Crystal structure of the [(THF)Cs(μ-η5:η5-Cp′)3Yb]n oligomer

Huh, D.N.; Ziller, J.W.; Evans, W.J.

doi:10.1107/S2056989020008051

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ISSN: 2056-9890

Volume 76| Part 7| July 2020| Pages 1131-1135

https://doi.org/10.1107/S2056989020008051

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Crystal structure of the [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n oligomer

Daniel N. Huh,^a Joseph W. Ziller ^a and William J. Evans ^a ^*

^aDepartment of Chemistry, University of California, Irvine, California, 92697, USA
^*Correspondence e-mail: wevans@uci.edu

Edited by M. Zeller, Purdue University, USA (Received 29 May 2020; accepted 16 June 2020; online 23 June 2020)

The green compound poly[(tetrahydrofuran)tris[μ-η⁵:η⁵-1-(trimethylsilyl)cyclopentadienyl]caesium(I)ytterbium(II)], [CsYb(C₈H₁₃Si)₃(C₄H₈O)]_n or [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb^II]_n was synthesized by reduction of a red THF solution of (C₅H₄SiMe₃)₃Yb^III with excess Cs metal and identified by X-ray diffraction. The compound crystallizes as a two-dimensional array of hexagons with alternating Cs^I and Yb^II ions at the vertices and cyclopentadienyl groups bridging each edge. This, based off the six-electron cyclopentadienyl rings occupying three coordination positions, gives a formally nine-coordinate tris(cyclopentadienyl) coordination environment to Yb and the Cs is ten-coordinate due to the three cyclopentadienyl rings and a coordinated molecule of THF. The complex comprises layers of Cs₃Yb₃ hexagons with THF ligands and Me₃Si groups in between the layers. The Yb—C metrical parameters are consistent with a 4f¹⁴ Yb^II electron configuration.

Keywords: lanthanide; caesium; cyclopentadienide; oligomer; crystal structure.

CCDC reference: 2010185

1. Chemical context

The new +2 oxidation states for the rare-earth metals Y, La, Ce, Pr, Gd, Tb, Ho, Er, and Lu were recently discovered by reduction of Cp^x₃Ln (Cp^x = C₅H₄SiMe₃, C₅H₃(SiMe₃)₂; Ln = rare-earth metal) using alkali metal reductants Li, Na, K, and KC₈ (Fig. 1) (Hitchcock et al., 2008 ; MacDonald et al., 2013 ; Fieser et al., 2015 ; Evans, 2016 ; Palumbo et al., 2018 ). In each of these cases, 2.2.2-cryptand was added in these reactions to encapsulate the alkali metal. It was thought that chelating agents were necessary to sequester the alkali metal to prevent interactions with cyclopentadienide ligands and subsequent ligand dissociation leading to product decomposition. This idea was challenged by examining reduction reactions of Cp′′₃M (Cp′′ = C₅H₃(SiMe₃)₂; M = La, Ce, U) with Li and Cs in the absence of chelating agents (Huh et al., 2018 ). The reaction resulted in the isolation of the first chelate-free synthesis of La^II, Ce^II, and U^II complexes. The [Li(THF)₄]¹⁺ cation of the Li salts in these chelate-free M^II complexes were well-separated from the (Cp′′₃M)¹⁻ anion. However, the Cs reductions yielded polymeric complexes of general formula [Cp′′M(μ-Cp′′)₂Cs(THF)₂]_n where the Cs cation has coordinated THF and cyclopentadienide ligands. Attempts to extend this chemistry to smaller rare-earth metals by reduction of Cp′₃Ln (Cp′ = C₅H₄SiMe₃; Ln = Y, Tb, Dy) showed evidence of Ln^II in solution; however, the reduction products were highly unstable and decomposed even at 238 K.

Figure 1
Synthesis of (Cp^x₃Ln^II)¹⁻ complexes by alkali metal reduction of Cp^x₃Ln^III precursors; Cp^x = C₅H₄SiMe₃, C₅H₃(SiMe₃)₂.

In this study, we were interested in examining the reduction of Cp′₃Yb^III with Cs metal. Unlike Y^II, Tb^II, and Dy^II ions, Yb^II complexes are more easily obtainable, as reflected by their less negative reduction potentials (Morss, 1976 ). A crystal containing the oligomeric compound; [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n, 1 (Cp′ = C₅H₄SiMe₃) was isolated by reduction of the Cp′₃Yb^III complex (Fieser et al., 2015) in THF using Cs metal (Figs. 2 and 3).

Figure 2
Synthesis of [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb^II]_n, 1, by caesium metal reduction of the Cp′₃Yb^III precursor.

Figure 3
ORTEP representation of an asymmetric unit of [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n, 1, with probability ellipsoids drawn at the 50% probability level. Hydrogen atoms were omitted for clarity.

2. Structural commentary

All three Cp′ rings remain coordinated to the Yb metal center after reduction and are coordinated in a trigonal–planar fashion. The Yb atom is within 0.107 Å of the plane of the three ring centroids. Each ring bridges Yb to Cs, which also is surrounded by three cyclopentadienyl ligands as well as a coordinated molecule of THF. The three ring centroids and the oxygen of THF are arranged in a pseudo-tetrahedral geometry around Cs with a calculated four-coordinate Cs τ′₄ value of 0.76 (τ′₄ = 1 for tetrahedral; τ′₄ = 0 for square planar; Rosiak et al., 2018 ). The Cs metal center has a pseudo-tetrahedral geometry with Cp′(centroid)⋯Cs⋯Cp′(centroid) angles of 109.0, 114.3, and 121.4° and Cp′(centroid)⋯Cs⋯O(THF) angles of 88.8, 94.1, and 127.8°.

The bond distances and angles in 1 are summarized in Table 1. The range of 2.504 (1)–2.513 (2) Å Cp′(centroid)⋯Yb bond distances in 1 is the same as that in the complex [K(crypt)][Cp′₃Yb^II] (crypt = 2.2.2-cryptand), which was fully characterized as a 4f¹⁴ Yb^II complex, Table 2 and Fig. 4. In Cp₃Ln reduction chemistry, the difference in Ln⋯Cp(centroid) distances between the Ln^III and Ln^II complexes provides important information on the electronic configuration of the lanthanide ion (Evans, 2016). Differences in Ln⋯Cp(centroid) distances for reduction of 4fⁿ Ln^III ions to 4fⁿ⁺¹ Ln^II ions range from 0.1 to 0.2 Å (Fieser et al., 2015). In this study, the difference of 0.14 Å in the Ln⋯Cp(centroid) distance is characteristic of a 4f¹³ Yb^III reduction to a 4f¹⁴ Yb^II ion. In contrast, Ln^II ions with 4fⁿ5d¹ configurations where the additional electron populates a d-orbital instead of the an f-orbital have differences of only 0.02–0.05 Å (Evans, 2016).

Table 1
Selected bond distances and angles for [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n, 1

Centroid1, centroid2, and centroid3 are the centroids of the Cp rings connected to Si1, Si2, and Si3, respectively.

Yb1⋯centroid1	2.510 (1)
Yb1⋯centroid2	2.513 (2)
Yb1⋯centroid3	2.504 (1)
Cs1⋯centroid1	3.197 (1)
Cs1⋯centroid2	3.268 (2)
Cs1⋯centroid3	3.159 (1)
Cs1—O1	3.095 (3)

centroid1—Yb1⋯centroid2	120.1
centroid1—Yb1⋯centroid3	116.6
centroid2—Yb1⋯centroid3	122.8
centroid1—Cs1⋯centroid2	121.4
centroid1—Cs1⋯centroid3	109.0
centroid2—Cs1⋯centroid3	114.3
Yb1⋯centroid1⋯Cs1	175.3
Yb1⋯centroid2⋯Cs1	172.3
Yb1⋯centroid3⋯Cs1	176.7
centroid1⋯Cs1⋯O1	88.8
centroid2⋯Cs1⋯O1	94.1
centroid3⋯Cs1⋯O1	127.8

Table 2
Bond distance (Å) ranges for Yb⋯Cp′(centroid) and bond angle (°) ranges for Cp′(centroid)⋯Yb⋯Cp′(centroid) in Cp′₃Yb (Fieser et al., 2015), [K(crypt)][Cp′₃Yb] (Fieser et al., 2015), and [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n

	Cp′₃Yb	[K(crypt)][Cp′₃Yb]	1
Yb⋯Cp′(centroid)	2.363–2.368	2.503–2.513	2.504 (1)–2.513 (2)
Cs⋯Cp′(centroid)			3.159 (1)–3.268 (2)
Cp′⋯Yb⋯Cp′	118.85–120.55	118.10–122.93	116.64–122.76
Cp′⋯Cs⋯Cp′			109.0–121.4

Figure 4
CHEMDRAW (Mills, 2006

) representation of [K(2.2.2-cryptand)][Cp′₃Yb^II] (left) and [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb^II]_n, 1, (right).

