Crystal structure of [tBuMgCl]2[MgCl2(Et2O)2]2

Metzler, M.; Bolte, M.; Wagner, M.; Lerner, H.-W.

doi:10.1107/S2056989023002190

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ISSN: 2056-9890

Volume 79| Part 4| April 2023| Pages 341-344

https://doi.org/10.1107/S2056989023002190

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Crystal structure of [tBuMgCl]₂[MgCl₂(Et₂O)₂]₂

Maurice Metzler,^a Michael Bolte,^a Matthias Wagner ^a and Hans-Wolfram Lerner ^a ^*

^aInstitut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany
^*Correspondence e-mail: lerner@chemie.uni-frankfurt.de

Edited by M. Weil, Vienna University of Technology, Austria (Received 23 February 2023; accepted 7 March 2023; online 15 March 2023)

The title compound, di-μ₃-chlorido-tetra-μ₂-chlorido-tetrakis(diethyl ether-κO)bis(1,1-dimethylethyl)tetramagnesium, [Mg₄(C₄H₉)₂Cl₆(C₄H₁₀O)₄], features an Mg₄Cl₆ open-cube cluster. The two four-coordinate Mg²⁺ ions show an almost tetrahedral coordination, whereas the two six-coordinate Mg²⁺ ions have their ligands in an octahedral environment. The Mg—Cl bond lengths differ depending on the coordination number (2 or 3) of the bridging μ-Cl⁻ ligands. There are few comparable structures deposited in the Cambridge Structural Database.

Keywords: crystal structure; Grignard reagent; open-cube cluster.

CCDC reference: 2246966

1. Chemical context

Grignard reagents (RMgX) are among the most commonly used organometallic reagents in synthesis. However, their molecular structures are highly diverse and therefore subject to ongoing research (Elschenbroich, 2008 ; Peltzer et al., 2020 ; Curtis et al., 2020 ). The structures of RMgX in solution depend on the nature of the solvent, the bulkiness of the organic moiety R, and the choice of the halide X (Peltzer et al., 2017 ). Moreover, the Schlenk equilibrium can convert RMgX into MgR₂ and MgX₂ (Schlenk & Schlenk jun., 1929 ). The formation of halide bridges between the Lewis-acidic Mg²⁺ ions (Mg—X—Mg) allows for dimeric and oligomeric structures that are in equilibrium with their monomeric units (Fig. 1). Further coordination sites at Mg²⁺ are often saturated by donor-solvent molecules (Seyferth, 2009 ).

Figure 1
Original and generalized Schlenk equilibrium (solvent molecules neglected; Peltzer et al., 2017

Since the analysis of Grignard reagents in solution is challenging, X-ray crystallography has emerged as an alternative, frequently used method to investigate their molecular compositions. A recurring structural motif in the solid state is the open-cube cluster [RMgCl(THF)]₂[MgCl₂(THF)₂]₂ (I; R = Me, Et, ⁱPr, ⁿBu, ^tBu). Toney & Stucky (1971 ), Sakamoto et al. (2001 ), as well as our group (Blasberg et al., 2012 ) provided evidence for such structures obtained by crystallization of RMgCl from THF. According to the Schlenk equilibrium, the formation of I can be rationalized by assuming aggregation of two RMgCl·MgCl₂ entities. The two independent Mg²⁺ ions in I exhibit five- and six-coordination, respectively. We now report [^tBuMgCl]₂[MgCl₂(Et₂O)₂]₂ (II) as the first example of such open-cube clusters obtained from Et₂O. It is noteworthy that, unlike those in I, the reactive Mg²⁺ ions in the title compound II are four-coordinate and, surprisingly, no solvent coordinates to these ^tBuMgCl₃ entities. Subtle changes such as exchanging THF for the weaker donor Et₂O seem to have a significant effect on the observed structural motifs (Fig. 2).

Figure 2
Open-cube structures like I (R = ^tBu) are obtained by crystallization of ^tBuMgCl from THF solutions, whereas the less-solvated title compound II crystallizes from Et₂O solutions of ^tBuMgCl.

2. Structural commentary

The title compound II features an open-cube cluster consisting of Mg²⁺ and Cl⁻ ions (Fig. 3). The Mg²⁺ ions (Mg1, Mg3) in the Mg₂Cl₂ plane are six-coordinate with four Cl⁻ ligands and the O atoms of two Et₂O molecules in an almost perfect octahedral mode. The Mg—Cl distances to the three-coordinate μ₃-Cl⁻ ligands (Cl1, Cl4) are significantly longer [2.6204 (7)–2.6629 (7) Å] than the Mg—Cl distances to the two-coordinate μ₂-Cl⁻ ligands (Cl2, Cl3, Cl5, Cl6) [2.4555 (7)–2.4676 (7) Å]. The other two Mg²⁺ ions (Mg2, Mg4) are four-coordinate with three Cl⁻ ligands and one tert-butyl group featuring a distorted tetrahedron. As a result of the geometric strain in these MgCl entities, the Cl—Mg—Cl angles are smaller than the Cl—Mg—C angles. Again, a difference in the Mg—Cl bond lengths can be observed: as expected, the bonds between Mg²⁺ and the μ₃-Cl⁻ ligands are longer [2.4687 (7) and 2.4689 (7) Å] than the bonds between Mg²⁺ and the μ₂-Cl⁻ ligands [2.3785 (7)–2.3905 (7) Å].

Figure 3
Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are omitted for clarity.

