > 2σ(I)
  • R int = 0.015

Refinement

  • R[F 2 > 2σ(F 2)] = 0.034
  • wR(F 2) = 0.110
  • S = 1.02
  • 4516 reflections
  • 298 parameters
  • 45 restraints
  • H-atom parameters constrained
  • Δρmax = 0.77 e Å−3
  • Δρmin = −0.30 e Å−3

Data collection: SMART (Bruker, 2001 [triangle]); cell refinement: SAINT (Bruker, 2000 [triangle]); data reduction: SAINT and SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: DIAMOND (Brandenburg, 2005 [triangle]); software used to prepare material for publication: enCIFer (Allen et al., 2004 [triangle]) and publCIF (Westrip, 2009 [triangle]).

Table 1
Selected geometric parameters (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809034965/jh2102sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809034965/jh2102Isup2.hkl

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

Acknowledgments

Financial support from the Thailand Research Fund (TRF), the Office of the National Research Council of Thailand (NRCT), the Center of Excellence for Innovation in Chemistry (PERCH-CIC) and the Development and Promotion of Science and Technology Talents Oroject (DPST) are gratefully acknowledged.

supplementary crystallographic information

Comment

Copper(II) complexes contaning ligands based on 2-alkyl-1-carbamimidoylisourea have been considered to be of importance in crystal engineering (Hubberstey et al., 2000). This ligand system shows versatile hydrogen bonding capability which is deployed to construct extended architectures. Moreover, it also exhibits growth inhibitory activity against pathogenic fungi and bacteria (Singh et al., 2005). Ethanolysis of the cyanoguanidine precursor in the presence of CuCl2 in a 1:1 molar ratio has been previously reported by Begley et al. (1986). The crystal structure of this product reveals that the mono-chelate complex is comprised solely of dinuclear [Cu(L1e)Cl2]2 units (L1e = 1-carbamimidoyl-2-ethylisourea) in which each CuII center is bridged by the neighboring chloride in the axial position to give a square-pyramidal geometry.

Herein, we present the structure of a copper(II) complex containing the same bidentate L1e ligand but with the charge balance provided by two perchlorate anions instead of the chloride anions as described above. The [Cu(L1e)2](ClO4)2 was obtained from the similar procedure as previously reported by Begley et al. (1986), but using a 2:1 molar ratio of 2-cyanoguanidine to copper(II) perchlorate hexahydrate. Structure determination on the title product reveals a [Cu(L1e)2]2+ cation and two ClO4- counter anions. Fig. 1 shows the [Cu(L1e)2]2+ unit. The CuII center is coordinated by two N,N-bidentate ligands, thus yielding a slightly distorted square-planar CuN4 geometry (Table 1) with Cu—N bond distances of 1.9376 (15)–1.9641 (15) Å. The bite angles of 89.00 (6)° for N1—Cu1—N4 and 89.27 (7) ° for N1—Cu1—N8 are slightly less than 90° with a dihedral angle of 5.17 (6) ° between the two six-membered chelate rings. Additionally, the intermolecular hydrogen bonds of the type N—H···O (perchlorate) also stabilize the [Cu(L1e)2]2+ cation to give a two-dimentional layered structure (Fig.2)

Experimental

Suitable single crystals of the title complex were raised from the initial product, which was obtained from the ethanolysis reaction of 2-cyanoguanidine precursor (0.1682 g, 2 mmol, Aldrich, 99%) in the presence of copper(II) perchlorate hexahydrate (0.3705 g, 1 mmol,Aldrich, 98%). The reaction was carried out in the refluxing condition for 24 h, then cooled down and filtered off to remove excess solid. The reddish-pink powder was obtained by reducing the solvent volume. The pink blocky single crystals were grown by slow vapor phase diffusion of diethylether into the methanolic solution of this product at room temperature over a few days.

Refinement

H atoms were positioned geometrically and refined as riding atoms, with N—H = 0.88, CH(methyl) = 0.98 and CH(methylene) = 0.99 Å, and with Uiso(H) = xUeq(C, N), where x = 1.5 for methyl H atoms and 1.2 for all others.

