Dichlorido{2-[(thio­phen-2-ylmeth­yl)imino­meth­yl]pyridine-κ2N,N′}palladium(II)

Onani, M.O.; Motswainyana, W.M.

doi:10.1107/S1600536811037214

metal-organic compounds

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ISSN: 2056-9890

Volume 67| Part 10| October 2011| Page m1392

https://doi.org/10.1107/S1600536811037214

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Dichlorido{2-[(thiophen-2-ylmethyl)iminomethyl]pyridine-κ²N,N′}palladium(II)

Martin O. Onani ^a ^* and William M. Motswainyana ^a

^aUniversity of the Western Cape, Cape Town, Bellville 7535, South Africa
^*Correspondence e-mail: monani@uwc.ac.za

(Received 28 August 2011; accepted 13 September 2011; online 17 September 2011)

In the title compound, [PdCl₂(C₁₁H₁₀N₂S)], the Pd^II ion is four-coordinated in a distorted square-planar environment by two N atoms of the chelating 2-[(thiophen-2-ylmethyl)iminomethyl]pyridine ligand and two chloride anions. The thiophene ring is rotationally disordered over two orientations in a 1:1 ratio. The crystal packing exhibits weak intermolecular C—H⋯Cl and C—H⋯S hydrogen bonds.

Related literature

For the synthesis of iminopyridyl ligands and their transition metal-based complexes, see: Zhang et al. (2006 ); Bianchini et al. (2010 ). For related structures, see: Doherty et al. (2002 ); Ojwach et al. (2009 ); Motswainyana et al. (2011 ). For similar structures with nickel, see: Britovsek et al. (2003 ).

Experimental

Crystal data

[PdCl₂(C₁₁H₁₀N₂S)]
M_r = 379.57
Monoclinic, P 2₁ /c
a = 8.0061 (19) Å
b = 17.768 (4) Å
c = 8.864 (2) Å
β = 98.353 (3)°
V = 1247.6 (5) Å³
Z = 4
Mo Kα radiation
μ = 2.06 mm⁻¹
T = 100 K
0.24 × 0.19 × 0.06 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.638, T_max = 0.887
6411 measured reflections
2656 independent reflections
2238 reflections with I > 2σ(I)
R_int = 0.036

Refinement

R[F² > 2σ(F²)] = 0.042
wR(F²) = 0.144
S = 1.07
2656 reflections
149 parameters
26 restraints
H-atom parameters constrained
Δρ_max = 0.96 e Å⁻³
Δρ_min = −0.98 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯Cl15ⁱ	0.95	2.70	3.508 (6)	143
C6B—H6B⋯Cl16ⁱⁱ	0.95	2.74	3.622 (14)	155
C7A—H7A⋯S8Aⁱⁱⁱ	0.95	2.69	3.468 (12)	139
Symmetry codes: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001 ; Atwood & Barbour, 2003 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536811037214/cv5147sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811037214/cv5147Isup2.hkl

checkCIF report

Comment top

Nitrogen based ligands have attracted considerable interest due to their stability and various activities (Bianchini et al., 2010; Zhang et al., 2006). These ligands can be complexed to various transition metals to form stable metal complexes which exhibit different colours and geometries (Bianchini et al., 2010; Britovsek et al., 2003; Motswainyana et al., 2011). Herewith we present the crystal stucture of the title compound (I).

The asymmetric unit of (I) contains one molecule of the Pd^II complex (Fig 1). All bond lengths and angles are normal and comparable with those observed in the related complexes (Zhang et al., 2006; Motswainyana et al., 2011; Doherty et al., 2002). Pd^II ion has a distorted square planar environment being coordinated by the N,N'-bidentate ligand and two Cl anios. The Pd – Cl bond length trans to the pyridyl N atom is slightly longer than the Pd – Cl bond length trans to the amine N atom showing the stronger trans influence of the pyridyl group compared to the secondary amine.

The crystal packing exhibits weak intermolecular C—H···Cl and C—H···S hydrogen bonds (Table 1).

Related literature top

For the synthesis of iminopyridyl ligands and their transition metal-based complexes, see: Zhang et al. (2006); Bianchini et al. (2010). For related structures, see: Doherty et al. (2002); Ojwach et al. (2009); Motswainyana et al. (2011). For similar structures with nickel, see: Britovsek et al. (2003).

