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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 6| June 2013| Pages m337-m338

Di-μ-azido-di­azidodi-μ-oxalato-di­histamine­tetra­copper(II) 0.9-hydrate

aDepartment of Chemistry and Environmental Science, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, Newfoundland, A2H 6P9, Canada, and bDepartment of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
*Correspondence e-mail: cliu@grenfell.mun.ca

(Received 10 March 2013; accepted 14 May 2013; online 22 May 2013)

The title compound, [Cu4(C2O4)2(N3)4(C5H9N3)2]·0.9H2O, contains a tetranuclear CuII-based molecule composed of two oxalate-bridged CuII dimers linked through end-on azide ions and related by an inversion center. The tetranuclear unit contains two crystallographically independent CuII ions. One CuII ion coordinates to two N atoms of a histamine mol­ecule, two O atoms of a bridging oxalate ligand, and an N atom of an end-on bridging azide ligand, leading to an elongated square-pyramidal coordination geometry in which the azide ion occupies the axial position. The other CuII ion, which has a square-planar coordination geometry, is coordinated by two O atoms of a bridging oxalate ligand and two N atoms of two different azide ligands, one which is bridging. In the crystal, a two-dimensional network parallel to (010) is formed by N—H⋯N and N—H⋯O hydrogen bonds. A partially occupied solvent water mol­ecule refined to an occupancy of 0.447 (5). Two of the azide ligands were refined as disordered over two sets of sites with refined occupancies in the ratios 0.517 (8):0.483 (8) and 0.553 (5):0.447 (5).

Related literature

For background to bridging oxalate and azide ligands, see: Coronado et al. (2003[Coronado, E., Giménez, M. C., Gómez-Garcia, C. J. & Romero, F. M. (2003). Polyhedron, 22, 3115-3122.]); Ribas et al. (1999[Ribas, J., Escuer, A., Monfort, M., Vicente, R., Cortes, R., Lezama, L. & Rojo, T. (1999). Coord. Chem. Rev. 193-195, 1027-1068.]); Pardo et al. (2010[Pardo, E., Train, C., Lescouezec, R., Boubekeru, K., Ruiz, E., Lloret, F. & Verdaguer, M. (2010). Dalton Trans. 39, 4951-4958.]); Sun et al. (1997[Sun, X. R., Miao, M. M., Cheng, P., Liao, D. Z., Jiang, Z. H. & Wang, G. L. (1997). Transition Met. Chem. 22, 302-303.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu4(C2O4)2(N3)4(C5H9N3)2]·0.9H2O

  • Mr = 838.62

  • Triclinic, [P \overline 1]

  • a = 7.7003 (10) Å

  • b = 8.2841 (11) Å

  • c = 11.8677 (15) Å

  • α = 106.005 (2)°

  • β = 91.715 (2)°

  • γ = 115.010 (2)°

  • V = 650.07 (15) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 3.31 mm−1

  • T = 173 K

  • 0.12 × 0.11 × 0.04 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: integration [based on measured indexed crystal faces (SHELXTL; Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.])] Tmin = 0.654, Tmax = 0.877

  • 5770 measured reflections

  • 2885 independent reflections

  • 2442 reflections with I > 2σ(I)

  • Rint = 0.041

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.073

  • S = 1.03

  • 2885 reflections

  • 238 parameters

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

  • Δρmax = 0.60 e Å−3

  • Δρmin = −0.56 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N9—H9⋯O5i 0.80 (4) 2.18 (4) 2.861 (6) 143 (3)
N9—H9⋯N6′i 0.80 (4) 2.59 (4) 3.171 (6) 130 (3)
N9—H9⋯N3′ii 0.80 (4) 2.60 (4) 3.145 (7) 127 (3)
N9—H9⋯N6iii 0.80 (4) 2.38 (4) 3.108 (6) 151 (3)
Symmetry codes: (i) -x, -y+1, -z; (ii) -x+1, -y+1, -z; (iii) x, y-1, z-1.

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The title compound is a polynuclear coordination complex involving mixed bridging ligands, both oxalate (Coronado et al. 2003; Pardo et al. 2010; Sun et al., 1997) and azide (Ribas, et al. 1999) anions. The tetrameric unit in the title compound is centrosymmetric (Fig.1), so pairs of equivalent ligands lie trans to each other. Two of the four azide ions within each tetramer are in end-on bridging mode, while the other two are non-bridging but form long N4A–Cu[1-x, 2-y, 1-z] (two-dimensional) bonds of 2.486 (3) Å with CuII ions on neighbouring tetramers and therefore link tetramers along the crystallographic b axis to produce one-dimensional chains (Fig.2). The distance between the two CuII ions linked by this long Cu—N bond is 3.2261 (8) Å.

