[η²,η⁵-Dicyclo­penta­dienyldimethyl­silane(2–)]bis­(tetra­hydro­furan-κO)magnesium: an Si-bridged magnesocene

In the title Si-bridged magnesocene, [Mg(C₁₂H₁₄Si)(C₄H₈O)₂], at 87 (2) K, the Mg atom is η⁵- and η²-bonded to the cyclo­penta­dienyl rings. The C_ipso—Si—C_ipso angle is 102.63 (6)°.

Key indicators

• Single-crystal X-ray study
• T = 87 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.035
• wR factor = 0.088
• Data-to-parameter ratio = 16.3

checkCIF/PLATON results

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: publCIF (Westrip, 2007).

[η²,η⁵-Dicyclopentadienyldimethylsilane(2-)]bis(tetrahydrofuran- κO)magnesium

Crystal data

[Mg(C12H14Si)(C4H8O)2]	F(000) = 768
Mr = 354.84	Dx = 1.193 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 8215 reflections
a = 8.7260 (4) Å	θ = 2.5–30.0°
b = 14.7521 (7) Å	µ = 0.16 mm^−1
c = 15.7421 (7) Å	T = 87 K
β = 102.866 (1)°	Plate, colorless
V = 1975.55 (16) Å^3	0.45 × 0.35 × 0.09 mm
Z = 4

Data collection

Bruker–Siemens SMART APEX diffractometer	3580 independent reflections
Radiation source: normal-focus sealed tube	3343 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 8.3 pixels mm^-1	θmax = 25.3°, θmin = 1.9°
ω scans	h = −10→10
Absorption correction: multi-scan (SADABS; Bruker, 2002)	k = −17→17
Tmin = 0.931, Tmax = 0.982	l = −18→18
30193 measured reflections

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.088	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0437P)^2 + 1.0755P] where P = (Fo^2 + 2Fc^2)/3
3580 reflections	(Δ/σ)max < 0.001
219 parameters	Δρmax = 0.40 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

Special details

Experimental. A solution of dibutylmagnesium in heptane (Aldrich, 13.2 mmol, 1M, 8 ml) was added to an ice-bath cooled solution of Me₂Si(C₅H₅)₂ (Frisch, 1953; Gomez-Garcia & Royo, 1999) (1.50 g, 7.96 mmol) in heptane (45 ml). The ice bath was removed and the reaction mixture warmed to 343 K. Bubbling was observed when the reaction mixture reached a temperature of ca 333 K and a white precipitate gradually formed. The reaction proceeded relatively slowly, so the butane generated by the reaction was simply allowed to exit by the argon line. After stirring under argon at 343 K overnight (15 h), the product was isolated by filtration and washed with pentane (2 × 20 ml) to yield 1.06 g (63%) of Me₂Si(C₅H₄)₂Mg as a white powder. THF (2–3 drops) in benzene-d6 (0.5 ml) was used as an NMR solvent (instead of THF-d8). ¹H NMR (C₆D₆/THF-d8, 303 K, 300 MHz): 6.36 (m, 4H, C₅H₄, J = 2.2 Hz), 6.24 (m, 4H, C₅H₄, J = 2.2 Hz), 0.80 [s, 6H, Si(CH₃)₂] p.p.m. THF signal at 3.50 and 1.46 p.p.m. ¹³C NMR (C₆D₆/THF-d8, 303 K, 75 MHz): 119.7, 113.4, 106.7 (C₅H₄), -1.9 Si(CH₃)₂), THF signal at 67.4 and 25.7 p.p.m. A slow cooling of a supersaturated hot (ca 343 K) solution of the magnesocene in a THF/benzene (ca 1:5) mixture afforded single crystals of solvated (I).