Figures

Fig. 1.
View of the title complex, showing the atom numbering of the cationic [Cu(L1e)2]2+ moiety of [Cu(L1e)2](ClO4)2. Displacement ellipsoids are drawn at the 50% probability level.
Fig. 2.
A view of the crystal packing along the b axis. Hydrogen bonds are shown as a dashed lines.

Crystal data

[Cu(C4H10N4O)2](ClO4)2F(000) = 1068
Mr = 522.76Dx = 1.773 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 6505 reflections
a = 10.6928 (7) Åθ = 2.8–27.6°
b = 13.8061 (9) ŵ = 1.46 mm1
c = 13.5977 (9) ÅT = 150 K
β = 102.657 (1)°Block, pink
V = 1958.6 (2) Å30.42 × 0.15 × 0.10 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer4516 independent reflections
Radiation source: sealed tube3738 reflections with I > 2σ(I)
graphiteRint = 0.015
ω scansθmax = 27.6°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)h = −13→13
Tmin = 0.846, Tmax = 1.000k = −17→17
16840 measured reflectionsl = −17→17

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)] = 0.034Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.110H-atom parameters constrained
S = 1.02w = 1/[σ2(Fo2) + (0.073P)2 + 0.715P] where P = (Fo2 + 2Fc2)/3
4516 reflections(Δ/σ)max = 0.003
298 parametersΔρmax = 0.77 e Å3
45 restraintsΔρmin = −0.30 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 F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ 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*/UeqOcc. (<1)
Cu10.255629 (17)0.501463 (12)0.002819 (13)0.01863 (11)
O10.34227 (13)0.23854 (9)−0.12296 (10)0.0234 (3)
O20.15463 (13)0.76578 (10)0.11725 (11)0.0263 (3)
N10.37087 (15)0.53760 (11)−0.08322 (11)0.0220 (3)
H1A0.38810.5999−0.08420.026*
N20.51010 (18)0.51972 (13)−0.19225 (14)0.0287 (4)
H2A0.52900.5818−0.18920.034*
H2B0.54550.4807−0.22950.034*
N30.40771 (15)0.38571 (12)−0.14711 (12)0.0236 (3)
H3C0.44590.3549−0.18900.028*
N40.27510 (15)0.36547 (11)−0.03258 (12)0.0240 (3)
H4D0.23740.3228−0.00070.029*
N50.13542 (15)0.46577 (12)0.08450 (12)0.0228 (3)
H5A0.12210.40320.08870.027*
N6−0.01529 (18)0.48529 (13)0.18399 (15)0.0308 (4)
H6A−0.03080.42270.18390.037*
H6B−0.05620.52510.21650.037*
N70.08417 (15)0.61897 (11)0.13659 (12)0.0239 (3)
H7C0.03410.65110.16850.029*
N80.24037 (15)0.63742 (11)0.04106 (12)0.0234 (3)
H8D0.29020.67880.01870.028*
C10.42637 (17)0.48409 (14)−0.13953 (14)0.0212 (4)
C20.33594 (16)0.33037 (13)−0.09646 (13)0.0196 (3)
C30.2658 (2)0.16826 (14)−0.08128 (15)0.0271 (4)
H3A0.17360.1848−0.10100.033*
H3B0.29180.1673−0.00680.033*
C40.2908 (3)0.07137 (15)−0.12418 (18)0.0394 (5)
H4A0.24150.0213−0.09830.059*
H4B0.38240.0562−0.10420.059*
H4C0.26470.0736−0.19790.059*
C50.07131 (18)0.52029 (14)0.13420 (14)0.0213 (4)
C60.16667 (17)0.67339 (13)0.09459 (13)0.0208 (4)
C70.23538 (19)0.83607 (13)0.08012 (15)0.0263 (4)
H7A0.21480.83750.00550.032*
H7B0.32710.81950.10390.032*
C80.2064 (2)0.93278 (15)0.12204 (18)0.0367 (5)
H8A0.25810.98320.09940.055*
H8B0.22710.93000.19590.055*
H8C0.11520.94780.09810.055*
Cl10.57714 (4)0.30297 (3)−0.35071 (3)0.02420 (13)
O1C0.56080 (16)0.24917 (11)−0.44314 (11)0.0352 (3)
O2C0.70647 (16)0.33555 (14)−0.32002 (14)0.0485 (4)
O3C0.49245 (17)0.38564 (12)−0.36660 (15)0.0479 (4)
O4C0.5435 (2)0.24293 (13)−0.27344 (13)0.0484 (4)
Cl20.07496 (4)0.20306 (3)0.14733 (3)0.02688 (13)
O5C−0.0235 (2)0.27739 (17)0.1328 (2)0.0474 (7)0.60
O6C0.1007 (2)0.1677 (2)0.24675 (19)0.0505 (8)0.60
O7C0.1915 (3)0.2497 (2)0.1312 (2)0.0464 (7)0.60
O8C0.0365 (4)0.1307 (2)0.0748 (3)0.0683 (11)0.60
O5B0.0565 (5)0.2553 (3)0.0573 (3)0.0443 (10)0.40
O6B0.0400 (5)0.2556 (3)0.2287 (3)0.0477 (11)0.40
O7B−0.0058 (4)0.1143 (3)0.1295 (4)0.0393 (10)0.40
O8B0.2052 (5)0.1690 (4)0.1763 (4)0.0613 (14)0.40