Related literature top

For background to bridging oxalate and azide ligands, see: Coronado et al. (2003); Ribas et al. (1999); Pardo et al. (2010); Sun et al. (1997).

Experimental top

An aqueous solution (15 ml) of copper(II) nitrate trihydrate (4.0 mmol, 0.97 g) was slowly added to an aqueous solution (50 ml) containing histamine dihydrochloride (4.0 mmol, 0.74 g), sodium oxalate (2.0 mmol, 0.27 g), sodium azide (4.0 mmol, 0.26 g), and sodium hydroxide (8.0 mmol, 0.32 g). The mixture was stirred for 10 minutes and allowed to stand in air. Green platelet crystals were collected after a few days and washed with deionized water and dried in air.

Refinement top

All H atoms were positioned geometrically (C—H = 0.93/1.00 Å) and allowed to ride with Uiso(H)= 1.2/1.5Ueq(C). Methyl H atoms were allowed to rotate around the corresponding C—C.

The N2—N3 and N5—N6 moieties were refined a disordered and each refined in two parts against N2'-N3' and N5'-N6'. A partial water molecule alternates with the N5'-N6' moiety in occupying the same space. The two N9 protons were obtained from a difference Fourier map but did not refine properly thus they were refined in idealized positions and were riding on their parent atom. The N9 proton is refined freely. All disordered parts have properly refined occupancy factors.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with ellipsoids drawn at 30% probability level. Unlabelled atoms are related by the symmetry transofrmation: -x + 1, -y + 1, -z + 1.
[Figure 2] Fig. 2. One-dimensional chain of tetramers of the title compound.
Di-µ-azido-diazidodi-µ-oxalato-dihistaminetetracopper(II) 0.9-hydrate top
Crystal data top
[Cu4(C2O4)2(N3)4(C5H9N3)2]·0.9H2OZ = 1
Mr = 838.62F(000) = 416
Triclinic, P1Dx = 2.137 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.7003 (10) ÅCell parameters from 29 reflections
b = 8.2841 (11) Åθ = 2.0–28.0°
c = 11.8677 (15) ŵ = 3.31 mm1
α = 106.005 (2)°T = 173 K
β = 91.715 (2)°Plate, green
γ = 115.010 (2)°0.12 × 0.11 × 0.04 mm
V = 650.07 (15) Å3
Data collection top
Bruker SMART CCD area-detector
diffractometer
2885 independent reflections
Radiation source: fine-focus sealed tube2442 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.041
ω and ϕ scansθmax = 27.5°, θmin = 1.8°
Absorption correction: integration
[based on measured indexed crystal faces (SHELXTL; Sheldrick, 2008)]
h = 99
Tmin = 0.654, Tmax = 0.877k = 1010
5770 measured reflectionsl = 1515
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)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.073H atoms treated by a mixture of independent and constrained refinement
S = 1.03 w = 1/[σ2(Fo2) + (0.0327P)2 + 0.5471P]
where P = (Fo2 + 2Fc2)/3
2885 reflections(Δ/σ)max < 0.001
238 parametersΔρmax = 0.60 e Å3
0 restraintsΔρmin = 0.56 e Å3
Crystal data top
[Cu4(C2O4)2(N3)4(C5H9N3)2]·0.9H2Oγ = 115.010 (2)°
Mr = 838.62V = 650.07 (15) Å3
Triclinic, P1Z = 1
a = 7.7003 (10) ÅMo Kα radiation
b = 8.2841 (11) ŵ = 3.31 mm1
