meso-Bis{[eta]⁵-1-[1-(dimethyl­amino)­ethenyl]-3-(trimethyl­silyl)cyclo­penta­dienyl}iron(II) and the cobalt(II) analogue

The two title crystalline compounds, viz. meso-bis­{[eta]⁵-1-[1-(dimethyl­amino)­ethenyl]-3-(trimethyl­silyl)cyclo­penta­dienyl}iron(II), [Fe(C₁₂H₂₀NSi)₂], (II), and meso-bis­{[eta]⁵-1-[1-(dimethyl­amino)­ethenyl]-3-(trimethyl­silyl)cyclo­penta­dienyl}cobalt(II), [Co(C₁₂H₂₀NSi)₂], (III), were obtained by the reaction of lithium 1-[1-(dimethyl­amino)­ethenyl]-3-(tri­methyl­silyl)cyclo­penta­dienide with FeCl₂ and CoCl₂, respectively. For (II), the trimethyl­silyl- and dimethyl­amino­ethenyl-substituted cyclo­penta­dienyl (Cp) rings present a nearly eclipsed conformation, and the two pairs of trimethyl­silyl and dimethyl­amino­ethenyl substituents on the Cp rings are arranged in an inter­locked fashion. In the case of (III), the same substituted Cp rings are perfectly staggered leading to a crystallographically centrosymmetric mol­ecular structure, and the two trimethyl­silyl and two dimethyl­amino­ethenyl substituents are oriented in opposite directions, respectively, with the trimethyl­silyl group of one Cp ring and the dimethyl­amino­ethenyl group of the other Cp ring arranged more closely than in (II).

S1. Comment

Group 4 ansa-metallocenes have played a significant role in organometallic chemistry and homogeneous Ziegler–Natta olefin polymerization catalysis. Over the years, Erker and co-workers have contributed to these and related aspects of metallocene chemistry (Erker, 2011; Knüppel et al., 2005). The reaction of (enamino-Cp)Li reagents (Cp = cyclopentadienyl) prepared from the deprotonation of various 6-(dialkylamino)fulvenes with the group 4 metal tetrahalides MCl₄ (M = Ti, Zr or Hf) in a 2:1 stoichiometry firstly gave the nonbridged bis(enamino-Cp)MCl₂ complexes, which readily underwent an intramolecular Mannich coupling reaction and thus led to the synthesis of the corresponding C₃-bridged ansa-metallocenes (Tumay et al., 2009; Venne-Dunker et al., 2003).

Using an analogous route, Erker has also reported the preparation of several similar C₃-bridged ansa-ferrocenes from the reaction of FeCl₂ with (enamino-Cp)Li reagents that bear different substituents at the enamino N atom, such as dimethyl, diethyl and piperidine (Liptau et al., 2001; Knüppel et al., 1999). In contrast, we now report the noncoupling reaction between FeCl₂ and two molar equivalents of lithium 1-[1-(dimethylamino)ethenyl]-3-(trimethylsilyl)cyclopentadienide, which results in the formation of the title nonbridged tetrasubstituted ferrocene compound meso-bis{η⁵-1-[1-(dimethylamino)ethenyl]-3-(trimethylsilyl)cyclopentadienyl}iron(II), (II). For comparison, the reaction of the same lithium cyclopentadienide with CoCl₂ was also undertaken and the similar nonbridged tetrasubstituted cobaltocene compound was isolated, the title compound, meso-bis{η⁵-1-[1-(dimethylamino)ethenyl]-3-(trimethylsilyl)cyclopentadienyl}cobalt(II), (III). The noncoupling reaction between lithium [1-(dimethylamino)ethyl]cyclopentadienide and CoCl₂ has been reported by our group previously (Bai et al., 2001), but to the best of our knowledge the nonbridged enamino-substituted ferrocene system prepared via the fulvene route has not been reported before. It is proposed that the introduction of the sterically bulky trimethylsilyl substituent into the dimethylaminoethyl-substituted Cp ring might exert an important effect on the formation of the nonbridged enamino-substituted ferrocene system.

In the molecule of the tetrasubstituted ferrocene, (II), the Fe^II cation is nearly symmetrically displaced between the two substituted Cp rings, with distances of 1.6492 (17) and 1.6517 (19) Å (PLATON; Spek, 2009) to the centroids of the Cp rings [Cp1_centr and Cp2_centr refer to the centroids of Cp rings C1–C5 and C13-C17, respectively]. The dihedral angle between the two planes of the Cp rings is small [3.41 (2)°] (Fig. 1a). As shown in Fig. 1(b), the two Cp rings adopt an almost eclipsed conformation with an average torsion angle of 13.7° [the mean of the five torsion angles: C1—Cp1_centr—Cp2_centr—C14 = 13.29°, C2—Cp1_centr—Cp2_centr—C15 = 13.36°, C3—Cp1_centr—Cp2_centr—C16 =13.63°, C4—Cp1_centr—Cp2_centr—C17 = 13.90° and C5—Cp1_centr—Cp2_centr—C13 = 14.19°; Mercury (Macrae et al., 2008)], and two pairs of substituents (two trimethylsilyl and two dimethylaminoethenyl) are interlocked to reduce interannular repulsive interactions. The two pairs of substituents are held at varying torsion angles C_sub—Cp1_centr—Cp2_centr—C_sub and the smallest such torsion angle C1—Cp1_centr—Cp2_centr—C15 = 59.10° (Macrae et al., 2008), where C_sub refers to the C atom of the Cp rings at which the substituents are attached. The conformation of the two Cp rings and the orientations of the four substituents in (II) are similar to those of 1,1',3,3'-tetra(trimethylsilyl)ferrocene (Okuda & Herdtweck, 1989) and 1,1',3,3'-tetra(tert-butyl)ferrocene (Abel et al., 1991), respectively. Atoms Si1, Si2, C6 and C18 are bent away from the plane of the Cp rings to which they are directly attached by 0.150, 0.155, 0.061 and 0.036 Å, respectively (Macrae et al., 2008), and away from the Fe^II cation. Obviously, the bulky trimethylsilyl substitutents are bent out of the Cp ring planes more than the dimethylaminoethenyl substituents. The Fe—C_Cp bond lengths of the substituted C atoms (C1, C3, C13 and C15) exceed those of the unsubstituted C atoms and the average Fe—C bond length in (II) of 2.046 Å compares well with that in ferrocene (2.052 Å for triclinic ferrocene and 2.045 Å for orthorhombic ferrocene; Reference?). Both the C7/C6/N1/C9 and C19/C18/N2/C21 frameworks lie approximately in a plane (with corresponding mean deviations of 0.0119 and 0.0134 Å) and display small angles of 32.76 (2) and 32.54 (11)°, respectively, with the Cp ring plane to which they are attached. The C6═C7 [1.327 (5) Å] and C18═C19 [1.329 (5) Å] bond lengths are typical for a normal C═C double bond [Standard reference?]; the shorter bond lengths for C6—N1 [1.398 (5) Å] and C18—N2 [1.391 (5) Å] indicate electronic delocalization between the N atoms (N1 and N2) and the double bonds attached to them.