3. Supramolecular features

In 1, all of the cyclopentadienyl ligands are bridging. The threefold symmetry of three bridging Cp′ ligands on each metal generates a hexagonal pattern as shown in Fig. 5. The Yb⋯Cp′(centroid)⋯Cs angles are 172.5–176.7° such that each side of the hexagon is nearly linear. The 112.4–117.3° Yb⋯Cs⋯Yb angles are smaller than the 120.8–125.6° Cs⋯Yb⋯Cs angles, which makes the hexagon slightly irregular. This could be of interest to quantum scientists trying to make thin-film layers of magnetic materials since the hexagonal pattern could lead to spin frustration with a paramagnetic lanthanide.

Figure 5
Top view of the extended structure of [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n, 1, with the SiMe₃ substituent of the C₅H₄SiMe₃ group and the THF attached to Cs removed for clarity.

The side view of these layers in Fig. 6 shows how the space in between them is filled with THF and Me₃Si substituent groups. The 116.6–122.8° Cp′(centroid)⋯Yb⋯Cp′(centroid) and 109.0–121.4° Cp′(centroid)⋯Cs⋯Cp′(centroid) angles generate the undulation of the hexagons shown in Fig. 6.

Figure 6
Side view of the extended structure of [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb]_n, 1. Magenta, Yb; brown, Cs; green, Si; red, O.

4. Database survey

The 3.159 (1), 3.197 (1), and 3.268 (2) Å Cs⋯Cp′(centroid) distances in 1 are shorter than the 3.278 and 3.435 Å Cs⋯Cp′′(centroid) distances in [(THF)₂Cs][(μ-η⁵:η⁵-Cp′′)₂U^II(η⁵-Cp′′)]_n, (Huh et al., 2018), the 3.396 Å Cs⋯C₅H₅(centroid) distances in {[(Me₃Si)₂NCs]₂·[(C₅H₅)₂Fe)] 0.5·(C₆H₅Me)}_n, (Morris et al., 2007 ) and the 3.337 Å Cs⋯C₅Me₅(centroid) distances in [(THF)₂Cs(μ₃-O)₃{[Ti(C₅Me₅)]₃-(μ₃-CCH₂)}] (González-del Moral et al., 2005 ). The 3.095 (3) Å Cs—O(THF) bond distance is consistent with the Cs—O(THF) distances of 3.081 (7) to 3.119 (8) Å in [(THF)₂Cs][(μ-η⁵:η⁵-Cp′′)₂U^II(η⁵-Cp′′)]_n (Huh et al., 2018) and 3.034 (9)–3.06 (1) Å in [(THF)₂Cs(μ₃-O)₃{[Ti(C₅Me₅)]₃(μ₃-CCH₂)}] (González-del Moral et al., 2005).

The extended structure of 1 differs from that of the [(THF)₂Cs][(μ-η⁵:η⁵-Cp′′)₂M^II(η⁵-Cp′′)]_n, complexes (M = La, U), which comprise zigzag chains of –M–(μ-Cp′′)–Cs–(μ-Cp′′)– repeat units with a terminal Cp′′ attached to M and two terminal THF ligands attached to Cs (Huh et al., 2018). These were obtained by reduction of Cp′′₃M^III compounds with Cs in THF. In those structures, La and U have a trigonal–planar tris(cyclopentadienyl) coordination like Yb in 1, but the Cs is coordinated by only two cyclopentadienyl ligands to give a bent metallocene Cp′′₂Cs(THF)₂ sub-structure with these larger rings.

A survey of the Cambridge Structural Database (CSD, version 5.41, March 2020; Groom et al., 2016 ) also revealed four oligomeric complexes containing Yb–Cp^x moieties with various types of cyclopentadienyl rings (Cp^x): [Na(μ-η⁵:η⁵-C₅H₅)₃Yb^II]_n (Apostolidis et al., 1997 ), [Na(μ-η⁵:η⁵-Cp′′)₂Yb^II₂(μ-η⁵:η⁵-Cp′′)₂]_n (Voskoboynikov et al., 1997 ), [(C₅Me₅)Yb(μ-I)(μ-η⁵:η⁵-C₅Me₅)Yb(C₅Me₅)]_n (Evans et al., 2006 ) and [Yb(μ-η⁵:η⁵-C₅H₅)(Ph₂Pz)(THF)]_n (Ph₂Pz = 3,5–diphenylpyrazolate) (Ali et al., 2018 ). The [Na(μ-η⁵:η⁵-C₅H₅)₃Yb^II]_n (Apostolidis et al., 1997) complex adopts a hexagonal net extended structure similar to that in 1 except the alkali metal does not have a coordinated solvent. The structure of [Na(μ-η⁵:η⁵-Cp^tBu)₃Sm^II] is similar (Bel'sky et al., 1990 ). Three oligomeric complexes containing Cs–cyclopentadienyl moieties have previously been reported: [(THF)₂Cs][(μ-η⁵:η⁵-Cp′′)₂U^II(η⁵-Cp′′)]_n (Huh et al., 2018), {[(Me₃Si)₂NCs]₂[(C₅H₅)₂Fe)]·0.5(C₆H₅Me)}_n (Morris et al., 2007) and [(THF)₂Cs(μ₃-O)₃{[Ti(C₅Me₅)]₃(μ₃-CCH₂)}] (González-del Moral et al., 2005). An oligomeric, base-free Li–Cp′ compound was also previously reported in the literature, [(μ-η⁵:η⁵-Cp′)Li]_n (Evans et al., 1992 ).

5. Synthesis and crystallization

In an argon-filled glovebox, addition of a red solution of Cp′₃Yb (50 mg, 0.085 mmol) in THF (2 mL) to excess Cs as a smear produced a green solution. This was stirred for 15 min at room temperature and then layered at the bottom of a vial below an Et₂O (10 mL) layer for crystallization at −35°C. After 1 d, X-ray quality dark-green crystals of [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb^II]_n were isolated. A small number of crystals were obtained and used for crystallographic analysis. Too little sample was available for other characterization.

6. Refinement

Crystal data and structure refinement for [(THF)Cs(μ-η⁵:η⁵-Cp′)₃Yb^II]_n, 1 are summarized in Table 3. Hydrogen atoms were included using a riding model with U_iso(H) values of 1.2U_eq(C) for CH₂ and aromatic hydrogens and 1.5U_eq(C) for CH₃ hydrogens with C—H distances of 0.99 (CH₂), 0.95 (aromatic), and 0.98 Å (CH₃).

Table 3
Experimental details

Crystal data
Chemical formula	[CsYb(C₈H₁₃Si)₃(C₄H₈O)]
M_r	789.87
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	88
a, b, c (Å)	9.4401 (4), 16.8718 (8), 21.0246 (10)
β (°)	92.0668 (6)
V (Å³)	3346.4 (3)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	3.99
Crystal size (mm)	0.15 × 0.09 × 0.08

Data collection
Diffractometer	Bruker SMART APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2014 )
T_min, T_max	0.374, 0.432
No. of measured, independent and observed [I > 2σ(I)] reflections	40586, 8223, 6580
R_int	0.055
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.056, 1.02
No. of reflections	8223
No. of parameters	316
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.14, −0.62
Computer programs: APEX2 (Bruker, 2014), SAINT (Bruker, 2013 ), SHELXT2014/4 (Sheldrick, 2015a ), SHELXL2014/7 (Sheldrick, 2015b ) and SHELXTL (Sheldrick, 2008 ).

