Centrosymmetric [Cr2(OAc)4(THF)2] consists of two CrII atoms that are bridged by four acetate ions to yield a typical paddle-wheel structure. Furthermore, each chromium atom bears an axially bound THF ligand to give a square-pyramidal coordination.
Keywords: crystal structure, chromium, acetate, tetrahydrofurane, paddle wheel
Abstract
The title compound, [Cr2(C2H3O2)4(C4H8O)2] or [Cr2(OAc)4(THF)2] (OAc is acetate, THF is tetrahydrofuran), was obtained by recrystallization of anhydrous chromium(II) acetate [Cr2(OAc)4] from hot tetrahydrofuran. The centrosymmetric complex forms monoclinic crystals, space group C2/c, and consists of two CrII atoms bridged by four acetate ligands. Additionally, each CrII atom is coordinated by a terminal THF ligand, which leads to a square-pyramidal coordination.
Structure description
Chromium(II) acetate was discovered as early as 1844 by Peligot (Peligot, 1844 ▸). Determinations of the crystal structure of the dihydrate date back to 1953 (van Niekerk et al., 1953 ▸) and 1971 (Cotton et al., 1971 ▸). A few years later, the crystal structure of anhydrous chromium(II) acetate was reported (Cotton et al., 1977 ▸). Chromium(II) acetate is frequently used as the starting compound for chromium(II) complexes (Cotton et al., 2005 ▸). Over the past decades, a large number of chromium(II) acetate complexes with different ligands L have been investigated. Typical compounds are of the type [Cr2(OAc)4 L 2]. In most cases, L represents a nitrogen ligand such as pyridine (Cotton & Felthouse, 1980 ▸), acetonitrile (Cotton et al., 2000 ▸) or 4,4′-bipyridine (Cotton & Felthouse, 1980 ▸). However, there are also examples with oxygen donor ligands, among them the dihydrate [Cr2(OAc)4(H2O)2] (van Niekerk et al., 1953 ▸) and the analogous derivative with acetic acid ligands [Cr2(OAc)4(HOAc)2] (Cotton & Rice, 1978 ▸). Crystal structures of chromium(II) acetate complexes with common ether donor ligands have not yet been reported. This is in contrast to other chromium(II) carboxylates, where 18 complexes with ether donors have been characterized by crystal-structure determinations. Apart from some dimethoxyethane (DME) and diethyl ether complexes such as [Cr2(9-anthracenecarboxylate)4(DME)] n (Cotton et al., 1978 ▸) and [Cr2(OOC—CF3)4(OEt2)2] (Cotton et al., 1978 ▸), this area is dominated by THF complexes. [Cr2{OOC—CH(PPh2)2}4(THF)2] (Kulangara et al., 2012 ▸), [Cr2(OOC—CPh3)4(THF)2] (Cotton & Thompson, 1981 ▸) and [Cr2(OOC—C6H4-p-F)4(THF)2] (Huang et al., 2019 ▸) may serve as representative examples.
Here we report on the crystal structure of [Cr2(OAc)4(THF)2] (1). Compound 1 was synthesized by dissolution of anhydrous chromium(II) acetate in hot THF. Upon cooling to room temperature, the product precipitated in the form of dark-red crystals that easily loose THF when separated from the mother liquor.
The crystal structure of 1 consists of discrete [Cr2(OAc)4(THF)2] molecules that possess crystallographic
symmetry. The {Cr2(OAc)4} core displays a characteristic paddle-wheel structure as was observed in the prototypes [Cr2(OAc)4] (Cotton et al., 1977 ▸) and [Cr2(OAc)4(H2O)2] (van Niekerk et al., 1953 ▸). Apart from four acetate O atoms, each CrII atom binds to the O atom of one THF ligand. This leads to a square-pyramidal coordination environment for the CrII atoms. A Cr—Cr contact completes the coordination sphere (Fig. 1 ▸). Compound 1 exhibits Cr—O(OAc) distances in the range from 2.0083 (13) to 2.0175 (13) Å (Table 1 ▸). The O(OAc)—Cr—O(OAc) angles are 89.37 (6)–90.40 (6)° for the cis arranged O atoms and 177.16 (5)–177.24 (5)° for the trans positions. The observed bond lengths and angles are typical for [Cr2(OAc)4
L
2] compounds. According to the Cambridge Structural Database (Groom et al., 2016 ▸), the Cr—O(OAc) distances vary from 1.988 to 2.036 Å with a median value of 2.014 Å (14 entries, 34 data). The cis-O(OAc)—Cr—O(OAc) angles range between 87.13 and 92.06° with a median of 89.80° (13 entries, 66 data) and the trans-O(OAc)—Cr—O(OAc) angles are distributed between 173.76 and 178.99° with a median value of 176.65° (14 entries, 25 data).