3. Supramolecular features

There are two short C—H⋯Cl contacts bridging adjacent molecules of the title compound II. These hydrogen bonds (Table 1) lead to the formation of chains extending parallel to [010]. A packing diagram showing one unit cell is depicted in Fig. 4. There are no other remarkable intermolecular interactions.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C32—H32A⋯Cl3ⁱ	0.98	2.96	3.876 (2)	155
C34—H34A⋯Cl6ⁱⁱ	0.98	2.92	3.602 (2)	127
Symmetry codes: (i) ; (ii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Figure 4
Packing diagram of the title compound II showing the C—H⋯Cl hydrogen bonds (cyan) between adjacent molecules of II. H atoms not involved in hydrogen bonding are omitted for clarity.

4. Database survey

Six comparable structures with a similar Mg₄Cl₆ open-cube cluster have been found in the Cambridge Structural Database (version 5.43, update of September 2022; Groom et al., 2016 ), viz., [EtMgCl(THF)]₂[MgCl₂(THF)₂]₂ (MGCLTF; Toney & Stucky, 1971), [MeMgCl(THF)]₂[MgCl₂(THF)₂]₂ (QUJSUJ; Sakamoto et al., 2001), [^tBuMgCl(THF)]₂[MgCl₂(THF)₂]₂ (QUJTAQ; Sakamoto et al., 2001), [benzylMgCl(THF)]₂[MgCl₂(THF)₂]₂ (QUJTEU; Sakamoto et al., 2001), [ⁱPrMgCl(THF)]₂[MgCl₂(THF)₂]₂ (SEJZUE; Blasberg et al., 2012), and [Me₂NCH₂CH₂CH₂MgCl]₂[MgCl₂(THF)₂]₂ (WILMIN; Casellato & Ossola, 1994 ). A seventh structure [ⁿBuMg₃Cl₅(THF)₄]₂ (ZIHQEO; Pirinen et al., 2013 ) also features an open-cube cluster; however, here the reactive Mg²⁺ ions are not part of the cubes. The latter structure is therefore not included in the comparison. Interestingly, all the above structures from the database show crystallographic centrosymmetry, with all of them being located at a center of inversion. The title compound, on the other hand, does not show any crystallographic symmetry, although it would be possible for II to comply with a crystallographic inversion center. A fundamental difference between the structure of the title compound and the published structures is the coordination sphere of the reactive Mg²⁺ ions. In all structures retrieved from the CSD, these Mg²⁺ ions are five-coordinate and the ligands form a distorted trigonal bipyramid. The calculated geometry indices τ₅ (0.65–0.84) show a varying degree of deviation from the ideal trigonal bipyramidal geometry (τ₅ = 1; Addison et al., 1984 ). The Mg⋯Cl distances to the μ₃-Cl⁻ ligands in the central Mg₂Cl₂ plane (Table 2) are significantly longer (mean value 2.806 Å) than in II (mean value 2.4688 Å), but in between the sum of van der Waals radii (Σr(vdW)[Mg,Cl] = 3.48 Å) and effective ionic radii (Σr(ion)[Mg²⁺,Cl⁻] = 2.47 Å) (Bondi, 1964 ; Shannon, 1976 ). Nevertheless, the sums of equatorial angles Σθ_eq (mean value 358.6°) indicate that the Mg²⁺ ions are five-coordinate in a trigonal bipyramidal mode and that interactions with the μ₃-Cl⁻ ions in the Mg₂Cl₂ planes exist. Structures with other halogens than Cl were not found.

Table 2
Comparison of Mg⋯Cl distances (Å) and sums of equatorial angles Σθ_eq (°) of the five-coordinate Mg²⁺ ions in the literature phases

There are two rows for the title compound because it does not show any symmetry, whereas all structures retrieved from the database are located at a center of inversion. Mg⋯μ₂-Cl: bond lengths are between the five-coordinate Mg²⁺ ions and the μ₂-Cl⁻ ions. Mg⋯μ₃-Cl: bond lengths are between the five-coordinate Mg²⁺ ion and the μ₃-Cl⁻ ion in the central Mg₂Cl₂ plane.

Structure	Mg⋯μ₃-Cl	Mg⋯μ₂-Cl	Mg⋯μ₂-Cl	Σθ_eq
Title compound	2.4687 (7)	2.3825 (7)	2.3905 (8)	–
Title compound	2.4689 (7)	2.3785 (7)	2.3796 (7)	–
MGCLTF	2.789	2.398	2.405	359.6
QUJSUJ	2.888	2.405	2.406	358.0
QUJTAG	2.819	2.415	2.429	358.4
QUJTEU	2.834	2.389	2.393	356.6
SEJZUE	2.727	2.404	2.431	359.2
WILMIN	2.779	2.397	2.402	359.5

5. Synthesis and crystallization

Magnesium turnings (9.74 g, 401 mmol, 1.7 eq.) were placed in a Schlenk flask and dried under vacuum by heating. Dry Et₂O (40 ml) was added to the flask and a solution of ^tBuCl (21.3 g, 230 mmol, 1.0 eq.) in Et₂O (20 ml) was added dropwise at such a rate as to maintain a gentle reflux (approx. 1 h). After cooling to room temperature, the Grignard solution was separated from residual Mg turnings by cannula transfer into a new Schlenk flask. Upon concentration of the solution at room temperature, colorless crystals of [^tBuMgCl]₂[MgCl₂(Et₂O)₂]₂ formed, which were suitable for single-crystal X-ray structure determination.