c = 11.8677 (15) ÅT = 173 K
α = 106.005 (2)°0.12 × 0.11 × 0.04 mm
β = 91.715 (2)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
2885 independent reflections
Absorption correction: integration
[based on measured indexed crystal faces (SHELXTL; Sheldrick, 2008)]
2442 reflections with I > 2σ(I)
Tmin = 0.654, Tmax = 0.877Rint = 0.041
5770 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.073H atoms treated by a mixture of independent and constrained refinement
S = 1.03Δρmax = 0.60 e Å3
2885 reflectionsΔρmin = 0.56 e Å3
238 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cu10.10361 (5)0.35821 (5)0.26714 (3)0.0187 (1)
Cu20.45210 (4)0.78190 (4)0.47013 (3)0.0146 (1)
O10.1735 (3)0.3957 (2)0.44160 (16)0.0177 (4)
O20.2983 (3)0.2567 (3)0.24786 (16)0.0196 (4)
O30.4798 (3)0.1874 (3)0.35955 (16)0.0194 (4)
O40.3611 (3)0.3319 (3)0.55217 (16)0.0172 (4)
O50.0013 (8)0.9226 (8)0.3473 (5)0.0304 (14)0.447 (5)
N10.3411 (3)0.6717 (3)0.3003 (2)0.0217 (5)
N20.4238 (7)0.6559 (8)0.2176 (4)0.0181 (11)*0.517 (8)
N30.5044 (9)0.6493 (9)0.1379 (5)0.0389 (17)*0.517 (8)
N2'0.4711 (8)0.7391 (9)0.2413 (5)0.0189 (12)*0.483 (8)
N3'0.5775 (9)0.7833 (9)0.1768 (6)0.0378 (18)*0.483 (8)
N40.2809 (4)0.9047 (3)0.5128 (2)0.0218 (5)
N5'0.1670 (6)0.8882 (5)0.4349 (3)0.0153 (10)0.553 (5)
N6'0.0499 (8)0.8764 (8)0.3687 (5)0.0245 (11)0.553 (5)
N50.2251 (7)0.9251 (7)0.6159 (4)0.0182 (12)0.447 (5)
N60.1813 (7)0.9522 (7)0.7129 (5)0.0228 (13)0.447 (5)
N70.1142 (4)0.4201 (5)0.3030 (2)0.0455 (9)
H7B0.20260.32810.32930.055*
H7C0.06650.53100.36510.055*
H7A0.245 (4)0.240 (4)0.028 (3)0.016 (7)*
N80.0241 (3)0.2683 (3)0.09526 (19)0.0183 (5)
N90.0241 (4)0.1696 (3)0.0948 (2)0.0215 (5)
H90.064 (5)0.142 (5)0.155 (3)0.036 (10)*
C10.3613 (4)0.2501 (3)0.3439 (2)0.0163 (5)
C20.2908 (3)0.3308 (3)0.4554 (2)0.0137 (5)
C30.2212 (4)0.4403 (5)0.2049 (3)0.0296 (7)
H3B0.13150.54580.17950.035*
H3A0.32750.46890.23370.035*
C40.3049 (4)0.2605 (4)0.1001 (2)0.0258 (6)
H4B0.37480.15260.12910.031*
H4A0.40040.26470.04460.031*
C50.1530 (4)0.2306 (4)0.0346 (2)0.0186 (5)
C60.1515 (4)0.1704 (4)0.0830 (3)0.0226 (6)
H6A0.237 (5)0.131 (5)0.143 (3)0.027 (9)*
C70.1261 (4)0.2291 (4)0.0137 (2)0.0205 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.01983 (18)0.02819 (19)0.01006 (17)0.01687 (15)0.00150 (12)0.00048 (13)
Cu20.01364 (16)0.01637 (16)0.01463 (17)0.00709 (13)0.00059 (12)0.00577 (12)
O10.0189 (9)0.0221 (9)0.0142 (9)0.0132 (8)0.0004 (7)0.0024 (7)
O20.0227 (10)0.0281 (10)0.0110 (9)0.0176 (8)0.0011 (7)0.0010 (7)
O30.0239 (10)0.0238 (9)0.0135 (9)0.0169 (8)0.0001 (7)0.0004 (8)
O40.0188 (9)0.0212 (9)0.0140 (9)0.0108 (8)0.0038 (7)0.0058 (7)
O50.026 (3)0.041 (3)0.014 (2)0.009 (2)0.003 (2)0.003 (2)
N10.0218 (12)0.0337 (13)0.0138 (11)0.0166 (10)0.0024 (9)0.0071 (10)
N40.0303 (13)0.0213 (11)0.0163 (11)0.0162 (10)0.0019 (10)0.0030 (9)
N5'0.017 (2)0.0134 (18)0.014 (2)0.0076 (16)0.0051 (16)0.0018 (15)
N6'0.020 (3)0.034 (3)0.023 (3)0.015 (2)0.001 (2)0.010 (2)
N50.018 (3)0.018 (2)0.023 (3)0.012 (2)0.004 (2)0.007 (2)
N60.019 (3)0.025 (3)0.029 (3)0.015 (2)0.006 (2)0.007 (2)
N70.0454 (17)0.089 (2)0.0143 (13)0.0549 (18)0.0038 (12)0.0055 (14)
N80.0199 (11)0.0245 (11)0.0121 (10)0.013 (1)0.0009 (8)0.0034 (9)
N90.0298 (13)0.0263 (12)0.0104 (11)0.0157 (11)0.004 (1)0.0037 (10)
C10.0168 (12)0.0147 (11)0.0140 (12)0.0068 (10)0.0002 (10)0.0003 (10)
C20.0131 (12)0.0117 (11)0.0126 (12)0.0042 (9)0.0007 (9)0.0011 (9)
C30.0287 (16)0.0449 (18)0.0234 (15)0.0297 (15)0.0015 (12)0.0019 (13)
C40.0208 (14)0.0399 (16)0.0176 (14)0.0168 (13)0.0009 (11)0.0053 (12)
C50.0194 (13)0.0202 (12)0.0143 (12)0.0104 (11)0.0042 (10)0.0011 (10)
C60.0252 (15)0.0252 (14)0.0151 (13)0.0127 (12)0.0038 (11)0.0017 (11)
C70.0220 (14)0.0272 (14)0.0155 (13)0.0164 (12)0.0034 (11)0.0029 (11)
Geometric parameters (Å, º) top
Cu1—N81.947 (2)N5'—N6'1.132 (7)
Cu1—N71.977 (2)N5—N61.197 (7)
Cu1—O21.9970 (18)N7—C31.493 (4)
Cu1—O12.0275 (18)N7—H7B0.9200
Cu1—N12.371 (3)N7—H7C0.9200
Cu2—N11.962 (2)N8—C71.322 (3)
Cu2—N41.980 (2)N8—C51.390 (3)
Cu2—O3i1.9915 (18)N9—C71.334 (4)
Cu2—O4i2.0148 (18)N9—C61.366 (4)
O1—C21.258 (3)N9—H90.80 (4)
O2—C11.249 (3)C1—C21.534 (3)
O3—C11.258 (3)C3—C41.516 (4)
O3—Cu2i1.9915 (18)C3—H3B0.9900
O4—C21.251 (3)C3—H3A0.9900
O4—Cu2i2.0148 (18)C4—C51.493 (4)
N1—N21.192 (5)C4—H4B0.9900
N1—N2'1.260 (6)C4—H4A0.9900
N2—N31.149 (7)C5—C61.348 (4)
N2'—N3'1.153 (7)C6—H6A0.84 (3)
N4—N5'1.192 (4)C7—H7A0.88 (3)
N4—N51.300 (5)
N8—Cu1—N795.03 (10)Cu1—N7—H7C107.9
N8—Cu1—O290.05 (8)H7B—N7—H7C107.2
N7—Cu1—O2168.22 (12)C7—N8—C5106.7 (2)
N8—Cu1—O1168.11 (8)C7—N8—Cu1126.94 (19)
N7—Cu1—O189.88 (9)C5—N8—Cu1126.40 (18)
O2—Cu1—O183.23 (7)C7—N9—C6108.3 (2)
N8—Cu1—N1101.85 (9)C7—N9—H9124 (3)
N7—Cu1—N195.97 (12)C6—N9—H9127 (3)
O2—Cu1—N193.37 (8)O2—C1—O3126.8 (2)
O1—Cu1—N188.36 (8)O2—C1—C2117.0 (2)
N1—Cu2—N494.99 (9)O3—C1—C2116.2 (2)
N1—Cu2—O3i162.53 (9)O4—C2—O1126.1 (2)
N4—Cu2—O3i90.34 (8)O4—C2—C1116.7 (2)
N1—Cu2—O4i91.90 (8)O1—C2—C1117.1 (2)
N4—Cu2—O4i173.09 (8)N7—C3—C4110.3 (3)
O3i—Cu2—O4i82.91 (7)N7—C3—H3B109.6
C2—O1—Cu1110.59 (16)C4—C3—H3B109.6
C1—O2—Cu1111.93 (17)N7—C3—H3A109.6
C1—O3—Cu2i112.47 (16)C4—C3—H3A109.6
C2—O4—Cu2i111.66 (16)H3B—C3—H3A108.1
N2—N1—Cu2128.1 (3)C5—C4—C3112.7 (2)
N2'—N1—Cu2109.1 (3)C5—C4—H4B109.0
N2—N1—Cu1102.3 (3)C3—C4—H4B109.0
N2'—N1—Cu1130.6 (3)C5—C4—H4A109.0
Cu2—N1—Cu1107.77 (10)C3—C4—H4A109.0
N3—N2—N1176.5 (6)H4B—C4—H4A107.8
N3'—N2'—N1172.4 (7)C6—C5—N8108.1 (2)
N5'—N4—N5114.0 (3)C6—C5—C4130.8 (2)
N5'—N4—Cu2117.9 (2)N8—C5—C4121.0 (2)
N5—N4—Cu2121.0 (3)C5—C6—N9106.8 (2)
N6'—N5'—N4173.9 (5)C5—C6—H6A132 (2)
N6—N5—N4176.8 (5)N9—C6—H6A121 (2)
C3—N7—Cu1117.6 (2)N8—C7—N9110.1 (2)
C3—N7—H7B107.9N8—C7—H7A125.6 (19)
Cu1—N7—H7B107.9N9—C7—H7A124.4 (19)
C3—N7—H7C107.9
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N9—H9···O5ii0.80 (4)2.18 (4)2.861 (6)143 (3)
N9—H9···N6ii0.80 (4)2.59 (4)3.171 (6)130 (3)
N9—H9···N3iii0.80 (4)2.60 (4)3.145 (7)127 (3)
N9—H9···N6iv0.80 (4)2.38 (4)3.108 (6)151 (3)
Symmetry codes: (ii) x, y+1, z; (iii) x+1, y+1, z; (iv) x, y1, z1.