Figure 1.
Molecular structure of 1 in the crystal. Displacement ellipsoids are drawn at the 50% probability level. H atoms are omitted for clarity.
Table 1. Selected geometric parameters (Å, °).
| Cr—Cri | 2.3242 (6) | O4—C3 | 1.261 (2) |
| Cr—O4i | 2.0121 (14) | O2—C1 | 1.262 (2) |
| Cr—O2i | 2.0146 (13) | O1—C1 | 1.263 (2) |
| Cr—O1 | 2.0083 (13) | O5—C5 | 1.447 (2) |
| Cr—O5 | 2.3267 (13) | O5—C8 | 1.444 (2) |
| Cr—O3 | 2.0175 (13) | O3—C3 | 1.262 (2) |
| O4i—Cr—O2i | 90.40 (6) | O1—Cr—O4i | 89.91 (6) |
| O4i—Cr—O5 | 89.29 (5) | O1—Cr—O2i | 177.24 (5) |
| O4i—Cr—O3 | 177.16 (5) | O1—Cr—O5 | 94.38 (5) |
| O2i—Cr—O5 | 88.36 (5) | O1—Cr—O3 | 90.19 (6) |
| O2i—Cr—O3 | 89.37 (6) | O3—Cr—O5 | 93.53 (5) |
Symmetry code: (i)
.
The Cr—O(THF) distance is 2.3267 (13) Å. [Cr2(OAc)4(H2O)2] (Cotton et al., 1971 ▸) and [Cr2(OAc)4(HOAc)2] (Cotton & Rice, 1978 ▸) exhibit corresponding Cr—O distances of 2.272 (3) and 2.306 (3) Å, respectively, for the axially bound ligand. Chromium(II) carboxylates with THF ligands show Cr—O(THF) distances from 2.228 to 2.316 Å with a median of 2.258 Å (14 entries, 14 data).
Compound 1 displays a Cr—Cr distance of 2.3242 (6) Å. This is very close to the median value of 2.337 Å that was obtained from 16 data (14 entries) of the CSD database. Generally, the Cr—Cr distances in [Cr2(OAc)4 L 2] complexes vary over a relatively large range from 2.270 to 2.452 Å. In [Cr2(OAc)4(H2O)2] (Cotton et al., 1971 ▸) and [Cr2(OAc)4(HOAc)2] (Cotton & Rice, 1978 ▸), the Cr—Cr distances are 2.362 (1) and 2.300 (1) Å.
Regarding supramolecular interactions, a Hirshfeld surface analysis with CrystalExplorer (Spackman et al., 2021 ▸) reveals weak C—H⋯O interactions (Table 2 ▸) between the acetate methyl group and acetate O atoms of neighbouring molecules (Fig. 2 ▸). As a result, linear chains along [101] are formed (Fig. 3 ▸).
Table 2. Hydrogen-bond geometry (Å, °).
| D—H⋯A | D—H | H⋯A | D⋯A | D—H⋯A |
|---|---|---|---|---|
| C4—H4B⋯O1ii | 0.98 | 2.60 | 3.472 (3) | 148 |
Symmetry code: (ii)
.
Figure 2.
View of the Hirshfeld surface of 1 mapped over d norm in the range of −0.062 to 1.826 au. Red-colored surfaces show short contacts, dashed green lines indicate hydrogen-bonding interactions.
Figure 3.
Crystal structure of 1, with intermolecular C—H⋯O hydrogen bonds shown as dashed lines.
Synthesis and crystallization
A suspension of chromium(II) acetate (0.5 g; 1.5 mmol) in THF (20 ml) was refluxed for 2 h. Afterwards, the hot solution was filtered and the solid residue further extracted with hot THF (2 × 5 ml). THF was evaporated under reduced pressure to give 20 ml of a concentrated solution. Upon storage at 248 K, the product precipitated after several days. The crystalline compound was filtered off and dried under reduced pressure. Yield: 0.57 g (80%). The chromium content was determined photometrically as chromate (Lange & Vejdělek, 1978 ▸). Analysis for C16H28Cr2O10 (484.38): calculated: Cr 21.5%, found: Cr 21.7%; IR (ATR; in cm−1): ν = 2962 w, 2937 w, 2896 w, 2867 w, 1581 m, 1482 m, 1435 s, 1351 m, 1297 m, 1249 w, 1233 w, 1178 w, 1035 m, 950 m, 916 m, 878 m, 672 s, 626 m, 583 m, 557 m, 542 m, 495 m, 395 s, 346 m, 297 s, 276 m, 229 m, 208 m.
Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3 ▸.
Table 3. Experimental details.
| Crystal data | |
| Chemical formula | [Cr2(C2H3O2)4(C4H8O)2] |
| M r | 484.38 |
| Crystal system, space group | Monoclinic, C2/c |
| Temperature (K) | 213 |
| a, b, c (Å) | 20.833 (4), 9.6413 (15), 15.654 (3) |
| β (°) | 136.283 (10) |
| V (Å3) | 2172.9 (7) |
| Z | 4 |
| Radiation type | Mo Kα |
| μ (mm−1) | 1.05 |
| Crystal size (mm) | 0.19 × 0.16 × 0.14 |
| Data collection | |
| Diffractometer | Stoe IPDSII |
| Absorption correction | Integration [Absorption correction with X-RED32 (Stoe, 2009 ▸) by Gaussian integration analogous to Coppens (1970 ▸)] |
| T min, T max | 0.736, 0.873 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 8042, 2297, 2085 |
| R int | 0.025 |
| (sin θ/λ)max (Å−1) | 0.634 |
| Refinement | |
| R[F 2 > 2σ(F 2)], wR(F 2), S | 0.028, 0.084, 1.06 |
| No. of reflections | 2297 |
| No. of parameters | 129 |
| H-atom treatment | H-atom parameters constrained |
| Δρmax, Δρmin (e Å−3) | 0.54, −0.25 |
Supplementary Material
Crystal structure: contains datablock(s) I. DOI: 10.1107/S2414314623008015/wm4196sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2414314623008015/wm4196Isup2.hkl
CCDC reference: 2294928
Additional supporting information: crystallographic information; 3D view; checkCIF report
Acknowledgments
We thank Andreas Kiowski for technical support.
full crystallographic data
Crystal data
| [Cr2(C2H3O2)4(C4H8O)2] | F(000) = 1008 |
| Mr = 484.38 | Dx = 1.481 Mg m−3 |
| Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
| a = 20.833 (4) Å | Cell parameters from 10024 reflections |
| b = 9.6413 (15) Å | θ = 1.9–27.1° |
| c = 15.654 (3) Å | µ = 1.05 mm−1 |
| β = 136.283 (10)° | T = 213 K |
| V = 2172.9 (7) Å3 | Block, clear red |
| Z = 4 | 0.19 × 0.16 × 0.14 mm |
Data collection
| Stoe IPDSII diffractometer | 2297 independent reflections |
| Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus | 2085 reflections with I > 2σ(I) |
| Plane graphite monochromator | Rint = 0.025 |
| Detector resolution: 6.67 pixels mm-1 | θmax = 26.8°, θmin = 2.5° |
| rotation method, ω scans | h = −26→26 |
| Absorption correction: integration [Absorption correction with X-Red32 (Stoe, 2009) by Gaussian integration analogous to Coppens (1970)] | k = −12→11 |
| Tmin = 0.736, Tmax = 0.873 | l = −19→19 |
| 8042 measured reflections |
Refinement
| Refinement on F2 | 0 restraints |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.028 | H-atom parameters constrained |
| wR(F2) = 0.084 | w = 1/[σ2(Fo2) + (0.0467P)2 + 2.3382P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.06 | (Δ/σ)max = 0.001 |
| 2297 reflections | Δρmax = 0.54 e Å−3 |
| 129 parameters | Δρmin = −0.25 e Å−3 |
Special details