6. Refinement

Crystal data, data collection, and structure refinement details are summarized in Table 3. H atoms were geometrically positioned and refined using a riding model with C_methylene—H = 0.99 Å and U(H) = 1.2U_eq(C) or with C_methyl—H = 0.98 Å and U(H) = 1.5U_eq(C).

Table 3
Experimental details

Crystal data
Chemical formula	[Mg₄(C₄H₉)₂Cl₆(C₄H₁₀O)₄]
M_r	720.64
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	173
a, b, c (Å)	11.5663 (5), 15.4045 (8), 22.8256 (11)
β (°)	99.209 (4)
V (Å³)	4014.5 (3)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.52
Crystal size (mm)	0.26 × 0.24 × 0.19

Data collection
Diffractometer	STOE IPDS II two-circle-diffractometer
Absorption correction	Multi-scan (X-AREA; Stoe & Cie, 2001 )
T_min, T_max	0.762, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	20835, 7482, 5674
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.608

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.030, 0.066, 0.93
No. of reflections	7482
No. of parameters	343
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.18
Computer programs: X-AREA (Stoe & Cie, 2001), SHELXS (Sheldrick, 2008 ), SHELXL (Sheldrick, 2015 ), XP (Sheldrick, 2008), Mercury (Macrae et al., 2020 ), PLATON (Spek, 2009 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 2246966

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2056989023002190/wm5675sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989023002190/wm5675Isup2.hkl

checkCIF report

Computing details top

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL (Sheldrick, 2015); molecular graphics: XP (Sheldrick, 2008) and Mercury (Macrae et al., 2020); software used to prepare material for publication: SHELXL (Sheldrick, 2015), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Di-µ₃-chlorido-tetra-µ₂-chlorido-tetrakis(diethyl ether-κO)bis(1,1-dimethylethyl)tetramagnesium top

Crystal data top

[Mg₄(C₄H₉)₂Cl₆(C₄H₁₀O)₄]	F(000) = 1536
M_r = 720.64	D_x = 1.192 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.5663 (5) Å	Cell parameters from 19794 reflections
b = 15.4045 (8) Å	θ = 3.2–25.9°
c = 22.8256 (11) Å	µ = 0.52 mm⁻¹
β = 99.209 (4)°	T = 173 K
V = 4014.5 (3) Å³	Block, colourless
Z = 4	0.26 × 0.24 × 0.19 mm

Data collection top

STOE IPDS II two-circle- diffractometer	5674 reflections with I > 2σ(I)
Radiation source: Genix 3D IµS microfocus X-ray source	R_int = 0.033
ω scans	θ_max = 25.6°, θ_min = 3.2°
Absorption correction: multi-scan (X-Area; Stoe & Cie, 2001)	h = −13→14
T_min = 0.762, T_max = 1.000	k = −18→18
20835 measured reflections	l = −27→27
7482 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.030	H-atom parameters constrained
wR(F²) = 0.066	w = 1/[σ²(F_o²) + (0.0337P)²] where P = (F_o² + 2F_c²)/3
S = 0.93	(Δ/σ)_max = 0.001
7482 reflections	Δρ_max = 0.23 e Å⁻³
343 parameters	Δρ_min = −0.18 e Å⁻³
0 restraints

