catena-Poly[[(1,10-phenanthroline)cadmium(II)]-μ-2-(1,3-benzimidazol-2-ylsulfan­yl)acetato-κ3N1,O:N3]

Cheng, L.; Sun, Y.-Y.; Zhang, Y.-W.; Wang, J.-Q.

doi:10.1107/S1600536808041044

metal-organic compounds

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ISSN: 2056-9890

Volume 65| Part 1| January 2009| Page m34

doi:10.1107/S1600536808041044

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catena-Poly[[(1,10-phenanthroline)cadmium(II)]-μ-2-(1,3-benzimidazol-2-ylsulfanyl)acetato-κ³N¹,O:N³]

Lin Cheng,^a ^* Yan-Yan Sun,^a Ya-Wen Zhang ^a and Jian-Quan Wang ^a

^aSchool of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China
^*Correspondence e-mail: cep02chl@yahoo.com.cn

(Received 22 November 2008; accepted 5 December 2008; online 10 December 2008)

In title compound, [Cd(C₉H₆N₂O₂S)(C₁₂H₈N₂)]_n, the Cd^II atom is in a distorted tetragonal-pyramidal environment, coordinated by one chelating 1,10-phenanthroline ligand, one chelating 2-(1,3-benzimidazol-2-ylsulfanyl)acetate (bia) ligand bound through one N atom and one O atom of the carboxyl group, and one N atom from a second bia ligand. Each bia ligand acts as bridge between Cd^II ions, forming one-dimensional coordination polymers along [010], with a shortest Cd⋯Cd distance of 4.27 (2) Å.

Related literature

For related structures, see: Matthews et al. (1998 ); Zhang et al. (2008 ).

Experimental

Crystal data

[Cd(C₉H₆N₂O₂S)(C₁₂H₈N₂)]
M_r = 498.84
Monoclinic, P 2₁ /c
a = 9.2195 (10) Å
b = 8.2577 (9) Å
c = 25.620 (3) Å
β = 103.215 (4)°
V = 1898.8 (4) Å³
Z = 4
Mo Kα radiation
μ = 1.29 mm⁻¹
T = 293 (2) K
0.20 × 0.18 × 0.15 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2000 ) T_min = 0.783, T_max = 0.831
9820 measured reflections
3724 independent reflections
3413 reflections with I > 2σ(I)
R_int = 0.025

Refinement

R[F² > 2σ(F²)] = 0.041
wR(F²) = 0.091
S = 1.04
3724 reflections
262 parameters
H-atom parameters constrained
Δρ_max = 0.62 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Data collection: SMART (Bruker, 2000 ); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808041044/bi2328sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808041044/bi2328Isup2.hkl

checkCIF report

Comment top

Recently, there has been significant interest in the rational design and synthesis of metal-organic coordination architectures by using flexible bridging units because the flexibility and conformational freedom of such ligands offers the possibility for construction of unprecedented frameworks (Zhang et al. 2008). Benzimidazole and thioether carboxylates have been widely used to construct many novel and interesting metal-organic frameworks. However, such metal-organic frameworks formed by bifunctional ligands including benzimidazole and thioether carboxylate have been rarely reported (Matthews et al. 1998). Herein, we report a new bifunctional flexible ligand 2-(1H-benzo[d]imidazol-2-ylthio)acetic acid (H₂bia), and present the synthesis and structural characterization of a one-dimensional coordination polymer {Cd(bia)(phen)}n (phen = 1,10-phenanthroline).

The asymmetric unit of the title compound, contains a Cd^II cation, a bia and a chelating phen. Each Cd^II displays a distorted tetragonal pyramidal geometry, being surrounded by one phen ligand, one chelating bia and a N atom of another bia ligand. Each bia ligand acts as a bridge between two Cd^II ions, forming one-dimensional coordination polymers along the b axis (Fig. 1). The shortest Cd···Cd distance in the chain is 4.27 (2) Å.

Related literature top

For related structures, see: Matthews et al. (1998); Zhang et al. (2008).

Experimental top

A mixture of H₂bia (0.0208 g, 0.1 mmol), phen (0.0180 g, 0.1 mmol), Cd(NO₃)₂.6H₂O (0.0345 g, 0.1 mmol) and H₂O (8 ml) was heated in a 15 ml Teflon-lined autoclave at 433 K for 3 days, followed by slow cooling (5 K h^-1) to room temperature. The resulting mixture was washed with water, and colourless block crystals were collected and dried in air. Yield 86% (42.9 mg), based on Mn^II.

