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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Di­aqua­bis­­(2-ethyl-5-methyl­imidazole-4-sulfonato-κ2N3,O)nickel(II) dihydrate

aChemistry Division, Code 6100 Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA, and bDepartment of Chemistry, Howard University, 525 College Street NW, Washington, DC 20059, USA
*Correspondence e-mail: andrew.purdy@nrl.navy.mil

(Received 13 October 2013; accepted 25 November 2013; online 14 December 2013)

In the title complex, [Ni(C6H9N2O3S)2(H2O)2]·2H2O, the NiII atom lies on an inversion center and is chelated by N and O atoms of two symmetry-equivalent imidazole­sulfonate ligands in the basal plane, and two water O atoms in axial positions in an overall octa­hedral configuration. The crystal structure displays O—H⋯O and N—H⋯O hydrogen bonds, which connect the components into an extended three-dimensional network.

Related literature

For examples of Ni–sulfonate complexes and MOFs, see: Lobana et al. (2004[Lobana, T. S., Kinoshita, I., Kimura, K., Nishioka, T., Shiomi, D. & Isobe, K. (2004). Eur. J. Inorg. Chem. pp. 356-367.]); Forbes & Sevov (2009[Forbes, T. Z. & Sevov, S. C. (2009). Inorg. Chem. 48, 6873-6878.]); Kim et al. (2004[Kim, D. S., Forster, P. M., Le Toquin, R. & Cheetham, A. K. (2004). Chem. Commun. pp. 2148-2149.]); Yang et al. (2010[Yang, F., Wu, Z.-H. & Cai, J.-H. (2010). Acta Cryst. E66, m748.]). A small number of structurally characterized imidazole sulfonates are known, see: Kuhn et al. (2001[Kuhn, N., Eichele, K. & Walker, M. (2001). Z. Anorg. Allg. Chem. 627, 2565-2567.], 2002[Kuhn, N., Eichele, K., Walker, M., Berends, T. & Minkwitz, R. (2002). Z. Anorg. Allg. Chem. 628, 2026-2032.]); Chidambaram et al. (1988[Chidambaram, Sp., Aravamudan, G. & Seshasayee, M. (1988). Acta Cryst. C44, 898-900.]). The 2-ethyl-4-methyl-5-sulfonate ligand is described by Purdy et al. (2007[Purdy, A. P., Gilardi, R., Luther, J. & Butcher, R. J. (2007). Polyhedron, 26, 3930-3938.]) and Purdy & Butcher (2011[Purdy, A. P. & Butcher, R. J. (2011). Acta Cryst. E67, m1303-m1304.]).

[Scheme 1]

Experimental

Crystal data
  • [Ni(C6H9N2O3S)2(H2O)2]·2H2O

  • Mr = 509.20

  • Monoclinic, P 21 /a

  • a = 7.6037 (2) Å

  • b = 16.8934 (4) Å

  • c = 8.6574 (3) Å

  • β = 111.303 (3)°

  • V = 1036.08 (5) Å3

  • Z = 2

  • Cu Kα radiation

  • μ = 3.77 mm−1

  • T = 123 K

  • 0.52 × 0.46 × 0.35 mm

Data collection
  • Agilent Xcalibur Ruby Gemini diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012[Agilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.]) Tmin = 0.209, Tmax = 1.000

  • 2126 measured reflections

  • 2126 independent reflections

  • 2062 reflections with I > 2σ(I)

Refinement
  • R[F2 > 2σ(F2)] = 0.045

  • wR(F2) = 0.112

  • S = 1.18

  • 2126 reflections

  • 151 parameters

  • 48 restraints

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

  • Δρmax = 0.73 e Å−3

  • Δρmin = −0.54 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1W—H1W1⋯O2W 0.82 (2) 2.02 (2) 2.837 (3) 174 (4)
O1W—H1W2⋯O3i 0.81 (2) 1.96 (2) 2.739 (3) 161 (4)
O2W—H2W1⋯O2ii 0.80 (2) 1.97 (2) 2.751 (3) 167 (4)
O2W—H2W2⋯O2iii 0.80 (2) 1.94 (2) 2.723 (3) 169 (4)
N2—H2A⋯O2Wiv 0.88 1.94 2.818 (3) 174
Symmetry codes: (i) -x, -y+1, -z+1; (ii) -x+1, -y+1, -z+1; (iii) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+1]; (iv) -x+1, -y+1, -z+2.