Special details top

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) top

	x	y	z	U_iso*/U_eq
Mg1	0.85944 (5)	0.39400 (4)	0.67934 (3)	0.02116 (13)
Mg2	0.55207 (5)	0.36837 (4)	0.63418 (3)	0.02481 (14)
Mg3	0.63926 (5)	0.34063 (4)	0.79150 (3)	0.02032 (13)
Mg4	0.94919 (5)	0.36222 (4)	0.83447 (3)	0.02314 (13)
Cl1	0.70075 (4)	0.27496 (3)	0.69305 (2)	0.02311 (10)
Cl2	0.69752 (4)	0.47151 (3)	0.61844 (2)	0.02928 (11)
Cl3	1.00678 (4)	0.30899 (3)	0.74566 (2)	0.02581 (10)
Cl4	0.79900 (4)	0.45596 (3)	0.77698 (2)	0.02215 (9)
Cl5	0.80093 (4)	0.26496 (3)	0.85501 (2)	0.02837 (10)
Cl6	0.48646 (4)	0.41593 (3)	0.72299 (2)	0.02612 (10)
C1	0.42463 (17)	0.32648 (13)	0.56138 (9)	0.0304 (4)
C2	0.3138 (2)	0.38179 (17)	0.55809 (12)	0.0535 (6)
H2A	0.283162	0.377124	0.595581	0.080*
H2B	0.332648	0.442554	0.551086	0.080*
H2C	0.254675	0.361090	0.525481	0.080*
C3	0.4687 (2)	0.33588 (19)	0.50227 (11)	0.0567 (7)
H3A	0.491852	0.396248	0.497100	0.085*
H3B	0.536381	0.297756	0.501815	0.085*
H3C	0.406223	0.319693	0.469862	0.085*
C4	0.3894 (2)	0.23210 (15)	0.56802 (12)	0.0520 (6)
H4A	0.360749	0.224622	0.605846	0.078*
H4B	0.327370	0.216466	0.535267	0.078*
H4C	0.457528	0.194528	0.567220	0.078*
C5	1.08079 (16)	0.40856 (12)	0.90376 (9)	0.0289 (4)
C6	1.20470 (18)	0.38137 (15)	0.89651 (11)	0.0417 (5)
H6A	1.209956	0.317874	0.896460	0.063*
H6B	1.222861	0.404082	0.858919	0.063*
H6C	1.260780	0.404700	0.929490	0.063*
C7	1.0590 (2)	0.37540 (19)	0.96411 (10)	0.0529 (6)
H7A	1.061154	0.311799	0.964420	0.079*
H7B	1.119848	0.397862	0.995260	0.079*
H7C	0.982052	0.395248	0.971362	0.079*
C8	1.0774 (3)	0.50716 (15)	0.90356 (13)	0.0589 (7)
H8A	1.091295	0.528701	0.864895	0.088*
H8B	1.000379	0.526878	0.910870	0.088*
H8C	1.138175	0.529492	0.934768	0.088*
O1	0.97092 (10)	0.49894 (8)	0.67575 (6)	0.0256 (3)
O2	0.90985 (12)	0.33409 (8)	0.60605 (6)	0.0304 (3)
O3	0.52786 (10)	0.23817 (7)	0.80081 (6)	0.0224 (3)
O4	0.59432 (11)	0.41160 (8)	0.86184 (6)	0.0271 (3)
C11	1.09484 (16)	0.48893 (13)	0.67206 (10)	0.0327 (4)
H11A	1.114637	0.526710	0.640001	0.039*
H11B	1.109828	0.428090	0.661473	0.039*
C12	1.1731 (2)	0.51158 (17)	0.72924 (12)	0.0499 (6)
H12A	1.255156	0.503804	0.724439	0.075*
H12B	1.159948	0.572157	0.739516	0.075*
H12C	1.155139	0.473516	0.760993	0.075*
C13	0.93368 (18)	0.58886 (12)	0.67816 (10)	0.0358 (5)
H13A	0.991791	0.620817	0.706772	0.043*
H13B	0.857846	0.590729	0.693006	0.043*
C14	0.9204 (2)	0.63357 (14)	0.61938 (12)	0.0505 (6)
H14A	0.895273	0.693650	0.623755	0.076*
H14B	0.995619	0.633238	0.604799	0.076*
H14C	0.861591	0.603132	0.591024	0.076*
C21	0.94137 (19)	0.24253 (13)	0.60446 (10)	0.0379 (5)
H21A	0.902128	0.216780	0.566729	0.045*
H21B	0.912618	0.211830	0.637414	0.045*
C22	1.0726 (2)	0.22900 (15)	0.60974 (12)	0.0460 (6)
H22A	1.089483	0.166741	0.608459	0.069*
H22B	1.101317	0.258229	0.576734	0.069*
H22C	1.111807	0.253278	0.647419	0.069*
C23	0.9223 (2)	0.38232 (16)	0.55274 (9)	0.0417 (5)
H23A	1.000960	0.371057	0.542566	0.050*
H23B	0.916738	0.445178	0.560898	0.050*
C24	0.8313 (3)	0.3590 (2)	0.50044 (11)	0.0675 (8)
H24A	0.843959	0.393417	0.465923	0.101*
H24B	0.837402	0.297114	0.491483	0.101*
H24C	0.753132	0.371277	0.509825	0.101*
C31	0.40608 (16)	0.24950 (13)	0.80824 (10)	0.0308 (4)
H31A	0.391010	0.311967	0.813877	0.037*
H31B	0.392537	0.218510	0.844534	0.037*
C32	0.3211 (2)	0.21645 (17)	0.75634 (13)	0.0540 (7)
H32A	0.240842	0.225693	0.763725	0.081*
H32B	0.332734	0.247793	0.720379	0.081*
H32C	0.334263	0.154292	0.751051	0.081*
C33	0.56613 (17)	0.14798 (11)	0.80251 (8)	0.0264 (4)
H33A	0.641665	0.144305	0.787481	0.032*
H33B	0.507978	0.113177	0.775802	0.032*
C34	0.58083 (18)	0.10973 (12)	0.86411 (9)	0.0330 (4)