Experimental top

To a solution of [PdCl₂(cod)] (0.10 g, 0.35 mmol) in CH₂Cl₂ (15 ml) was added a solution of 1-phenyl-N-(2-thienylmethyl)methanimine (0.07 g, 0.35 mmol) in CH₂Cl₂ (5 ml). The solution was stirred for 6 h to give a light yellow precipitate. The precipitate was filtered to obtain a light yellow solid. Recrystallization from a mixture of CH₂Cl₂: hexane solution afforded single crystals suitable for X-ray analysis. Yield = 0.110 g (85%).

Structure description top

The crystal packing exhibits weak intermolecular C—H···Cl and C—H···S hydrogen bonds (Table 1).

For the synthesis of iminopyridyl ligands and their transition metal-based complexes, see: Zhang et al. (2006); Bianchini et al. (2010). For related structures, see: Doherty et al. (2002); Ojwach et al. (2009); Motswainyana et al. (2011). For similar structures with nickel, see: Britovsek et al. (2003).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001; Atwood & Barbour, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of (I) showing atomic numbering and 50% probability displacement ellipsoids. For the rotationally disordered thiophene ring only one orientation is shown.

Dichlorido{2-[(thiophen-2-ylmethyl)iminomethyl]pyridine- κ²N,N'}palladium(II) top

Crystal data top

[PdCl₂(C₁₁H₁₀N₂S)]	F(000) = 744
M_r = 379.57	D_x = 2.021 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3002 reflections
a = 8.0061 (19) Å	θ = 2.3–27.6°
b = 17.768 (4) Å	µ = 2.06 mm⁻¹
c = 8.864 (2) Å	T = 100 K
β = 98.353 (3)°	Plate, yellow
V = 1247.6 (5) Å³	0.24 × 0.19 × 0.06 mm
Z = 4

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	2656 independent reflections
Radiation source: fine-focus sealed tube	2238 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.036
ω scans	θ_max = 27.8°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −9→9
T_min = 0.638, T_max = 0.887	k = −22→22
6411 measured reflections	l = −11→8

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.144	H-atom parameters constrained
S = 1.07	w = 1/[σ²(F_o²) + (0.096P)²] where P = (F_o² + 2F_c²)/3
2656 reflections	(Δ/σ)_max = 0.017
149 parameters	Δρ_max = 0.96 e Å⁻³
26 restraints	Δρ_min = −0.98 e Å⁻³

Crystal data top

[PdCl₂(C₁₁H₁₀N₂S)]	V = 1247.6 (5) Å³
M_r = 379.57	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 8.0061 (19) Å	µ = 2.06 mm⁻¹
b = 17.768 (4) Å	T = 100 K
c = 8.864 (2) Å	0.24 × 0.19 × 0.06 mm
β = 98.353 (3)°

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	2656 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	2238 reflections with I > 2σ(I)
T_min = 0.638, T_max = 0.887	R_int = 0.036
6411 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.042	26 restraints
wR(F²) = 0.144	H-atom parameters constrained
S = 1.07	Δρ_max = 0.96 e Å⁻³
2656 reflections	Δρ_min = −0.98 e Å⁻³
149 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	Occ. (<1)
Pd1	0.30571 (5)	−0.01089 (2)	0.58087 (4)	0.01686 (18)
Cl15	0.40550 (17)	−0.08117 (7)	0.79082 (15)	0.0254 (3)
Cl16	0.16329 (16)	−0.11300 (7)	0.46964 (15)	0.0238 (3)
N2	0.2291 (5)	0.0612 (2)	0.4078 (5)	0.0179 (9)
N9	0.4236 (5)	0.0838 (2)	0.6682 (5)	0.0167 (8)
C1	0.2820 (6)	0.1286 (3)	0.4327 (6)	0.0186 (10)
H1	0.2521	0.1669	0.3590	0.022*
C3	0.1145 (6)	0.0400 (3)	0.2666 (6)	0.0211 (10)
H3A	0.1563	−0.0078	0.2285	0.025*
H3B	0.0016	0.0298	0.2950	0.025*
C10	0.3879 (6)	0.1454 (3)	0.5747 (6)	0.0208 (10)
C11	0.4519 (6)	0.2153 (3)	0.6190 (6)	0.0218 (11)
H11	0.4243	0.2577	0.5548	0.026*
C12	0.5564 (7)	0.2239 (3)	0.7569 (6)	0.0225 (11)
H12	0.6009	0.2720	0.7881	0.027*
C13	0.5949 (7)	0.1613 (3)	0.8484 (6)	0.0219 (10)
H13	0.6690	0.1653	0.9420	0.026*
C14	0.5223 (6)	0.0922 (3)	0.8001 (6)	0.0203 (10)
H14	0.5449	0.0496	0.8647	0.024*
S8A	−0.0145 (4)	0.1806 (2)	0.1442 (4)	0.0239 (7)*	0.50
C4A	0.095 (2)	0.0978 (8)	0.1389 (14)	0.024 (9)*	0.50
C5A	0.1525 (17)	0.0901 (7)	−0.0021 (15)	0.029 (4)*	0.50
H5A	0.2128	0.0473	−0.0287	0.035*	0.50
C6A	0.1126 (18)	0.1522 (8)	−0.1017 (14)	0.018 (4)*	0.50
H6A	0.1439	0.1564	−0.2007	0.021*	0.50
C7A	0.0239 (15)	0.2047 (6)	−0.0361 (13)	0.016 (3)*	0.50
H7A	−0.0137	0.2506	−0.0848	0.019*	0.50
S8B	0.1827 (5)	0.07989 (19)	−0.0198 (4)	0.0248 (8)*	0.50
C4B	0.093 (3)	0.0937 (10)	0.1403 (18)	0.011 (12)*	0.50
C5B	0.0011 (15)	0.1601 (7)	0.1324 (13)	0.025 (3)*	0.50
H5B	−0.0583	0.1773	0.2111	0.030*	0.50
C6B	0.0055 (17)	0.1999 (8)	−0.0075 (15)	0.030 (4)*	0.50
H6B	−0.0496	0.2466	−0.0327	0.036*	0.50
C7B	0.098 (2)	0.1628 (9)	−0.0980 (19)	0.037 (6)*	0.50
H7B	0.1144	0.1804	−0.1959	0.045*	0.50

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Pd1	0.0192 (3)	0.0166 (3)	0.0149 (3)	0.00044 (13)	0.00286 (17)	0.00049 (13)
Cl15	0.0346 (7)	0.0195 (6)	0.0212 (7)	0.0002 (5)	0.0014 (5)	0.0049 (5)
Cl16	0.0279 (7)	0.0199 (6)	0.0233 (7)	−0.0034 (5)	0.0028 (5)	−0.0032 (5)
N2	0.016 (2)	0.024 (2)	0.014 (2)	0.0025 (17)	0.0029 (16)	0.0014 (16)
N9	0.016 (2)	0.019 (2)	0.015 (2)	0.0022 (15)	0.0009 (16)	0.0031 (15)
C1	0.022 (3)	0.020 (2)	0.014 (2)	0.0006 (19)	0.0036 (19)	0.0013 (18)
C3	0.021 (3)	0.021 (2)	0.022 (3)	−0.002 (2)	0.002 (2)	−0.003 (2)
C10	0.017 (2)	0.023 (2)	0.023 (3)	0.0010 (19)	0.004 (2)	0.003 (2)
C11	0.024 (3)	0.022 (2)	0.019 (3)	−0.001 (2)	0.003 (2)	0.004 (2)
C12	0.028 (3)	0.018 (2)	0.021 (3)	0.000 (2)	0.005 (2)	−0.0017 (19)
C13	0.023 (3)	0.027 (3)	0.015 (2)	−0.002 (2)	−0.0009 (19)	−0.001 (2)
C14	0.021 (3)	0.019 (2)	0.022 (3)	−0.0049 (19)	0.006 (2)	0.003 (2)

Geometric parameters (Å, º) top

Pd1—N2	2.024 (4)	C13—C14	1.400 (7)
Pd1—N9	2.027 (4)	C13—H13	0.9500
Pd1—Cl15	2.2866 (13)	C14—H14	0.9500
Pd1—Cl16	2.2885 (13)	S8A—C4A	1.715 (13)
N2—C1	1.279 (6)	S8A—C7A	1.725 (11)
N2—C3	1.489 (6)	C4A—C5A	1.402 (14)
N9—C14	1.321 (7)	C5A—C6A	1.420 (14)
N9—C10	1.378 (6)	C5A—H5A	0.9500
C1—C10	1.443 (7)	C6A—C7A	1.354 (14)
C1—H1	0.9500	C6A—H6A	0.9500
C3—C4B	1.462 (13)	C7A—H7A	0.9500
C3—C4A	1.519 (12)	S8B—C4B	1.698 (14)
C3—H3A	0.9900	S8B—C7B	1.726 (14)
C3—H3B	0.9900	C4B—C5B	1.388 (15)
C10—C11	1.379 (7)	C5B—C6B	1.432 (14)
C11—C12	1.386 (7)	C5B—H5B	0.9500
C11—H11	0.9500	C6B—C7B	1.340 (15)
C12—C13	1.385 (7)	C6B—H6B	0.9500
C12—H12	0.9500	C7B—H7B	0.9500

N2—Pd1—N9	80.64 (16)	C12—C13—C14	118.6 (5)
N2—Pd1—Cl15	173.71 (12)	C12—C13—H13	120.7
N9—Pd1—Cl15	93.10 (12)	C14—C13—H13	120.7
N2—Pd1—Cl16	95.62 (13)	N9—C14—C13	122.6 (5)
N9—Pd1—Cl16	176.22 (11)	N9—C14—H14	118.7
Cl15—Pd1—Cl16	90.63 (5)	C13—C14—H14	118.7
C1—N2—C3	122.0 (4)	C4A—S8A—C7A	91.6 (5)
C1—N2—Pd1	113.9 (3)	C5A—C4A—C3	125.9 (10)
C3—N2—Pd1	124.0 (3)	C5A—C4A—S8A	110.1 (9)
C14—N9—C10	119.2 (4)	C3—C4A—S8A	123.9 (8)
C14—N9—Pd1	128.1 (3)	C4A—C5A—C6A	113.9 (11)
C10—N9—Pd1	112.7 (3)	C4A—C5A—H5A	123.2
N2—C1—C10	118.8 (4)	C6A—C5A—H5A	122.9
N2—C1—H1	120.6	C7A—C6A—C5A	110.7 (11)
C10—C1—H1	120.6	C7A—C6A—H6A	124.7
C4B—C3—N2	117.9 (10)	C5A—C6A—H6A	124.7
N2—C3—C4A	116.2 (8)	C6A—C7A—S8A	113.7 (9)
C4B—C3—H3A	108.0	C6A—C7A—H7A	123.2
N2—C3—H3A	107.8	S8A—C7A—H7A	123.1
C4A—C3—H3A	109.4	C4B—S8B—C7B	91.3 (7)
C4B—C3—H3B	107.6	C5B—C4B—C3	126.5 (11)
N2—C3—H3B	107.8	C5B—C4B—S8B	111.5 (9)
C4A—C3—H3B	108.1	C3—C4B—S8B	122.0 (10)
H3A—C3—H3B	107.2	C4B—C5B—C6B	112.6 (11)
N9—C10—C11	120.6 (5)	C4B—C5B—H5B	123.7
N9—C10—C1	113.9 (4)	C6B—C5B—H5B	123.7
C11—C10—C1	125.6 (5)	C7B—C6B—C5B	111.1 (12)
C10—C11—C12	120.2 (5)	C7B—C6B—H6B	124.5
C10—C11—H11	119.9	C5B—C6B—H6B	124.4
C12—C11—H11	119.9	C6B—C7B—S8B	113.5 (11)
C13—C12—C11	118.8 (5)	C6B—C7B—H7B	123.2
C13—C12—H12	120.6	S8B—C7B—H7B	123.2
C11—C12—H12	120.6

N9—Pd1—N2—C1	−1.8 (3)	Pd1—N9—C14—C13	−179.1 (4)
Cl16—Pd1—N2—C1	177.6 (3)	C12—C13—C14—N9	2.5 (8)
N9—Pd1—N2—C3	−178.8 (4)	C4B—C3—C4A—C5A	−50 (37)
Cl16—Pd1—N2—C3	0.6 (4)	N2—C3—C4A—C5A	112.1 (13)
N2—Pd1—N9—C14	−179.2 (4)	C4B—C3—C4A—S8A	126 (39)
Cl15—Pd1—N9—C14	1.4 (4)	N2—C3—C4A—S8A	−71.9 (14)
N2—Pd1—N9—C10	2.5 (3)	C7A—S8A—C4A—C5A	−1.8 (10)
Cl15—Pd1—N9—C10	−176.8 (3)	C7A—S8A—C4A—C3	−178.4 (14)
C3—N2—C1—C10	177.8 (4)	C3—C4A—C5A—C6A	178.5 (15)
Pd1—N2—C1—C10	0.7 (6)	S8A—C4A—C5A—C6A	2.0 (13)
C1—N2—C3—C4B	13.7 (10)	C4A—C5A—C6A—C7A	−1.0 (14)
Pd1—N2—C3—C4B	−169.5 (8)	C5A—C6A—C7A—S8A	−0.4 (13)
C1—N2—C3—C4A	13.0 (8)	C4A—S8A—C7A—C6A	1.3 (11)
Pd1—N2—C3—C4A	−170.2 (6)	N2—C3—C4B—C5B	−74 (2)
C14—N9—C10—C11	−1.0 (7)	C4A—C3—C4B—C5B	−56 (37)
Pd1—N9—C10—C11	177.4 (4)	N2—C3—C4B—S8B	106.1 (15)
C14—N9—C10—C1	178.7 (4)	C4A—C3—C4B—S8B	124 (39)
Pd1—N9—C10—C1	−2.9 (5)	C7B—S8B—C4B—C5B	0.0 (14)
N2—C1—C10—N9	1.5 (7)	C7B—S8B—C4B—C3	179.7 (18)
N2—C1—C10—C11	−178.7 (5)	C3—C4B—C5B—C6B	−179.9 (19)
N9—C10—C11—C12	1.5 (8)	S8B—C4B—C5B—C6B	−0.2 (15)
C1—C10—C11—C12	−178.2 (5)	C4B—C5B—C6B—C7B	0.4 (15)
C10—C11—C12—C13	0.0 (8)	C5B—C6B—C7B—S8B	−0.4 (17)
C11—C12—C13—C14	−2.0 (8)	C4B—S8B—C7B—C6B	0.2 (16)
C10—N9—C14—C13	−1.0 (7)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···Cl15ⁱ	0.95	2.70	3.508 (6)	143
C6B—H6B···Cl16ⁱⁱ	0.95	2.74	3.622 (14)	155
C7A—H7A···S8Aⁱⁱⁱ	0.95	2.69	3.468 (12)	139

Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) −x, y+1/2, −z+1/2; (iii) x, −y+1/2, z−1/2.

Experimental details

Crystal data
Chemical formula	[PdCl₂(C₁₁H₁₀N₂S)]
M_r	379.57
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	8.0061 (19), 17.768 (4), 8.864 (2)
β (°)	98.353 (3)
V (Å³)	1247.6 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	2.06
Crystal size (mm)	0.24 × 0.19 × 0.06

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.638, 0.887
No. of measured, independent and observed [I > 2σ(I)] reflections	6411, 2656, 2238
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.656

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.042, 0.144, 1.07
No. of reflections	2656
No. of parameters	149
No. of restraints	26
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.96, −0.98

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001; Atwood & Barbour, 2003).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···Cl15ⁱ	0.95	2.70	3.508 (6)	143
C6B—H6B···Cl16ⁱⁱ	0.95	2.74	3.622 (14)	155
C7A—H7A···S8Aⁱⁱⁱ	0.95	2.69	3.468 (12)	139

Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) −x, y+1/2, −z+1/2; (iii) x, −y+1/2, z−1/2.

Acknowledgements

We acknowledge financial support from the Botswanan Government (WMM) and the University of the Western Cape Senate Research and NRF (Thuthuka).

References

Atwood, J. L. & Barbour, L. J. (2003). Cryst. Growth Des. 3, 3–11. Web of Science CrossRef CAS Google Scholar
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bianchini, C., Giambastiani, G., Luconi, L. & Meli, A. (2010). Coord. Chem. Rev. 254, 431–455. Web of Science CrossRef CAS Google Scholar
Britovsek, G. J. P., Baugh, S. P. D., Hoarau, O., Gibson, V. C., Wass, D. F., White, A. J. P. & Williams, D. J. (2003). Inorg. Chim. Acta, 345, 279–291. Web of Science CSD CrossRef CAS Google Scholar
Bruker (2009). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Doherty, S., Knight, J. G., Scanlam, T. H., Elsegood, M. R. J. & Clegg, W. (2002). J. Organomet. Chem. 650, 231–248. Web of Science CSD CrossRef CAS Google Scholar
Motswainyana, W. M., Ojwach, S. O., Onani, M. O., Iwuoha, E. I. & Darkwa, J. (2011). Polyhedron, 30, 2574-2580. Web of Science CSD CrossRef CAS Google Scholar
Ojwach, S. O., Guzei, I. A. & Darkwa, J. (2009). J. Organomet. Chem. 694, 1393–1399. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhang, W., Sun, W.-H., Wu, B., Zhang, S., Ma, H., Li, Y., Cheng, J. & Hao, P. (2006). J. Organomet. Chem. 691, 4759–4767. Web of Science CrossRef CAS Google Scholar

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