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
C1	−0.12264 (16)	0.47745 (10)	0.08997 (9)	0.0159 (3)
H1	−0.1224	0.5303	0.0555	0.019*
C2	−0.09188 (17)	0.38866 (10)	0.06529 (10)	0.0180 (3)
H2	−0.0690	0.3714	0.0113	0.022*
C3	−0.10097 (17)	0.32998 (10)	0.13447 (10)	0.0184 (3)
H3	−0.0843	0.2663	0.1357	0.022*
C4	−0.13911 (16)	0.38257 (10)	0.20142 (10)	0.0169 (3)
H4	−0.1527	0.3599	0.2557	0.020*
C5	−0.15428 (16)	0.47516 (10)	0.17513 (9)	0.0154 (3)
C6	0.09048 (17)	0.58347 (9)	0.28307 (10)	0.0162 (3)
C7	0.19250 (17)	0.59255 (10)	0.22292 (10)	0.0175 (3)
H7	0.1596	0.5971	0.1613	0.021*
C8	0.34969 (17)	0.59355 (10)	0.27122 (11)	0.0200 (3)
H8	0.4406	0.6003	0.2479	0.024*
C9	0.34818 (18)	0.58296 (10)	0.35908 (10)	0.0214 (3)
H9	0.4380	0.5806	0.4060	0.026*
C10	0.19116 (18)	0.57639 (10)	0.36631 (10)	0.0192 (3)
H10	0.1578	0.5684	0.4193	0.023*
C11	−0.22709 (18)	0.67491 (11)	0.19693 (11)	0.0228 (3)
H11A	−0.1904	0.6865	0.1434	0.034*
H11B	−0.2025	0.7272	0.2359	0.034*
H11C	−0.3410	0.6650	0.1824	0.034*
C12	−0.20150 (19)	0.54505 (12)	0.35192 (11)	0.0259 (4)
H12A	−0.3159	0.5377	0.3358	0.039*
H12B	−0.1747	0.5947	0.3940	0.039*
H12C	−0.1532	0.4887	0.3781	0.039*
C13	0.28017 (17)	0.30487 (10)	0.09434 (10)	0.0199 (3)
H13A	0.1947	0.2952	0.0421	0.024*
H13B	0.2672	0.2612	0.1399	0.024*
C14	0.43987 (18)	0.29381 (11)	0.07231 (10)	0.0212 (3)
H14A	0.4356	0.2494	0.0247	0.025*
H14B	0.5202	0.2742	0.1239	0.025*
C15	0.47418 (17)	0.38900 (10)	0.04358 (10)	0.0190 (3)
H15A	0.5883	0.3984	0.0491	0.023*
H15B	0.4184	0.4008	−0.0174	0.023*
C16	0.41167 (17)	0.44838 (10)	0.10668 (10)	0.0183 (3)
H16A	0.4934	0.4586	0.1605	0.022*
H16B	0.3770	0.5078	0.0799	0.022*
C17	0.17382 (19)	0.33494 (11)	0.37130 (10)	0.0237 (3)
H17A	0.1371	0.2713	0.3644	0.028*
H17B	0.0852	0.3741	0.3781	0.028*
C18	0.3110 (2)	0.34450 (12)	0.44871 (10)	0.0261 (4)
H18A	0.2993	0.3038	0.4969	0.031*
H18B	0.3221	0.4078	0.4702	0.031*
C19	0.44991 (19)	0.31657 (12)	0.41088 (10)	0.0253 (4)
H19A	0.5479	0.3462	0.4425	0.030*
H19B	0.4647	0.2500	0.4138	0.030*
C20	0.40522 (18)	0.34875 (11)	0.31711 (10)	0.0219 (3)
H20A	0.4608	0.4058	0.3100	0.026*
H20B	0.4333	0.3025	0.2776	0.026*
O1	0.27854 (11)	0.39834 (7)	0.12598 (6)	0.0159 (2)
O2	0.23541 (12)	0.36343 (7)	0.29730 (6)	0.0169 (2)
Si1	−0.12653 (4)	0.57181 (3)	0.25240 (3)	0.01551 (12)
Mg1	0.12052 (5)	0.43981 (3)	0.19561 (3)	0.01351 (13)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0110 (7)	0.0190 (7)	0.0165 (7)	−0.0008 (5)	0.0010 (5)	0.0022 (6)
C2	0.0125 (7)	0.0238 (8)	0.0163 (7)	−0.0006 (6)	0.0005 (6)	−0.0045 (6)
C3	0.0151 (7)	0.0147 (7)	0.0236 (8)	−0.0011 (6)	0.0005 (6)	−0.0030 (6)
C4	0.0145 (7)	0.0179 (7)	0.0177 (7)	−0.0047 (6)	0.0023 (6)	0.0004 (6)
C5	0.0100 (6)	0.0173 (7)	0.0183 (7)	−0.0017 (5)	0.0022 (5)	−0.0017 (6)
C6	0.0151 (7)	0.0115 (7)	0.0218 (8)	0.0009 (5)	0.0039 (6)	−0.0029 (6)
C7	0.0160 (7)	0.0148 (7)	0.0211 (7)	−0.0015 (6)	0.0030 (6)	−0.0002 (6)
C8	0.0142 (7)	0.0155 (7)	0.0303 (8)	−0.0022 (6)	0.0049 (6)	−0.0029 (6)
C9	0.0166 (7)	0.0198 (8)	0.0249 (8)	0.0008 (6)	−0.0016 (6)	−0.0069 (6)
C10	0.0204 (8)	0.0164 (7)	0.0200 (8)	0.0012 (6)	0.0027 (6)	−0.0059 (6)
C11	0.0168 (7)	0.0193 (8)	0.0305 (9)	0.0028 (6)	0.0017 (6)	−0.0042 (6)
C12	0.0215 (8)	0.0339 (9)	0.0241 (8)	−0.0006 (7)	0.0087 (6)	−0.0054 (7)
C13	0.0192 (7)	0.0173 (8)	0.0243 (8)	−0.0018 (6)	0.0073 (6)	−0.0043 (6)
C14	0.0186 (7)	0.0222 (8)	0.0240 (8)	0.0024 (6)	0.0070 (6)	−0.0003 (6)
C15	0.0141 (7)	0.0253 (8)	0.0181 (7)	0.0003 (6)	0.0046 (6)	0.0017 (6)
C16	0.0141 (7)	0.0216 (8)	0.0199 (7)	−0.0051 (6)	0.0051 (6)	0.0011 (6)
C17	0.0267 (8)	0.0280 (9)	0.0183 (8)	0.0018 (7)	0.0093 (6)	0.0063 (6)
C18	0.0321 (9)	0.0298 (9)	0.0158 (8)	0.0076 (7)	0.0039 (7)	0.0043 (6)
C19	0.0268 (8)	0.0272 (9)	0.0195 (8)	0.0055 (7)	−0.0001 (6)	0.0028 (6)
C20	0.0172 (8)	0.0265 (8)	0.0212 (8)	0.0052 (6)	0.0026 (6)	0.0050 (6)
O1	0.0145 (5)	0.0151 (5)	0.0190 (5)	−0.0025 (4)	0.0056 (4)	−0.0010 (4)
O2	0.0161 (5)	0.0197 (5)	0.0147 (5)	0.0021 (4)	0.0029 (4)	0.0035 (4)
Si1	0.0120 (2)	0.0156 (2)	0.0190 (2)	0.00039 (15)	0.00358 (16)	−0.00350 (15)
Mg1	0.0121 (2)	0.0139 (2)	0.0142 (2)	0.00020 (18)	0.00212 (18)	0.00102 (18)