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cu10.02119 (16)0.01737 (16)0.01994 (16)0.00250 (7)0.01016 (11)−0.00086 (8)
O10.0291 (7)0.0187 (6)0.0247 (6)0.0015 (5)0.0109 (5)−0.0030 (5)
O20.0329 (7)0.0189 (6)0.0309 (7)0.0044 (5)0.0153 (6)−0.0005 (5)
N10.0262 (8)0.0184 (8)0.0245 (8)0.0013 (6)0.0120 (6)−0.0023 (6)
N20.0347 (9)0.0245 (8)0.0340 (10)−0.0030 (7)0.0232 (8)−0.0044 (7)
N30.0273 (8)0.0225 (8)0.0258 (8)−0.0006 (6)0.0159 (6)−0.0060 (6)
N40.0312 (8)0.0185 (7)0.0264 (8)0.0023 (6)0.0153 (6)0.0011 (6)
N50.0273 (8)0.0193 (8)0.0255 (8)0.0015 (6)0.0137 (6)−0.0012 (6)
N60.0348 (9)0.0272 (8)0.0382 (10)−0.0007 (7)0.0249 (8)−0.0021 (7)
N70.0255 (8)0.0223 (8)0.0283 (8)0.0035 (6)0.0152 (6)−0.0028 (6)
N80.0268 (8)0.0188 (7)0.0284 (8)0.0011 (6)0.0145 (6)−0.0002 (6)
C10.0190 (8)0.0256 (9)0.0209 (9)0.0012 (7)0.0086 (7)−0.0011 (7)
C20.0210 (8)0.0192 (8)0.0192 (8)0.0021 (6)0.0054 (6)−0.0016 (6)
C30.0359 (10)0.0200 (9)0.0282 (10)−0.0006 (7)0.0131 (8)−0.0006 (7)
C40.0589 (15)0.0227 (10)0.0404 (12)−0.0013 (9)0.0192 (11)−0.0065 (9)
C50.0207 (8)0.0245 (8)0.0207 (9)0.0023 (7)0.0087 (7)−0.0007 (7)
C60.0230 (8)0.0190 (8)0.0204 (8)0.0034 (6)0.0050 (6)−0.0014 (7)
C70.0323 (10)0.0200 (9)0.0283 (10)0.0010 (7)0.0100 (8)0.0001 (7)
C80.0469 (13)0.0233 (10)0.0413 (12)0.0019 (9)0.0127 (10)−0.0068 (9)
Cl10.0286 (2)0.0230 (2)0.0226 (2)−0.00094 (16)0.00904 (17)−0.00272 (16)
O1C0.0452 (9)0.0319 (8)0.0297 (8)0.0036 (6)0.0106 (6)−0.0061 (6)
O2C0.0362 (9)0.0562 (11)0.0490 (10)−0.0109 (8)0.0002 (7)0.0025 (9)
O3C0.0492 (10)0.0360 (9)0.0576 (11)0.0121 (7)0.0098 (8)−0.0116 (8)
O4C0.0669 (12)0.0479 (10)0.0355 (9)−0.0089 (9)0.0222 (8)0.0061 (8)
Cl20.0333 (3)0.0238 (2)0.0238 (2)0.00216 (17)0.00677 (18)0.00258 (17)
O5C0.0423 (15)0.0277 (13)0.0681 (19)0.0100 (11)0.0033 (13)−0.0050 (12)
O6C0.0375 (14)0.078 (2)0.0338 (14)−0.0190 (14)0.0026 (11)0.0286 (14)
O7C0.0493 (16)0.0528 (17)0.0457 (16)0.0050 (13)0.0293 (13)0.0186 (13)
O8C0.081 (3)0.0444 (18)0.063 (2)0.0169 (17)−0.0195 (19)−0.0222 (17)
O5B0.062 (3)0.034 (2)0.037 (2)−0.0087 (19)0.0114 (19)0.0070 (17)
O6B0.066 (3)0.042 (2)0.047 (3)−0.010 (2)0.039 (2)−0.015 (2)
O7B0.052 (3)0.026 (2)0.041 (2)−0.0100 (17)0.014 (2)0.0061 (17)
O8B0.040 (2)0.072 (3)0.065 (3)0.014 (2)−0.004 (2)−0.022 (3)

