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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Di­carbonyl­di­chlorido(N,N,N′,N′-tetra­methyl­ethylenedi­amine)­ruthenium(II)

aChemistry Department, Faculty of Science, King Abdul Aziz University, PO Box 80203, Jeddah 21589, Saudi Arabia, bThe Center of Excellence for Advanced Materials Research, King Abdul Aziz University, Jeddah, PO Box 80203, Saudi Arabia, and cX-ray Diffraction and Crystallography Laboratory, Department of Physics, School of Physical Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan
*Correspondence e-mail: mnachemist@hotmail.com

(Received 31 May 2011; accepted 8 June 2011; online 18 June 2011)

In the title compound, [RuCl2(C6H16N2)(CO)2], the geometry around the RuII atom is a distorted RuC2N2Cl2 octa­hedron, with pairs of C and Cl atoms trans to each other and the N atoms of the bidentate ligand in a cis conformation. The five-membered chelate ring is puckered on the C—C bond.

Related literature

For background to ruthenium carbonyl derivatives, see: Manchot & Konig (1924[Manchot, W. & Konig, J. (1924). Chem. Ber. 57, 2130-2133.]); Stephenson & Wilkinson (1966[Stephenson, T. A. & Wilkinson, G. (1966). J. Inorg. Nucl. Chem. 28, 945-956.]); Kingston et al. (1967[Kingston, J. Y., Jamieson, T. W. S. & Wilkinson, G. (1967). J. Inorg. Nucl. Chem. 29, 133-138.]); Baghlaf et al. (2007[Baghlaf, A. O., Al-Yami, F. A. & Ishaq, M. (2007). JKAU Sci. 19, 41-46.]); Campbell (1975[Campbell, M. J. M. (1975). Coord. Chem. Rev. 15, 279-312.]); Padhey & Kaufman (1985[Padhey, S. & Kaufman, G. B. (1985). Coord. Chem. Rev. 63, 127-160.]). For a related structure, see: Bakar et al. (1993[Bakar, M. A., Fun, H.-K., Chinnakali, K., Teoh, S.-G., Shawkataly, O. B. & Lopez, F. M. (1993). Acta Cryst. C49, 582-584.]).

[Scheme 1]

Experimental

Crystal data
  • [RuCl2(C6H16N2)(CO)2]

  • Mr = 344.20

  • Monoclinic, P 21 /c

  • a = 7.463 (6) Å

  • b = 14.579 (6) Å

  • c = 12.718 (12) Å

  • β = 106.37 (8)°

  • V = 1327.7 (17) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 1.57 mm−1

  • T = 160 K

  • 0.38 × 0.38 × 0.25 mm

Data collection
  • Enraf–Nonius CAD-4 diffractometer

  • Absorption correction: ψ scan (North et al., 1968[North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.]) Tmin = 0.591, Tmax = 0.69

  • 3153 measured reflections

  • 2877 independent reflections

  • 2644 reflections with I > 2σ(I)

  • Rint = 0.015

  • 2 standard reflections every 100 reflections intensity decay: 5%

Refinement
  • R[F2 > 2σ(F2)] = 0.023

  • wR(F2) = 0.061

  • S = 1.07

  • 2877 reflections

  • 184 parameters

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

  • Δρmax = 1.06 e Å−3

  • Δρmin = −0.48 e Å−3

Table 1
Selected geometric parameters (Å, °)

Ru1—C1 1.872 (3)
Ru1—C2 1.872 (2)
Ru1—N2 2.211 (2)
Ru1—N1 2.220 (2)
Ru1—Cl1 2.413 (2)
Ru1—Cl2 2.408 (2)
N2—Ru1—N1 82.75 (9)

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994[Enraf-Nonius (1994). CAD-4 EXPRESS. Enraf-Nonius, Delft, The Netherlands.]); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]); program(s) used to solve structure: DIRDIF99 (Beurskens et al., 1999[Beurskens, P. T., Beurskens, G., de Gelder, R., Garcia-Granda, S., Gould, R. O., Israel, R. & Smits, J. M. M. (1999). The DIRDIF99 Program System. Technical Report of the Crystallography Laboratory, University of Nijmegen, The Netherlands.]); 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, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