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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

Fig. 1. The one-dimensional chain of the title compound. Displacement ellipsoids are shown at 50% probability and H atoms are omitted for clarity.

catena-Poly[[(1,10-phenanthroline)cadmium(II)]-µ-2-(1,3-benzimidazol- 2-ylsulfanyl)acetato-κ³N¹,O:N³] top

Crystal data top

[Cd(C₉H₆N₂O₂S)(C₁₂H₈N₂)]	F(000) = 992
M_r = 498.84	D_x = 1.745 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 781 reflections
a = 9.2195 (10) Å	θ = 2.4–28.0°
b = 8.2577 (9) Å	µ = 1.29 mm⁻¹
c = 25.620 (3) Å	T = 293 K
β = 103.215 (4)°	Block, colorless
V = 1898.8 (4) Å³	0.20 × 0.18 × 0.15 mm
Z = 4

Data collection top

Bruker APEX CCD diffractometer	3724 independent reflections
Radiation source: fine-focus sealed tube	3413 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.025
ϕ and ω scans	θ_max = 26.0°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −11→11
T_min = 0.783, T_max = 0.831	k = −9→10
9820 measured reflections	l = −31→26

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.091	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0401P)² + 3.0611P] where P = (F_o² + 2F_c²)/3
3724 reflections	(Δ/σ)_max < 0.001
262 parameters	Δρ_max = 0.62 e Å⁻³
0 restraints	Δρ_min = −0.46 e Å⁻³

Crystal data top

[Cd(C₉H₆N₂O₂S)(C₁₂H₈N₂)]	V = 1898.8 (4) Å³
M_r = 498.84	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 9.2195 (10) Å	µ = 1.29 mm⁻¹
b = 8.2577 (9) Å	T = 293 K
c = 25.620 (3) Å	0.20 × 0.18 × 0.15 mm
β = 103.215 (4)°

Data collection top

Bruker APEX CCD diffractometer	3724 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	3413 reflections with I > 2σ(I)
T_min = 0.783, T_max = 0.831	R_int = 0.025
9820 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.041	0 restraints
wR(F²) = 0.091	H-atom parameters constrained
S = 1.04	Δρ_max = 0.62 e Å⁻³
3724 reflections	Δρ_min = −0.46 e Å⁻³
262 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

