research communications
κS)manganese(I)
of pentacarbonyl(2,2-difluoropropanethioato-aLCC-CNRS, Université de Toulouse, CNRS, INPT, Toulouse, France, and bICGM CNRS, Univ Montpellier, ENSCM, Montpellier, France
*Correspondence e-mail: daran@lcc-toulouse.fr
The title compound, [Mn{SC(O)CF2CH3}(CO)5], has been isolated as a by-product during the reaction of K[Mn(CO)5] with CH3CF2COCl. It is built up from a difluoromethylpropanethioate bonded to an Mn(CO)5 moiety through the S atom. The Mn atom has an almost perfect octahedral coordination sphere. It is one of the rare examples of compounds containing the (CO)5MnS—C fragment. In the crystal, the methyl group occupies a pocket surrounded by the O atoms of three carbonyl groups of the Mn(CO)5 moiety; however, the H⋯O distances are rather long. These interactions lead to the formation of layers lying parallel to (101), which enclose R44(15) and R44(16) ring motifs. The CF2 group is disordered over two sets of sites with occupancies of 0.849 (3) and 0.151 (3).
CCDC reference: 1906042
1. Chemical context
Alkylpentacarbonylmanganese(I) complexes containing fluorinated RF(CO)5], have been known since 1960 (Kaesz et al., 1960; Beck et al., 1961) but X-ray structures have been scarcely investigated until recently (Morales-Cerrada, Fliedel, Daran et al., 2019). Our interest in these compounds is related to a study of the homolytic Mn—C bond strength and how this is affected by the F substitution at the α and β positions of the alkyl chain (Morales-Cerrada, Fliedel, Gayet et al., 2019). The compounds where RF stands for CH2CF3 and CF2CH3 may be considered as models for the role of [Mn(CO)5] as a radical-trapping species in the polymerization of vinylidene fluoride, where the Mn—C bonds may be formed and cleaved reversibly. While the synthesis of the CH2CF3 derivative could be accomplished as planned and the product could be obtained in a pure form and crystallized (Morales-Cerrada, Fliedel, Daran et al., 2019), the synthesis of the CF2CH3 derivative led to the unexpected compound, [Mn{SC(O)CH3CF2}(CO)5] (1), reported here.
[Mn2. Structural commentary
The title compound (1), is built up from a difluoromethylpropanethioate bonded to an Mn(CO)5 moiety through the S atom (Fig. 1). Selected bond distances and bond angles involving atom Mn1 are given in Table 1, and it can be seen that this atom has a nearly perfect octahedral coordination sphere. As expected, the Mn1—S1—C1—C2 fragment is almost planar, as shown by the value of the torsion angle of −177.98 (11)°. This plane roughly bisects the dihedral angle formed by the C11/Mn1/C12/S1 and C11/Mn1/C13/S1 planes with values of 50.06 (7) and 39.9 (1)°, respectively, placing the O2 atom relatively close to the O atoms of the two carbonyl groups C12=O12 and C13=O13 with distances O2⋯O12 = 3.058 (2) Å and O2⋯O13 = 3.257 (2) Å. The smallest bond angles, 86.01 (5)° for C14—Mn1—S1 and 86.14 (5)° for C15—Mn1—S1, are certainly related to resulting from these relatively short intramolecular O⋯O contacts. These short interactions might force the Mn1—S1 bond to bend slightly towards the equatorial plane [C12/C13/C14/C15]. The shortest Mn—C(O) distance is observed for the carbonyl group trans to the S atom; Mn1—C11 = 1.8376 (17) Å
|
3. Supramolecular features
In the crystal, the methyl group occupies a pocket surrounded by O atoms of three carbonyl groups, C11=O11, C12=O12 and C14=O14, forming a two-dimensional network that develops parallel to (101); see Table 2 and Fig. 2. These rather weak C—H⋯O interactions result in the formation of two graph-set motifs, R44(15) and R44(16), as shown in Fig. 2.