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The Ni atom lies on an inversion center and is chelated by N1 and O1 of the 2 symmetry equivalent imidazolesulfonate ligands in a plane, and 2 axial water molecules coordinated in an overall octahedral configuration. All of the Ni—O bond lengths (2.083 (2), 2.094 (2) Å) are about the same, and are in the normal range for octahedral coordinated Ni (2.05–2.12 Å). The largest deviation from the 90 ° angles of the octahedron is N1—Ni—O1, a result of the sulfonate group being attached to the imidazole ring. Two additional uncoordinated water molecules are present, but do not lie on any symmetry elements. There are no links other than hydrogen bonds between molecules, in contrast to the analogous unsolvated Cu(II) derivative (Purdy & Butcher, 2011). Hydrogen bonding links all the water molecules and N2, O2, and O3 into an extended structure in all three dimensions.

Related literature top

For examples of Ni–sulfonate complexes and MOFs, see: Lobana et al. (2004); Forbes & Sevov (2009); Kim et al. (2004); Yang et al. (2010). A small number of structurally characterized imidazole sulfonates are known, see: Kuhn et al. (2001, 2002); Chidambaram et al. (1988). The 2-ethyl-4-methyl-5-sulfonate ligand is described by Purdy et al. (2007) and Purdy & Butcher (2011).

Experimental top

A solution of the potassium salt of the 2-ethyl-4-methyl-imidazole-5-sulfonic acid was prepared by combining 1 g (5.25 mmol) of the free acid with 1.5 equivalents of KOH solution, and diluting the solution to 1M based on K+. (All solutions were made with distilled water.) Two test reactions were done in vials with 0.5 M solutions of Ni(BF4)2·6H2O and MnSO4·H2O, a 0.2 ml metered pipet was used for the additions, and each vial contained one addition of all three solutions. After 1 month, one vial were heated to a boil and allowed to cool and the other remained at room temperature. After one year, large blue crystals of the title compound grew in the solution that was not heated.

Structure description top

The Ni atom lies on an inversion center and is chelated by N1 and O1 of the 2 symmetry equivalent imidazolesulfonate ligands in a plane, and 2 axial water molecules coordinated in an overall octahedral configuration. All of the Ni—O bond lengths (2.083 (2), 2.094 (2) Å) are about the same, and are in the normal range for octahedral coordinated Ni (2.05–2.12 Å). The largest deviation from the 90 ° angles of the octahedron is N1—Ni—O1, a result of the sulfonate group being attached to the imidazole ring. Two additional uncoordinated water molecules are present, but do not lie on any symmetry elements. There are no links other than hydrogen bonds between molecules, in contrast to the analogous unsolvated Cu(II) derivative (Purdy & Butcher, 2011). Hydrogen bonding links all the water molecules and N2, O2, and O3 into an extended structure in all three dimensions.