| 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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| Cr | 0.26094 (2) | 0.66145 (3) | 0.46117 (2) | 0.02544 (11) | |
| O4 | 0.14551 (9) | 0.92201 (13) | 0.36838 (12) | 0.0342 (3) | |
| O2 | 0.34181 (9) | 0.94502 (13) | 0.57992 (12) | 0.0333 (3) | |
| O1 | 0.36182 (9) | 0.77547 (14) | 0.50418 (12) | 0.0345 (3) | |
| O5 | 0.28145 (10) | 0.47338 (14) | 0.38969 (12) | 0.0372 (3) | |
| O3 | 0.16586 (9) | 0.75243 (13) | 0.29340 (11) | 0.0323 (3) | |
| C1 | 0.38244 (12) | 0.8921 (2) | 0.55545 (16) | 0.0318 (4) | |
| C7 | 0.2675 (2) | 0.2300 (2) | 0.3690 (3) | 0.0598 (7) | |
| H7A | 0.256700 | 0.153198 | 0.399458 | 0.072* | |
| H7B | 0.302134 | 0.193893 | 0.352458 | 0.072* | |
| C4 | 0.05644 (14) | 0.9286 (2) | 0.15474 (18) | 0.0437 (5) | |
| H4A | 0.028412 | 1.008695 | 0.156494 | 0.065* | |
| H4B | 0.008049 | 0.860582 | 0.094730 | 0.065* | |
| H4C | 0.086525 | 0.959150 | 0.130761 | 0.065* | |
| C6 | 0.17708 (19) | 0.2950 (3) | 0.2548 (2) | 0.0557 (6) | |
| H6A | 0.149691 | 0.245473 | 0.179140 | 0.067* | |
| H6B | 0.131657 | 0.296526 | 0.258606 | 0.067* | |
| C2 | 0.46056 (14) | 0.9713 (2) | 0.5899 (2) | 0.0447 (5) | |
| H2A | 0.451210 | 1.070872 | 0.590081 | 0.067* | |
| H2B | 0.461851 | 0.951885 | 0.529713 | 0.067* | |
| H2C | 0.519618 | 0.942836 | 0.672441 | 0.067* | |
| C5 | 0.20714 (15) | 0.4391 (2) | 0.25966 (19) | 0.0396 (4) | |
| H5A | 0.229504 | 0.441548 | 0.221381 | 0.048* | |
| H5B | 0.154969 | 0.505239 | 0.215539 | 0.048* | |
| C3 | 0.12762 (12) | 0.86336 (19) | 0.28110 (16) | 0.0296 (4) | |
| C8 | 0.31894 (19) | 0.3462 (2) | 0.4601 (2) | 0.0537 (6) | |
| H8A | 0.310317 | 0.343141 | 0.514527 | 0.064* | |
| H8B | 0.386159 | 0.339342 | 0.512128 | 0.064* |
Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Cr | 0.02569 (16) | 0.02424 (17) | 0.02535 (16) | 0.00141 (10) | 0.01810 (14) | 0.00139 (10) |
| O4 | 0.0342 (7) | 0.0303 (6) | 0.0301 (6) | 0.0073 (5) | 0.0206 (6) | 0.0046 (5) |
| O2 | 0.0330 (6) | 0.0300 (6) | 0.0358 (7) | −0.0039 (5) | 0.0245 (6) | −0.0014 (5) |
| O1 | 0.0324 (6) | 0.0367 (7) | 0.0387 (7) | −0.0011 (5) | 0.0272 (6) | −0.0005 (6) |
| O5 | 0.0429 (7) | 0.0283 (6) | 0.0389 (7) | 0.0034 (6) | 0.0290 (6) | −0.0013 (5) |
| O3 | 0.0353 (6) | 0.0321 (6) | 0.0276 (6) | 0.0030 (5) | 0.0221 (6) | 0.0024 (5) |
| C1 | 0.0269 (8) | 0.0356 (9) | 0.0257 (8) | −0.0001 (7) | 0.0167 (7) | 0.0068 (7) |
| C7 | 0.090 (2) | 0.0343 (11) | 0.0689 (16) | 0.0016 (12) | 0.0617 (16) | 0.0012 (11) |
| C4 | 0.0388 (10) | 0.0433 (11) | 0.0299 (9) | 0.0054 (9) | 0.0185 (9) | 0.0106 (8) |
| C6 | 0.0637 (15) | 0.0443 (12) | 0.0557 (14) | −0.0147 (11) | 0.0420 (13) | −0.0109 (11) |
| C2 | 0.0333 (10) | 0.0517 (12) | 0.0432 (11) | −0.0084 (9) | 0.0257 (9) | 0.0034 (9) |
| C5 | 0.0444 (11) | 0.0372 (10) | 0.0373 (10) | 0.0029 (8) | 0.0296 (9) | −0.0014 (8) |