H34A	0.606551	0.049237	0.862843	0.049*
H34B	0.639597	0.143118	0.890586	0.049*
H34C	0.505882	0.111984	0.878904	0.049*
C41	0.57470 (18)	0.50510 (12)	0.85886 (10)	0.0318 (4)
H41A	0.597755	0.527616	0.821778	0.038*
H41B	0.625584	0.533061	0.892609	0.038*
C42	0.4488 (2)	0.53006 (14)	0.86053 (11)	0.0431 (5)
H42A	0.440950	0.593379	0.858404	0.065*
H42B	0.397974	0.503768	0.826703	0.065*
H42C	0.425820	0.509216	0.897577	0.065*
C43	0.57826 (19)	0.37161 (14)	0.91760 (9)	0.0338 (4)
H43A	0.584839	0.307827	0.913959	0.041*
H43B	0.498345	0.384782	0.925418	0.041*
C44	0.6661 (3)	0.40219 (19)	0.96956 (11)	0.0620 (7)
H44A	0.651058	0.373178	1.005806	0.093*
H44B	0.745380	0.388142	0.962586	0.093*
H44C	0.658839	0.465138	0.974051	0.093*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Mg1	0.0192 (3)	0.0236 (3)	0.0206 (3)	0.0005 (2)	0.0030 (2)	0.0011 (2)
Mg2	0.0200 (3)	0.0326 (3)	0.0209 (3)	−0.0027 (2)	0.0005 (2)	0.0008 (3)
Mg3	0.0190 (3)	0.0215 (3)	0.0204 (3)	0.0005 (2)	0.0032 (2)	0.0020 (2)
Mg4	0.0193 (3)	0.0290 (3)	0.0206 (3)	−0.0014 (2)	0.0016 (2)	0.0004 (2)
Cl1	0.0219 (2)	0.02278 (19)	0.0247 (2)	−0.00015 (16)	0.00402 (16)	0.00018 (17)
Cl2	0.0214 (2)	0.0340 (2)	0.0312 (3)	−0.00148 (17)	0.00056 (18)	0.01139 (19)
Cl3	0.0240 (2)	0.0295 (2)	0.0241 (2)	0.00730 (17)	0.00460 (17)	0.00182 (18)
Cl4	0.0214 (2)	0.02222 (19)	0.0231 (2)	0.00049 (15)	0.00457 (16)	0.00038 (17)
Cl5	0.0212 (2)	0.0320 (2)	0.0306 (3)	−0.00177 (17)	0.00012 (18)	0.01217 (19)
Cl6	0.0246 (2)	0.0295 (2)	0.0242 (2)	0.00760 (17)	0.00389 (17)	0.00337 (18)
C1	0.0279 (10)	0.0358 (10)	0.0259 (10)	−0.0027 (8)	−0.0004 (8)	−0.0018 (8)
C2	0.0400 (13)	0.0587 (15)	0.0559 (16)	0.0074 (11)	−0.0106 (11)	−0.0109 (13)
C3	0.0619 (17)	0.0775 (18)	0.0307 (13)	−0.0147 (14)	0.0071 (12)	−0.0069 (12)
C4	0.0538 (15)	0.0444 (13)	0.0549 (16)	−0.0087 (11)	0.0003 (12)	0.0011 (12)
C5	0.0244 (10)	0.0361 (10)	0.0247 (10)	−0.0025 (8)	−0.0008 (8)	−0.0037 (8)
C6	0.0265 (11)	0.0512 (13)	0.0453 (14)	−0.0048 (9)	−0.0005 (9)	−0.0040 (11)
C7	0.0470 (14)	0.0851 (18)	0.0252 (12)	−0.0094 (13)	0.0014 (10)	−0.0011 (12)
C8	0.0718 (18)	0.0395 (13)	0.0577 (17)	0.0032 (12)	−0.0127 (14)	−0.0152 (12)
O1	0.0195 (6)	0.0238 (6)	0.0339 (8)	−0.0012 (5)	0.0058 (5)	0.0012 (5)
O2	0.0332 (7)	0.0340 (7)	0.0252 (7)	−0.0026 (6)	0.0083 (6)	−0.0053 (6)
O3	0.0175 (6)	0.0210 (6)	0.0294 (7)	0.0000 (5)	0.0058 (5)	0.0000 (5)
O4	0.0331 (7)	0.0260 (6)	0.0235 (7)	−0.0016 (5)	0.0085 (5)	−0.0020 (5)
C11	0.0211 (10)	0.0391 (11)	0.0395 (12)	−0.0020 (8)	0.0095 (8)	0.0051 (9)
C12	0.0276 (12)	0.0617 (15)	0.0572 (16)	−0.0121 (11)	−0.0033 (10)	0.0053 (12)
C13	0.0338 (11)	0.0224 (9)	0.0506 (14)	0.0012 (8)	0.0046 (10)	−0.0013 (9)
C14	0.0425 (13)	0.0361 (12)	0.0695 (18)	−0.0088 (10)	−0.0009 (12)	0.0204 (12)
C21	0.0367 (12)	0.0360 (11)	0.0426 (13)	−0.0063 (9)	0.0109 (9)	−0.0163 (9)
C22	0.0395 (13)	0.0475 (13)	0.0536 (15)	0.0014 (10)	0.0148 (11)	−0.0190 (11)
C23	0.0416 (13)	0.0609 (14)	0.0247 (11)	−0.0049 (10)	0.0119 (9)	0.0027 (10)
C24	0.0683 (19)	0.104 (2)	0.0274 (13)	−0.0037 (16)	0.0001 (12)	−0.0077 (14)
C31	0.0188 (9)	0.0338 (10)	0.0422 (12)	0.0014 (7)	0.0125 (8)	0.0012 (9)
C32	0.0231 (11)	0.0653 (16)	0.0713 (19)	−0.0060 (10)	0.0009 (11)	−0.0117 (13)
C33	0.0317 (10)	0.0200 (8)	0.0273 (10)	0.0011 (7)	0.0045 (8)	−0.0035 (7)
C34	0.0384 (11)	0.0270 (10)	0.0327 (11)	−0.0036 (8)	0.0033 (9)	0.0045 (8)
C41	0.0363 (11)	0.0225 (9)	0.0377 (12)	−0.0029 (8)	0.0096 (9)	−0.0068 (8)
C42	0.0415 (13)	0.0384 (12)	0.0521 (15)	0.0049 (9)	0.0152 (11)	−0.0074 (10)
C43	0.0396 (12)	0.0409 (11)	0.0222 (10)	−0.0051 (9)	0.0092 (9)	−0.0017 (9)
C44	0.0760 (19)	0.0776 (19)	0.0286 (13)	−0.0134 (15)	−0.0031 (12)	−0.0065 (13)