For examples of Ni–sulfonate complexes and MOFs, see: Lobana et al. (2004); Forbes & Sevov (2009); Kim et al. (2004); Yang et al. (2010). A small number of structurally characterized imidazole sulfonates are known, see: Kuhn et al. (2001, 2002); Chidambaram et al. (1988). The 2-ethyl-4-methyl-5-sulfonate ligand is described by Purdy et al. (2007) and Purdy & Butcher (2011).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Diagram of C12H22N4O8S2Ni, with uncoordinated water molecules not shown.
[Figure 2] Fig. 2. Packing diagram viewed down the c axis, displaying the hydrogen bonded interactions of both the coordinated and uncoordinated water molecules.
Diaquabis(2-ethyl-5-methylimidazole-4-sulfonato-κ2N3,O)nickel(II) dihydrate top
Crystal data top
[Ni(C6H9N2O3S)2(H2O)2]·2H2OF(000) = 532
Mr = 509.20Dx = 1.632 Mg m3
Monoclinic, P21/aCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2yabCell parameters from 4614 reflections
a = 7.6037 (2) Åθ = 5.2–75.5°
b = 16.8934 (4) ŵ = 3.77 mm1
c = 8.6574 (3) ÅT = 123 K
β = 111.303 (3)°Block, blue
V = 1036.08 (5) Å30.52 × 0.46 × 0.35 mm
Z = 2
Data collection top
Agilent Xcalibur Ruby Gemini
diffractometer
2126 independent reflections
Radiation source: Enhance (Cu) X-ray Source2062 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.000
Detector resolution: 10.5081 pixels mm-1θmax = 75.8°, θmin = 5.2°
ω scansh = 98
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2012)
k = 021
Tmin = 0.209, Tmax = 1.000l = 010
2126 measured 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)] = 0.045Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.112H atoms treated by a mixture of independent and constrained refinement
S = 1.18 w = 1/[σ2(Fo2) + (0.0411P)2 + 2.2827P]
where P = (Fo2 + 2Fc2)/3
2126 reflections(Δ/σ)max < 0.001
151 parametersΔρmax = 0.73 e Å3
48 restraintsΔρmin = 0.54 e Å3
Crystal data top
[Ni(C6H9N2O3S)2(H2O)2]·2H2OV = 1036.08 (5) Å3
Mr = 509.20Z = 2
Monoclinic, P21/aCu Kα radiation
a = 7.6037 (2) ŵ = 3.77 mm1
b = 16.8934 (4) ÅT = 123 K
c = 8.6574 (3) Å0.52 × 0.46 × 0.35 mm
β = 111.303 (3)°
Data collection top
Agilent Xcalibur Ruby Gemini
diffractometer
2126 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2012)
2062 reflections with I > 2σ(I)
Tmin = 0.209, Tmax = 1.000Rint = 0.000
2126 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.04548 restraints
wR(F2) = 0.112H atoms treated by a mixture of independent and constrained refinement
S = 1.18Δρmax = 0.73 e Å3
2126 reflectionsΔρmin = 0.54 e Å3
151 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
Ni0.50000.50000.50000.00455 (19)
S10.13784 (8)0.60394 (4)0.38692 (7)0.00676 (18)
O10.2439 (3)0.54424 (11)0.3337 (2)0.0082 (4)
O20.1485 (3)0.68145 (12)0.3149 (2)0.0148 (4)
O30.0536 (3)0.58051 (13)0.3598 (2)0.0165 (4)
O1W0.3581 (3)0.40250 (11)0.5452 (2)0.0104 (4)
H1W10.422 (5)0.378 (2)0.629 (4)0.027 (11)*
H1W20.267 (4)0.417 (2)0.563 (5)0.027 (11)*
O2W0.5754 (3)0.30842 (12)0.8196 (2)0.0129 (4)
H2W10.667 (4)0.309 (2)0.795 (5)0.014 (9)*
H2W20.519 (5)0.2680 (16)0.790 (5)0.019 (10)*
N10.4281 (3)0.56704 (13)0.6667 (3)0.0065 (4)
N20.3814 (3)0.63709 (13)0.8610 (3)0.0094 (5)
H2A0.39960.65670.95980.011*
C10.2651 (4)0.61089 (15)0.5997 (3)0.0072 (5)
C20.2329 (4)0.65519 (15)0.7178 (3)0.0085 (5)
C30.0834 (4)0.71410 (17)0.7081 (4)0.0155 (6)
H3A0.03660.69720.62410.023*
H3B0.11880.76590.67770.023*
H3C0.06960.71790.81610.023*
C40.4953 (4)0.58422 (15)0.8257 (3)0.0083 (5)
C50.6769 (4)0.55417 (16)0.9505 (3)0.0110 (5)
H5A0.68840.49680.93280.013*
H5B0.67520.56151.06340.013*
C60.8474 (4)0.59737 (17)0.9371 (4)0.0152 (6)
H6A0.96370.57381.01470.023*
H6B0.84200.65340.96410.023*
H6C0.84570.59250.82370.023*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ni0.0030 (3)0.0058 (3)0.0026 (3)0.0012 (2)0.0017 (2)0.0004 (2)
S10.0039 (3)0.0098 (3)0.0042 (3)0.0027 (2)0.0014 (2)0.0007 (2)
O10.0067 (7)0.0098 (7)0.0051 (7)0.0030 (6)0.0012 (5)0.0014 (6)
O20.0208 (11)0.0099 (9)0.0122 (9)0.0059 (8)0.0043 (8)0.0056 (7)