| C3 | 0.0245 (8) | 0.0303 (8) | 0.0264 (8) | −0.0014 (7) | 0.0159 (7) | 0.0038 (7) |
| C8 | 0.0604 (14) | 0.0347 (11) | 0.0486 (13) | 0.0132 (10) | 0.0336 (12) | 0.0067 (9) |
Geometric parameters (Å, º)
| Cr—Cri | 2.3242 (6) | C7—C8 | 1.492 (3) |
| Cr—O4i | 2.0121 (14) | C4—H4A | 0.9800 |
| Cr—O2i | 2.0146 (13) | C4—H4B | 0.9800 |
| Cr—O1 | 2.0083 (13) | C4—H4C | 0.9800 |
| Cr—O5 | 2.3267 (13) | C4—C3 | 1.506 (2) |
| Cr—O3 | 2.0175 (13) | C6—H6A | 0.9900 |
| O4—C3 | 1.261 (2) | C6—H6B | 0.9900 |
| O2—C1 | 1.262 (2) | C6—C5 | 1.503 (3) |
| O1—C1 | 1.263 (2) | C2—H2A | 0.9800 |
| O5—C5 | 1.447 (2) | C2—H2B | 0.9800 |
| O5—C8 | 1.444 (2) | C2—H2C | 0.9800 |
| O3—C3 | 1.262 (2) | C5—H5A | 0.9900 |
| C1—C2 | 1.501 (3) | C5—H5B | 0.9900 |
| C7—H7A | 0.9900 | C8—H8A | 0.9900 |
| C7—H7B | 0.9900 | C8—H8B | 0.9900 |
| C7—C6 | 1.506 (4) | ||
| Cri—Cr—O5 | 176.08 (4) | H4A—C4—H4C | 109.5 |
| O4i—Cr—Cri | 88.19 (4) | H4B—C4—H4C | 109.5 |
| O4i—Cr—O2i | 90.40 (6) | C3—C4—H4A | 109.5 |
| O4i—Cr—O5 | 89.29 (5) | C3—C4—H4B | 109.5 |
| O4i—Cr—O3 | 177.16 (5) | C3—C4—H4C | 109.5 |
| O2i—Cr—Cri | 88.66 (4) | C7—C6—H6A | 111.4 |
| O2i—Cr—O5 | 88.36 (5) | C7—C6—H6B | 111.4 |
| O2i—Cr—O3 | 89.37 (6) | H6A—C6—H6B | 109.2 |
| O1—Cr—Cri | 88.61 (4) | C5—C6—C7 | 101.9 (2) |
| O1—Cr—O4i | 89.91 (6) | C5—C6—H6A | 111.4 |
| O1—Cr—O2i | 177.24 (5) | C5—C6—H6B | 111.4 |
| O1—Cr—O5 | 94.38 (5) | C1—C2—H2A | 109.5 |
| O1—Cr—O3 | 90.19 (6) | C1—C2—H2B | 109.5 |
| O3—Cr—Cri | 88.98 (4) | C1—C2—H2C | 109.5 |
| O3—Cr—O5 | 93.53 (5) | H2A—C2—H2B | 109.5 |
| C3—O4—Cri | 120.14 (11) | H2A—C2—H2C | 109.5 |
| C1—O2—Cri | 119.21 (12) | H2B—C2—H2C | 109.5 |
| C1—O1—Cr | 119.57 (12) | O5—C5—C6 | 105.37 (17) |
| C5—O5—Cr | 118.23 (11) | O5—C5—H5A | 110.7 |
| C8—O5—Cr | 118.74 (13) | O5—C5—H5B | 110.7 |
| C8—O5—C5 | 108.56 (15) | C6—C5—H5A | 110.7 |
| C3—O3—Cr | 118.98 (11) | C6—C5—H5B | 110.7 |
| O2—C1—O1 | 123.94 (17) | H5A—C5—H5B | 108.8 |
| O2—C1—C2 | 118.42 (18) | O4—C3—O3 | 123.71 (16) |
| O1—C1—C2 | 117.64 (18) | O4—C3—C4 | 118.37 (17) |
| H7A—C7—H7B | 109.0 | O3—C3—C4 | 117.92 (17) |
| C6—C7—H7A | 111.0 | O5—C8—C7 | 106.84 (19) |
| C6—C7—H7B | 111.0 | O5—C8—H8A | 110.4 |
| C8—C7—H7A | 111.0 | O5—C8—H8B | 110.4 |
| C8—C7—H7B | 111.0 | C7—C8—H8A | 110.4 |
| C8—C7—C6 | 103.9 (2) | C7—C8—H8B | 110.4 |
| H4A—C4—H4B | 109.5 | H8A—C8—H8B | 108.6 |
| Cri—O4—C3—O3 | −0.4 (2) | Cr—O3—C3—O4 | 0.2 (2) |
| Cri—O4—C3—C4 | 179.40 (13) | Cr—O3—C3—C4 | −179.60 (13) |
| Cri—O2—C1—O1 | 1.2 (2) | C7—C6—C5—O5 | −34.4 (2) |
| Cri—O2—C1—C2 | −178.35 (12) | C6—C7—C8—O5 | −23.6 (3) |
| Cr—O1—C1—O2 | −1.6 (2) | C5—O5—C8—C7 | 1.9 (3) |
| Cr—O1—C1—C2 | 177.88 (12) | C8—O5—C5—C6 | 20.7 (2) |
| Cr—O5—C5—C6 | −118.42 (16) | C8—C7—C6—C5 | 35.1 (3) |
| Cr—O5—C8—C7 | 140.80 (18) |
Symmetry code: (i) −x+1/2, −y+3/2, −z+1.