The salt [Ru(CO)2Cl2]n was first reported by (Manchot & Konig, 1924) but its importance and chemistry was shown in late 1960's by (Stephenson & Wilkinson, 1966), (Kingston et al., 1967) who have reported several compounds of the type [Ru(CO)2Cl2L2] where L=monodentate ligand. This was due to the fact that the salt [Ru(CO)2Cl2]n has proved a useful precursor for the synthesis of a variety of organometallic compounds. We have also reported from our laboratories compounds with ligands containing N, O and S atom as electron donor (e.g. Baghlaf et al., 2007). However (Campbell (1975) and Padhey & Kaufman (1985) have reported about remarkable biological activities of such compounds against microbes, viruses and tumours. This has been the main reason for our research activity in the field of bio-inorganic chemistry of transition metal complexes. The metal atom Ru in the salt [Ru(CO)2Cl2]n being electron deficient acts as electron acceptor. This enhances its ability to coordinate with electron donor ligand (TMEDA) to give a stable octahedral electron rich compound of low ionization energy [Ru(CO)2Cl2TMEDA]. The bidentate nature of the ligand (TMEDA) has also been reported in the X-ray structure of the complex [Mo(CO)4TMEDA] by (Bakar et al., 1993).

In the crystal structure of title compound, ruthenium atom is almost octahedrally coordinated to the two nitrogen-donors atoms of tetramethyl ethylene-1,2-diamine (TMEDA), two chloro and two carbonyl groups. A five membered non-planer ring formed through Ru1/N1/C5/C6/N2 as both of the carbon atoms are sp3 hybridized. The root mean square deniavtion for the ring measure 0.2149Å with the maximum deviation from C5 and C6 measures -0.2999 (19) Å and 0.3144 (19)Å respectively.

Related literature top

For background to ruthenium carbonyl derivatives, see: Manchot & Konig (1924); Stephenson & Wilkinson (1966); Kingston et al. (1967); Baghlaf et al., (2007); Campbell (1975). Padhey & Kaufman (1985). For a related structure, see: Bakar et al. (1993).

Experimental top

In a 100-ml round bottom flask fitted with nitrogen gas inlet, water condenser and magnetic stirrer was added 0.2 g of [Ru(CO)2 Cl2]n and 0.5 ml of tetramethylethylene diamine (TMEDA) in 15 ml MeOH. The reaction mixture was heated at about 70 °C for 1 h. The yellow green solution was reduced in volume and passed through a small alumina column (15 g. Al2O3). The yellow band was eluted with MeOH. The solvent was reduced in volume and on cooling it gave yellow blocks of (I). Yield 70%.