O30.0112 (8)0.0241 (8)0.0131 (7)0.0003 (6)0.0031 (6)0.0012 (6)
O1W0.0087 (9)0.0105 (9)0.0108 (9)0.0002 (7)0.0023 (7)0.0014 (7)
O2W0.0164 (10)0.0113 (9)0.0105 (9)0.0051 (8)0.0042 (8)0.0044 (7)
N10.0054 (8)0.0070 (8)0.0056 (7)0.0000 (6)0.0002 (6)0.0002 (6)
N20.0121 (11)0.0102 (11)0.0050 (10)0.0014 (8)0.0020 (8)0.0025 (8)
C10.0065 (8)0.0075 (8)0.0065 (8)0.0002 (7)0.0008 (7)0.0005 (7)
C20.0078 (12)0.0081 (11)0.0085 (12)0.0012 (9)0.0015 (10)0.0021 (9)
C30.0132 (14)0.0129 (13)0.0197 (14)0.0028 (11)0.0052 (11)0.0049 (11)
C40.0110 (13)0.0059 (11)0.0077 (12)0.0021 (9)0.0029 (10)0.0003 (9)
C50.0115 (9)0.0116 (9)0.0081 (8)0.0007 (7)0.0013 (7)0.0007 (7)
C60.0104 (13)0.0177 (14)0.0122 (13)0.0012 (10)0.0023 (10)0.0014 (10)
Geometric parameters (Å, º) top
Ni—N12.058 (2)N2—C41.354 (4)
Ni—N1i2.058 (2)N2—C21.374 (3)
Ni—O1W2.0825 (19)N2—H2A0.8800
Ni—O1Wi2.0825 (19)C1—C21.359 (4)
Ni—O12.0941 (18)C2—C31.490 (4)
Ni—O1i2.0941 (18)C3—H3A0.9800
S1—O31.443 (2)C3—H3B0.9800
S1—O21.465 (2)C3—H3C0.9800
S1—O11.4662 (18)C4—C51.499 (4)
S1—C11.746 (3)C5—C61.528 (4)
O1W—H1W10.823 (19)C5—H5A0.9900
O1W—H1W20.808 (19)C5—H5B0.9900
O2W—H2W10.798 (18)C6—H6A0.9800
O2W—H2W20.796 (18)C6—H6B0.9800
N1—C41.315 (3)C6—H6C0.9800
N1—C11.378 (3)
N1—Ni—N1i180.0C4—N2—H2A125.5
N1—Ni—O1W90.90 (8)C2—N2—H2A125.5
N1i—Ni—O1W89.10 (8)C2—C1—N1111.1 (2)
N1—Ni—O1Wi89.10 (8)C2—C1—S1130.4 (2)
N1i—Ni—O1Wi90.90 (8)N1—C1—S1118.48 (19)
O1W—Ni—O1Wi180.00 (6)C1—C2—N2104.1 (2)
N1—Ni—O182.42 (8)C1—C2—C3131.9 (2)
N1i—Ni—O197.58 (8)N2—C2—C3124.0 (2)
O1W—Ni—O189.75 (8)C2—C3—H3A109.5
O1Wi—Ni—O190.25 (8)C2—C3—H3B109.5
N1—Ni—O1i97.58 (8)H3A—C3—H3B109.5
N1i—Ni—O1i82.42 (8)C2—C3—H3C109.5
O1W—Ni—O1i90.25 (8)H3A—C3—H3C109.5
O1Wi—Ni—O1i89.75 (8)H3B—C3—H3C109.5
O1—Ni—O1i180.00 (14)N1—C4—N2110.2 (2)
O3—S1—O2112.61 (13)N1—C4—C5125.8 (2)
O3—S1—O1113.45 (12)N2—C4—C5123.9 (2)
O2—S1—O1111.06 (11)C4—C5—C6111.6 (2)
O3—S1—C1109.24 (12)C4—C5—H5A109.3
O2—S1—C1107.09 (12)C6—C5—H5A109.3
O1—S1—C1102.73 (11)C4—C5—H5B109.3
S1—O1—Ni120.66 (10)C6—C5—H5B109.3
Ni—O1W—H1W1112 (3)H5A—C5—H5B108.0
Ni—O1W—H1W2109 (3)C5—C6—H6A109.5
H1W1—O1W—H1W2105 (3)C5—C6—H6B109.5
H2W1—O2W—H2W2110 (3)H6A—C6—H6B109.5
C4—N1—C1105.7 (2)C5—C6—H6C109.5
C4—N1—Ni138.96 (19)H6A—C6—H6C109.5
C1—N1—Ni115.34 (16)H6B—C6—H6C109.5
C4—N2—C2109.0 (2)
O3—S1—O1—Ni124.06 (13)Ni—N1—C1—S11.0 (3)
O2—S1—O1—Ni107.92 (14)O3—S1—C1—C257.4 (3)
C1—S1—O1—Ni6.27 (15)O2—S1—C1—C264.8 (3)
N1—Ni—O1—S16.10 (13)O1—S1—C1—C2178.1 (3)
N1i—Ni—O1—S1173.90 (13)O3—S1—C1—N1124.0 (2)
O1W—Ni—O1—S197.04 (13)O2—S1—C1—N1113.8 (2)
O1Wi—Ni—O1—S182.96 (13)O1—S1—C1—N13.2 (2)
O1i—Ni—O1—S189 (6)N1—C1—C2—N20.2 (3)
N1i—Ni—N1—C481 (8)S1—C1—C2—N2178.9 (2)
O1W—Ni—N1—C489.7 (3)N1—C1—C2—C3177.0 (3)
O1Wi—Ni—N1—C490.3 (3)S1—C1—C2—C31.7 (5)
O1—Ni—N1—C4179.4 (3)C4—N2—C2—C10.2 (3)
O1i—Ni—N1—C40.6 (3)C4—N2—C2—C3177.3 (3)
N1i—Ni—N1—C1102 (8)C1—N1—C4—N20.1 (3)
O1W—Ni—N1—C193.13 (18)Ni—N1—C4—N2177.21 (19)
O1Wi—Ni—N1—C186.87 (18)C1—N1—C4—C5176.8 (2)
O1—Ni—N1—C13.50 (17)Ni—N1—C4—C50.5 (4)
O1i—Ni—N1—C1176.50 (17)C2—N2—C4—N10.0 (3)
C4—N1—C1—C20.2 (3)C2—N2—C4—C5176.7 (2)
Ni—N1—C1—C2177.83 (17)N1—C4—C5—C676.8 (3)
C4—N1—C1—S1179.10 (18)N2—C4—C5—C699.4 (3)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1W1···O2W0.82 (2)2.02 (2)2.837 (3)174 (4)
O1W—H1W2···O3ii0.81 (2)1.96 (2)2.739 (3)161 (4)
O2W—H2W1···O2i0.80 (2)1.97 (2)2.751 (3)167 (4)
O2W—H2W1···S1i0.80 (2)2.92 (3)3.602 (2)145 (3)
O2W—H2W2···O2iii0.80 (2)1.94 (2)2.723 (3)169 (4)
N2—H2A···O2Wiv0.881.942.818 (3)174
Symmetry codes: (i) x+1, y+1, z+1; (ii) x, y+1, z+1; (iii) x+1/2, y1/2, z+1; (iv) x+1, y+1, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1W1···O2W0.823 (19)2.017 (19)2.837 (3)174 (4)
O1W—H1W2···O3i0.808 (19)1.96 (2)2.739 (3)161 (4)
O2W—H2W1···O2ii0.798 (18)1.97 (2)2.751 (3)167 (4)
O2W—H2W1···S1ii0.798 (18)2.92 (3)3.602 (2)145 (3)
O2W—H2W2···O2iii0.796 (18)1.94 (2)2.723 (3)169 (4)
N2—H2A···O2Wiv0.881.942.818 (3)174.4
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y+1, z+1; (iii) x+1/2, y1/2, z+1; (iv) x+1, y+1, z+2.
 