Geometric parameters (Å, º) top

Mg1—O2	2.0742 (14)	O3—C31	1.456 (2)
Mg1—O1	2.0776 (13)	O3—C33	1.457 (2)
Mg1—Cl2	2.4560 (7)	O4—C43	1.453 (2)
Mg1—Cl3	2.4668 (7)	O4—C41	1.458 (2)
Mg1—Cl4	2.6204 (7)	C11—C12	1.506 (3)
Mg1—Cl1	2.6483 (7)	C11—H11A	0.9900
Mg1—Mg4	3.5608 (9)	C11—H11B	0.9900
Mg1—Mg2	3.5615 (8)	C12—H12A	0.9800
Mg2—C1	2.137 (2)	C12—H12B	0.9800
Mg2—Cl2	2.3825 (7)	C12—H12C	0.9800
Mg2—Cl6	2.3905 (8)	C13—C14	1.494 (3)
Mg2—Cl1	2.4687 (7)	C13—H13A	0.9900
Mg2—Mg3	3.5967 (9)	C13—H13B	0.9900
Mg3—O3	2.0698 (13)	C14—H14A	0.9800
Mg3—O4	2.0761 (14)	C14—H14B	0.9800
Mg3—Cl6	2.4555 (7)	C14—H14C	0.9800
Mg3—Cl5	2.4676 (7)	C21—C22	1.518 (3)
Mg3—Cl4	2.6222 (7)	C21—H21A	0.9900
Mg3—Cl1	2.6629 (7)	C21—H21B	0.9900
Mg3—Mg4	3.5774 (8)	C22—H22A	0.9800
Mg4—C5	2.135 (2)	C22—H22B	0.9800
Mg4—Cl3	2.3785 (7)	C22—H22C	0.9800
Mg4—Cl5	2.3796 (7)	C23—C24	1.503 (3)
Mg4—Cl4	2.4689 (7)	C23—H23A	0.9900
C1—C3	1.524 (3)	C23—H23B	0.9900
C1—C4	1.524 (3)	C24—H24A	0.9800
C1—C2	1.531 (3)	C24—H24B	0.9800
C2—H2A	0.9800	C24—H24C	0.9800
C2—H2B	0.9800	C31—C32	1.502 (3)
C2—H2C	0.9800	C31—H31A	0.9900
C3—H3A	0.9800	C31—H31B	0.9900
C3—H3B	0.9800	C32—H32A	0.9800
C3—H3C	0.9800	C32—H32B	0.9800
C4—H4A	0.9800	C32—H32C	0.9800
C4—H4B	0.9800	C33—C34	1.509 (3)
C4—H4C	0.9800	C33—H33A	0.9900
C5—C8	1.519 (3)	C33—H33B	0.9900
C5—C7	1.527 (3)	C34—H34A	0.9800
C5—C6	1.527 (3)	C34—H34B	0.9800
C6—H6A	0.9800	C34—H34C	0.9800
C6—H6B	0.9800	C41—C42	1.513 (3)
C6—H6C	0.9800	C41—H41A	0.9900
C7—H7A	0.9800	C41—H41B	0.9900
C7—H7B	0.9800	C42—H42A	0.9800
C7—H7C	0.9800	C42—H42B	0.9800
C8—H8A	0.9800	C42—H42C	0.9800
C8—H8B	0.9800	C43—C44	1.508 (3)
C8—H8C	0.9800	C43—H43A	0.9900
O1—C13	1.454 (2)	C43—H43B	0.9900
O1—C11	1.457 (2)	C44—H44A	0.9800
O2—C23	1.452 (2)	C44—H44B	0.9800
O2—C21	1.459 (2)	C44—H44C	0.9800