	x	y	z	U_iso*/U_eq
Cd1	−0.02266 (3)	−0.35415 (3)	−0.160159 (10)	0.03702 (11)
S1	−0.16960 (11)	−0.61304 (14)	−0.27062 (4)	0.0438 (2)
O1	−0.2554 (4)	−0.4866 (4)	−0.42417 (12)	0.0656 (9)
O2	−0.1646 (3)	−0.7175 (4)	−0.38778 (11)	0.0536 (8)
N1	0.0906 (3)	−0.5378 (4)	−0.20121 (12)	0.0375 (7)
N2	0.1161 (3)	−0.6933 (4)	−0.27140 (12)	0.0382 (7)
N3	−0.2011 (4)	−0.2403 (4)	−0.11518 (12)	0.0420 (8)
N4	−0.0690 (3)	−0.5365 (4)	−0.09663 (12)	0.0372 (7)
C1	0.3638 (5)	−0.5327 (6)	−0.15550 (18)	0.0543 (11)
H1A	0.3548	−0.4674	−0.1268	0.065*
C2	0.4989 (5)	−0.5924 (7)	−0.1596 (2)	0.0638 (13)
H2A	0.5829	−0.5674	−0.1331	0.077*
C3	0.5142 (5)	−0.6896 (6)	−0.2025 (2)	0.0578 (12)
H3A	0.6080	−0.7285	−0.2038	0.069*
C4	0.3944 (4)	−0.7286 (6)	−0.24257 (17)	0.0481 (10)
H4A	0.4049	−0.7929	−0.2713	0.058*
C5	0.2560 (4)	−0.6688 (5)	−0.23888 (15)	0.0369 (8)
C6	0.2405 (4)	−0.5729 (5)	−0.19558 (15)	0.0382 (8)
C7	0.0246 (4)	−0.6129 (4)	−0.24705 (14)	0.0350 (8)
C8	−0.1951 (5)	−0.4915 (5)	−0.33087 (16)	0.0503 (10)
H8A	−0.2856	−0.4290	−0.3335	0.060*
H8B	−0.1133	−0.4147	−0.3255	0.060*
C9	−0.2050 (4)	−0.5725 (5)	−0.38529 (15)	0.0401 (9)
C10	−0.2683 (5)	−0.0977 (6)	−0.12479 (18)	0.0533 (11)
H10A	−0.2493	−0.0352	−0.1527	0.064*
C11	−0.3653 (5)	−0.0372 (6)	−0.09554 (19)	0.0600 (12)
H11A	−0.4117	0.0624	−0.1042	0.072*
C12	−0.3913 (5)	−0.1260 (6)	−0.05392 (18)	0.0577 (12)
H12A	−0.4549	−0.0865	−0.0335	0.069*
C13	−0.3225 (4)	−0.2768 (6)	−0.04181 (16)	0.0443 (9)
C14	−0.3439 (5)	−0.3777 (6)	0.00100 (18)	0.0551 (12)
H14A	−0.4031	−0.3409	0.0234	0.066*
C15	−0.2810 (5)	−0.5237 (6)	0.00960 (17)	0.0519 (11)
H15A	−0.2986	−0.5873	0.0375	0.062*
C16	−0.1871 (4)	−0.5838 (5)	−0.02325 (15)	0.0400 (9)
C17	−0.1199 (5)	−0.7361 (6)	−0.01553 (16)	0.0480 (10)
H17A	−0.1378	−0.8042	0.0112	0.058*
C18	−0.0281 (5)	−0.7844 (5)	−0.04729 (17)	0.0497 (10)
H18A	0.0185	−0.8849	−0.0423	0.060*
C19	−0.0053 (5)	−0.6804 (5)	−0.08740 (16)	0.0450 (10)
H19A	0.0579	−0.7139	−0.1088	0.054*
C20	−0.1588 (4)	−0.4874 (5)	−0.06459 (14)	0.0351 (8)
C21	−0.2282 (4)	−0.3303 (5)	−0.07459 (14)	0.0372 (8)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cd1	0.04657 (18)	0.03648 (18)	0.02956 (16)	0.00219 (12)	0.01194 (11)	0.00272 (11)
S1	0.0372 (5)	0.0561 (6)	0.0393 (5)	−0.0041 (5)	0.0109 (4)	−0.0040 (5)
O1	0.093 (3)	0.056 (2)	0.0449 (18)	0.0063 (18)	0.0098 (17)	0.0128 (15)
O2	0.0666 (19)	0.0493 (18)	0.0396 (16)	0.0129 (15)	0.0011 (14)	−0.0080 (13)
N1	0.0437 (18)	0.0410 (18)	0.0279 (15)	−0.0012 (14)	0.0085 (13)	−0.0034 (13)
N2	0.0396 (17)	0.0422 (18)	0.0341 (16)	−0.0015 (14)	0.0112 (13)	−0.0054 (14)
N3	0.0515 (19)	0.0405 (19)	0.0335 (17)	0.0040 (16)	0.0088 (14)	0.0000 (14)
N4	0.0410 (17)	0.0374 (18)	0.0352 (16)	0.0000 (14)	0.0129 (13)	−0.0012 (14)
C1	0.056 (3)	0.054 (3)	0.047 (2)	−0.007 (2)	−0.002 (2)	−0.011 (2)
C2	0.043 (3)	0.071 (3)	0.068 (3)	−0.012 (2)	−0.007 (2)	−0.006 (3)
C3	0.037 (2)	0.067 (3)	0.069 (3)	0.001 (2)	0.011 (2)	0.014 (3)
C4	0.043 (2)	0.058 (3)	0.047 (2)	0.003 (2)	0.0191 (19)	0.003 (2)
C5	0.041 (2)	0.038 (2)	0.0325 (19)	−0.0045 (16)	0.0108 (16)	0.0054 (16)
C6	0.043 (2)	0.035 (2)	0.036 (2)	−0.0044 (17)	0.0074 (16)	0.0038 (16)
C7	0.040 (2)	0.035 (2)	0.0314 (18)	−0.0031 (16)	0.0113 (15)	0.0004 (15)
C8	0.058 (3)	0.045 (2)	0.042 (2)	0.010 (2)	−0.0002 (19)	−0.0038 (19)
C9	0.0336 (19)	0.045 (2)	0.041 (2)	−0.0077 (17)	0.0084 (16)	−0.0029 (18)
C10	0.069 (3)	0.045 (3)	0.047 (2)	0.009 (2)	0.016 (2)	0.004 (2)
C11	0.067 (3)	0.053 (3)	0.059 (3)	0.020 (2)	0.012 (2)	−0.004 (2)
C12	0.051 (3)	0.075 (3)	0.049 (3)	0.013 (2)	0.016 (2)	−0.013 (2)
C13	0.038 (2)	0.057 (3)	0.039 (2)	0.0047 (19)	0.0106 (16)	−0.0069 (19)
C14	0.047 (2)	0.079 (4)	0.045 (2)	0.003 (2)	0.0223 (19)	−0.001 (2)
C15	0.046 (2)	0.071 (3)	0.042 (2)	−0.003 (2)	0.0172 (19)	0.007 (2)
C16	0.0342 (19)	0.051 (2)	0.0332 (19)	−0.0069 (17)	0.0040 (15)	0.0030 (17)
C17	0.052 (2)	0.051 (3)	0.040 (2)	−0.007 (2)	0.0079 (18)	0.0110 (19)
C18	0.061 (3)	0.038 (2)	0.047 (2)	0.003 (2)	0.007 (2)	0.0075 (19)
C19	0.053 (2)	0.041 (2)	0.043 (2)	0.0037 (19)	0.0153 (19)	0.0003 (18)
C20	0.0297 (18)	0.043 (2)	0.0309 (18)	−0.0052 (16)	0.0031 (14)	−0.0026 (16)
C21	0.0360 (19)	0.044 (2)	0.0305 (18)	−0.0016 (16)	0.0050 (15)	−0.0051 (16)