Supporting information

CCDC reference: 2010185

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989020008051/zl2785sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989020008051/zl2785Isup2.hkl

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXT2014/4 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015b); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Poly[(tetrahydrofuran)tris[µ-η⁵:η⁵-1-(trimethylsilyl)cyclopentadienyl]caesium(I)ytterbium(II)] top

Crystal data top

[CsYb(C₈H₁₃Si)₃(C₄H₈O)]	F(000) = 1560
M_r = 789.87	D_x = 1.568 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 9.4401 (4) Å	Cell parameters from 9869 reflections
b = 16.8718 (8) Å	θ = 2.3–28.5°
c = 21.0246 (10) Å	µ = 3.99 mm⁻¹
β = 92.0668 (6)°	T = 88 K
V = 3346.4 (3) Å³	Prism, green
Z = 4	0.15 × 0.09 × 0.08 mm

Data collection top

Bruker SMART APEXII CCD diffractometer	6580 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.055
φ and ω scans	θ_max = 28.3°, θ_min = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −12→12
T_min = 0.374, T_max = 0.432	k = −22→22
40586 measured reflections	l = −27→27
8223 independent reflections

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.056	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0229P)² + 0.1327P] where P = (F_o² + 2F_c²)/3
8223 reflections	(Δ/σ)_max = 0.001
316 parameters	Δρ_max = 1.14 e Å⁻³
0 restraints	Δρ_min = −0.62 e Å⁻³

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.

Refinement. A green crystal of approximate dimensions 0.079 x 0.086 x 0.148 mm was mounted in a cryoloop and transferred to a Bruker SMART APEX II diffractometer. The APEX2 program package was used to determine the unit-cell parameters and for data collection (90 sec/frame scan time for a sphere of diffraction data). The raw frame data was processed using SAINT and SADABS to yield the reflection data file. Subsequent calculations were carried out using the SHELXTL program. The diffraction symmetry was 2/m and the systematic absences were consistent with the monoclinic space group P21/n that was later determined to be correct.

The structure was solved by dual space methods and refined on F2 by full-matrix least-squares techniques. The analytical scattering factors for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. The structure is polymeric.

Least-squares analysis yielded wR2 = 0.0562 and Goof = 1.017 for 316 variables refined against 8223 data (0.75 Å), R1 = 0.0315 for those 6580 data with I > 2.0sigma(I).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Yb1	0.48657 (2)	0.44122 (2)	0.25290 (2)	0.01341 (4)
Cs1	0.99437 (2)	0.27157 (2)	0.31696 (2)	0.01493 (5)
Si1	0.69834 (10)	0.29048 (6)	0.15029 (5)	0.0184 (2)
Si2	0.23952 (11)	0.57037 (6)	0.11663 (5)	0.0204 (2)
Si3	0.25791 (10)	0.45182 (6)	0.40988 (5)	0.0187 (2)
O1	0.8795 (3)	0.24593 (16)	0.45145 (12)	0.0285 (6)
C1	0.7108 (3)	0.33895 (19)	0.22942 (16)	0.0161 (7)
C2	0.6551 (3)	0.3115 (2)	0.28743 (17)	0.0174 (8)
H2A	0.6070	0.2626	0.2929	0.021*
C3	0.6826 (3)	0.3680 (2)	0.33517 (17)	0.0196 (8)
H3A	0.6554	0.3643	0.3781	0.024*
C4	0.7575 (4)	0.4310 (2)	0.30831 (17)	0.0194 (8)
H4A	0.7902	0.4774	0.3298	0.023*
C5	0.7751 (3)	0.4129 (2)	0.24430 (17)	0.0184 (8)
H5A	0.8231	0.4453	0.2150	0.022*
C6	0.6270 (4)	0.1878 (2)	0.15741 (18)	0.0257 (9)
H6A	0.6848	0.1582	0.1890	0.039*
H6B	0.6299	0.1611	0.1161	0.039*
H6C	0.5288	0.1902	0.1709	0.039*
C7	0.5764 (4)	0.3487 (2)	0.09635 (17)	0.0276 (9)
H7A	0.6159	0.4017	0.0900	0.041*
H7B	0.4836	0.3533	0.1155	0.041*
H7C	0.5656	0.3216	0.0552	0.041*
C8	0.8767 (4)	0.2878 (2)	0.11484 (18)	0.0263 (9)
H8A	0.9435	0.2601	0.1438	0.039*
H8B	0.9099	0.3421	0.1081	0.039*
H8C	0.8702	0.2599	0.0740	0.039*
C9	0.3846 (3)	0.57009 (19)	0.17806 (16)	0.0162 (7)
C10	0.5320 (4)	0.56244 (19)	0.16482 (17)	0.0173 (7)
H10A	0.5679	0.5462	0.1253	0.021*
C11	0.6148 (4)	0.58254 (19)	0.21886 (17)	0.0171 (8)
H11A	0.7154	0.5833	0.2220	0.021*
C12	0.5224 (4)	0.60152 (19)	0.26788 (17)	0.0190 (8)
H12A	0.5497	0.6163	0.3102	0.023*
C13	0.3823 (4)	0.59465 (19)	0.24280 (16)	0.0180 (8)
H13A	0.2992	0.6048	0.2656	0.022*
C14	0.2553 (5)	0.4858 (2)	0.0598 (2)	0.0380 (11)
H14A	0.2394	0.4358	0.0822	0.057*
H14B	0.3503	0.4856	0.0425	0.057*
H14C	0.1843	0.4916	0.0249	0.057*
C15	0.0612 (4)	0.5700 (3)	0.1518 (2)	0.0379 (11)
H15A	0.0433	0.5178	0.1705	0.057*
H15B	−0.0113	0.5811	0.1185	0.057*
H15C	0.0577	0.6107	0.1849	0.057*
C16	0.2543 (4)	0.6620 (2)	0.06760 (17)	0.0230 (8)
H16A	0.3509	0.6665	0.0524	0.034*
H16B	0.2329	0.7085	0.0936	0.034*
H16C	0.1869	0.6593	0.0311	0.034*
C17	0.2651 (3)	0.4025 (2)	0.33118 (16)	0.0151 (7)
C18	0.1959 (3)	0.42821 (19)	0.27347 (17)	0.0169 (7)
H18A	0.1408	0.4751	0.2686	0.020*
C19	0.2216 (3)	0.3741 (2)	0.22535 (17)	0.0187 (8)
H19A	0.1879	0.3780	0.1823	0.022*
C20	0.3061 (4)	0.3127 (2)	0.25131 (17)	0.0206 (8)
H20A	0.3395	0.2678	0.2291	0.025*
C21	0.3320 (3)	0.3300 (2)	0.31617 (17)	0.0173 (8)
H21A	0.3858	0.2981	0.3453	0.021*
C22	0.2748 (5)	0.3775 (2)	0.47533 (18)	0.0346 (10)
H22A	0.1956	0.3400	0.4718	0.052*
H22B	0.2732	0.4047	0.5165	0.052*
H22C	0.3644	0.3487	0.4721	0.052*
C23	0.4026 (4)	0.5264 (2)	0.42253 (18)	0.0280 (9)
H23A	0.3884	0.5702	0.3923	0.042*
H23B	0.4944	0.5012	0.4158	0.042*
H23C	0.4008	0.5469	0.4661	0.042*
C24	0.0843 (4)	0.5039 (3)	0.4147 (2)	0.0399 (11)
H24A	0.0071	0.4652	0.4106	0.060*
H24B	0.0748	0.5429	0.3803	0.060*
H24C	0.0798	0.5309	0.4559	0.060*
C25	0.8427 (4)	0.3003 (2)	0.50059 (19)	0.0306 (9)
H25A	0.8093	0.3512	0.4820	0.037*
H25B	0.9255	0.3108	0.5296	0.037*
C26	0.7248 (4)	0.2603 (2)	0.53629 (19)	0.0338 (10)
H26A	0.7634	0.2246	0.5700	0.041*
H26B	0.6615	0.2998	0.5555	0.041*
C27	0.6489 (4)	0.2145 (2)	0.4835 (2)	0.0315 (10)
H27A	0.5959	0.1690	0.5005	0.038*
H27B	0.5827	0.2489	0.4585	0.038*
C28	0.7700 (4)	0.1873 (2)	0.44422 (18)	0.0278 (9)
H28A	0.8052	0.1351	0.4593	0.033*
H28B	0.7388	0.1823	0.3989	0.033*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Yb1	0.01020 (7)	0.01233 (7)	0.01766 (8)	−0.00136 (6)	−0.00014 (6)	0.00251 (6)
Cs1	0.01034 (10)	0.01249 (10)	0.02208 (12)	−0.00018 (8)	0.00232 (8)	0.00028 (9)
Si1	0.0150 (5)	0.0213 (5)	0.0190 (5)	0.0031 (4)	0.0009 (4)	−0.0011 (4)
Si2	0.0214 (5)	0.0157 (5)	0.0236 (6)	−0.0009 (4)	−0.0052 (4)	0.0028 (4)
Si3	0.0177 (5)	0.0192 (5)	0.0191 (5)	−0.0009 (4)	0.0012 (4)	−0.0017 (4)
O1	0.0207 (14)	0.0355 (16)	0.0295 (16)	−0.0014 (12)	0.0062 (12)	−0.0009 (13)
C1	0.0112 (16)	0.0161 (17)	0.0209 (19)	0.0018 (14)	0.0018 (14)	0.0027 (15)
C2	0.0130 (17)	0.0140 (17)	0.025 (2)	0.0030 (14)	0.0021 (15)	0.0029 (15)
C3	0.0184 (18)	0.024 (2)	0.0162 (19)	0.0082 (15)	0.0003 (15)	0.0016 (15)
C4	0.0151 (17)	0.0177 (19)	0.025 (2)	0.0022 (14)	−0.0071 (15)	−0.0016 (16)
C5	0.0083 (16)	0.0175 (18)	0.030 (2)	−0.0002 (13)	0.0033 (15)	0.0049 (16)
C6	0.027 (2)	0.023 (2)	0.027 (2)	0.0011 (16)	−0.0006 (17)	−0.0044 (17)
C7	0.029 (2)	0.033 (2)	0.021 (2)	0.0055 (18)	−0.0059 (17)	0.0013 (17)
C8	0.023 (2)	0.031 (2)	0.024 (2)	0.0038 (17)	0.0045 (17)	−0.0018 (17)
C9	0.0162 (17)	0.0111 (17)	0.0212 (19)	0.0006 (13)	0.0003 (14)	0.0012 (14)
C10	0.0208 (18)	0.0103 (16)	0.0210 (19)	0.0006 (14)	0.0037 (15)	0.0040 (15)
C11	0.0133 (17)	0.0139 (17)	0.024 (2)	−0.0047 (13)	−0.0014 (15)	0.0047 (15)
C12	0.0241 (19)	0.0118 (17)	0.021 (2)	−0.0067 (15)	−0.0054 (15)	0.0020 (15)
C13	0.0208 (18)	0.0118 (17)	0.022 (2)	−0.0011 (14)	0.0012 (15)	0.0009 (15)
C14	0.056 (3)	0.020 (2)	0.037 (3)	0.004 (2)	−0.023 (2)	−0.0014 (19)
C15	0.022 (2)	0.049 (3)	0.043 (3)	0.0003 (19)	−0.0048 (19)	0.024 (2)
C16	0.028 (2)	0.0204 (19)	0.021 (2)	0.0025 (16)	−0.0007 (16)	0.0022 (16)
C17	0.0097 (16)	0.0196 (18)	0.0162 (19)	−0.0037 (14)	0.0024 (14)	0.0003 (15)
C18	0.0099 (16)	0.0156 (18)	0.025 (2)	−0.0029 (13)	0.0026 (14)	0.0024 (15)
C19	0.0129 (17)	0.028 (2)	0.0149 (19)	−0.0086 (15)	−0.0025 (14)	0.0029 (15)
C20	0.0165 (18)	0.0192 (19)	0.027 (2)	−0.0062 (15)	0.0096 (16)	−0.0061 (16)
C21	0.0124 (17)	0.0176 (18)	0.022 (2)	−0.0025 (14)	0.0044 (14)	0.0051 (15)
C22	0.056 (3)	0.026 (2)	0.023 (2)	−0.009 (2)	0.006 (2)	−0.0032 (18)
C23	0.031 (2)	0.029 (2)	0.024 (2)	−0.0056 (18)	0.0015 (18)	−0.0038 (17)
C24	0.028 (2)	0.044 (3)	0.048 (3)	0.008 (2)	0.002 (2)	−0.020 (2)
C25	0.034 (2)	0.030 (2)	0.028 (2)	−0.0032 (18)	−0.0060 (19)	0.0018 (18)
C26	0.042 (3)	0.032 (2)	0.028 (2)	0.006 (2)	0.012 (2)	−0.0031 (19)
C27	0.024 (2)	0.026 (2)	0.044 (3)	0.0008 (17)	0.0085 (19)	0.0089 (19)
C28	0.033 (2)	0.025 (2)	0.026 (2)	−0.0010 (17)	0.0071 (18)	0.0006 (17)