Geometric parameters (Å, °)

Cu1—N11.9411 (15)Cl2—O6C1.406 (2)
Cu1—N41.9606 (15)Cl2—O6B1.439 (4)
Cu1—N51.9376 (15)Cl2—O8B1.441 (5)
Cu1—N81.9641 (15)Cl2—O5C1.453 (2)
O1—C21.324 (2)Cl2—O7C1.461 (3)
O1—C31.461 (2)Cl2—O7B1.488 (4)
O2—C61.325 (2)N1—H1A0.8800
O2—C71.461 (2)N2—H2A0.8800
N1—C11.297 (2)N2—H2B0.8800
N2—C11.356 (2)N3—H3C0.8800
N3—C21.371 (2)N4—H4D0.8800
N3—C11.373 (2)N5—H5A0.8800
N4—C21.288 (2)N6—H6A0.8800
N5—C51.302 (2)N6—H6B0.8800
N6—C51.351 (3)N7—H7C0.8800
N7—C51.369 (2)N8—H8D0.8800
N7—C61.375 (2)C3—H3A0.9900
N8—C61.284 (2)C3—H3B0.9898
C3—C41.506 (3)C4—H4A0.9802
C7—C81.510 (3)C4—H4B0.9800
Cl1—O2C1.4269 (17)C4—H4C0.9804
Cl1—O1C1.4372 (15)C7—H7A0.9902
Cl1—O3C1.4435 (16)C7—H7B0.9898
Cl1—O4C1.4445 (16)C8—H8A0.9796
Cl2—O5B1.397 (4)C8—H8B0.9807
Cl2—O8C1.400 (3)C8—H8C0.9802
N1—Cu1—N489.00 (6)C6—N7—H7C116.4
N1—Cu1—N5177.92 (5)C6—N8—H8D115.9
N1—Cu1—N890.83 (7)Cu1—N8—H8D115.9
N4—Cu1—N590.95 (7)O1—C3—H3A110.5
N4—Cu1—N8178.47 (6)C4—C3—H3A110.4
N5—Cu1—N889.27 (7)O1—C3—H3B110.5
C2—O1—C3117.66 (14)C4—C3—H3B110.5
C6—O2—C7117.66 (15)H3A—C3—H3B108.7
C1—N1—Cu1129.95 (14)C3—C4—H4A109.5
C2—N3—C1126.99 (15)C3—C4—H4B109.4
C2—N4—Cu1128.47 (13)H4A—C4—H4B109.5
C5—N5—Cu1129.88 (14)C3—C4—H4C109.5
C5—N7—C6127.18 (16)H4A—C4—H4C109.5
C6—N8—Cu1128.07 (13)H4B—C4—H4C109.5
N1—C1—N2123.07 (18)O2—C7—H7A110.6
N1—C1—N3121.99 (17)C8—C7—H7A110.5
N2—C1—N3114.90 (17)O2—C7—H7B110.6
N4—C2—O1127.38 (16)C8—C7—H7B110.5
N4—C2—N3123.38 (16)H7A—C7—H7B108.7
O1—C2—N3109.23 (15)C7—C8—H8A109.6
O1—C3—C4106.13 (16)C7—C8—H8B109.4
N5—C5—N6123.37 (18)H8A—C8—H8B109.5
N5—C5—N7121.73 (17)C7—C8—H8C109.4