O2—Mg1—O1	93.33 (5)	C5—C6—H6A	109.5
O2—Mg1—Cl2	92.70 (5)	C5—C6—H6B	109.5
O1—Mg1—Cl2	91.22 (4)	H6A—C6—H6B	109.5
O2—Mg1—Cl3	90.17 (4)	C5—C6—H6C	109.5
O1—Mg1—Cl3	93.73 (4)	H6A—C6—H6C	109.5
Cl2—Mg1—Cl3	174.12 (3)	H6B—C6—H6C	109.5
O2—Mg1—Cl4	174.73 (5)	C5—C7—H7A	109.5
O1—Mg1—Cl4	90.10 (4)	C5—C7—H7B	109.5
Cl2—Mg1—Cl4	91.21 (2)	H7A—C7—H7B	109.5
Cl3—Mg1—Cl4	85.61 (2)	C5—C7—H7C	109.5
O2—Mg1—Cl1	94.41 (4)	H7A—C7—H7C	109.5
O1—Mg1—Cl1	171.76 (4)	H7B—C7—H7C	109.5
Cl2—Mg1—Cl1	85.61 (2)	C5—C8—H8A	109.5
Cl3—Mg1—Cl1	89.07 (2)	C5—C8—H8B	109.5
Cl4—Mg1—Cl1	82.38 (2)	H8A—C8—H8B	109.5
O2—Mg1—Mg4	131.76 (5)	C5—C8—H8C	109.5
O1—Mg1—Mg4	93.56 (4)	H8A—C8—H8C	109.5
Cl2—Mg1—Mg4	134.76 (3)	H8B—C8—H8C	109.5
Cl3—Mg1—Mg4	41.745 (17)	C13—O1—C11	113.76 (14)
Cl4—Mg1—Mg4	43.883 (16)	C13—O1—Mg1	123.38 (11)
Cl1—Mg1—Mg4	83.37 (2)	C11—O1—Mg1	122.84 (11)
O2—Mg1—Mg2	96.53 (4)	C23—O2—C21	114.54 (16)
O1—Mg1—Mg2	132.21 (4)	C23—O2—Mg1	121.76 (13)
Cl2—Mg1—Mg2	41.808 (17)	C21—O2—Mg1	123.63 (12)
Cl3—Mg1—Mg2	132.72 (2)	C31—O3—C33	113.99 (13)
Cl4—Mg1—Mg2	84.07 (2)	C31—O3—Mg3	123.39 (10)
Cl1—Mg1—Mg2	43.851 (16)	C33—O3—Mg3	122.58 (10)
Mg4—Mg1—Mg2	113.03 (2)	C43—O4—C41	114.78 (15)
C1—Mg2—Cl2	120.00 (6)	C43—O4—Mg3	122.50 (11)
C1—Mg2—Cl6	118.61 (6)	C41—O4—Mg3	122.72 (11)
Cl2—Mg2—Cl6	104.54 (3)	O1—C11—C12	112.69 (18)
C1—Mg2—Cl1	125.52 (6)	O1—C11—H11A	109.1
Cl2—Mg2—Cl1	91.35 (2)	C12—C11—H11A	109.1
Cl6—Mg2—Cl1	90.28 (3)	O1—C11—H11B	109.1
C1—Mg2—Mg1	142.27 (6)	C12—C11—H11B	109.1
Cl2—Mg2—Mg1	43.408 (17)	H11A—C11—H11B	107.8
Cl6—Mg2—Mg1	99.10 (2)	C11—C12—H12A	109.5
Cl1—Mg2—Mg1	48.005 (17)	C11—C12—H12B	109.5
C1—Mg2—Mg3	142.07 (6)	H12A—C12—H12B	109.5
Cl2—Mg2—Mg3	97.92 (2)	C11—C12—H12C	109.5
Cl6—Mg2—Mg3	42.779 (17)	H12A—C12—H12C	109.5
Cl1—Mg2—Mg3	47.751 (17)	H12B—C12—H12C	109.5
Mg1—Mg2—Mg3	67.468 (17)	O1—C13—C14	113.18 (19)
O3—Mg3—O4	94.89 (5)	O1—C13—H13A	108.9
O3—Mg3—Cl6	91.67 (4)	C14—C13—H13A	108.9
O4—Mg3—Cl6	90.00 (4)	O1—C13—H13B	108.9
O3—Mg3—Cl5	90.29 (4)	C14—C13—H13B	108.9
O4—Mg3—Cl5	93.12 (4)	H13A—C13—H13B	107.8
Cl6—Mg3—Cl5	176.16 (3)	C13—C14—H14A	109.5
O3—Mg3—Cl4	172.94 (4)	C13—C14—H14B	109.5
O4—Mg3—Cl4	90.55 (4)	H14A—C14—H14B	109.5
Cl6—Mg3—Cl4	92.83 (2)	C13—C14—H14C	109.5
Cl5—Mg3—Cl4	84.91 (2)	H14A—C14—H14C	109.5
O3—Mg3—Cl1	92.96 (4)	H14B—C14—H14C	109.5
O4—Mg3—Cl1	170.55 (4)	O2—C21—C22	112.44 (16)
Cl6—Mg3—Cl1	84.50 (2)	O2—C21—H21A	109.1
Cl5—Mg3—Cl1	92.10 (2)	C22—C21—H21A	109.1
Cl4—Mg3—Cl1	82.07 (2)	O2—C21—H21B	109.1
O3—Mg3—Mg4	130.97 (4)	C22—C21—H21B	109.1
O4—Mg3—Mg4	95.91 (4)	H21A—C21—H21B	107.8
Cl6—Mg3—Mg4	135.91 (3)	C21—C22—H22A	109.5
Cl5—Mg3—Mg4	41.493 (17)	C21—C22—H22B	109.5
Cl4—Mg3—Mg4	43.636 (16)	H22A—C22—H22B	109.5
Cl1—Mg3—Mg4	82.84 (2)	C21—C22—H22C	109.5
O3—Mg3—Mg2	96.51 (4)	H22A—C22—H22C	109.5
O4—Mg3—Mg2	130.14 (4)	H22B—C22—H22C	109.5
Cl6—Mg3—Mg2	41.392 (17)	O2—C23—C24	113.1 (2)
Cl5—Mg3—Mg2	135.04 (3)	O2—C23—H23A	109.0
Cl4—Mg3—Mg2	83.34 (2)	C24—C23—H23A	109.0
Cl1—Mg3—Mg2	43.334 (16)	O2—C23—H23B	109.0
Mg4—Mg3—Mg2	111.79 (2)	C24—C23—H23B	109.0
C5—Mg4—Cl3	118.88 (6)	H23A—C23—H23B	107.8
C5—Mg4—Cl5	121.03 (6)	C23—C24—H24A	109.5
Cl3—Mg4—Cl5	105.06 (3)	C23—C24—H24B	109.5
C5—Mg4—Cl4	123.76 (6)	H24A—C24—H24B	109.5
Cl3—Mg4—Cl4	91.02 (2)	C23—C24—H24C	109.5
Cl5—Mg4—Cl4	90.29 (2)	H24A—C24—H24C	109.5
C5—Mg4—Mg1	138.64 (6)	H24B—C24—H24C	109.5
Cl3—Mg4—Mg1	43.673 (17)	O3—C31—C32	112.99 (17)
Cl5—Mg4—Mg1	100.25 (2)	O3—C31—H31A	109.0
Cl4—Mg4—Mg1	47.368 (17)	C32—C31—H31A	109.0
C5—Mg4—Mg3	142.99 (6)	O3—C31—H31B	109.0
Cl3—Mg4—Mg3	98.01 (2)	C32—C31—H31B	109.0
Cl5—Mg4—Mg3	43.395 (17)	H31A—C31—H31B	107.8
Cl4—Mg4—Mg3	47.132 (17)	C31—C32—H32A	109.5
Mg1—Mg4—Mg3	67.685 (17)	C31—C32—H32B	109.5
Mg2—Cl1—Mg1	88.14 (2)	H32A—C32—H32B	109.5
Mg2—Cl1—Mg3	88.92 (2)	C31—C32—H32C	109.5
Mg1—Cl1—Mg3	96.92 (2)	H32A—C32—H32C	109.5
Mg2—Cl2—Mg1	94.78 (3)	H32B—C32—H32C	109.5
Mg4—Cl3—Mg1	94.58 (2)	O3—C33—C34	112.69 (15)
Mg4—Cl4—Mg1	88.75 (2)	O3—C33—H33A	109.1
Mg4—Cl4—Mg3	89.23 (2)	C34—C33—H33A	109.1
Mg1—Cl4—Mg3	98.63 (2)	O3—C33—H33B	109.1
Mg4—Cl5—Mg3	95.11 (2)	C34—C33—H33B	109.1
Mg2—Cl6—Mg3	95.83 (2)	H33A—C33—H33B	107.8
C3—C1—C4	108.14 (19)	C33—C34—H34A	109.5
C3—C1—C2	107.4 (2)	C33—C34—H34B	109.5
C4—C1—C2	107.51 (19)	H34A—C34—H34B	109.5
C3—C1—Mg2	111.90 (15)	C33—C34—H34C	109.5
C4—C1—Mg2	111.89 (15)	H34A—C34—H34C	109.5
C2—C1—Mg2	109.76 (14)	H34B—C34—H34C	109.5
C1—C2—H2A	109.5	O4—C41—C42	113.16 (16)
C1—C2—H2B	109.5	O4—C41—H41A	108.9
H2A—C2—H2B	109.5	C42—C41—H41A	108.9
C1—C2—H2C	109.5	O4—C41—H41B	108.9
H2A—C2—H2C	109.5	C42—C41—H41B	108.9
H2B—C2—H2C	109.5	H41A—C41—H41B	107.8
C1—C3—H3A	109.5	C41—C42—H42A	109.5
C1—C3—H3B	109.5	C41—C42—H42B	109.5
H3A—C3—H3B	109.5	H42A—C42—H42B	109.5
C1—C3—H3C	109.5	C41—C42—H42C	109.5
H3A—C3—H3C	109.5	H42A—C42—H42C	109.5
H3B—C3—H3C	109.5	H42B—C42—H42C	109.5
C1—C4—H4A	109.5	O4—C43—C44	113.08 (18)
C1—C4—H4B	109.5	O4—C43—H43A	109.0
H4A—C4—H4B	109.5	C44—C43—H43A	109.0
C1—C4—H4C	109.5	O4—C43—H43B	109.0
H4A—C4—H4C	109.5	C44—C43—H43B	109.0
H4B—C4—H4C	109.5	H43A—C43—H43B	107.8
C8—C5—C7	109.2 (2)	C43—C44—H44A	109.5
C8—C5—C6	107.36 (19)	C43—C44—H44B	109.5
C7—C5—C6	107.40 (18)	H44A—C44—H44B	109.5
C8—C5—Mg4	108.47 (15)	C43—C44—H44C	109.5
C7—C5—Mg4	110.82 (14)	H44A—C44—H44C	109.5
C6—C5—Mg4	113.46 (14)	H44B—C44—H44C	109.5