Geometric parameters (Å, º) top

Yb1—Cnt1	2.510	C7—H7B	0.9800
Yb1—Cnt2	2.513	C7—H7C	0.9800
Yb1—Cnt3	2.504	C8—H8A	0.9800
Cs1—Cnt1	3.197	C8—H8B	0.9800
Cs1—Cnt2	3.268	C8—H8C	0.9800
Cs1—Cnt3	3.159	C9—C13	1.424 (5)
Yb1—C12	2.742 (3)	C9—C10	1.434 (5)
Yb1—C21	2.750 (3)	C9—Cs1ⁱⁱⁱ	3.587 (3)
Yb1—C20	2.757 (3)	C10—C11	1.398 (5)
Yb1—C13	2.775 (3)	C10—Cs1ⁱⁱⁱ	3.559 (3)
Yb1—C3	2.777 (3)	C10—H10A	0.9500
Yb1—C4	2.778 (3)	C11—C12	1.410 (5)
Yb1—C5	2.778 (3)	C11—Cs1ⁱⁱⁱ	3.427 (3)
Yb1—C11	2.779 (3)	C11—H11A	0.9500
Yb1—C17	2.785 (3)	C12—C13	1.411 (5)
Yb1—C2	2.787 (3)	C12—Cs1ⁱⁱⁱ	3.379 (3)
Yb1—C19	2.787 (3)	C12—H12A	0.9500
Yb1—C1	2.788 (3)	C13—Cs1ⁱⁱⁱ	3.457 (3)
Yb1—C18	2.802 (3)	C13—H13A	0.9500
Yb1—C10	2.802 (3)	C14—H14A	0.9800
Yb1—C9	2.832 (3)	C14—H14B	0.9800
Cs1—O1	3.095 (3)	C14—H14C	0.9800
Cs1—C2	3.309 (3)	C15—H15A	0.9800
Cs1—C21ⁱ	3.337 (3)	C15—H15B	0.9800
Cs1—C20ⁱ	3.367 (3)	C15—H15C	0.9800
Cs1—C12ⁱⁱ	3.379 (3)	C16—Cs1ⁱⁱⁱ	3.810 (4)
Cs1—C17ⁱ	3.383 (3)	C16—H16A	0.9800
Cs1—C1	3.390 (3)	C16—H16B	0.9800
Cs1—C3	3.396 (3)	C16—H16C	0.9800
Cs1—C18ⁱ	3.401 (3)	C17—C21	1.417 (5)
Cs1—C19ⁱ	3.407 (3)	C17—C18	1.425 (5)
Cs1—C11ⁱⁱ	3.427 (3)	C17—Cs1^iv	3.383 (3)
Cs1—C13ⁱⁱ	3.457 (3)	C18—C19	1.390 (5)
Cs1—C5	3.475 (3)	C18—Cs1^iv	3.401 (3)
Cs1—C4	3.499 (3)	C18—H18A	0.9500
Cs1—C10ⁱⁱ	3.559 (3)	C19—C20	1.406 (5)
Cs1—C9ⁱⁱ	3.587 (3)	C19—Cs1^iv	3.407 (3)
Si1—C1	1.854 (4)	C19—H19A	0.9500
Si1—C8	1.866 (4)	C20—C21	1.407 (5)
Si1—C7	1.866 (4)	C20—Cs1^iv	3.367 (3)
Si1—C6	1.867 (4)	C20—H20A	0.9500
Si2—C9	1.848 (4)	C21—Cs1^iv	3.337 (3)
Si2—C15	1.863 (4)	C21—H21A	0.9500
Si2—C16	1.867 (3)	C22—H22A	0.9800
Si2—C14	1.871 (4)	C22—H22B	0.9800
Si3—C17	1.856 (3)	C22—H22C	0.9800
Si3—C22	1.864 (4)	C23—H23A	0.9800
Si3—C24	1.865 (4)	C23—H23B	0.9800
Si3—C23	1.869 (4)	C23—H23C	0.9800
O1—C25	1.434 (5)	C24—H24A	0.9800
O1—C28	1.435 (4)	C24—H24B	0.9800
C1—C5	1.418 (5)	C24—H24C	0.9800
C1—C2	1.423 (5)	C25—C26	1.522 (5)
C2—C3	1.402 (5)	C25—H25A	0.9900
C2—H2A	0.9500	C25—H25B	0.9900
C3—C4	1.407 (5)	C26—C27	1.511 (6)
C3—H3A	0.9500	C26—H26A	0.9900
C4—C5	1.396 (5)	C26—H26B	0.9900
C4—H4A	0.9500	C27—C28	1.507 (5)
C5—H5A	0.9500	C27—H27A	0.9900
C6—H6A	0.9800	C27—H27B	0.9900
C6—H6B	0.9800	C28—H28A	0.9900
C6—H6C	0.9800	C28—H28B	0.9900
C7—H7A	0.9800