Refinement top

All the C—H H-atoms were positioned via fourier map with C—H = 0.91 (3)—1.11 (3) Å with Uiso(H) = 1.2 Ueqfor aromatic C atoms.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: DIRDIF99 (Beurskens et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level.
[Figure 2] Fig. 2. Unit cell packing for (I).
Dicarbonyldichlorido(N,N,N',N'- tetramethylethylenediamine)ruthenium(II) top
Crystal data top
[RuCl2(C6H16N2)(CO)2]F(000) = 688
Mr = 344.20Dx = 1.722 Mg m3
Monoclinic, P21/cMelting point: 493 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 7.463 (6) ÅCell parameters from 25 reflections
b = 14.579 (6) Åθ = 10.6–14.0°
c = 12.718 (12) ŵ = 1.57 mm1
β = 106.37 (8)°T = 160 K
V = 1327.7 (17) Å3Block, yellow
Z = 40.38 × 0.38 × 0.25 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
2644 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.015
Graphite monochromatorθmax = 27.0°, θmin = 2.2°
Nonprofiled ω/2θ scansh = 99
Absorption correction: ψ scan
(North et al., 1968)
k = 018
Tmin = 0.591, Tmax = 0.69l = 016
3153 measured reflections2 standard reflections every 100 reflections
2877 independent reflections intensity decay: 5%
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)] = 0.023Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.061H atoms treated by a mixture of independent and constrained refinement
S = 1.07 w = 1/[σ2(Fo2) + (0.0385P)2 + 0.6002P]
where P = (Fo2 + 2Fc2)/3
2877 reflections(Δ/σ)max = 0.001
184 parametersΔρmax = 1.06 e Å3
0 restraintsΔρmin = 0.48 e Å3
Crystal data top
[RuCl2(C6H16N2)(CO)2]V = 1327.7 (17) Å3
Mr = 344.20Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.463 (6) ŵ = 1.57 mm1
b = 14.579 (6) ÅT = 160 K
c = 12.718 (12) Å0.38 × 0.38 × 0.25 mm
β = 106.37 (8)°
Data collection top
Enraf–Nonius CAD-4
diffractometer
2644 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.015
Tmin = 0.591, Tmax = 0.692 standard reflections every 100 reflections
3153 measured reflections intensity decay: 5%
2877 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0230 restraints
wR(F2) = 0.061H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 1.06 e Å3
2877 reflectionsΔρmin = 0.48 e Å3
184 parameters
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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
C10.0497 (3)0.14822 (15)0.31835 (17)0.0244 (4)
C20.1219 (3)0.01145 (15)0.39077 (17)0.0237 (4)
C30.5479 (3)0.00447 (17)0.3248 (2)0.0269 (4)
H3A0.634 (4)0.025 (2)0.292 (2)0.032*
H3B0.542 (4)0.025 (2)0.386 (2)0.032*
H3C0.587 (4)0.065 (2)0.342 (2)0.032*
C40.3204 (4)0.09661 (19)0.2146 (3)0.0397 (6)
H4A0.197 (5)0.105 (2)0.163 (3)0.048*
H4B0.331 (4)0.131 (2)0.294 (3)0.048*
H4C0.417 (5)0.121 (2)0.187 (3)0.048*
C50.3756 (4)0.0491 (2)0.1397 (2)0.0376 (6)
H5A0.269 (5)0.028 (2)0.078 (3)0.045*
H5B0.496 (5)0.032 (2)0.127 (3)0.045*
C60.3660 (4)0.1513 (2)0.1516 (2)0.0362 (6)
H6A0.459 (5)0.170 (2)0.218 (3)0.043*
H6B0.373 (4)0.180 (2)0.087 (3)0.043*
C70.0379 (4)0.17649 (19)0.0602 (2)0.0352 (5)
H7A0.077 (5)0.197 (2)0.078 (2)0.042*
H7B0.026 (4)0.115 (2)0.023 (3)0.042*
H7C0.077 (4)0.219 (2)0.010 (3)0.042*
C80.1967 (4)0.27503 (17)0.2056 (2)0.0385 (6)
H8A0.229 (5)0.311 (2)0.152 (3)0.046*
H8B0.285 (5)0.285 (2)0.277 (3)0.046*
H8C0.075 (5)0.294 (2)0.214 (2)0.046*
Cl10.36315 (7)0.16019 (4)0.43227 (4)0.02799 (12)
Cl20.09471 (7)0.00421 (4)0.15266 (4)0.02621 (12)
O10.1658 (2)0.19233 (12)0.33235 (15)0.0343 (4)
O20.1117 (3)0.06675 (12)0.45157 (15)0.0377 (4)
Ru10.14044 (2)0.078019 (10)0.288724 (12)0.01683 (7)
N10.3635 (2)0.00254 (13)0.24068 (15)0.0233 (4)