4. Database survey
A search in the Cambridge Structural Database (CSD, V5.40, update February 2019; Groom et al., 2016) using a (CO)5MnS—C fragment revealed only three hits. These include, [μ2-1,2-bis(p-fluorophenyl)-ethylene-1,2-dithiolato-S,S′]decacarbonyldi-manganese (CSD refcode CECCES; Lindner et al., 1983), pentacarbonyl-[(N-pentafluorothio)fluorothioformimido-S]manganese (JEBNOT; Damerius et al., 1989) and μ-1,2-dithiooxalatobis(pentacarbonyl)manganese (TOXCMN; Weber & Mattes, 1979). The Mn—S, S—C, Mn—C bond distances and Mn—S—C bond angles are compared to those for compound (1) in Table 3. As in compound (1), the Mn—C bond trans to the S atom is significantly shorter than the four other Mn—C bonds. The longest Mn—S bond, 2.405 Å in CECCES, may be related to the presence of the bulky fluorophenyl group attached to the C(S) atom. For compound (1) and TOXCMN, both having an oxo group attached to the C(S) atom, the Mn—S—C angle is nearly identical, 106.26 (6) and ca 105.64°, respectively (Table 3). In contrast, this angle is slightly larger for CECCES and for JEBNOT, ca 108.8 and 108.1°, respectively.
|
5. Synthesis and crystallization
The synthesis of the target compound, [Mn(CF2CH3)(CO)5], requires transit through the corresponding acyl derivative, [Mn(COCF2CH3)(CO)5], because direct alkylation of CH3CF2-X (X = Cl, Br) reagents by the powerful [Mn(CO)5]− suffers from the inverted polarity of the C—X bond, leading to [MnX(CO)5] instead (Beck et al., 1961). The corresponding acylation using CH3CF2COCl as acylating agent was successful (Morales-Cerrada, Fliedel, Daran et al., 2019). However, the pure product could only be obtained when the 2,2-difluoropropanoyl chloride was synthesized by the action of oxalyl chloride on 2,2-difluoropropionic acid. In a first synthetic study, 2,2-difluoropropionic acid was chlorinated by the more common thionyl chloride reagent, SOCl2. When the resulting acyl chloride was used to acylate [Mn(CO)5]−, the title compound crystallized as colourless single crystals. The sulfur atom must have been provided by the thionyl chloride remaining as a contaminant in the acyl chloride reagent.
2,2-Difluoropropanoyl chloride was freshly prepared as follows. To a 50 ml round flask equipped with a reflux condenser, was introduced 5.28 g of 2,2-difluoropropionic acid (47.97 mmol) and 10.05 g of thionyl chloride (84.48 mmol; previously purified by reflux in the presence of sulfur powder and then distilled) was added dropwise. The mixture was then heated up to 363 K over 2 h (reflux). The product was purified by distillation (b.p. 308–313 K), giving 4.85 g of a colourless liquid. The amount of thionyl chloride contaminant in the distilled product could not be estimated by NMR spectroscopy.
Synthesis of the title compound (1): To a Schlenk tube were introduced 390 mg (9.97 mmol) of metallic potassium and 358 mg (15.57 mmol) of metallic sodium under argon. They were crushed together to generate a liquid NaK alloy. A solution of dimanganese decacarbonyl (2.00 g, 5.13 mmol) in 30 ml of dry THF was added and the resulting mixture was stirred for 3 h at room temperature, leading to the formation of K+[Mn(CO)5]−. The mixture was filtered through Celite to yield a greenish brown solution, rinsing the Celite with 10 ml of dry THF. Then, 2,2-trifluoropropanoyl chloride (1.31 g, 10.19 mmol), made as described above, was added dropwise at room temperature. The resulting solution was further stirred at room temperature for 3 h, followed by evaporation of the solvents under reduced pressure. The product was purified by through a silica gel column, using n-pentane as the mobile phase. After elimination of a first yellow fraction corresponding to [Mn2(CO)10], the mobile phase polarity was increased using a mixture of n-pentane and diethyl ether (2:1). An orange band was collected, followed by evaporation to dryness under reduced pressure to afford the product as an orange–brown liquid. The product was stored in the fridge (276–277 K), leading to the growth of thin colourless plate-like crystals of the title compound which were collected after two days.