Cnt1—Yb1—Cnt2	120.1	C15—Si2—C14	110.1 (2)
Cnt1—Yb1—Cnt3	116.6	C16—Si2—C14	105.67 (18)
Cnt2—Yb1—Cnt3	122.8	C17—Si3—C22	110.60 (16)
Cnt1—Cs1—O1	88.8	C17—Si3—C24	108.68 (17)
Cnt2—Cs1—O1	94.1	C22—Si3—C24	109.2 (2)
Cnt3—Cs1—O1	127.8	C17—Si3—C23	112.26 (16)
Cnt1—Cs1—Cnt3	109.0	C22—Si3—C23	107.77 (19)
Cnt1—Cs1—Cnt2	121.4	C24—Si3—C23	108.32 (19)
Cnt2—Cs1—Cnt3	114.3	C25—O1—C28	109.0 (3)
Yb1—Cnt1—Cs1	175.3	C25—O1—Cs1	132.2 (2)
Yb1—Cnt2—Cs1	172.5	C28—O1—Cs1	105.9 (2)
Yb1—Cnt3—Cs1	176.7	C5—C1—C2	105.4 (3)
C12—Yb1—C21	133.07 (10)	C5—C1—Si1	126.8 (3)
C12—Yb1—C20	148.28 (10)	C2—C1—Si1	127.7 (3)
C21—Yb1—C20	29.62 (10)	C5—C1—Yb1	74.82 (18)
C12—Yb1—C13	29.63 (10)	C2—C1—Yb1	75.16 (18)
C21—Yb1—C13	118.73 (10)	Si1—C1—Yb1	114.08 (15)
C20—Yb1—C13	121.02 (10)	C5—C1—Cs1	81.47 (19)
C12—Yb1—C3	106.89 (10)	C2—C1—Cs1	74.58 (18)
C21—Yb1—C3	75.43 (10)	Si1—C1—Cs1	111.25 (13)
C20—Yb1—C3	93.17 (11)	Yb1—C1—Cs1	134.51 (12)
C13—Yb1—C3	133.57 (10)	C3—C2—C1	109.1 (3)
C12—Yb1—C4	84.54 (10)	C3—C2—Yb1	75.02 (19)
C21—Yb1—C4	104.58 (10)	C1—C2—Yb1	75.27 (19)
C20—Yb1—C4	121.05 (10)	C3—C2—Cs1	81.44 (19)
C13—Yb1—C4	114.11 (10)	C1—C2—Cs1	80.94 (19)
C3—Yb1—C4	29.34 (10)	Yb1—C2—Cs1	138.44 (12)
C12—Yb1—C5	93.42 (10)	C3—C2—H2A	125.4
C21—Yb1—C5	116.94 (10)	C1—C2—H2A	125.4
C20—Yb1—C5	118.11 (10)	Yb1—C2—H2A	116.2
C13—Yb1—C5	120.08 (10)	Cs1—C2—H2A	105.3
C3—Yb1—C5	48.02 (10)	C2—C3—C4	108.0 (3)
C4—Yb1—C5	29.10 (10)	C2—C3—Yb1	75.79 (19)
C12—Yb1—C11	29.58 (10)	C4—C3—Yb1	75.34 (19)
C21—Yb1—C11	162.49 (10)	C2—C3—Cs1	74.48 (18)
C20—Yb1—C11	161.12 (11)	C4—C3—Cs1	82.34 (19)
C13—Yb1—C11	48.43 (10)	Yb1—C3—Cs1	134.71 (12)
C3—Yb1—C11	104.80 (10)	C2—C3—H3A	126.0
C4—Yb1—C11	76.00 (10)	C4—C3—H3A	126.0
C5—Yb1—C11	72.15 (10)	Yb1—C3—H3A	115.1
C12—Yb1—C17	104.81 (10)	Cs1—C3—H3A	110.0
C21—Yb1—C17	29.67 (9)	C5—C4—C3	107.5 (3)
C20—Yb1—C17	49.15 (10)	C5—C4—Yb1	75.45 (19)
C13—Yb1—C17	89.55 (10)	C3—C4—Yb1	75.31 (19)
C3—Yb1—C17	91.45 (10)	C5—C4—Cs1	77.52 (19)
C4—Yb1—C17	115.93 (10)	C3—C4—Cs1	74.17 (18)
C5—Yb1—C17	139.21 (10)	Yb1—C4—Cs1	130.28 (12)
C11—Yb1—C17	134.15 (10)	C5—C4—H4A	126.3
C12—Yb1—C2	132.66 (10)	C3—C4—H4A	126.3
C21—Yb1—C2	69.27 (10)	Yb1—C4—H4A	115.3
C20—Yb1—C2	74.47 (10)	Cs1—C4—H4A	114.4
C13—Yb1—C2	161.85 (10)	C4—C5—C1	109.9 (3)
C3—Yb1—C2	29.18 (10)	C4—C5—Yb1	75.44 (19)
C4—Yb1—C2	48.21 (10)	C1—C5—Yb1	75.66 (18)
C5—Yb1—C2	47.93 (10)	C4—C5—Cs1	79.4 (2)
C11—Yb1—C2	119.41 (10)	C1—C5—Cs1	74.73 (19)
C17—Yb1—C2	95.49 (10)	Yb1—C5—Cs1	131.24 (12)
C12—Yb1—C19	122.04 (10)	C4—C5—H5A	125.0
C21—Yb1—C19	48.35 (10)	C1—C5—H5A	125.0
C20—Yb1—C19	29.37 (10)	Yb1—C5—H5A	115.8
C13—Yb1—C19	92.85 (10)	Cs1—C5—H5A	112.9
C3—Yb1—C19	121.44 (10)	Si1—C6—H6A	109.5
C4—Yb1—C19	150.23 (10)	Si1—C6—H6B	109.5
C5—Yb1—C19	142.33 (10)	H6A—C6—H6B	109.5
C11—Yb1—C19	133.69 (10)	Si1—C6—H6C	109.5
C17—Yb1—C19	48.72 (10)	H6A—C6—H6C	109.5
C2—Yb1—C19	103.58 (10)	H6B—C6—H6C	109.5
C12—Yb1—C1	122.63 (10)	Si1—C7—H7A	109.5
C21—Yb1—C1	94.75 (10)	Si1—C7—H7B	109.5
C20—Yb1—C1	89.08 (10)	H7A—C7—H7B	109.5
C13—Yb1—C1	146.41 (10)	Si1—C7—H7C	109.5
C3—Yb1—C1	48.85 (10)	H7A—C7—H7C	109.5
C4—Yb1—C1	48.90 (10)	H7B—C7—H7C	109.5
C5—Yb1—C1	29.52 (9)	Si1—C8—H8A	109.5
C11—Yb1—C1	98.33 (10)	Si1—C8—H8B	109.5
C17—Yb1—C1	123.39 (10)	H8A—C8—H8B	109.5
C2—Yb1—C1	29.57 (9)	Si1—C8—H8C	109.5
C19—Yb1—C1	113.15 (10)	H8A—C8—H8C	109.5
C12—Yb1—C18	100.20 (10)	H8B—C8—H8C	109.5
C21—Yb1—C18	48.09 (10)	C13—C9—C10	105.1 (3)
C20—Yb1—C18	48.09 (10)	C13—C9—Si2	129.1 (3)
C13—Yb1—C18	74.83 (10)	C10—C9—Si2	124.3 (3)
C3—Yb1—C18	120.22 (10)	C13—C9—Yb1	73.08 (19)
C4—Yb1—C18	145.35 (10)	C10—C9—Yb1	74.11 (18)
C5—Yb1—C18	164.74 (10)	Si2—C9—Yb1	128.22 (15)
C11—Yb1—C18	123.02 (10)	C13—C9—Cs1ⁱⁱⁱ	73.26 (18)
C17—Yb1—C18	29.55 (9)	C10—C9—Cs1ⁱⁱⁱ	77.33 (18)
C2—Yb1—C18	116.83 (10)	Si2—C9—Cs1ⁱⁱⁱ	104.19 (12)
C19—Yb1—C18	28.80 (10)	Yb1—C9—Cs1ⁱⁱⁱ	127.59 (11)
C1—Yb1—C18	137.11 (10)	C11—C10—C9	109.8 (3)
C12—Yb1—C10	48.31 (10)	C11—C10—Yb1	74.58 (19)
C21—Yb1—C10	156.10 (10)	C9—C10—Yb1	76.40 (19)
C20—Yb1—C10	132.46 (11)	C11—C10—Cs1ⁱⁱⁱ	73.21 (18)
C13—Yb1—C10	48.00 (10)	C9—C10—Cs1ⁱⁱⁱ	79.51 (18)
C3—Yb1—C10	128.46 (10)	Yb1—C10—Cs1ⁱⁱⁱ	129.76 (12)
C4—Yb1—C10	99.32 (10)	C11—C10—H10A	125.1
C5—Yb1—C10	84.76 (10)	C9—C10—H10A	125.1
C11—Yb1—C10	29.00 (10)	Yb1—C10—H10A	115.8
C17—Yb1—C10	134.24 (10)	Cs1ⁱⁱⁱ—C10—H10A	114.2
C2—Yb1—C10	130.23 (10)	C10—C11—C12	107.9 (3)
C19—Yb1—C10	108.45 (10)	C10—C11—Yb1	76.42 (18)
C1—Yb1—C10	101.51 (10)	C12—C11—Yb1	73.76 (18)
C18—Yb1—C10	109.46 (10)	C10—C11—Cs1ⁱⁱⁱ	83.81 (19)
C12—Yb1—C9	49.06 (10)	C12—C11—Cs1ⁱⁱⁱ	76.14 (19)
C21—Yb1—C9	128.10 (10)	Yb1—C11—Cs1ⁱⁱⁱ	136.45 (12)
C20—Yb1—C9	113.55 (10)	C10—C11—H11A	126.1
C13—Yb1—C9	29.39 (9)	C12—C11—H11A	126.1
C3—Yb1—C9	153.27 (10)	Yb1—C11—H11A	115.9
C4—Yb1—C9	124.75 (10)	Cs1ⁱⁱⁱ—C11—H11A	107.2
C5—Yb1—C9	114.22 (10)	C11—C12—C13	107.7 (3)
C11—Yb1—C9	48.76 (10)	C11—C12—Yb1	76.66 (19)
C17—Yb1—C9	105.13 (10)	C13—C12—Yb1	76.46 (19)
C2—Yb1—C9	158.00 (10)	C11—C12—Cs1ⁱⁱⁱ	79.95 (19)
C19—Yb1—C9	84.94 (10)	C13—C12—Cs1ⁱⁱⁱ	81.20 (19)
C1—Yb1—C9	128.44 (10)	Yb1—C12—Cs1ⁱⁱⁱ	140.67 (13)
C18—Yb1—C9	80.25 (10)	C11—C12—H12A	126.1
C10—Yb1—C9	29.49 (9)	C13—C12—H12A	126.1
O1—Cs1—C2	80.28 (8)	Yb1—C12—H12A	113.2
O1—Cs1—C21ⁱ	114.33 (8)	Cs1ⁱⁱⁱ—C12—H12A	106.1
C2—Cs1—C21ⁱ	148.98 (8)	C12—C13—C9	109.6 (3)
O1—Cs1—C20ⁱ	138.03 (8)	C12—C13—Yb1	73.92 (19)
C2—Cs1—C20ⁱ	137.32 (9)	C9—C13—Yb1	77.53 (19)
C21ⁱ—Cs1—C20ⁱ	24.23 (8)	C12—C13—Cs1ⁱⁱⁱ	75.02 (18)
O1—Cs1—C12ⁱⁱ	110.63 (8)	C9—C13—Cs1ⁱⁱⁱ	83.51 (19)
C2—Cs1—C12ⁱⁱ	92.69 (8)	Yb1—C13—Cs1ⁱⁱⁱ	135.26 (12)
C21ⁱ—Cs1—C12ⁱⁱ	105.96 (8)	C12—C13—H13A	125.2
C20ⁱ—Cs1—C12ⁱⁱ	89.07 (8)	C9—C13—H13A	125.2
O1—Cs1—C17ⁱ	107.40 (7)	Yb1—C13—H13A	115.3
C2—Cs1—C17ⁱ	127.34 (8)	Cs1ⁱⁱⁱ—C13—H13A	108.8
C21ⁱ—Cs1—C17ⁱ	24.34 (8)	Si2—C14—H14A	109.5
C20ⁱ—Cs1—C17ⁱ	39.93 (8)	Si2—C14—H14B	109.5
C12ⁱⁱ—Cs1—C17ⁱ	128.47 (8)	H14A—C14—H14B	109.5
O1—Cs1—C1	104.30 (7)	Si2—C14—H14C	109.5
C2—Cs1—C1	24.49 (8)	H14A—C14—H14C	109.5
C21ⁱ—Cs1—C1	129.35 (8)	H14B—C14—H14C	109.5
C20ⁱ—Cs1—C1	113.14 (8)	Si2—C15—H15A	109.5
C12ⁱⁱ—Cs1—C1	88.68 (8)	Si2—C15—H15B	109.5
C17ⁱ—Cs1—C1	114.09 (8)	H15A—C15—H15B	109.5
O1—Cs1—C3	68.30 (8)	Si2—C15—H15C	109.5
C2—Cs1—C3	24.09 (8)	H15A—C15—H15C	109.5
C21ⁱ—Cs1—C3	133.69 (8)	H15B—C15—H15C	109.5
C20ⁱ—Cs1—C3	136.14 (9)	Si2—C16—Cs1ⁱⁱⁱ	96.16 (13)
C12ⁱⁱ—Cs1—C3	116.22 (8)	Si2—C16—H16A	109.5
C17ⁱ—Cs1—C3	109.40 (8)	Cs1ⁱⁱⁱ—C16—H16A	66.8
C1—Cs1—C3	39.65 (8)	Si2—C16—H16B	109.5
O1—Cs1—C18ⁱ	124.90 (8)	Cs1ⁱⁱⁱ—C16—H16B	52.7
C2—Cs1—C18ⁱ	109.78 (8)	H16A—C16—H16B	109.5
C21ⁱ—Cs1—C18ⁱ	39.23 (8)	Si2—C16—H16C	109.5
C20ⁱ—Cs1—C18ⁱ	39.10 (8)	Cs1ⁱⁱⁱ—C16—H16C	153.3
C12ⁱⁱ—Cs1—C18ⁱ	122.27 (8)	H16A—C16—H16C	109.5
C17ⁱ—Cs1—C18ⁱ	24.24 (8)	H16B—C16—H16C	109.5
C1—Cs1—C18ⁱ	91.83 (8)	C21—C17—C18	105.5 (3)
C3—Cs1—C18ⁱ	98.84 (8)	C21—C17—Si3	128.0 (3)
O1—Cs1—C19ⁱ	146.73 (8)	C18—C17—Si3	126.4 (3)
C2—Cs1—C19ⁱ	114.55 (8)	C21—C17—Yb1	73.79 (18)
C21ⁱ—Cs1—C19ⁱ	39.29 (8)	C18—C17—Yb1	75.89 (18)
C20ⁱ—Cs1—C19ⁱ	23.95 (8)	Si3—C17—Yb1	118.31 (14)
C12ⁱⁱ—Cs1—C19ⁱ	98.71 (9)	C21—C17—Cs1^iv	75.99 (18)
C17ⁱ—Cs1—C19ⁱ	39.57 (8)	C18—C17—Cs1^iv	78.58 (18)
C1—Cs1—C19ⁱ	91.36 (8)	Si3—C17—Cs1^iv	108.65 (13)
C3—Cs1—C19ⁱ	112.73 (8)	Yb1—C17—Cs1^iv	132.98 (11)
C18ⁱ—Cs1—C19ⁱ	23.56 (8)	C19—C18—C17	109.5 (3)
O1—Cs1—C11ⁱⁱ	87.61 (8)	C19—C18—Yb1	75.02 (19)
C2—Cs1—C11ⁱⁱ	82.35 (8)	C17—C18—Yb1	74.57 (18)
C21ⁱ—Cs1—C11ⁱⁱ	123.61 (8)	C19—C18—Cs1^iv	78.45 (19)
C20ⁱ—Cs1—C11ⁱⁱ	111.22 (8)	C17—C18—Cs1^iv	77.18 (18)