Geometric parameters (Å, º) top

Cd1—O2ⁱ	2.189 (3)	C4—C5	1.391 (5)
Cd1—N2ⁱ	2.211 (3)	C4—H4A	0.930
Cd1—N1	2.236 (3)	C5—C6	1.397 (5)
Cd1—N4	2.327 (3)	C8—C9	1.530 (5)
Cd1—N3	2.405 (3)	C8—H8A	0.970
S1—C7	1.754 (4)	C8—H8B	0.970
S1—C8	1.811 (4)	C10—C11	1.384 (6)
O1—C9	1.225 (5)	C10—H10A	0.930
O2—C9	1.260 (5)	C11—C12	1.360 (7)
O2—Cd1ⁱⁱ	2.189 (3)	C11—H11A	0.930
N1—C7	1.344 (5)	C12—C13	1.400 (6)
N1—C6	1.387 (5)	C12—H12A	0.930
N2—C7	1.334 (5)	C13—C21	1.411 (5)
N2—C5	1.382 (5)	C13—C14	1.427 (6)
N2—Cd1ⁱⁱ	2.211 (3)	C14—C15	1.333 (6)
N3—C10	1.327 (5)	C14—H14A	0.930
N3—C21	1.347 (5)	C15—C16	1.427 (6)
N4—C19	1.323 (5)	C15—H15A	0.930
N4—C20	1.355 (5)	C16—C17	1.396 (6)
C1—C2	1.365 (6)	C16—C20	1.396 (5)
C1—C6	1.387 (5)	C17—C18	1.361 (6)
C1—H1A	0.930	C17—H17A	0.930
C2—C3	1.394 (7)	C18—C19	1.392 (6)
C2—H2A	0.930	C18—H18A	0.930
C3—C4	1.363 (6)	C19—H19A	0.930
C3—H3A	0.930	C20—C21	1.443 (5)