Experimental details

Crystal data
Chemical formula[Cu4(C2O4)2(N3)4(C5H9N3)2]·0.9H2O
Mr838.62
Crystal system, space groupTriclinic, P1
Temperature (K)173
a, b, c (Å)7.7003 (10), 8.2841 (11), 11.8677 (15)
α, β, γ (°)106.005 (2), 91.715 (2), 115.010 (2)
V3)650.07 (15)
Z1
Radiation typeMo Kα
µ (mm1)3.31
Crystal size (mm)0.12 × 0.11 × 0.04
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionIntegration
[based on measured indexed crystal faces (SHELXTL; Sheldrick, 2008)]
Tmin, Tmax0.654, 0.877
No. of measured, independent and
observed [I > 2σ(I)] reflections
5770, 2885, 2442
Rint0.041
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.073, 1.03
No. of reflections2885
No. of parameters238
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.60, 0.56

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N9—H9···O5i0.80 (4)2.18 (4)2.861 (6)143 (3)
N9—H9···N6'i0.80 (4)2.59 (4)3.171 (6)130 (3)
N9—H9···N3'ii0.80 (4)2.60 (4)3.145 (7)127 (3)
N9—H9···N6iii0.80 (4)2.38 (4)3.108 (6)151 (3)
Symmetry codes: (i) x, y+1, z; (ii) x+1, y+1, z; (iii) x, y1, z1.
 

Acknowledgements

CL wishes to thank the Vice President (Grenfell Campus) Research Fund 208384 47333 2000 from Grenfell Campus, Memorial University of Newfoundland, for supporting this work. KAA wishes to acknowledge the National Science Foundation and the University of Florida for funding the purchase of the X-ray equipment.

References

First citationBruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCoronado, E., Giménez, M. C., Gómez-Garcia, C. J. & Romero, F. M. (2003). Polyhedron, 22, 3115–3122.  Web of Science CSD CrossRef CAS Google Scholar
First citationPardo, E., Train, C., Lescouezec, R., Boubekeru, K., Ruiz, E., Lloret, F. & Verdaguer, M. (2010). Dalton Trans. 39, 4951–4958.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationRibas, J., Escuer, A., Monfort, M., Vicente, R., Cortes, R., Lezama, L. & Rojo, T. (1999). Coord. Chem. Rev. 193–195, 1027–1068.  Web of Science CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSun, X. R., Miao, M. M., Cheng, P., Liao, D. Z., Jiang, Z. H. & Wang, G. L. (1997). Transition Met. Chem. 22, 302–303.  CrossRef CAS Web of Science Google Scholar

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Volume 69| Part 6| June 2013| Pages m337-m338
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