C12ⁱⁱ—Cs1—C11ⁱⁱ	23.90 (8)	Yb1—C18—Cs1^iv	131.52 (11)
C17ⁱ—Cs1—C11ⁱⁱ	147.92 (8)	C19—C18—H18A	125.3
C1—Cs1—C11ⁱⁱ	88.14 (8)	C17—C18—H18A	125.3
C3—Cs1—C11ⁱⁱ	102.45 (8)	Yb1—C18—H18A	117.0
C18ⁱ—Cs1—C11ⁱⁱ	146.18 (8)	Cs1^iv—C18—H18A	111.4
C19ⁱ—Cs1—C11ⁱⁱ	122.61 (8)	C18—C19—C20	108.2 (3)
O1—Cs1—C13ⁱⁱ	110.19 (8)	C18—C19—Yb1	76.18 (19)
C2—Cs1—C13ⁱⁱ	116.34 (8)	C20—C19—Yb1	74.12 (19)
C21ⁱ—Cs1—C13ⁱⁱ	85.36 (8)	C18—C19—Cs1^iv	77.99 (19)
C20ⁱ—Cs1—C13ⁱⁱ	73.64 (8)	C20—C19—Cs1^iv	76.46 (19)
C12ⁱⁱ—Cs1—C13ⁱⁱ	23.79 (8)	Yb1—C19—Cs1^iv	131.87 (12)
C17ⁱ—Cs1—C13ⁱⁱ	109.44 (8)	C18—C19—H19A	125.9
C1—Cs1—C13ⁱⁱ	111.22 (8)	C20—C19—H19A	125.9
C3—Cs1—C13ⁱⁱ	139.38 (8)	Yb1—C19—H19A	115.9
C18ⁱ—Cs1—C13ⁱⁱ	111.98 (8)	Cs1^iv—C19—H19A	112.2
C19ⁱ—Cs1—C13ⁱⁱ	90.34 (8)	C19—C20—C21	107.4 (3)
C11ⁱⁱ—Cs1—C13ⁱⁱ	38.65 (8)	C19—C20—Yb1	76.50 (19)
O1—Cs1—C5	105.94 (7)	C21—C20—Yb1	74.91 (19)
C2—Cs1—C5	38.83 (8)	C19—C20—Cs1^iv	79.59 (19)
C21ⁱ—Cs1—C5	110.42 (8)	C21—C20—Cs1^iv	76.66 (18)
C20ⁱ—Cs1—C5	101.17 (8)	Yb1—C20—Cs1^iv	134.91 (12)
C12ⁱⁱ—Cs1—C5	109.56 (8)	C19—C20—H20A	126.3
C17ⁱ—Cs1—C5	91.53 (8)	C21—C20—H20A	126.3
C1—Cs1—C5	23.80 (8)	Yb1—C20—H20A	114.7
C3—Cs1—C5	38.38 (8)	Cs1^iv—C20—H20A	110.3
C18ⁱ—Cs1—C5	71.25 (8)	C20—C21—C17	109.3 (3)
C19ⁱ—Cs1—C5	77.29 (8)	C20—C21—Yb1	75.48 (19)
C11ⁱⁱ—Cs1—C5	111.87 (8)	C17—C21—Yb1	76.54 (18)
C13ⁱⁱ—Cs1—C5	129.48 (8)	C20—C21—Cs1^iv	79.11 (19)
O1—Cs1—C4	84.87 (8)	C17—C21—Cs1^iv	79.67 (18)
C2—Cs1—C4	38.88 (8)	Yb1—C21—Cs1^iv	136.70 (12)
C21ⁱ—Cs1—C4	112.41 (8)	C20—C21—H21A	125.3
C20ⁱ—Cs1—C4	112.73 (8)	C17—C21—H21A	125.3
C12ⁱⁱ—Cs1—C4	127.43 (8)	Yb1—C21—H21A	114.7
C17ⁱ—Cs1—C4	88.95 (8)	Cs1^iv—C21—H21A	108.6
C1—Cs1—C4	39.03 (8)	Si3—C22—H22A	109.5
C3—Cs1—C4	23.49 (8)	Si3—C22—H22B	109.5
C18ⁱ—Cs1—C4	75.59 (8)	H22A—C22—H22B	109.5
C19ⁱ—Cs1—C4	89.67 (8)	Si3—C22—H22C	109.5
C11ⁱⁱ—Cs1—C4	121.18 (8)	H22A—C22—H22C	109.5
C13ⁱⁱ—Cs1—C4	150.24 (8)	H22B—C22—H22C	109.5
C5—Cs1—C4	23.09 (8)	Si3—C23—H23A	109.5
O1—Cs1—C10ⁱⁱ	74.63 (7)	Si3—C23—H23B	109.5
C2—Cs1—C10ⁱⁱ	98.69 (8)	H23A—C23—H23B	109.5
C21ⁱ—Cs1—C10ⁱⁱ	111.34 (8)	Si3—C23—H23C	109.5
C20ⁱ—Cs1—C10ⁱⁱ	108.30 (8)	H23A—C23—H23C	109.5
C12ⁱⁱ—Cs1—C10ⁱⁱ	38.08 (8)	H23B—C23—H23C	109.5
C17ⁱ—Cs1—C10ⁱⁱ	133.90 (8)	Si3—C24—H24A	109.5
C1—Cs1—C10ⁱⁱ	109.52 (8)	Si3—C24—H24B	109.5
C3—Cs1—C10ⁱⁱ	113.49 (8)	H24A—C24—H24B	109.5
C18ⁱ—Cs1—C10ⁱⁱ	147.28 (8)	Si3—C24—H24C	109.5
C19ⁱ—Cs1—C10ⁱⁱ	127.76 (8)	H24A—C24—H24C	109.5
C11ⁱⁱ—Cs1—C10ⁱⁱ	22.98 (8)	H24B—C24—H24C	109.5
C13ⁱⁱ—Cs1—C10ⁱⁱ	37.70 (8)	O1—C25—C26	105.8 (3)
C5—Cs1—C10ⁱⁱ	133.23 (8)	O1—C25—H25A	110.6
C4—Cs1—C10ⁱⁱ	136.14 (8)	C26—C25—H25A	110.6
O1—Cs1—C9ⁱⁱ	87.86 (7)	O1—C25—H25B	110.6
C2—Cs1—C9ⁱⁱ	120.23 (8)	C26—C25—H25B	110.6
C21ⁱ—Cs1—C9ⁱⁱ	88.67 (8)	H25A—C25—H25B	108.7
C20ⁱ—Cs1—C9ⁱⁱ	85.71 (8)	C27—C26—C25	101.6 (3)
C12ⁱⁱ—Cs1—C9ⁱⁱ	38.69 (8)	C27—C26—H26A	111.5
C17ⁱ—Cs1—C9ⁱⁱ	112.18 (8)	C25—C26—H26A	111.5
C1—Cs1—C9ⁱⁱ	125.32 (8)	C27—C26—H26B	111.5
C3—Cs1—C9ⁱⁱ	136.64 (8)	C25—C26—H26B	111.5
C18ⁱ—Cs1—C9ⁱⁱ	124.31 (8)	H26A—C26—H26B	109.3
C19ⁱ—Cs1—C9ⁱⁱ	106.95 (8)	C28—C27—C26	102.1 (3)
C11ⁱⁱ—Cs1—C9ⁱⁱ	38.49 (8)	C28—C27—H27A	111.3
C13ⁱⁱ—Cs1—C9ⁱⁱ	23.23 (8)	C26—C27—H27A	111.3
C5—Cs1—C9ⁱⁱ	147.92 (8)	C28—C27—H27B	111.3
C4—Cs1—C9ⁱⁱ	158.85 (8)	C26—C27—H27B	111.3
C10ⁱⁱ—Cs1—C9ⁱⁱ	23.16 (7)	H27A—C27—H27B	109.2
C1—Si1—C8	109.90 (16)	O1—C28—C27	106.8 (3)
C1—Si1—C7	109.33 (16)	O1—C28—Cs1	52.50 (16)
C8—Si1—C7	108.40 (17)	C27—C28—Cs1	137.3 (2)
C1—Si1—C6	110.42 (16)	O1—C28—H28A	110.4
C8—Si1—C6	110.06 (17)	C27—C28—H28A	110.4
C7—Si1—C6	108.70 (18)	Cs1—C28—H28A	112.0
C9—Si2—C15	112.34 (18)	O1—C28—H28B	110.4
C9—Si2—C16	108.64 (16)	C27—C28—H28B	110.4
C15—Si2—C16	107.99 (17)	Cs1—C28—H28B	60.1
C9—Si2—C14	111.75 (17)	H28A—C28—H28B	108.6