O2ⁱ—Cd1—N2ⁱ	104.44 (11)	C9—C8—S1	120.2 (3)
O2ⁱ—Cd1—N1	102.73 (12)	C9—C8—H8A	107.3
N2ⁱ—Cd1—N1	99.99 (11)	S1—C8—H8A	107.3
O2ⁱ—Cd1—N4	100.86 (11)	C9—C8—H8B	107.3
N2ⁱ—Cd1—N4	147.43 (11)	S1—C8—H8B	107.3
N1—Cd1—N4	94.03 (11)	H8A—C8—H8B	106.9
O2ⁱ—Cd1—N3	93.88 (12)	O1—C9—O2	124.8 (4)
N2ⁱ—Cd1—N3	87.71 (11)	O1—C9—C8	114.9 (4)
N1—Cd1—N3	159.18 (12)	O2—C9—C8	120.3 (4)
N4—Cd1—N3	70.30 (11)	N3—C10—C11	123.5 (4)
C7—S1—C8	102.5 (2)	N3—C10—H10A	118.2
C9—O2—Cd1ⁱⁱ	131.8 (3)	C11—C10—H10A	118.2
C7—N1—C6	103.6 (3)	C12—C11—C10	118.8 (4)
C7—N1—Cd1	123.9 (2)	C12—C11—H11A	120.6
C6—N1—Cd1	130.9 (2)	C10—C11—H11A	120.6
C7—N2—C5	104.4 (3)	C11—C12—C13	120.1 (4)
C7—N2—Cd1ⁱⁱ	119.8 (2)	C11—C12—H12A	120.0
C5—N2—Cd1ⁱⁱ	135.0 (3)	C13—C12—H12A	120.0
C10—N3—C21	118.2 (3)	C12—C13—C21	117.2 (4)
C10—N3—Cd1	126.8 (3)	C12—C13—C14	123.7 (4)
C21—N3—Cd1	114.9 (2)	C21—C13—C14	119.1 (4)
C19—N4—C20	117.9 (3)	C15—C14—C13	121.6 (4)
C19—N4—Cd1	124.2 (3)	C15—C14—H14A	119.2
C20—N4—Cd1	117.8 (2)	C13—C14—H14A	119.2
C2—C1—C6	117.7 (4)	C14—C15—C16	121.1 (4)
C2—C1—H1A	121.2	C14—C15—H15A	119.5
C6—C1—H1A	121.2	C16—C15—H15A	119.5
C1—C2—C3	121.8 (4)	C17—C16—C20	117.8 (4)
C1—C2—H2A	119.1	C17—C16—C15	122.6 (4)
C3—C2—H2A	119.1	C20—C16—C15	119.5 (4)
C4—C3—C2	121.3 (4)	C18—C17—C16	119.7 (4)
C4—C3—H3A	119.4	C18—C17—H17A	120.1
C2—C3—H3A	119.4	C16—C17—H17A	120.1
C3—C4—C5	117.5 (4)	C17—C18—C19	118.7 (4)
C3—C4—H4A	121.2	C17—C18—H18A	120.7
C5—C4—H4A	121.2	C19—C18—H18A	120.7
N2—C5—C4	130.7 (4)	N4—C19—C18	123.4 (4)
N2—C5—C6	108.1 (3)	N4—C19—H19A	118.3
C4—C5—C6	121.2 (4)	C18—C19—H19A	118.3
N1—C6—C1	131.0 (4)	N4—C20—C16	122.4 (4)
N1—C6—C5	108.5 (3)	N4—C20—C21	118.0 (3)
C1—C6—C5	120.5 (4)	C16—C20—C21	119.7 (3)
N2—C7—N1	115.5 (3)	N3—C21—C13	122.3 (4)
N2—C7—S1	122.9 (3)	N3—C21—C20	118.7 (3)
N1—C7—S1	121.5 (3)	C13—C21—C20	119.0 (4)

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

Experimental details

Crystal data
Chemical formula	[Cd(C₉H₆N₂O₂S)(C₁₂H₈N₂)]
M_r	498.84
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	9.2195 (10), 8.2577 (9), 25.620 (3)
β (°)	103.215 (4)
V (Å³)	1898.8 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	1.29
Crystal size (mm)	0.20 × 0.18 × 0.15

Data collection
Diffractometer	Bruker APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2000)
T_min, T_max	0.783, 0.831
No. of measured, independent and observed [I > 2σ(I)] reflections	9820, 3724, 3413
R_int	0.025
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.041, 0.091, 1.04
No. of reflections	3724
No. of parameters	262
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.62, −0.46

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXTL (Sheldrick, 2008).

Acknowledgements

The authors thank the Program for Young Excellent Talents in Southeast University for financial support.

References

Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Matthews, C. J., Heath, S. L., Elsegood, M. R. J., Clegg, W., Leese, T. A. & Lockhart, J. C. (1998). Dalton Trans. pp. 1973–1977. CrossRef Google Scholar
Sheldrick, G. M. (2000). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhang, Y.-W., Dong, H.-Z. & Cheng, L. (2008). Acta Cryst. E64, m868. Web of Science CSD CrossRef IUCr Journals Google Scholar

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