Acknowledgements

We thank The Office of Naval Research for financial support. RJB wishes to acknowledge the NSF–MRI program (grant CHE-0619278) for funds to purchase the diffractometer.

References

First citationAgilent (2012). CrysAlis PRO and CrysAlis RED. Agilent Technologies, Yarnton, England.  Google Scholar
First citationChidambaram, Sp., Aravamudan, G. & Seshasayee, M. (1988). Acta Cryst. C44, 898–900.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationForbes, T. Z. & Sevov, S. C. (2009). Inorg. Chem. 48, 6873–6878.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationKim, D. S., Forster, P. M., Le Toquin, R. & Cheetham, A. K. (2004). Chem. Commun. pp. 2148–2149.  Web of Science CSD CrossRef Google Scholar
First citationKuhn, N., Eichele, K. & Walker, M. (2001). Z. Anorg. Allg. Chem. 627, 2565–2567.  CrossRef CAS Google Scholar
First citationKuhn, N., Eichele, K., Walker, M., Berends, T. & Minkwitz, R. (2002). Z. Anorg. Allg. Chem. 628, 2026–2032.  CrossRef CAS Google Scholar
First citationLobana, T. S., Kinoshita, I., Kimura, K., Nishioka, T., Shiomi, D. & Isobe, K. (2004). Eur. J. Inorg. Chem. pp. 356–367.  Web of Science CSD CrossRef Google Scholar
First citationPurdy, A. P. & Butcher, R. J. (2011). Acta Cryst. E67, m1303–m1304.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationPurdy, A. P., Gilardi, R., Luther, J. & Butcher, R. J. (2007). Polyhedron, 26, 3930–3938.  Web of Science CSD CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYang, F., Wu, Z.-H. & Cai, J.-H. (2010). Acta Cryst. E66, m748.  Web of Science CSD CrossRef 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 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