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

Selected bond distances and angles for [(THF)Cs(µ-η⁵:η⁵-Cp')₃Yb]_n, 1 top

Yb1···centroid1	2.510
Yb1···centroid2	2.513
Yb1···centroid3	2.504
Cs1···centroid1	3.197
Cs1···centroid2	3.268
Cs1···centroid3	3.159
Cs1—O1	3.095 (3)

centroid1—Yb1···centroid2	120.1
centroid1—Yb1···centroid3	116.6
centroid2—Yb1···centroid3	122.8
centroid1—Cs1···centroid2	121.4
centroid1—Cs1···centroid3	109.0
centroid2—Cs1···centroid3	114.3
Yb1···centroid1···Cs1	175.3
Yb1···centroid2···Cs1	172.3
Yb1···centroid3···Cs1	176.7
centroid1···Cs1···O1	88.8
centroid2···Cs1···O1	94.1
centroid3···Cs1···O1	127.8

Bond distance (Å) ranges for Yb···Cp'(centroid) and bond angle (°) ranges for Cp'(centroid)···Yb···Cp'(centroid) in Cp'₃Yb (Fieser et al., 2015), [K(crypt)][Cp'₃Yb] (Fieser et al., 2015), and [(THF)Cs(µ-η⁵:η⁵-Cp')₃Yb]_n top

	Cp'₃Yb	[K(crypt)][Cp'₃Yb]	1
Yb···Cp'(centroid)	2.363–2.368	2.503–2.513	2.504–2.513
Cs···Cp'(centroid)			3.159–3.268
Cp'···Yb···Cp'	118.85–120.55	118.10–122.93	116.64–122.76
Cp'···Cs···Cp'			109.0–121.4

Acknowledgements

WJE would like to acknowledge the National Science Foundation for continued support.

Funding information

Funding for this research was provided by: National Science Foundation, Directorate for Mathematical and Physical Sciences (grant No. CHE-1855328 to William J. Evans).

References

Ali, S. H., Deacon, G. B., Junk, P. C., Hamidi, S., Wiecko, M. & Wang, J. (2018). Chem. Eur. J. 24, 230–242. CSD CrossRef CAS PubMed Google Scholar
Apostolidis, C. B., Deacon, G., Dornberger, E. T., Edelmann, F., Kanellakopulos, B., MacKinnon, P. & Stalke, D. (1997). Chem. Commun. pp. 1047–1048. CSD CrossRef Google Scholar
Bel'sky, V. K., Gunko, Y. K., Bulychev, B. M., Sizov, A. I. & Soloveichik, G. L. (1990). J. Organomet. Chem. 390, 35–44. Google Scholar
Bruker (2013). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2014). APEX2 and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Evans, W. J. (2016). Organometallics, 35, 3088–3100. CrossRef CAS Google Scholar
Evans, W. J., Boyle, T. J. & Ziller, J. W. (1992). Organometallics, 11, 3903–3907. CSD CrossRef CAS Web of Science Google Scholar
Evans, W. J., Champagne, T. M., Davis, B. L., Allen, N. T., Nyce, G. W., Johnston, M. A., Lin, Y.-C., Khvostov, A. & Ziller, J. W. (2006). J. Coord. Chem. 59, 1069–1087. CSD CrossRef Google Scholar
Fieser, M. E., MacDonald, M. R., Krull, B. T., Bates, J. E., Ziller, J. W., Furche, F. & Evans, W. J. (2015). J. Am. Chem. Soc. 137, 369–382. CSD CrossRef CAS PubMed Google Scholar
González-del Moral, O., Martín, A., Mena, M., Morales-Varela, M. del C. & Santamaría, C. (2005). Chem. Commun. pp. 3682–3684. 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
Hitchcock, P. B., Lappert, M. F., Maron, L. & Protchenko, A. V. (2008). Angew. Chem. Int. Ed. 47, 1488–1491. CSD CrossRef CAS Google Scholar
Huh, D. N., Ziller, J. W. & Evans, W. J. (2018). Inorg. Chem. 57, 11809–11814. CSD CrossRef CAS PubMed Google Scholar
MacDonald, M. R., Bates, J. E., Ziller, J. W., Furche, F. & Evans, W. J. (2013). J. Am. Chem. Soc. 135, 9857–9868. CSD CrossRef CAS PubMed Google Scholar
Mills, N. (2006). J. Am. Chem. Soc. 128, 13649–13650. Web of Science CrossRef CAS Google Scholar
Morris, J. J., Noll, B. C., Honeyman, G. W., O'Hara, C. T., Kennedy, A. R., Mulvey, R. E. & Henderson, K. W. (2007). Chem. Eur. J. 13, 4418–4432. Web of Science CSD CrossRef PubMed CAS Google Scholar
Morss, L. R. (1976). Chem. Rev. 76, 827–841. CrossRef CAS Google Scholar
Palumbo, C. T., Darago, L. E., Windorff, C. J., Ziller, J. W. & Evans, W. J. (2018). Organometallics, 37, 900–905. CSD CrossRef CAS Google Scholar
Rosiak, D., Okuniewski, A. & Chojnacki, J. (2018). Polyhedron, 146, 35–41. 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
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Voskoboynikov, A. Z., Argarkov, A. Y., Shestakova, A. K., Beletskaya, I. P., Kuz'mina, L. O. & Howard, J. A. K. (1997). J. Organomet. Chem. 544, 65–68. CSD CrossRef CAS Google Scholar