N20.1815 (3)0.17845 (13)0.16732 (15)0.0246 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0238 (10)0.0231 (10)0.0239 (10)0.0067 (9)0.0027 (8)0.0024 (8)
C20.0224 (10)0.0243 (10)0.0224 (9)0.0033 (8)0.0034 (8)0.0050 (8)
C30.0185 (10)0.0303 (12)0.0289 (11)0.0033 (9)0.0018 (8)0.0029 (9)
C40.0287 (12)0.0310 (13)0.0561 (18)0.0060 (10)0.0064 (12)0.0169 (12)
C50.0329 (13)0.0558 (16)0.0263 (12)0.0170 (12)0.0120 (10)0.0091 (11)
C60.0270 (12)0.0467 (15)0.0368 (13)0.0019 (11)0.0119 (10)0.0174 (12)
C70.0338 (13)0.0380 (14)0.0281 (12)0.0010 (11)0.0007 (10)0.0110 (10)
C80.0492 (16)0.0200 (11)0.0423 (14)0.0074 (11)0.0065 (12)0.0060 (10)
Cl10.0275 (3)0.0288 (3)0.0241 (2)0.0044 (2)0.0016 (2)0.0063 (2)
Cl20.0198 (2)0.0304 (3)0.0266 (2)0.00546 (19)0.00355 (19)0.0077 (2)
O10.0267 (8)0.0290 (9)0.0485 (10)0.0042 (7)0.0129 (7)0.0069 (7)
O20.0473 (11)0.0342 (9)0.0326 (9)0.0072 (8)0.0129 (8)0.0088 (8)
Ru10.01583 (10)0.01612 (10)0.01779 (10)0.00122 (5)0.00351 (7)0.00079 (5)
N10.0207 (8)0.0256 (9)0.0229 (8)0.0035 (7)0.0049 (7)0.0021 (7)
N20.0242 (9)0.0230 (9)0.0244 (9)0.0019 (7)0.0035 (7)0.0046 (7)
Geometric parameters (Å, º) top
Ru1—C11.872 (3)C5—N11.477 (3)
Ru1—C21.872 (2)C5—C61.502 (4)
Ru1—N22.211 (2)C5—H5A1.00 (3)
Ru1—N12.220 (2)C5—H5B0.99 (3)
Ru1—Cl12.413 (2)C6—N21.500 (3)
Ru1—Cl22.408 (2)C6—H6A0.97 (3)
C1—O11.133 (3)C6—H6B0.94 (3)
C2—O21.134 (3)C7—N21.477 (3)
C3—N11.486 (3)C7—H7A1.00 (3)
C3—H3A0.96 (3)C7—H7B1.00 (3)
C3—H3B0.91 (3)C7—H7C0.99 (3)
C3—H3C0.93 (3)C8—N21.484 (3)
C4—N11.498 (3)C8—H8A0.94 (3)
C4—H4A0.98 (4)C8—H8B0.97 (3)
C4—H4B1.11 (3)C8—H8C0.98 (3)
C4—H4C0.95 (4)
O1—C1—Ru1177.3 (2)N2—C8—H8B114.7 (19)
O2—C2—Ru1178.8 (2)H8A—C8—H8B110 (3)
N1—C3—H3A106.0 (16)N2—C8—H8C108.2 (19)
N1—C3—H3B110.6 (18)H8A—C8—H8C111 (3)
H3A—C3—H3B111 (2)H8B—C8—H8C105 (3)
N1—C3—H3C110.5 (19)C1—Ru1—C291.90 (11)
H3A—C3—H3C109 (3)C1—Ru1—N292.33 (10)
H3B—C3—H3C110 (3)C2—Ru1—N2175.71 (8)
N1—C4—H4A111.8 (19)C1—Ru1—N1174.94 (8)
N1—C4—H4B106.3 (17)C2—Ru1—N193.04 (10)
H4A—C4—H4B111 (3)N2—Ru1—N182.75 (9)
N1—C4—H4C108 (2)C1—Ru1—Cl288.66 (9)
H4A—C4—H4C112 (3)C2—Ru1—Cl288.29 (9)
H4B—C4—H4C107 (3)N2—Ru1—Cl292.53 (8)
N1—C5—C6110.6 (2)N1—Ru1—Cl290.38 (8)
N1—C5—H5A108.2 (18)C1—Ru1—Cl188.62 (9)
C6—C5—H5A109.8 (18)C2—Ru1—Cl189.49 (9)
N1—C5—H5B108.0 (18)N2—Ru1—Cl189.89 (8)
C6—C5—H5B110.0 (19)N1—Ru1—Cl192.53 (8)
H5A—C5—H5B110 (3)Cl2—Ru1—Cl1176.424 (19)
N2—C6—C5110.3 (2)C5—N1—C3110.3 (2)
N2—C6—H6A105.4 (18)C5—N1—C4108.2 (2)
C5—C6—H6A108.6 (18)C3—N1—C4105.97 (18)
N2—C6—H6B106.0 (19)C5—N1—Ru1104.24 (15)
C5—C6—H6B110.2 (19)C3—N1—Ru1113.96 (15)
H6A—C6—H6B116 (3)C4—N1—Ru1114.10 (15)
N2—C7—H7A103.4 (18)C7—N2—C8106.8 (2)
N2—C7—H7B113.4 (18)C7—N2—C6109.1 (2)
H7A—C7—H7B114 (3)C8—N2—C6107.8 (2)
N2—C7—H7C108.3 (19)C7—N2—Ru1115.10 (15)
H7A—C7—H7C113 (2)C8—N2—Ru1114.35 (16)
H7B—C7—H7C105 (2)C6—N2—Ru1103.38 (14)
N2—C8—H8A107.7 (19)
N1—C5—C6—N262.9 (3)C5—C6—N2—C778.1 (2)
C6—C5—N1—C380.0 (2)C5—C6—N2—C8166.3 (2)
C6—C5—N1—C4164.5 (2)C5—C6—N2—Ru144.8 (2)
C6—C5—N1—Ru142.7 (2)C1—Ru1—N2—C776.26 (19)
C1—Ru1—N1—C50.1 (9)C2—Ru1—N2—C7113.4 (10)
C2—Ru1—N1—C5167.17 (16)N1—Ru1—N2—C7102.56 (18)
N2—Ru1—N1—C513.63 (16)Cl2—Ru1—N2—C712.49 (17)
Cl2—Ru1—N1—C578.87 (17)Cl1—Ru1—N2—C7164.88 (17)
Cl1—Ru1—N1—C5103.20 (17)C1—Ru1—N2—C848.00 (19)
C1—Ru1—N1—C3120.1 (9)C2—Ru1—N2—C8122.3 (10)
C2—Ru1—N1—C372.57 (17)N1—Ru1—N2—C8133.18 (18)
N2—Ru1—N1—C3106.62 (16)Cl2—Ru1—N2—C8136.76 (17)
Cl2—Ru1—N1—C3160.87 (15)Cl1—Ru1—N2—C840.61 (17)
Cl1—Ru1—N1—C317.05 (15)C1—Ru1—N2—C6164.90 (16)
C1—Ru1—N1—C4117.9 (9)C2—Ru1—N2—C65.4 (11)
C2—Ru1—N1—C449.35 (19)N1—Ru1—N2—C616.28 (15)
N2—Ru1—N1—C4131.46 (18)Cl2—Ru1—N2—C6106.34 (16)
Cl2—Ru1—N1—C438.96 (17)Cl1—Ru1—N2—C676.29 (16)
Cl1—Ru1—N1—C4138.97 (17)