6. Refinement
Crystal data, data collection and structure . The methyl H atoms were fixed geometrically and treated as riding: C—H = 0.98 Å with Uiso(H) = 1.5Ueq(CH3). The two fluorine atoms presented elongated ellipsoids, which could be related to disorder. To consider a realistic chemical disorder, we defined a model by rotation around the C1—C2 bond. Initially, the model could be refined isotropically to define the occupancy factors using a free variable. The result showed a major component with an occupancy factor of 85% and a minor one at 15%. As a result, it was impossible to freely refine the thermal ellipsoids for the disordered CF2 group. The anisotropic has been realized using severe EADP restraints for the C and F atoms.
details are summarized in Table 4
|
Supporting information
CCDC reference: 1906042
Data collection: APEX2 (Bruker, 2014); cell
SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).[Mn(C3H3F2OS)(CO)5] | F(000) = 632 |
Mr = 320.10 | Dx = 1.832 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 6.3503 (4) Å | Cell parameters from 9996 reflections |
b = 14.9583 (9) Å | θ = 2.2–28.9° |
c = 12.3127 (9) Å | µ = 1.36 mm−1 |
β = 97.149 (3)° | T = 173 K |
V = 1160.49 (13) Å3 | Thin_plate, colourless |
Z = 4 | 0.40 × 0.26 × 0.04 mm |
Nonius CAD-4 with APEXII CCD diffractometer | 2554 independent reflections |
Radiation source: fine-focus sealed tube | 2261 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.043 |
φ and ω scans | θmax = 27.1°, θmin = 2.7° |
Absorption correction: multi-scan (Blessing, 1995) | h = −8→8 |
Tmin = 0.621, Tmax = 0.746 | k = −19→19 |
43723 measured reflections | l = −15→15 |
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)] = 0.023 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.062 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.033P)2 + 0.5266P] where P = (Fo2 + 2Fc2)/3 |
2554 reflections | (Δ/σ)max = 0.001 |
175 parameters | Δρmax = 0.55 e Å−3 |
6 restraints | Δρmin = −0.28 e Å−3 |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Mn1 | 0.43292 (4) | 0.29392 (2) | 0.45193 (2) | 0.01827 (8) | |
S1 | 0.53795 (7) | 0.42961 (3) | 0.37381 (4) | 0.02705 (11) | |
O2 | 0.6662 (2) | 0.32546 (9) | 0.22242 (11) | 0.0380 (3) | |
O11 | 0.2678 (2) | 0.13030 (8) | 0.54815 (10) | 0.0335 (3) | |
O12 | 0.8262 (2) | 0.19606 (9) | 0.40668 (12) | 0.0386 (3) | |
O13 | 0.1947 (2) | 0.24358 (10) | 0.23502 (10) | 0.0374 (3) | |
O14 | 0.0554 (2) | 0.39501 (10) | 0.50870 (13) | 0.0429 (3) | |