C13—O1—C11—C12	71.5 (2)	C33—O3—C31—C32	−68.9 (2)
Mg1—O1—C11—C12	−107.09 (18)	Mg3—O3—C31—C32	113.14 (17)
C11—O1—C13—C14	76.2 (2)	C31—O3—C33—C34	−72.6 (2)
Mg1—O1—C13—C14	−105.27 (18)	Mg3—O3—C33—C34	105.41 (16)
C23—O2—C21—C22	72.4 (2)	C43—O4—C41—C42	−66.1 (2)
Mg1—O2—C21—C22	−104.48 (19)	Mg3—O4—C41—C42	112.98 (17)
C21—O2—C23—C24	71.3 (3)	C41—O4—C43—C44	−64.8 (2)
Mg1—O2—C23—C24	−111.7 (2)	Mg3—O4—C43—C44	116.12 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C32—H32A···Cl3ⁱ	0.98	2.96	3.876 (2)	155
C34—H34A···Cl6ⁱⁱ	0.98	2.92	3.602 (2)	127

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

Comparison of Mg···Cl distances (Å) and sums of equatorial angles Σθ_eq (°) of the five-coordinate Mg²⁺ ions in the literature phases top

There are two columns for the title compound because it does not show any symmetry, whereas all structures retrieved from the database are located at a center of inversion. Mg···µ₂-Cl: bond lengths are between the five-coordinate Mg²⁺ ions and the µ₂-Cl^- ions. Mg···µ₃-Cl: bond lengths are between the five-coordinate Mg²⁺ ion and the µ₃-Cl^- ion in the central Mg₂Cl₂ plane.

Structure	Mg···µ₃-Cl	Mg···µ₂-Cl	Mg···µ₂-Cl	Σθ_eq
Title compound	2.4687 (7)	2.3825 (7)	2.3905 (8)	–
Title compound	2.4689 (7)	2.3785 (7)	2.3796 (7)	–
MGCLTF	2.789	2.398	2.405	359.6
QUJSUJ	2.888	2.405	2.406	358.0
QUJTAO	2.819	2.415	2.429	358.4
QUJTEU	2.834	2.389	2.393	356.6
SEJZUE	2.727	2.404	2.431	359.2
WILMIN	2.779	2.397	2.402	359.5

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