The molecule of the tetrasubstituted cobaltocene, (III), displays a rigorously planar sandwich geometry and the Co^II cation occupies a crystallographic inversion centre at (-x + 1, -y, -z + 2), affording a staggered conformation of the Cp ligands with the same distance of 1.7315 (4) Å from the Co^II cation to the centroids of the two Cp rings (Cp_centr) (Fig. 2) C1–C5 and C1A–C5A (Spek, 2009). The conformation of the Cp rings in (III) is different from those found in (II) and in 1,1',3,3'-tetra(tert-butyl)cobaltocene (Schneider et al., 1997) so as to meet the steric demands in (III). Just as observed in (II), the Co—C_sub (substituted C atoms of the Cp rings) bond lengths exceed those of the unsubstituted C atoms; the average Co—C(ring) distance of 2.112 Å is comparable with the average metal—carbon distances in Cp₂Co (2.096 Å) and Cp*₂Co (2.105 Å [Which ring is Cp*?]). The slightly longer M—C(ring) bonds in (III) than in (II) are favourable to reduce the transannular steric repulsive interactions. As shown in Fig. 2(b), the two trimethylsilyl and two dimethylaminoethenyl substituents are oriented in opposite directions, respectively, and the trimethylsilyl of one Cp ring and the dimethylaminoethenyl of the other are arranged more closely (torsion angle C1—Cp1_centr—Cp2_centr—C3A = 35.06°; Macrae et al., 2008) than in II. Furthermore, the trimethylsilyl and dimethylaminoethenyl substitutents are bent away from the Co centre to reduce the transannular steric repulsion interactions from neighbouring substitutents; the perpendicular distances from atoms SiA and C6A to the attached Cp ring plane are 0.243 and 0.077 Å, respectively (Macrae et al., 2008). The planar C7/C6/N/C9 skeleton (mean deviation 0.0223 Å) forms a dihedral angle of 35.51 (2)° with Cp ring plane to which it is attached. The bond distances and angles involving the trimethylsilyl and dimethylaminoethenyl substitutents are as expected and are well within the corresponding range observed in (II).

Although previous studies of the eclipsed and staggered forms of metallocenes have already shown that the eclipsed conformation is energetically more favourable than the staggered one (Swart, 2007; Zlatar et al., 2009), no systematics for the adoption of a certain conformation in multiply ring-substituted metallocenes can be deduced so far. Conformational preferences appear to be even more delicately balanced by the interannular repulsive interactions, metal–ring distances, substitutents on the Cp rings etc. (Okuda, 1991; Phillips et al., 2010).

Related literature

For related literature, see: Abel et al. (1991); Bai et al. (1999, 2001); Duan et al. (2007); Erker (2011); Knüppel et al. (1999, 2005); Liptau et al. (2001); Macrae et al. (2008); Okuda (1991); Okuda & Herdtweck (1989); Phillips et al. (2010); Schneider et al. (1997); Spek (2009); Swart (2007); Tumay et al. (2009); Venne-Dunker, Kehr, Fröhlich & Erker (2003); Zlatar et al. (2009).

S2. Experimental

6-Dimethylamino-6-methyl-3-(trimethylsilyl)fulvene, (I), was prepared as a pale-yellow solid in high yield by the successive reaction of 6-dimethylamino-6-methylfulvene, which was prepared as described in the literature (Bai et al., 1999; Duan et al., 2007), with equal equivalents of lithium diisopropylamide (LDA) and Me₃SiCl. Crystallization from hexane yielded yellow needles of (I) (78%); m.p. = 369–371 K. ¹H NMR (300 MHz, CDCl₃, δ, p.p.m.): 6.73–6.33 (m, 3H, Cp-H), 3.27, 3.25 [d, 6H, N(CH₃)₂], 2.41, 2.38 (d, 3H, CH₃), 0.09 [s, 9H, Si(CH₃)₃].

LDA (0.802 g, 7.48 mmol) was added to a diethyl ether solution (30 ml) of (I) (1.552 g, 7.48 mmol) at 273 K. The reaction mixture was warmed to room temperature and stirred for 12 h to give a diethyl ether solution of lithium 1-[1-(dimethylamino)ethenyl]-3-(trimethylsilyl)cyclopentadienide, which was used in situ in the subsequent reactions with FeCl₂ or CoCl₂.

To a diethyl ether solution (30 ml) of lithium 1-[1-(dimethylamino)ethenyl]-3-(trimethylsilyl)cyclopentadienide (7.48 mmol), solid iron dichloride (0.475 g, 3.74 mmol) was added at 195 K. The reaction mixture was warmed to room temperature and stirred for 12 h. After removal of the volatiles in vacuo, the resulting orange residue was extracted with hexane and filtered. The orange filtrate was concentrated in vacuo to ca 5 ml, from which orange single crystals of (II) (0.656 g, 37.4%) were isolated after storage at 253 K for several days (m.p. 350–353 K). Compound (II) was a slightly air-sensitive crystalline solid. ¹H NMR (300 MHz, CDCl₃, δ, p.p.m.): 4.69, 4.17–3.81 (m, 10H, Cp-H and CH₂), 2.59, 2.45 [d, 12H, N(CH₃)₂], 0.08 [s, 18H, Si(CH₃)₃].

Solid CoCl₂ (0.485 g, 3.74 mmol) was added to a diethyl ether solution (30 ml) of lithium 1-[1-(dimethylamino)ethenyl]-3-(trimethylsilyl)cyclopentadienide (7.48 mmol) at 195 K. The reaction mixture was warmed to room temperature and stirred for 12 h. After remove of the volatiles in vacuo, the resultant brown residue was extracted into hexane. Concentration of the extract in vacuo and storage at 253 K for 3 d yielded brown single crystals of (III) (0.624 g, 35.4%; m.p. 353–355 K). Compound (III) is paramagnetic and air sensitive.

S3. Refinement

All H atoms were placed in calculated positions, with C—H = 0.94–0.99 Å, and allowed to ride on their parent atoms, with U_iso(H) = 1.2–1.5U_eq(C).

Computing details

For both compounds, data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. (a) Side view and (b) top view of the molecular structure of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. (a) Side view and (b) top view of the molecular structure of (III), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

(II) meso-bis{η⁵-1-[1-(dimethylamino)ethenyl]-3- (trimethylsilyl)cyclopentadienyl}iron(II)

Crystal data

[Fe(C12H20NSi)2]	F(000) = 1008
Mr = 468.61	Dx = 1.196 Mg m^−3
Monoclinic, P21/n	Melting point = 350–353 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 10.186 (2) Å	Cell parameters from 2478 reflections
b = 11.736 (3) Å	θ = 2.4–22.9°
c = 22.341 (5) Å	µ = 0.68 mm^−1
β = 102.978 (3)°	T = 213 K
V = 2602.6 (9) Å^3	Block, orange
Z = 4	0.30 × 0.20 × 0.20 mm

Data collection

Siemens SMART CCD area-detector diffractometer	4563 independent reflections
Radiation source: fine-focus sealed tube	3637 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
ω scans	θmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.821, Tmax = 0.875	k = −13→13
10503 measured reflections	l = −13→26

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.062	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.136	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0516P)^2 + 1.9533P] where P = (Fo^2 + 2Fc^2)/3
4563 reflections	(Δ/σ)max < 0.001
272 parameters	Δρmax = 0.44 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Fe1	0.44403 (5)	0.60960 (5)	0.20887 (2)	0.03458 (18)
N1	0.0458 (3)	0.6962 (3)	0.12229 (14)	0.0428 (8)
N2	0.5682 (3)	0.4059 (3)	0.08073 (14)	0.0415 (8)
Si1	0.42970 (11)	0.68184 (11)	0.36246 (5)	0.0469 (3)
Si2	0.48011 (12)	0.87583 (10)	0.13649 (6)	0.0499 (3)
C10	0.2852 (4)	0.7026 (4)	0.39965 (19)	0.0564 (12)
H10A	0.3163	0.7404	0.4389	0.085*
H10B	0.2471	0.6291	0.4061	0.085*
H10C	0.2171	0.7490	0.3734	0.085*
C11	0.5471 (6)	0.5759 (5)	0.4071 (2)	0.090 (2)
H11A	0.6250	0.5678	0.3892	0.135*
H11B	0.5017	0.5030	0.4061	0.135*
H11C	0.5759	0.6014	0.4493	0.135*
C12	0.5145 (4)	0.8206 (5)	0.3596 (2)	0.0697 (15)
H12A	0.5240	0.8592	0.3987	0.105*
H12B	0.4612	0.8671	0.3273	0.105*
H12C	0.6030	0.8080	0.3514	0.105*
C22	0.4778 (5)	0.9739 (4)	0.2013 (2)	0.0646 (14)
H22A	0.3991	0.9583	0.2176	0.097*
H22B	0.4744	1.0520	0.1869	0.097*
H22C	0.5586	0.9627	0.2333	0.097*
C24	0.6049 (5)	0.9286 (5)	0.0940 (3)	0.0798 (17)
H24A	0.6917	0.9377	0.1222	0.120*
H24B	0.5753	1.0014	0.0752	0.120*
H24C	0.6129	0.8742	0.0623	0.120*
C23	0.3120 (5)	0.8676 (4)	0.0835 (2)	0.0643 (13)
H23A	0.3121	0.8076	0.0537	0.096*
H23B	0.2914	0.9398	0.0624	0.096*
H23C	0.2445	0.8510	0.1068	0.096*
C3	0.3610 (3)	0.6230 (3)	0.28451 (16)	0.0350 (9)
C4	0.3719 (4)	0.5063 (3)	0.26703 (17)	0.0390 (9)
H4	0.4239	0.4463	0.2933	0.047*
C5	0.2977 (3)	0.4913 (3)	0.20631 (17)	0.0370 (9)
H5	0.2889	0.4189	0.1830	0.044*
C1	0.2371 (3)	0.5959 (3)	0.18425 (17)	0.0353 (9)
C2	0.2775 (3)	0.6770 (3)	0.23247 (16)	0.0334 (9)
H2	0.2527	0.7587	0.2299	0.040*
C16	0.6206 (4)	0.6991 (4)	0.22255 (19)	0.0466 (11)
H16	0.6547	0.7511	0.2575	0.056*
C17	0.6463 (4)	0.5814 (4)	0.22230 (18)	0.0454 (11)
H17	0.7020	0.5376	0.2566	0.054*
C13	0.5792 (3)	0.5359 (4)	0.16479 (17)	0.0383 (9)
C14	0.5098 (4)	0.6288 (3)	0.13080 (17)	0.0360 (9)
H14	0.4524	0.6231	0.0888	0.043*
C15	0.5362 (4)	0.7320 (3)	0.16556 (18)	0.0411 (10)
C6	0.1458 (4)	0.6142 (3)	0.12319 (17)	0.0382 (9)
C7	0.1650 (4)	0.5581 (4)	0.07430 (18)	0.0485 (11)
H7A	0.1090	0.5724	0.0355	0.058*
H7B	0.2345	0.5040	0.0785	0.058*
C9	−0.0354 (5)	0.7237 (4)	0.06204 (19)	0.0604 (13)
H9A	0.0229	0.7475	0.0355	0.091*
H9C	−0.0971	0.7849	0.0656	0.091*
H9B	−0.0862	0.6569	0.0447	0.091*
C8	−0.0385 (4)	0.6814 (4)	0.16650 (19)	0.0517 (11)
H8A	−0.0999	0.6182	0.1539	0.078*
H8B	−0.0897	0.7505	0.1683	0.078*
H8C	0.0180	0.6657	0.2067	0.078*
C18	0.5798 (4)	0.4171 (4)	0.14367 (18)	0.0399 (10)
C19	0.5841 (4)	0.3300 (4)	0.1821 (2)	0.0529 (11)
H19A	0.5793	0.2549	0.1671	0.064*
H19B	0.5921	0.3434	0.2242	0.064*
C20	0.6608 (4)	0.4717 (4)	0.05345 (19)	0.0484 (11)
H20A	0.6745	0.5461	0.0728	0.073*
H20B	0.6233	0.4808	0.0098	0.073*
H20C	0.7464	0.4321	0.0596	0.073*
C21	0.5513 (5)	0.2915 (4)	0.0561 (2)	0.0605 (13)
H21A	0.6351	0.2498	0.0690	0.091*
H21B	0.5267	0.2949	0.0116	0.091*
H21C	0.4808	0.2531	0.0711	0.091*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.0268 (3)	0.0466 (4)	0.0309 (3)	−0.0025 (2)	0.0079 (2)	−0.0071 (3)
N1	0.0353 (18)	0.060 (2)	0.0307 (18)	−0.0023 (16)	0.0018 (14)	0.0019 (16)
N2	0.0425 (19)	0.046 (2)	0.0380 (19)	0.0033 (16)	0.0131 (15)	−0.0064 (16)
Si1	0.0372 (6)	0.0675 (8)	0.0324 (6)	0.0117 (6)	−0.0001 (5)	−0.0123 (6)
Si2	0.0482 (7)	0.0433 (7)	0.0633 (8)	−0.0140 (6)	0.0237 (6)	−0.0106 (6)
C10	0.062 (3)	0.072 (3)	0.035 (2)	0.007 (2)	0.011 (2)	−0.005 (2)
C11	0.086 (4)	0.113 (5)	0.055 (3)	0.046 (4)	−0.016 (3)	−0.015 (3)
C12	0.045 (3)	0.097 (4)	0.067 (3)	−0.008 (3)	0.013 (2)	−0.038 (3)
C22	0.060 (3)	0.058 (3)	0.079 (4)	−0.011 (2)	0.023 (3)	−0.023 (3)
C24	0.085 (4)	0.065 (3)	0.104 (4)	−0.021 (3)	0.052 (3)	−0.002 (3)
C23	0.063 (3)	0.053 (3)	0.076 (4)	−0.006 (2)	0.012 (3)	−0.003 (2)
C3	0.0270 (18)	0.051 (2)	0.027 (2)	0.0008 (17)	0.0066 (16)	−0.0064 (18)
C4	0.034 (2)	0.049 (3)	0.036 (2)	0.0028 (18)	0.0112 (17)	0.0005 (19)
C5	0.033 (2)	0.043 (2)	0.038 (2)	−0.0055 (18)	0.0141 (17)	−0.0065 (18)
C1	0.0261 (18)	0.048 (2)	0.033 (2)	−0.0056 (17)	0.0096 (16)	−0.0052 (18)
C2	0.0261 (18)	0.045 (2)	0.029 (2)	−0.0014 (17)	0.0073 (16)	−0.0025 (17)
C16	0.028 (2)	0.065 (3)	0.048 (3)	−0.012 (2)	0.0127 (19)	−0.018 (2)
C17	0.0230 (19)	0.078 (3)	0.033 (2)	0.0038 (19)	0.0030 (17)	−0.003 (2)
C13	0.0268 (19)	0.056 (3)	0.037 (2)	0.0026 (18)	0.0154 (17)	0.0004 (19)
C14	0.0310 (19)	0.047 (2)	0.032 (2)	−0.0042 (17)	0.0114 (16)	−0.0029 (18)
C15	0.034 (2)	0.048 (2)	0.045 (3)	−0.0128 (18)	0.0168 (19)	−0.012 (2)
C6	0.035 (2)	0.049 (2)	0.031 (2)	−0.0131 (19)	0.0076 (17)	−0.0043 (19)
C7	0.044 (2)	0.069 (3)	0.031 (2)	−0.013 (2)	0.0060 (19)	−0.009 (2)
C9	0.058 (3)	0.074 (3)	0.041 (3)	−0.005 (2)	−0.006 (2)	0.011 (2)
C8	0.037 (2)	0.070 (3)	0.048 (3)	0.006 (2)	0.011 (2)	−0.003 (2)
C18	0.030 (2)	0.052 (3)	0.039 (2)	0.0117 (18)	0.0109 (17)	0.001 (2)
C19	0.055 (3)	0.059 (3)	0.048 (3)	0.013 (2)	0.021 (2)	0.009 (2)
C20	0.044 (2)	0.062 (3)	0.043 (2)	0.007 (2)	0.017 (2)	0.006 (2)
C21	0.076 (3)	0.055 (3)	0.055 (3)	−0.001 (2)	0.023 (3)	−0.009 (2)

Geometric parameters (Å, º)

Fe1—C14	2.017 (4)	C23—H23A	0.9700
Fe1—C5	2.029 (4)	C23—H23B	0.9700
Fe1—C4	2.031 (4)	C23—H23C	0.9700
Fe1—C17	2.041 (4)	C3—C2	1.425 (5)
Fe1—C16	2.046 (4)	C3—C4	1.435 (5)
Fe1—C2	2.045 (3)	C4—C5	1.408 (5)
Fe1—C13	2.055 (4)	C4—H4	0.9900
Fe1—C3	2.058 (4)	C5—C1	1.412 (5)
Fe1—C1	2.062 (3)	C5—H5	0.9900
Fe1—C15	2.071 (4)	C1—C2	1.427 (5)
N1—C6	1.398 (5)	C1—C6	1.484 (5)
N1—C9	1.449 (5)	C2—H2	0.9900
N1—C8	1.457 (5)	C16—C17	1.407 (6)
N2—C18	1.391 (5)	C16—C15	1.420 (6)
N2—C21	1.446 (5)	C16—H16	0.9900
N2—C20	1.454 (5)	C17—C13	1.417 (5)
Si1—C12	1.851 (5)	C17—H17	0.9900
Si1—C11	1.853 (5)	C13—C14	1.422 (5)
Si1—C10	1.861 (4)	C13—C18	1.473 (6)
Si1—C3	1.858 (4)	C14—C15	1.431 (5)
Si2—C23	1.853 (5)	C14—H14	0.9900
Si2—C22	1.854 (4)	C6—C7	1.327 (5)
Si2—C15	1.852 (4)	C7—H7A	0.9400
Si2—C24	1.855 (5)	C7—H7B	0.9400
C10—H10A	0.9700	C9—H9A	0.9700
C10—H10B	0.9700	C9—H9C	0.9700
C10—H10C	0.9700	C9—H9B	0.9700
C11—H11A	0.9700	C8—H8A	0.9700
C11—H11B	0.9700	C8—H8B	0.9700
C11—H11C	0.9700	C8—H8C	0.9700
C12—H12A	0.9700	C18—C19	1.329 (5)
C12—H12B	0.9700	C19—H19A	0.9400
C12—H12C	0.9700	C19—H19B	0.9400
C22—H22A	0.9700	C20—H20A	0.9700
C22—H22B	0.9700	C20—H20B	0.9700
C22—H22C	0.9700	C20—H20C	0.9700
C24—H24A	0.9700	C21—H21A	0.9700
C24—H24B	0.9700	C21—H21B	0.9700
C24—H24C	0.9700	C21—H21C	0.9700
C14—Fe1—C5	115.92 (15)	H23B—C23—H23C	109.5
C14—Fe1—C4	149.12 (16)	C2—C3—C4	105.7 (3)
C5—Fe1—C4	40.59 (14)	C2—C3—Si1	129.0 (3)
C14—Fe1—C17	67.96 (15)	C4—C3—Si1	125.0 (3)
C5—Fe1—C17	127.17 (17)	C2—C3—Fe1	69.2 (2)
C4—Fe1—C17	107.90 (16)	C4—C3—Fe1	68.4 (2)
C14—Fe1—C16	67.66 (16)	Si1—C3—Fe1	131.34 (19)
C5—Fe1—C16	166.31 (17)	C5—C4—C3	108.9 (3)
C4—Fe1—C16	130.02 (17)	C5—C4—Fe1	69.6 (2)
C17—Fe1—C16	40.26 (17)	C3—C4—Fe1	70.5 (2)
C14—Fe1—C2	129.48 (15)	C5—C4—H4	125.5
C5—Fe1—C2	67.98 (15)	C3—C4—H4	125.5
C4—Fe1—C2	68.01 (15)	Fe1—C4—H4	125.5
C17—Fe1—C2	153.25 (15)	C4—C5—C1	109.0 (3)
C16—Fe1—C2	121.00 (16)	C4—C5—Fe1	69.8 (2)
C14—Fe1—C13	40.88 (15)	C1—C5—Fe1	71.1 (2)
C5—Fe1—C13	105.40 (15)	C4—C5—H5	125.5
C4—Fe1—C13	115.66 (16)	C1—C5—H5	125.5
C17—Fe1—C13	40.49 (15)	Fe1—C5—H5	125.5
C16—Fe1—C13	68.08 (16)	C5—C1—C2	106.7 (3)
C2—Fe1—C13	165.96 (14)	C5—C1—C6	125.5 (3)
C14—Fe1—C3	168.23 (16)	C2—C1—C6	127.8 (4)
C5—Fe1—C3	68.96 (15)	C5—C1—Fe1	68.6 (2)
C4—Fe1—C3	41.09 (15)	C2—C1—Fe1	69.03 (19)
C17—Fe1—C3	118.61 (15)	C6—C1—Fe1	128.8 (3)
C16—Fe1—C3	110.33 (15)	C3—C2—C1	109.8 (3)
C2—Fe1—C3	40.65 (14)	C3—C2—Fe1	70.2 (2)
C13—Fe1—C3	150.30 (15)	C1—C2—Fe1	70.3 (2)
C14—Fe1—C1	107.25 (15)	C3—C2—H2	125.1
C5—Fe1—C1	40.38 (14)	C1—C2—H2	125.1
C4—Fe1—C1	68.23 (15)	Fe1—C2—H2	125.1
C17—Fe1—C1	164.63 (16)	C17—C16—C15	109.8 (4)
C16—Fe1—C1	153.09 (17)	C17—C16—Fe1	69.7 (2)
C2—Fe1—C1	40.66 (14)	C15—C16—Fe1	70.8 (2)
C13—Fe1—C1	126.46 (15)	C17—C16—H16	125.1
C3—Fe1—C1	68.97 (14)	C15—C16—H16	125.1
C14—Fe1—C15	40.94 (14)	Fe1—C16—H16	125.1
C5—Fe1—C15	150.33 (15)	C16—C17—C13	108.7 (4)
C4—Fe1—C15	168.46 (15)	C16—C17—Fe1	70.1 (2)
C17—Fe1—C15	68.44 (17)	C13—C17—Fe1	70.3 (2)
C16—Fe1—C15	40.35 (16)	C16—C17—H17	125.6
C2—Fe1—C15	109.98 (15)	C13—C17—H17	125.6
C13—Fe1—C15	69.21 (16)	Fe1—C17—H17	125.6
C3—Fe1—C15	130.04 (15)	C17—C13—C14	106.0 (4)
C1—Fe1—C15	118.24 (16)	C17—C13—C18	127.7 (4)
C6—N1—C9	115.3 (3)	C14—C13—C18	126.3 (3)
C6—N1—C8	116.5 (3)	C17—C13—Fe1	69.2 (2)
C9—N1—C8	110.9 (3)	C14—C13—Fe1	68.1 (2)
C18—N2—C21	116.6 (3)	C18—C13—Fe1	127.1 (3)
C18—N2—C20	117.3 (3)	C13—C14—C15	110.4 (3)
C21—N2—C20	111.5 (3)	C13—C14—Fe1	71.0 (2)
C12—Si1—C11	111.0 (3)	C15—C14—Fe1	71.6 (2)
C12—Si1—C10	108.8 (2)	C13—C14—H14	124.8
C11—Si1—C10	109.1 (2)	C15—C14—H14	124.8
C12—Si1—C3	112.0 (2)	Fe1—C14—H14	124.8
C11—Si1—C3	108.4 (2)	C16—C15—C14	105.0 (4)
C10—Si1—C3	107.34 (18)	C16—C15—Si2	129.7 (3)
C23—Si2—C22	111.1 (2)	C14—C15—Si2	125.1 (3)
C23—Si2—C15	110.14 (19)	C16—C15—Fe1	68.9 (2)
C22—Si2—C15	110.4 (2)	C14—C15—Fe1	67.5 (2)
C23—Si2—C24	109.4 (3)	Si2—C15—Fe1	131.3 (2)
C22—Si2—C24	108.9 (2)	C7—C6—N1	124.8 (4)
C15—Si2—C24	106.9 (2)	C7—C6—C1	120.4 (4)
Si1—C10—H10A	109.5	N1—C6—C1	114.7 (3)
Si1—C10—H10B	109.5	C6—C7—H7A	120.0
H10A—C10—H10B	109.5	C6—C7—H7B	120.0
Si1—C10—H10C	109.5	H7A—C7—H7B	120.0
H10A—C10—H10C	109.5	N1—C9—H9A	109.5
H10B—C10—H10C	109.5	N1—C9—H9C	109.5
Si1—C11—H11A	109.5	H9A—C9—H9C	109.5
Si1—C11—H11B	109.5	N1—C9—H9B	109.5
H11A—C11—H11B	109.5	H9A—C9—H9B	109.5
Si1—C11—H11C	109.5	H9C—C9—H9B	109.5
H11A—C11—H11C	109.5	N1—C8—H8A	109.5
H11B—C11—H11C	109.5	N1—C8—H8B	109.5
Si1—C12—H12A	109.5	H8A—C8—H8B	109.5
Si1—C12—H12B	109.5	N1—C8—H8C	109.5
H12A—C12—H12B	109.5	H8A—C8—H8C	109.5
Si1—C12—H12C	109.5	H8B—C8—H8C	109.5
H12A—C12—H12C	109.5	C19—C18—N2	124.3 (4)
H12B—C12—H12C	109.5	C19—C18—C13	121.6 (4)
Si2—C22—H22A	109.5	N2—C18—C13	114.1 (3)
Si2—C22—H22B	109.5	C18—C19—H19A	120.0
H22A—C22—H22B	109.5	C18—C19—H19B	120.0
Si2—C22—H22C	109.5	H19A—C19—H19B	120.0
H22A—C22—H22C	109.5	N2—C20—H20A	109.5
H22B—C22—H22C	109.5	N2—C20—H20B	109.5
Si2—C24—H24A	109.5	H20A—C20—H20B	109.5
Si2—C24—H24B	109.5	N2—C20—H20C	109.5
H24A—C24—H24B	109.5	H20A—C20—H20C	109.5
Si2—C24—H24C	109.5	H20B—C20—H20C	109.5
H24A—C24—H24C	109.5	N2—C21—H21A	109.5
H24B—C24—H24C	109.5	N2—C21—H21B	109.5
Si2—C23—H23A	109.5	H21A—C21—H21B	109.5
Si2—C23—H23B	109.5	N2—C21—H21C	109.5
H23A—C23—H23B	109.5	H21A—C21—H21C	109.5
Si2—C23—H23C	109.5	H21B—C21—H21C	109.5
H23A—C23—H23C	109.5

(III) meso-bis{η⁵-1-[1-(dimethylamino)ethenyl]-3- (trimethylsilyl)cyclopentadienyl}cobalt(II)

Crystal data

[Co(C12H20NSi)2]	Z = 1
Mr = 471.69	F(000) = 253
Triclinic, P1	Dx = 1.206 Mg m^−3
Hall symbol: -P 1	Melting point = 353–355 K
a = 7.891 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.363 (3) Å	Cell parameters from 1963 reflections
c = 10.440 (3) Å	θ = 2.3–27.1°
α = 105.531 (3)°	µ = 0.77 mm^−1
β = 111.101 (3)°	T = 213 K
γ = 102.658 (3)°	Prism, brown
V = 649.2 (3) Å^3	0.30 × 0.20 × 0.20 mm

Data collection

Siemens SMART CCD area-detector diffractometer	2240 independent reflections
Radiation source: fine-focus sealed tube	2076 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.017
ω scans	θmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.803, Tmax = 0.862	k = −11→11
3180 measured reflections	l = −9→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0464P)^2 + 0.1772P] where P = (Fo^2 + 2Fc^2)/3
2240 reflections	(Δ/σ)max < 0.001
138 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.38 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Co1	0.5000	0.0000	1.0000	0.02347 (15)
N1	0.2661 (3)	−0.1351 (2)	0.5285 (2)	0.0366 (5)
Si1	0.36534 (10)	0.33374 (8)	1.14930 (7)	0.03285 (19)
C1	0.3288 (3)	−0.0069 (3)	0.7832 (2)	0.0272 (5)
C2	0.2594 (3)	0.0526 (3)	0.8870 (3)	0.0283 (5)
H2	0.1366	0.0042	0.8794	0.034*
C3	0.4037 (3)	0.1971 (3)	1.0053 (3)	0.0279 (5)
C4	0.5682 (3)	0.2181 (3)	0.9774 (3)	0.0289 (5)
H4	0.6880	0.3013	1.0376	0.035*
C5	0.5238 (3)	0.0931 (3)	0.8436 (3)	0.0298 (5)
H5	0.6100	0.0796	0.8024	0.036*
C6	0.2186 (3)	−0.1477 (3)	0.6431 (3)	0.0297 (5)
C7	0.0921 (4)	−0.2758 (3)	0.6322 (3)	0.0408 (6)
H7A	0.0279	−0.3656	0.5432	0.049*
H7B	0.0668	−0.2764	0.7135	0.049*
C8	0.2561 (4)	0.0037 (4)	0.4914 (3)	0.0490 (7)
H8A	0.1232	−0.0153	0.4250	0.074*
H8B	0.3382	0.0234	0.4431	0.074*
H8C	0.3002	0.0951	0.5815	0.074*
C9	0.1853 (5)	−0.2786 (4)	0.3966 (3)	0.0575 (8)
H9A	0.2107	−0.3649	0.4252	0.086*
H9B	0.2448	−0.2621	0.3325	0.086*
H9C	0.0463	−0.3045	0.3438	0.086*
C10	0.5746 (4)	0.5225 (3)	1.2467 (3)	0.0538 (8)
H10A	0.6930	0.5022	1.2919	0.081*
H10B	0.5571	0.5945	1.3230	0.081*
H10C	0.5832	0.5697	1.1760	0.081*
C11	0.1368 (4)	0.3667 (4)	1.0503 (3)	0.0546 (8)
H11A	0.1521	0.4163	0.9827	0.082*
H11B	0.1092	0.4350	1.1221	0.082*
H11C	0.0305	0.2659	0.9947	0.082*
C12	0.3350 (4)	0.2487 (4)	1.2844 (3)	0.0495 (7)
H12A	0.2241	0.1508	1.2323	0.074*
H12B	0.3141	0.3233	1.3566	0.074*
H12C	0.4508	0.2276	1.3349	0.074*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.0237 (2)	0.0235 (3)	0.0257 (3)	0.00977 (18)	0.01146 (18)	0.01116 (18)
N1	0.0443 (12)	0.0380 (12)	0.0254 (11)	0.0148 (10)	0.0153 (9)	0.0091 (9)
Si1	0.0372 (4)	0.0318 (4)	0.0314 (4)	0.0190 (3)	0.0140 (3)	0.0109 (3)
C1	0.0310 (12)	0.0284 (12)	0.0266 (12)	0.0149 (10)	0.0124 (10)	0.0142 (10)
C2	0.0277 (12)	0.0296 (13)	0.0305 (13)	0.0135 (10)	0.0125 (10)	0.0134 (10)
C3	0.0306 (12)	0.0260 (12)	0.0284 (12)	0.0134 (10)	0.0113 (10)	0.0121 (10)
C4	0.0310 (12)	0.0238 (12)	0.0315 (13)	0.0088 (10)	0.0118 (10)	0.0134 (10)
C5	0.0354 (13)	0.0295 (13)	0.0319 (13)	0.0139 (10)	0.0173 (11)	0.0174 (11)
C6	0.0306 (12)	0.0309 (13)	0.0280 (13)	0.0154 (10)	0.0114 (10)	0.0107 (10)
C7	0.0416 (14)	0.0361 (15)	0.0356 (14)	0.0083 (12)	0.0149 (12)	0.0080 (12)
C8	0.0586 (18)	0.0593 (19)	0.0399 (16)	0.0259 (15)	0.0226 (14)	0.0293 (15)
C9	0.069 (2)	0.0542 (19)	0.0350 (16)	0.0118 (16)	0.0249 (15)	0.0023 (14)
C10	0.0604 (19)	0.0377 (16)	0.0472 (18)	0.0132 (14)	0.0181 (15)	0.0044 (13)
C11	0.0560 (18)	0.063 (2)	0.0485 (18)	0.0424 (16)	0.0175 (15)	0.0173 (15)
C12	0.0551 (17)	0.065 (2)	0.0512 (18)	0.0353 (16)	0.0340 (15)	0.0289 (15)

Geometric parameters (Å, º)

Co1—C2	2.084 (2)	C3—C4	1.414 (3)
Co1—C2^i	2.084 (2)	C4—C5	1.427 (3)
Co1—C5	2.091 (2)	C4—H4	0.9400
Co1—C5^i	2.091 (2)	C5—H5	0.9400
Co1—C4	2.093 (2)	C6—C7	1.329 (3)
Co1—C4^i	2.093 (2)	C7—H7A	0.9400
Co1—C3	2.140 (2)	C7—H7B	0.9400
Co1—C3^i	2.140 (2)	C8—H8A	0.9700
Co1—C1	2.153 (2)	C8—H8B	0.9700
Co1—C1^i	2.153 (2)	C8—H8C	0.9700
N1—C6	1.402 (3)	C9—H9A	0.9700
N1—C9	1.452 (3)	C9—H9B	0.9700
N1—C8	1.462 (3)	C9—H9C	0.9700
Si1—C10	1.853 (3)	C10—H10A	0.9700
Si1—C12	1.855 (3)	C10—H10B	0.9700
Si1—C3	1.859 (2)	C10—H10C	0.9700
Si1—C11	1.868 (3)	C11—H11A	0.9700
C1—C5	1.412 (3)	C11—H11B	0.9700
C1—C2	1.422 (3)	C11—H11C	0.9700
C1—C6	1.477 (3)	C12—H12A	0.9700
C2—C3	1.439 (3)	C12—H12B	0.9700
C2—H2	0.9400	C12—H12C	0.9700
C2—Co1—C2^i	180.000 (1)	C1—C2—C3	110.5 (2)
C2—Co1—C5	65.67 (9)	C1—C2—Co1	73.00 (13)
C2^i—Co1—C5	114.33 (9)	C3—C2—Co1	72.17 (12)
C2—Co1—C5^i	114.33 (9)	C1—C2—H2	124.8
C2^i—Co1—C5^i	65.67 (9)	C3—C2—H2	124.8
C5—Co1—C5^i	180.000 (1)	Co1—C2—H2	121.7
C2—Co1—C4	65.68 (9)	C4—C3—C2	105.2 (2)
C2^i—Co1—C4	114.32 (9)	C4—C3—Si1	128.71 (18)
C5—Co1—C4	39.89 (9)	C2—C3—Si1	125.81 (17)
C5^i—Co1—C4	140.11 (9)	C4—C3—Co1	68.73 (12)
C2—Co1—C4^i	114.32 (9)	C2—C3—Co1	68.03 (12)
C2^i—Co1—C4^i	65.68 (9)	Si1—C3—Co1	132.05 (12)
C5—Co1—C4^i	140.11 (9)	C3—C4—C5	109.4 (2)
C5^i—Co1—C4^i	39.89 (9)	C3—C4—Co1	72.27 (13)
C4—Co1—C4^i	180.0	C5—C4—Co1	69.98 (13)
C2—Co1—C3	39.80 (9)	C3—C4—H4	125.3
C2^i—Co1—C3	140.20 (9)	C5—C4—H4	125.3
C5—Co1—C3	66.43 (9)	Co1—C4—H4	124.0
C5^i—Co1—C3	113.57 (9)	C1—C5—C4	108.7 (2)
C4—Co1—C3	39.00 (9)	C1—C5—Co1	72.93 (13)
C4^i—Co1—C3	141.00 (9)	C4—C5—Co1	70.13 (13)
C2—Co1—C3^i	140.20 (9)	C1—C5—H5	125.6
C2^i—Co1—C3^i	39.80 (9)	C4—C5—H5	125.6
C5—Co1—C3^i	113.57 (9)	Co1—C5—H5	122.9
C5^i—Co1—C3^i	66.43 (9)	C7—C6—N1	124.3 (2)
C4—Co1—C3^i	141.00 (9)	C7—C6—C1	121.6 (2)
C4^i—Co1—C3^i	39.00 (9)	N1—C6—C1	114.1 (2)
C3—Co1—C3^i	180.000 (1)	C6—C7—H7A	120.0
C2—Co1—C1	39.19 (9)	C6—C7—H7B	120.0
C2^i—Co1—C1	140.81 (9)	H7A—C7—H7B	120.0
C5—Co1—C1	38.84 (9)	N1—C8—H8A	109.5
C5^i—Co1—C1	141.16 (9)	N1—C8—H8B	109.5
C4—Co1—C1	65.85 (9)	H8A—C8—H8B	109.5
C4^i—Co1—C1	114.15 (9)	N1—C8—H8C	109.5
C3—Co1—C1	66.39 (9)	H8A—C8—H8C	109.5
C3^i—Co1—C1	113.61 (9)	H8B—C8—H8C	109.5
C2—Co1—C1^i	140.81 (9)	N1—C9—H9A	109.5
C2^i—Co1—C1^i	39.19 (9)	N1—C9—H9B	109.5
C5—Co1—C1^i	141.16 (9)	H9A—C9—H9B	109.5
C5^i—Co1—C1^i	38.84 (9)	N1—C9—H9C	109.5
C4—Co1—C1^i	114.15 (9)	H9A—C9—H9C	109.5
C4^i—Co1—C1^i	65.85 (9)	H9B—C9—H9C	109.5
C3—Co1—C1^i	113.61 (9)	Si1—C10—H10A	109.5
C3^i—Co1—C1^i	66.39 (9)	Si1—C10—H10B	109.5
C1—Co1—C1^i	180.000 (1)	H10A—C10—H10B	109.5
C6—N1—C9	116.3 (2)	Si1—C10—H10C	109.5
C6—N1—C8	117.0 (2)	H10A—C10—H10C	109.5
C9—N1—C8	111.9 (2)	H10B—C10—H10C	109.5
C10—Si1—C12	110.25 (15)	Si1—C11—H11A	109.5
C10—Si1—C3	108.65 (13)	Si1—C11—H11B	109.5
C12—Si1—C3	112.33 (12)	H11A—C11—H11B	109.5
C10—Si1—C11	110.58 (15)	Si1—C11—H11C	109.5
C12—Si1—C11	108.16 (14)	H11A—C11—H11C	109.5
C3—Si1—C11	106.82 (12)	H11B—C11—H11C	109.5
C5—C1—C2	106.0 (2)	Si1—C12—H12A	109.5
C5—C1—C6	127.7 (2)	Si1—C12—H12B	109.5
C2—C1—C6	126.3 (2)	H12A—C12—H12B	109.5
C5—C1—Co1	68.22 (12)	Si1—C12—H12C	109.5
C2—C1—Co1	67.81 (12)	H12A—C12—H12C	109.5
C6—C1—Co1	127.23 (15)	H12B—C12—H12C	109.5

Symmetry code: (i) −x+1, −y, −z+2.