O15 | 0.6894 (2) | 0.35866 (9) | 0.65865 (11) | 0.0361 (3) | |
C1 | 0.6470 (3) | 0.40015 (11) | 0.25739 (14) | 0.0258 (3) | |
C11 | 0.3361 (3) | 0.19238 (11) | 0.51356 (13) | 0.0231 (3) | |
C12 | 0.6773 (3) | 0.23362 (11) | 0.41940 (14) | 0.0249 (3) | |
C13 | 0.2873 (3) | 0.26287 (11) | 0.31555 (14) | 0.0246 (3) | |
C14 | 0.1982 (3) | 0.35751 (11) | 0.48685 (14) | 0.0264 (3) | |
C15 | 0.5915 (3) | 0.33322 (10) | 0.58282 (14) | 0.0238 (3) | |
C2 | 0.7351 (3) | 0.47775 (12) | 0.19361 (16) | 0.0348 (4) | |
C3A | 0.9645 (4) | 0.4925 (2) | 0.2222 (2) | 0.0413 (6) | 0.849 (3) |
H3A1 | 0.993454 | 0.510299 | 0.299223 | 0.062* | 0.849 (3) |
H3A2 | 1.011515 | 0.539893 | 0.175822 | 0.062* | 0.849 (3) |
H3A3 | 1.041157 | 0.437149 | 0.210635 | 0.062* | 0.849 (3) |
F1A | 0.6207 (3) | 0.55205 (11) | 0.2005 (2) | 0.0672 (7) | 0.849 (3) |
F2A | 0.6999 (3) | 0.45454 (13) | 0.08233 (12) | 0.0604 (6) | 0.849 (3) |
C3B | 0.952 (2) | 0.4766 (13) | 0.1799 (15) | 0.0413 (6) | 0.151 (3) |
H3B1 | 1.037235 | 0.468084 | 0.251102 | 0.062* | 0.151 (3) |
H3B2 | 0.990454 | 0.533469 | 0.148047 | 0.062* | 0.151 (3) |
H3B3 | 0.979264 | 0.427449 | 0.130863 | 0.062* | 0.151 (3) |
F1B | 0.7158 (19) | 0.5589 (6) | 0.2621 (11) | 0.0672 (7) | 0.151 (3) |
F2B | 0.5979 (18) | 0.4975 (8) | 0.1138 (8) | 0.0604 (6) | 0.151 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Mn1 | 0.01945 (13) | 0.01603 (13) | 0.01948 (13) | 0.00083 (8) | 0.00298 (9) | 0.00078 (9) |
S1 | 0.0315 (2) | 0.01629 (19) | 0.0345 (2) | 0.00001 (15) | 0.00874 (18) | 0.00293 (16) |
O2 | 0.0568 (9) | 0.0261 (7) | 0.0341 (7) | −0.0052 (6) | 0.0176 (6) | 0.0000 (5) |
O11 | 0.0430 (7) | 0.0257 (6) | 0.0326 (7) | −0.0076 (5) | 0.0081 (6) | 0.0041 (5) |
O12 | 0.0318 (7) | 0.0426 (8) | 0.0422 (8) | 0.0146 (6) | 0.0076 (6) | 0.0002 (6) |
O13 | 0.0402 (7) | 0.0454 (8) | 0.0250 (7) | −0.0088 (6) | −0.0029 (6) | 0.0005 (6) |
O14 | 0.0294 (7) | 0.0434 (8) | 0.0570 (9) | 0.0104 (6) | 0.0106 (6) | −0.0062 (7) |
O15 | 0.0456 (8) | 0.0279 (7) | 0.0319 (7) | −0.0035 (6) | −0.0072 (6) | −0.0033 (5) |
C1 | 0.0239 (8) | 0.0256 (8) | 0.0276 (8) | −0.0028 (6) | 0.0021 (6) | 0.0077 (7) |
C11 | 0.0254 (8) | 0.0241 (8) | 0.0197 (8) | 0.0009 (6) | 0.0028 (6) | −0.0022 (6) |
C12 | 0.0285 (9) | 0.0223 (8) | 0.0238 (8) | −0.0002 (7) | 0.0025 (6) | 0.0010 (6) |
C13 | 0.0263 (8) | 0.0217 (8) | 0.0266 (9) | −0.0010 (6) | 0.0069 (7) | 0.0047 (6) |
C14 | 0.0265 (8) | 0.0247 (8) | 0.0279 (9) | −0.0010 (7) | 0.0026 (7) | 0.0008 (7) |
C15 | 0.0270 (8) | 0.0163 (8) | 0.0286 (8) | 0.0014 (6) | 0.0053 (7) | 0.0018 (6) |