N6—C5—N7114.87 (17)H8A—C8—H8C109.5
N8—C6—O2127.38 (17)H8B—C8—H8C109.5
N8—C6—N7123.61 (17)O2C—Cl1—O1C110.06 (11)
O2—C6—N7109.00 (15)O2C—Cl1—O3C109.30 (11)
O2—C7—C8105.74 (16)O1C—Cl1—O3C109.01 (10)
C1—N1—H1A115.1O2C—Cl1—O4C110.38 (11)
Cu1—N1—H1A115.0O1C—Cl1—O4C109.74 (10)
C1—N2—H2A120.0O3C—Cl1—O4C108.32 (12)
C1—N2—H2B120.0O8C—Cl2—O6C113.3 (2)
H2A—N2—H2B120.0O5B—Cl2—O6B113.7 (3)
C2—N3—H3C116.5O5B—Cl2—O8B110.5 (3)
C1—N3—H3C116.5O6B—Cl2—O8B110.7 (3)
C2—N4—H4D115.7O8C—Cl2—O5C108.38 (17)
Cu1—N4—H4D115.8O6C—Cl2—O5C111.07 (18)
C5—N5—H5A115.0O8C—Cl2—O7C109.7 (2)
Cu1—N5—H5A115.1O6C—Cl2—O7C107.69 (15)
C5—N6—H6A120.0O5C—Cl2—O7C106.54 (16)
C5—N6—H6B120.0O5B—Cl2—O7B108.5 (3)
H6A—N6—H6B120.0O6B—Cl2—O7B107.5 (3)
C5—N7—H7C116.4O8B—Cl2—O7B105.5 (3)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1A···O1Ci0.882.143.013 (2)169
N1—H1A···Cl1i0.882.993.842 (2)164
N2—H2A···O4Ci0.882.373.150 (3)147
N2—H2B···O3C0.882.252.981 (3)141
N3—H3C···O4C0.882.313.168 (2)166
N3—H3C···Cl10.882.943.801 (2)165
N4—H4D···O7C0.882.203.031 (3)156
N4—H4D···O5B0.882.433.244 (4)154
N5—H5A···O5B0.882.173.026 (4)164
N5—H5A···O7C0.882.283.081 (3)152
N5—H5A···Cl20.882.953.814 (2)168
N6—H6A···O5C0.882.132.950 (3)155
N6—H6A···O6B0.882.463.258 (5)151
N6—H6B···O6Cii0.882.112.905 (3)150
N6—H6B···O7Bii0.882.393.067 (5)133
N7—H7C···O6Cii0.882.052.872 (3)156
N7—H7C···O6Bii0.882.273.122 (4)163
N8—H8D···O1Ci0.882.293.149 (2)164

Symmetry codes: (i) −x+1, y+1/2, −z−1/2; (ii) −x, y+1/2, −z+1/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: JH2102).

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