Experimental details

Crystal data
Chemical formula[RuCl2(C6H16N2)(CO)2]
Mr344.20
Crystal system, space groupMonoclinic, P21/c
Temperature (K)160
a, b, c (Å)7.463 (6), 14.579 (6), 12.718 (12)
β (°) 106.37 (8)
V3)1327.7 (17)
Z4
Radiation typeMo Kα
µ (mm1)1.57
Crystal size (mm)0.38 × 0.38 × 0.25
Data collection
DiffractometerEnraf–Nonius CAD-4
diffractometer
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.591, 0.69
No. of measured, independent and
observed [I > 2σ(I)] reflections
3153, 2877, 2644
Rint0.015
(sin θ/λ)max1)0.638
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.023, 0.061, 1.07
No. of reflections2877
No. of parameters184
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)1.06, 0.48

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), DIRDIF99 (Beurskens et al., 1999), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top
Ru1—C11.872 (3)Ru1—N12.220 (2)
Ru1—C21.872 (2)Ru1—Cl12.413 (2)
Ru1—N22.211 (2)Ru1—Cl22.408 (2)
N2—Ru1—N182.75 (9)
 

Footnotes

Chemistry Department, Faculty of Science, King Abdul Aziz University, PO Box 80203, Jeddah 21589, Saudi Arabia.

Acknowledgements

The authors would like to thank the Chemistry Department, King Abdul Aziz University, Jeddah, Saudi Arabia, for providing the research facilities.

References

First citationBaghlaf, A. O., Al-Yami, F. A. & Ishaq, M. (2007). JKAU Sci. 19, 41–46.  CrossRef Google Scholar
First citationBakar, M. A., Fun, H.-K., Chinnakali, K., Teoh, S.-G., Shawkataly, O. B. & Lopez, F. M. (1993). Acta Cryst. C49, 582–584.  CSD CrossRef IUCr Journals Google Scholar
First citationBeurskens, P. T., Beurskens, G., de Gelder, R., Garcia-Granda, S., Gould, R. O., Israel, R. & Smits, J. M. M. (1999). The DIRDIF99 Program System. Technical Report of the Crystallography Laboratory, University of Nijmegen, The Netherlands.  Google Scholar
First citationCampbell, M. J. M. (1975). Coord. Chem. Rev. 15, 279–312.  CrossRef CAS Google Scholar
First citationEnraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationHarms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.  Google Scholar
First citationKingston, J. Y., Jamieson, T. W. S. & Wilkinson, G. (1967). J. Inorg. Nucl. Chem. 29, 133–138.  CrossRef CAS Google Scholar
First citationManchot, W. & Konig, J. (1924). Chem. Ber. 57, 2130–2133.  CrossRef Google Scholar
First citationNorth, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.  CrossRef IUCr Journals Web of Science Google Scholar
First citationPadhey, S. & Kaufman, G. B. (1985). Coord. Chem. Rev. 63, 127–160.  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 citationStephenson, T. A. & Wilkinson, G. (1966). J. Inorg. Nucl. Chem. 28, 945–956.  CrossRef CAS Web of Science 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 logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds