Aqua­tricarbon­yl(3,5,7-tribromo­tropolonato)rhenium(I) methanol solvate

Schutte, M.; Visser, H.G.; Roodt, A.

doi:10.1107/S1600536808038737

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 12| December 2008| Pages m1610-m1611

doi:10.1107/S1600536808038737

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Aquatricarbonyl(3,5,7-tribromotropolonato)rhenium(I) methanol solvate

Marietjie Schutte,^a ^* Hendrik G. Visser ^a and Andreas Roodt ^a

^aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
^*Correspondence e-mail: schuttem.sci@ufs.ac.za

(Received 9 September 2008; accepted 19 November 2008; online 22 November 2008)

The title complex, [Re(C₇H₂Br₃O₂)(CO)₃(H₂O)]·CH₃OH, crystallized as a neutral Re^I compound and one methanol solvent molecule in the asymmetric unit. The metal centre is coordinated facially by three carbonyl groups. The bidentate tribromotropolanate ligand and a water molecule complete the distorted octahedral coordination around the central metal. Intermolecular Br⋯O [3.226 (5) Å] and Br⋯Br [3.590 (2) Å] contacts are observed between adjacent molecules. These contacts, together with an array of O—H⋯O, O—H⋯Br and C—H⋯O hydrogen bonds, complete a three-dimensional polymeric network formed between the methanol solvent and the complex.

Related literature

For a smiliar tribromotropolonato Re^I structure, see: Schutte et al. (2007 ). For other related structures, see: Kemp (2006 ); Roodt et al. (2003 ); Wang et al. (2003 ); Alvarez et al. (2007 ); Brasey et al. (2004 ); Gibson et al. (1999 ); Bochkova et al. (1987 ); Cheng et al. (1988 ); Mundwiler et al. (2004 ). For the synthesis of the precursor, see: Alberto et al. (1996 ). For synthesis of the tribromotropolone ligand, see: Steyl & Roodt (2006 ).

Experimental

Crystal data

[Re(C₇H₂Br₃O₂)(CO)₃(H₂O)]·CH₄O
M_r = 678.1
Triclinic, $[P \overline 1]$
a = 9.090 (5) Å
b = 9.379 (5) Å
c = 10.010 (5) Å
α = 109.569 (5)°
β = 94.285 (5)°
γ = 102.133 (5)°
V = 776.3 (7) Å³
Z = 2
Mo Kα radiation
μ = 15.58 mm⁻¹
T = 100 (2) K
0.19 × 0.06 × 0.03 mm

Data collection

Bruker APEX diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ) T_min = 0.150, T_max = 0.626
8673 measured reflections
3599 independent reflections
3018 reflections with I > 2σ(I)
R_int = 0.035

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.079
S = 1.05
3599 reflections
207 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 2.40 e Å⁻³
Δρ_min = −2.11 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

Re01—C1	1.882 (7)
Re01—C3	1.897 (6)
Re01—C2	1.899 (7)
Re01—O4	2.123 (5)
Re01—O5	2.146 (4)
Re01—O6	2.170 (5)

O4—Re01—O5	74.07 (16)
O4—Re01—O6	78.93 (19)
O5—Re01—O6	79.17 (18)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H6B⋯Br1ⁱ	1.06 (8)	2.68 (8)	3.421 (6)	127 (5)
O6—H6B⋯O5ⁱ	1.06 (8)	1.86 (8)	2.825 (7)	149 (6)
C15—H15⋯O2ⁱⁱ	0.93	2.5	3.409 (8)	166
O7—H7⋯O1ⁱⁱⁱ	0.82	2.39	2.986 (7)	130
O6—H6A⋯O7	0.99 (8)	1.69 (8)	2.665 (7)	167 (7)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x-1, y-1, z; (iii) -x+1, -y+1, -z+2.

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenberg & Putz, 2005 ) and ORTEP-3 (Farrugia, 1999 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808038737/kj2103sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808038737/kj2103Isup2.hkl

checkCIF report

Comment top

This structure forms part of an ongoing investigation of the structural and kinetic behaviour of fac-Re(CO)₃ compounds (Schutte et al., 2007; Roodt et al., 2003). The title complex crystallized as a neutral Re^I compound and one methanol solvate molecule in the assymetric unit. The Re—CO bond distances are well within the normal range. The Re—O bond distances compare well with the analogous bromido complex (Schutte et al., 2007) and other related structures (Alvarez et al., 2007; Brasey et al., 2004; Gibson et al., 1999; Bochkova et al., 1987; Cheng et al., 1988; Wang et al., 2003). The Re—OH₂ distance is also comparable to that of related structures (Mundwiler et al., 2004; Kemp, 2006). The small bite angle O4—Re01—O5 might be the reason for the slightly distorted octahedral geometry around the Re¹ metal centre.