Hydrogen-bond geometry (Å, º)
| D—H···A | D—H | H···A | D···A | D—H···A |
| C4—H4B···O1ii | 0.98 | 2.60 | 3.472 (3) | 148 |
Symmetry code: (ii) x−1/2, −y+3/2, z−1/2.
Funding Statement
We acknowledge the financial support within the funding programme Open Access Publishing by the German Research Foundation (DFG).
References
- Brandenburg, K. (2019). DIAMOND. Crystal Impact GbR, Bonn, Germany.
- Coppens, P. (1970). Crystallographic Computing, edited by F. R. Ahmed, S. R. Hall & C. P. Huber, pp. 255–270. Copenhagen: Munksgaard.
- Cotton, F. A., DeBoer, B. G., LaPrade, M. D., Pipal, J. R. & Ucko, D. A. (1971). Acta Cryst. B27, 1664–1671.
- Cotton, F. A., Extine, M. & Rice, G. W. (1978). Inorg. Chem. 17, 176–186.
- Cotton, F. A. & Felthouse, T. R. (1980). Inorg. Chem. 19, 328–331.
- Cotton, F. A., Hillard, E. A., Murillo, C. A. & Zhou, H.-C. (2000). J. Am. Chem. Soc. 122, 416–417.
- Cotton, F. A., Murillo, C. A. & Walton, R. A. (2005). Multiple Bonds between Metal Atoms, 3rd ed. New York: Springer Science and Business Media Inc.
- Cotton, F. A., Rice, C. E. & Rice, G. W. (1977). J. Am. Chem. Soc. 99, 4704–4707.
- Cotton, F. A. & Rice, G. W. (1978). Inorg. Chem. 17, 2004–2009.
- Cotton, F. A. & Thompson, J. L. (1981). Inorg. Chem. 20, 1292–1296.
- Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.
- Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. [DOI] [PMC free article] [PubMed]
- Huang, P.-J., Natori, Y., Kitagawa, Y., Sekine, Y., Kosaka, W. & Miyasaka, H. (2019). Dalton Trans. 48, 908–914. [DOI] [PubMed]
- Kulangara, S. V., Mason, C., Juba, M., Yang, Y., Thapa, I., Gambarotta, S., Korobkov, I. & Duchateau, R. (2012). Organometallics, 31, 6438–6449.
- Lange, B. & Vejdělek, Z. J. (1978). Photometrische Analyse, 1st ed. Weinheim, New York: VCH.
- Niekerk, J. N. van, Schoening, F. R. L. & de Wet, J. F. (1953). Acta Cryst. 6, 501–504.
- Peligot, M. E. (1844). C. R. Acad. Sci. pp. 609–615.
- Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.
- Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.
- Spackman, P. R., Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Jayatilaka, D. & Spackman, M. A. (2021). J. Appl. Cryst. 54, 1006–1011. [DOI] [PMC free article] [PubMed]
- Stoe (2009). X-RED32. Stoe & Cie, Darmstadt, Germany.
- Stoe (2016). X-AREA. Stoe & Cie, Darmstadt, Germany.
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablock(s) I. DOI: 10.1107/S2414314623008015/wm4196sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2414314623008015/wm4196Isup2.hkl
CCDC reference: 2294928
Additional supporting information: crystallographic information; 3D view; checkCIF report