C2 | 0.0370 (10) | 0.0293 (9) | 0.0384 (10) | −0.0031 (8) | 0.0065 (8) | 0.0118 (8) |
C3A | 0.0401 (12) | 0.0418 (16) | 0.0438 (18) | −0.0138 (10) | 0.0117 (13) | 0.0001 (13) |
F1A | 0.0639 (12) | 0.0365 (8) | 0.1106 (19) | 0.0244 (9) | 0.0482 (12) | 0.0455 (11) |
F2A | 0.0864 (14) | 0.0664 (12) | 0.0267 (8) | −0.0336 (10) | 0.0003 (8) | 0.0110 (7) |
C3B | 0.0401 (12) | 0.0418 (16) | 0.0438 (18) | −0.0138 (10) | 0.0117 (13) | 0.0001 (13) |
F1B | 0.0639 (12) | 0.0365 (8) | 0.1106 (19) | 0.0244 (9) | 0.0482 (12) | 0.0455 (11) |
F2B | 0.0864 (14) | 0.0664 (12) | 0.0267 (8) | −0.0336 (10) | 0.0003 (8) | 0.0110 (7) |
Mn1—C11 | 1.8376 (17) | C1—C2 | 1.545 (2) |
Mn1—C12 | 1.8807 (17) | C2—F2B | 1.264 (9) |
Mn1—C13 | 1.8720 (17) | C2—F1A | 1.336 (2) |
Mn1—C14 | 1.8631 (17) | C2—F2A | 1.404 (3) |
Mn1—C15 | 1.8849 (17) | C2—C3B | 1.409 (13) |
Mn1—S1 | 2.3768 (5) | C2—C3A | 1.472 (3) |
S1—C1 | 1.7250 (18) | C2—F1B | 1.492 (11) |
O2—C1 | 1.209 (2) | C3A—H3A1 | 0.9800 |
O11—C11 | 1.131 (2) | C3A—H3A2 | 0.9800 |
O12—C12 | 1.127 (2) | C3A—H3A3 | 0.9800 |
O13—C13 | 1.126 (2) | C3B—H3B1 | 0.9800 |
O14—C14 | 1.127 (2) | C3B—H3B2 | 0.9800 |
O15—C15 | 1.122 (2) | C3B—H3B3 | 0.9800 |
C11—Mn1—C12 | 91.08 (7) | F1A—C2—F2A | 104.25 (18) |
C11—Mn1—C13 | 90.69 (7) | F2B—C2—C3B | 119.9 (9) |
C11—Mn1—C14 | 90.47 (7) | F1A—C2—C3A | 112.9 (2) |
C11—Mn1—C15 | 94.32 (7) | F2A—C2—C3A | 107.65 (19) |
C11—Mn1—S1 | 176.45 (5) | F2B—C2—F1B | 98.7 (7) |
C12—Mn1—C15 | 87.96 (7) | C3B—C2—F1B | 103.2 (8) |
C12—Mn1—S1 | 92.46 (5) | F2B—C2—C1 | 108.2 (4) |
C13—Mn1—C12 | 91.07 (7) | F1A—C2—C1 | 110.99 (16) |
C13—Mn1—C15 | 174.92 (7) | F2A—C2—C1 | 106.65 (15) |
C13—Mn1—S1 | 88.91 (5) | C3B—C2—C1 | 118.3 (8) |
C14—Mn1—C12 | 177.58 (7) | C3A—C2—C1 | 113.66 (18) |
C14—Mn1—C13 | 90.77 (7) | F1B—C2—C1 | 105.3 (4) |
C14—Mn1—C15 | 90.07 (7) | C2—C3A—H3A1 | 109.5 |
C14—Mn1—S1 | 86.01 (5) | C2—C3A—H3A2 | 109.5 |
C15—Mn1—S1 | 86.14 (5) | H3A1—C3A—H3A2 | 109.5 |
C1—S1—Mn1 | 106.26 (6) | C2—C3A—H3A3 | 109.5 |
O2—C1—C2 | 117.03 (16) | H3A1—C3A—H3A3 | 109.5 |
O2—C1—S1 | 126.92 (13) | H3A2—C3A—H3A3 | 109.5 |
C2—C1—S1 | 116.02 (13) | C2—C3B—H3B1 | 109.5 |
O11—C11—Mn1 | 176.70 (15) | C2—C3B—H3B2 | 109.5 |
O12—C12—Mn1 | 175.65 (15) | H3B1—C3B—H3B2 | 109.5 |
O13—C13—Mn1 | 177.98 (15) | C2—C3B—H3B3 | 109.5 |
O14—C14—Mn1 | 179.09 (17) | H3B1—C3B—H3B3 | 109.5 |
O15—C15—Mn1 | 177.59 (15) | H3B2—C3B—H3B3 | 109.5 |
Mn1—S1—C1—C2 | −177.98 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