Interesting intermolecular Br···O and Br···Br contacts are observed between adjacent molecules with distances of 3.226 (5) Å between Br1 and O3 and 3.590 (2) Å between Br2 and Br2 of the next molecule. These contacts together with an array of O—H···O, O—H···Br and C—H···O hydrogen bonds (see Table 2), complete a complex three-dimensional polymeric network.

Related literature top

For a smiliar tribromotropolonato Re^I structure, see: Schutte et al. (2007). For other related structures, see: Kemp (2006); Roodt et al. (2003); Wang, et al. (2003); Alvarez et al. (2007); Brasey et al. (2004); Gibson et al. (1999); Bochkova et al. (1987); Cheng et al. (1988); Mundwiler et al. (2004). For the synthesis of the precursor, see: Alberto et al. (1996). For synthesis of the tribromotropolone ligand, see: Steyl & Roodt (2006).

Experimental top

[NEt₄]₂[Re(CO)₃Br₃] was prepared as described by Alberto et al. (1996). 300 mg (0.3894 mmole) of [NEt₄]₂[Re(CO)₃Br₃] was dissolved in 10 ml of H₂O at pH 2.2 and stirred for 30 minutes (until dissolved). AgNO₃ (198 mg, 1.167 mmol) was added to the solution and stirred for 24 h at room temperature. AgBr was formed as a grey precipitate and was filtered off and weighed (0.220 g). Tribromotroplone [151 mg, 0.4514 mmol for synthesis see Steyl & Roodt (2006)] in 2 ml of methanol was added the solution and stirred for 40 h at room temperature. The filtrate was left to stand for a few days and orange plate-like crystals suitable for X-ray diffraction were collected.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenberg & Putz, 2005) and ORTEP-3 (Farrugia, 1999); software used to prepare material for publication: SHELXS97 (Sheldrick, 2008).

Figures top

Fig. 1. Representation of the title compound, showing the numbering scheme and displacement ellipsoids (50% probability).

Aquatricarbonyl(3,5,7-tribromotropolonato)rhenium(I) methanol solvate top

Crystal data top

[Re(C₇H₂Br₃O₂)(CO)₃(H₂O)]·CH₄O	Z = 2
M_r = 678.1	F(000) = 620
Triclinic, P1	D_x = 2.901 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 9.090 (5) Å	Cell parameters from 3145 reflections
b = 9.379 (5) Å	θ = 2.2–28.2°
c = 10.010 (5) Å	µ = 15.58 mm⁻¹
α = 109.569 (5)°	T = 100 K
β = 94.285 (5)°	Plate, orange
γ = 102.133 (5)°	0.19 × 0.06 × 0.03 mm
V = 776.3 (7) Å³

Data collection top

Bruker APEX diffractometer	3018 reflections with I > 2σ(I)
ϕ and ω scans	R_int = 0.035
Absorption correction: multi-scan (SADABS; Bruker, 2004)	θ_max = 28.3°, θ_min = 2.2°
T_min = 0.150, T_max = 0.626	h = −8→12
8673 measured reflections	k = −11→12
3599 independent reflections	l = −13→10

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.033	w = 1/[σ²(F_o²) + (0.0385P)²] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.079	(Δ/σ)_max < 0.001
S = 1.05	Δρ_max = 2.41 e Å⁻³
3599 reflections	Δρ_min = −2.11 e Å⁻³
207 parameters

Crystal data top

[Re(C₇H₂Br₃O₂)(CO)₃(H₂O)]·CH₄O	γ = 102.133 (5)°
M_r = 678.1	V = 776.3 (7) Å³
Triclinic, P1	Z = 2
a = 9.090 (5) Å	Mo Kα radiation
b = 9.379 (5) Å	µ = 15.58 mm⁻¹
c = 10.010 (5) Å	T = 100 K
α = 109.569 (5)°	0.19 × 0.06 × 0.03 mm
β = 94.285 (5)°

Data collection top

Bruker APEX diffractometer	3599 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2004)	3018 reflections with I > 2σ(I)
T_min = 0.150, T_max = 0.626	R_int = 0.035
8673 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	0 restraints
wR(F²) = 0.079	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 2.41 e Å⁻³
3599 reflections	Δρ_min = −2.11 e Å⁻³
207 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

	x	y	z	U_iso*/U_eq
Re01	0.54228 (3)	0.51098 (3)	0.75340 (3)	0.00853 (8)
Br1	0.46576 (7)	0.05513 (7)	0.28520 (6)	0.01185 (14)
O4	0.3428 (5)	0.3587 (5)	0.7724 (4)	0.0107 (9)
C11	0.3852 (7)	0.1903 (7)	0.5557 (7)	0.0098 (13)
C2	0.7128 (8)	0.6389 (7)	0.7149 (7)	0.0141 (8)
C15	0.1120 (7)	−0.0432 (8)	0.6174 (7)	0.0130 (13)
H15	0.0347	−0.093	0.6543	0.016 (19)*
C3	0.5502 (8)	0.6908 (8)	0.9164 (7)	0.0141 (8)
C17	0.2988 (7)	0.2213 (7)	0.6772 (6)	0.0079 (12)
O5	0.4976 (5)	0.3042 (5)	0.5642 (4)	0.0096 (9)
C16	0.1735 (7)	0.1137 (7)	0.6939 (6)	0.0100 (13)
C12	0.3491 (7)	0.0514 (7)	0.4343 (6)	0.0084 (12)
C13	0.2524 (7)	−0.0921 (7)	0.4077 (7)	0.0101 (13)
H13	0.2554	−0.1698	0.3217	0.012 (18)*
C14	0.1514 (7)	−0.1368 (7)	0.4909 (7)	0.0135 (13)
Br2	0.04885 (8)	−0.35228 (8)	0.42285 (7)	0.01741 (15)
Br3	0.08290 (7)	0.19489 (8)	0.85829 (7)	0.01438 (15)
O2	0.8201 (5)	0.7193 (5)	0.6960 (5)	0.0181 (11)
O3	0.5530 (6)	0.8006 (6)	1.0157 (5)	0.0191 (11)
O1	0.7678 (6)	0.4158 (6)	0.9272 (5)	0.0221 (11)
C1	0.6804 (8)	0.4526 (8)	0.8620 (7)	0.0153 (14)
O7	0.1793 (6)	0.6493 (6)	0.8032 (5)	0.0186 (11)
H7	0.1438	0.5913	0.8449	0.028*
C4	0.1962 (8)	0.8155 (7)	0.8974 (7)	0.0141 (8)
H4C	0.2448	0.833	0.992	0.021*
H4A	0.0974	0.8365	0.9024	0.021*
H4B	0.2572	0.8837	0.8583	0.021*
O6	0.3692 (6)	0.5548 (6)	0.6216 (5)	0.0214 (11)
H6A	0.295 (9)	0.599 (9)	0.681 (8)	0.032*
H6B	0.406 (9)	0.640 (9)	0.575 (8)	0.032*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Re01	0.00886 (14)	0.00633 (14)	0.00918 (13)	−0.00064 (10)	0.00140 (9)	0.00280 (10)
Br1	0.0139 (3)	0.0099 (3)	0.0110 (3)	0.0015 (3)	0.0039 (2)	0.0033 (2)
O4	0.016 (3)	0.006 (2)	0.010 (2)	0.001 (2)	0.0039 (18)	0.0042 (18)
C11	0.007 (3)	0.012 (3)	0.015 (3)	0.005 (3)	0.004 (2)	0.008 (3)
C2	0.024 (2)	0.0071 (19)	0.0122 (17)	0.0075 (18)	0.0005 (15)	0.0033 (15)
C15	0.010 (3)	0.017 (4)	0.014 (3)	0.002 (3)	−0.002 (2)	0.009 (3)
C3	0.024 (2)	0.0071 (19)	0.0122 (17)	0.0075 (18)	0.0005 (15)	0.0033 (15)
C17	0.010 (3)	0.007 (3)	0.010 (3)	0.001 (3)	0.000 (2)	0.006 (2)
O5	0.010 (2)	0.004 (2)	0.011 (2)	−0.0030 (19)	0.0036 (17)	−0.0002 (17)
C16	0.011 (3)	0.012 (3)	0.008 (3)	0.002 (3)	0.003 (2)	0.005 (3)
C12	0.006 (3)	0.013 (3)	0.007 (3)	0.001 (3)	0.001 (2)	0.005 (2)
C13	0.004 (3)	0.010 (3)	0.014 (3)	0.000 (3)	−0.002 (2)	0.004 (3)
C14	0.010 (3)	0.007 (3)	0.019 (3)	−0.004 (3)	−0.004 (3)	0.004 (3)
Br2	0.0181 (4)	0.0091 (3)	0.0225 (3)	−0.0015 (3)	0.0040 (3)	0.0052 (3)
Br3	0.0123 (3)	0.0144 (3)	0.0140 (3)	−0.0005 (3)	0.0057 (3)	0.0036 (3)
O2	0.016 (3)	0.015 (3)	0.025 (3)	0.001 (2)	0.010 (2)	0.011 (2)
O3	0.017 (3)	0.017 (3)	0.018 (2)	0.005 (2)	0.003 (2)	−0.001 (2)
O1	0.022 (3)	0.025 (3)	0.020 (3)	0.008 (2)	−0.001 (2)	0.010 (2)
C1	0.020 (4)	0.009 (3)	0.012 (3)	0.000 (3)	0.003 (3)	−0.001 (3)
O7	0.025 (3)	0.021 (3)	0.022 (3)	0.013 (2)	0.008 (2)	0.018 (2)
C4	0.024 (2)	0.0071 (19)	0.0122 (17)	0.0075 (18)	0.0005 (15)	0.0033 (15)
O6	0.025 (3)	0.025 (3)	0.025 (3)	0.013 (3)	0.008 (2)	0.018 (2)

Geometric parameters (Å, º) top

Re01—C1	1.882 (7)	C3—O3	1.162 (8)
Re01—C3	1.897 (6)	C17—C16	1.415 (8)
Re01—C2	1.899 (7)	C16—Br3	1.895 (6)
Re01—O4	2.123 (5)	C12—C13	1.372 (9)
Re01—O5	2.146 (4)	C13—C14	1.378 (9)
Re01—O6	2.170 (5)	C13—H13	0.93
Br1—C12	1.899 (6)	C14—Br2	1.900 (6)
O4—C17	1.278 (7)	O1—C1	1.168 (8)
C11—O5	1.289 (7)	O7—C4	1.495 (8)
C11—C12	1.408 (9)	O7—H7	0.82
C11—C17	1.477 (8)	C4—H4C	0.96
C2—O2	1.171 (8)	C4—H4A	0.96
C15—C16	1.379 (9)	C4—H4B	0.96
C15—C14	1.398 (9)	O6—H6A	0.99 (8)
C15—H15	0.93	O6—H6B	1.06 (8)

C1—Re01—C3	89.5 (3)	C16—C17—C11	125.5 (6)
C1—Re01—C2	87.8 (3)	C11—O5—Re01	117.1 (4)
C3—Re01—C2	85.0 (3)	C15—C16—C17	131.3 (6)
C1—Re01—O4	96.2 (2)	C15—C16—Br3	113.9 (5)
C3—Re01—O4	99.6 (2)	C17—C16—Br3	114.6 (4)
C2—Re01—O4	173.9 (2)	C13—C12—C11	131.5 (6)
C1—Re01—O5	96.7 (2)	C13—C12—Br1	113.1 (4)
C3—Re01—O5	171.5 (2)	C11—C12—Br1	115.2 (5)
C2—Re01—O5	100.9 (2)	C12—C13—C14	128.9 (6)
O4—Re01—O5	74.07 (16)	C12—C13—H13	115.6
C1—Re01—O6	174.3 (3)	C14—C13—H13	115.6
C3—Re01—O6	94.2 (2)	C13—C14—C15	128.3 (6)
C2—Re01—O6	96.8 (2)	C13—C14—Br2	115.9 (5)
O4—Re01—O6	78.93 (19)	C15—C14—Br2	115.8 (5)
O5—Re01—O6	79.17 (18)	O1—C1—Re01	178.7 (6)
C17—O4—Re01	118.0 (4)	C4—O7—H7	109.5
O5—C11—C12	120.1 (5)	O7—C4—H4C	109.5
O5—C11—C17	115.0 (5)	O7—C4—H4A	109.5
C12—C11—C17	124.9 (6)	H4C—C4—H4A	109.5
O2—C2—Re01	177.7 (6)	O7—C4—H4B	109.5
C16—C15—C14	128.0 (6)	H4C—C4—H4B	109.5
C16—C15—H15	116	H4A—C4—H4B	109.5
C14—C15—H15	116	Re01—O6—H6A	110 (4)
O3—C3—Re01	179.1 (6)	Re01—O6—H6B	117 (4)
O4—C17—C16	119.0 (5)	H6A—O6—H6B	102 (6)
O4—C17—C11	115.4 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6B···Br1ⁱ	1.06 (8)	2.68 (8)	3.421 (6)	127 (5)
O6—H6B···O5ⁱ	1.06 (8)	1.86 (8)	2.825 (7)	149 (6)
C15—H15···O2ⁱⁱ	0.93	2.5	3.409 (8)	166
O7—H7···O1ⁱⁱⁱ	0.82	2.39	2.986 (7)	130
O6—H6A···O7	0.99 (8)	1.69 (8)	2.665 (7)	167 (7)

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

Experimental details

Crystal data
Chemical formula	[Re(C₇H₂Br₃O₂)(CO)₃(H₂O)]·CH₄O
M_r	678.1
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	9.090 (5), 9.379 (5), 10.010 (5)
α, β, γ (°)	109.569 (5), 94.285 (5), 102.133 (5)
V (Å³)	776.3 (7)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	15.58
Crystal size (mm)	0.19 × 0.06 × 0.03

Data collection
Diffractometer	Bruker APEX diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2004)
T_min, T_max	0.150, 0.626
No. of measured, independent and observed [I > 2σ(I)] reflections	8673, 3599, 3018
R_int	0.035
(sin θ/λ)_max (Å⁻¹)	0.666

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.079, 1.05
No. of reflections	3599
No. of parameters	207
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	2.41, −2.11

Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2004), SHELXS97 (Sheldrick, 2008), DIAMOND (Brandenberg & Putz, 2005) and ORTEP-3 (Farrugia, 1999).

Selected geometric parameters (Å, º) top

Re01—C1	1.882 (7)	Re01—O4	2.123 (5)
Re01—C3	1.897 (6)	Re01—O5	2.146 (4)
Re01—C2	1.899 (7)	Re01—O6	2.170 (5)

O4—Re01—O5	74.07 (16)	O5—Re01—O6	79.17 (18)
O4—Re01—O6	78.93 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6B···Br1ⁱ	1.06 (8)	2.68 (8)	3.421 (6)	127 (5)
O6—H6B···O5ⁱ	1.06 (8)	1.86 (8)	2.825 (7)	149 (6)
C15—H15···O2ⁱⁱ	0.93	2.5	3.409 (8)	166
O7—H7···O1ⁱⁱⁱ	0.82	2.39	2.986 (7)	130
O6—H6A···O7	0.99 (8)	1.69 (8)	2.665 (7)	167 (7)

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

Acknowledgements

The University of the Free State is gratefully acknowledged for financial support, Dr A.J. Muller for the data collection and Dr G. Steyl for providing the ligand.

References

Alberto, R., Schibli, R. & Schubiger, P. A. (1996). Polyhedron, 15, 1079–1083. CSD CrossRef CAS Web of Science Google Scholar
Alvarez, C. M., Garcia-Rodriguez, R. & Miguel, D. (2007). Dalton Trans. pp. 3546–3554. Web of Science CSD CrossRef PubMed Google Scholar
Bochkova, R. I., Zakharov, L. N., Patrikeeva, N. V., Shal'nova, K. G., Abakumov, G. A. & Cherkasov, V. K. (1987). Koord. Khim. 13, 702–705. CAS Google Scholar
Brandenberg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Brasey, T., Buryak, A., Scopelliti, R. & Severin, K. (2004). Eur. J. Inorg. Chem. pp. 964–967. Web of Science CSD CrossRef Google Scholar
Bruker (2004). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cheng, C. P., Wang, S. R., Lin, J. C. & Wang, S.-L. (1988). J. Organomet. Chem. 349, 375–382. CSD CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Gibson, D. H., Ding, Y., Miller, R. L., Sleadd, B. A., Mashuta, M. S. & Richardson, J. F. (1999). Polyhedron, 18, 1189–1200. Web of Science CSD CrossRef CAS Google Scholar
Kemp, G. (2006). PhD thesis, University of Johannesburg, South Africa. Google Scholar
Mundwiler, S., Kundig, M., Ortner, K. & Alberto, R. (2004). Dalton Trans., pp. 1320–1328. Google Scholar
Roodt, A., Otto, S. & Steyl, G. (2003). Coord. Chem. Rev. 245, 121–129. Web of Science CSD CrossRef CAS Google Scholar
Schutte, M., Visser, H. G. & Steyl, G. (2007). Acta Cryst. E63, m3195–m3196. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Steyl, G. & Roodt, A. (2006). S. Afr. J. Chem. 49, 21–22. Google Scholar
Wang, W., Spingler, B. & Alberto, R. (2003). Inorg. Chim. Acta, 355, 386–391. Web of Science CSD CrossRef CAS Google Scholar