C3A—H3A1···O14i | 0.98 | 2.81 | 3.732 (3) | 158 |
C3A—H3A2···O12ii | 0.98 | 2.79 | 3.753 (3) | 166 |
C3A—H3A3···O11iii | 0.98 | 2.79 | 3.564 (3) | 136 |
C3B—H3B2···O12ii | 0.98 | 2.81 | 3.777 (19) | 168 |
C3B—H3B3···O11iii | 0.98 | 2.37 | 3.165 (15) | 138 |
C3B—H3B3···O11iii | 0.98 | 2.37 | 3.165 (15) | 138 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, y+1/2, −z+1/2; (iii) x+1, −y+1/2, z−1/2. |
Parameter | (1) | CECCESa | JEBNOTb | TOXCMNc |
Mn—S | 2.3768 (5) | 2.405 | 2.384 | 2.379 |
C—S | 1.725 (2) | 1.741 | 1.723 | 1.737 |
Mn—S—C | 106.26 (6) | 108.84 | 108.12 | 105.64 |
Mn—C11 | 1.838 (2) | 1.803 | 1.835 | 1.840 |
Mn—C12 | 1.881 (2) | 1.867 | 1.871 | 1.883 |
Mn—C13 | 1.872 (2) | 1.861 | 1.891 | 1.857 |
Mn—C14 | 1.863 (3) | 1.864 | 1.871 | 1.880 |
Mn—C15 | 1.885 (2) | 1.878 | 1.891 | 1.857 |
Notes: (a) Lindner et al. (1983); (b) Damerius et al. (1989); (b) Weber & Mattes (1979). |
Funding information
Funding for this research was provided by: Centre National de la Recherche Scientifique and Agence Nationale de la Recherche (ANR, French National Agency) through the project FLUPOL (grant No. ANR-14-CE07-0012).
References
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Beck, W., Hieber, W. & Tengler, H. (1961). Chem. Ber. 94, 862–872. CrossRef CAS Web of Science Google Scholar
Blessing, R. H. (1995). Acta Cryst. A51, 33–38. CrossRef CAS Web of Science IUCr Journals Google Scholar
Bruker (2014). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA. Google Scholar
Damerius, R., Leopold, D., Schulze, W. & Seppelt, K. (1989). Z. Anorg. Allg. Chem. 578, 110–118. CSD CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CrossRef IUCr Journals Google Scholar
Kaesz, H. D., King, R. B. & Stone, F. G. A. (1960). Z. Naturforsch. Teil B, 15, 763–764. CrossRef Google Scholar
Lindner, E., Butz, I. P., Hiller, W., Fawzi, R. & Hoehne, S. (1983). Angew. Chem. Int. Ed. 22, 996–997. CrossRef Web of Science Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CrossRef CAS IUCr Journals Google Scholar
Morales-Cerrada, R., Fliedel, C., Daran, J.-C., Gayet, F., Ladmiral, V., Améduri, B. & Poli, R. (2019). Chem. Eur. J. 25, 296–308. CAS PubMed Google Scholar
Morales-Cerrada, R., Fliedel, C., Gayet, F., Ladmiral, V., Améduri, B. & Poli, R. (2019). Organometallics, 38, 1021–1030. . CAS Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Weber, H. & Mattes, R. (1979). Chem. Ber. 112, 95–98. CSD CrossRef CAS Web of Science 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.