Geometric parameters (Å, º)

C1—C2	1.409 (2)	C12—H12A	0.9800
C1—C5	1.428 (2)	C12—H12B	0.9800
C1—Mg1	2.4504 (14)	C12—H12C	0.9800
C1—H1	0.9500	C13—O1	1.4672 (17)
C2—C3	1.407 (2)	C13—C14	1.518 (2)
C2—Mg1	2.5534 (15)	C13—H13A	0.9900
C2—H2	0.9500	C13—H13B	0.9900
C3—C4	1.407 (2)	C14—C15	1.525 (2)
C3—Mg1	2.5413 (15)	C14—H14A	0.9900
C3—H3	0.9500	C14—H14B	0.9900
C4—C5	1.425 (2)	C15—C16	1.514 (2)
C4—Mg1	2.4385 (15)	C15—H15A	0.9900
C4—H4	0.9500	C15—H15B	0.9900
C5—Si1	1.8548 (15)	C16—O1	1.4642 (17)
C5—Mg1	2.4045 (14)	C16—H16A	0.9900
C6—C10	1.410 (2)	C16—H16B	0.9900
C6—C7	1.443 (2)	C17—O2	1.4495 (18)
C6—Si1	1.8551 (15)	C17—C18	1.513 (2)
C6—Mg1	2.5723 (15)	C17—H17A	0.9900
C7—C8	1.413 (2)	C17—H17B	0.9900
C7—Mg1	2.3529 (15)	C18—C19	1.522 (2)
C7—H7	0.9500	C18—H18A	0.9900
C8—C9	1.395 (2)	C18—H18B	0.9900
C8—H8	0.9500	C19—C20	1.517 (2)
C9—C10	1.403 (2)	C19—H19A	0.9900
C9—H9	0.9500	C19—H19B	0.9900
C10—H10	0.9500	C20—O2	1.4608 (18)
C11—Si1	1.8720 (16)	C20—H20A	0.9900
C11—H11A	0.9800	C20—H20B	0.9900
C11—H11B	0.9800	O1—Mg1	2.0372 (11)
C11—H11C	0.9800	O2—Mg1	2.0305 (11)
C12—Si1	1.8694 (16)	Si1—Mg1	3.1776 (6)
C2—C1—C5	108.99 (13)	H16A—C16—H16B	108.8
C2—C1—Mg1	77.71 (8)	O2—C17—C18	104.59 (13)
C5—C1—Mg1	71.14 (8)	O2—C17—H17A	110.8
C2—C1—H1	125.5	C18—C17—H17A	110.8
C5—C1—H1	125.5	O2—C17—H17B	110.8
Mg1—C1—H1	117.5	C18—C17—H17B	110.8
C3—C2—C1	108.15 (13)	H17A—C17—H17B	108.9
C3—C2—Mg1	73.49 (8)	C17—C18—C19	102.47 (13)
C1—C2—Mg1	69.66 (8)	C17—C18—H18A	111.3
C3—C2—H2	125.9	C19—C18—H18A	111.3
C1—C2—H2	125.9	C17—C18—H18B	111.3
Mg1—C2—H2	122.6	C19—C18—H18B	111.3
C2—C3—C4	107.70 (13)	H18A—C18—H18B	109.2
C2—C3—Mg1	74.44 (8)	C20—C19—C18	103.98 (13)
C4—C3—Mg1	69.61 (8)	C20—C19—H19A	111.0
C2—C3—H3	126.1	C18—C19—H19A	111.0
C4—C3—H3	126.1	C20—C19—H19B	111.0
Mg1—C3—H3	121.5	C18—C19—H19B	111.0
C3—C4—C5	109.46 (13)	H19A—C19—H19B	109.0
C3—C4—Mg1	77.65 (9)	O2—C20—C19	106.44 (12)
C5—C4—Mg1	71.59 (8)	O2—C20—H20A	110.4
C3—C4—H4	125.3	C19—C20—H20A	110.4
C5—C4—H4	125.3	O2—C20—H20B	110.4
Mg1—C4—H4	117.3	C19—C20—H20B	110.4
C4—C5—C1	105.69 (12)	H20A—C20—H20B	108.6
C4—C5—Si1	123.81 (11)	C16—O1—C13	109.59 (10)
C1—C5—Si1	124.97 (11)	C16—O1—Mg1	128.58 (9)
C4—C5—Mg1	74.20 (8)	C13—O1—Mg1	121.59 (8)
C1—C5—Mg1	74.66 (8)	C17—O2—C20	108.99 (11)
Si1—C5—Mg1	95.63 (6)	C17—O2—Mg1	126.03 (9)
C10—C6—C7	105.60 (13)	C20—O2—Mg1	123.36 (9)
C10—C6—Si1	128.60 (12)	C5—Si1—C6	102.63 (6)
C7—C6—Si1	125.52 (11)	C5—Si1—C12	111.61 (7)
C10—C6—Mg1	108.65 (9)	C6—Si1—C12	109.20 (7)
C7—C6—Mg1	64.78 (8)	C5—Si1—C11	109.85 (7)
Si1—C6—Mg1	90.23 (6)	C6—Si1—C11	113.04 (7)
C8—C7—C6	108.35 (13)	C12—Si1—C11	110.32 (8)
C8—C7—Mg1	107.22 (10)	C5—Si1—Mg1	48.86 (4)
C6—C7—Mg1	81.52 (8)	C6—Si1—Mg1	54.05 (4)
C8—C7—H7	125.8	C12—Si1—Mg1	119.49 (6)
C6—C7—H7	125.8	C11—Si1—Mg1	130.06 (5)
Mg1—C7—H7	82.7	O2—Mg1—O1	89.03 (4)
C9—C8—C7	108.07 (13)	O2—Mg1—C7	108.82 (5)
C9—C8—H8	126.0	O1—Mg1—C7	101.58 (5)
C7—C8—H8	126.0	O2—Mg1—C5	121.92 (5)
C8—C9—C10	108.25 (14)	O1—Mg1—C5	140.11 (5)
C8—C9—H9	125.9	C7—Mg1—C5	91.98 (5)
C10—C9—H9	125.9	O2—Mg1—C4	94.48 (5)
C9—C10—C6	109.71 (14)	O1—Mg1—C4	131.45 (5)
C9—C10—H10	125.1	C7—Mg1—C4	122.50 (5)
C6—C10—H10	125.1	C5—Mg1—C4	34.21 (5)
Si1—C11—H11A	109.5	O2—Mg1—C1	149.51 (5)
Si1—C11—H11B	109.5	O1—Mg1—C1	106.88 (5)
H11A—C11—H11B	109.5	C7—Mg1—C1	93.59 (5)
Si1—C11—H11C	109.5	C5—Mg1—C1	34.19 (5)
H11A—C11—H11C	109.5	C4—Mg1—C1	55.43 (5)
H11B—C11—H11C	109.5	O2—Mg1—C3	98.35 (5)
Si1—C12—H12A	109.5	O1—Mg1—C3	98.83 (5)
Si1—C12—H12B	109.5	C7—Mg1—C3	146.03 (5)
H12A—C12—H12B	109.5	C5—Mg1—C3	55.66 (5)
Si1—C12—H12C	109.5	C4—Mg1—C3	32.74 (5)
H12A—C12—H12C	109.5	C1—Mg1—C3	54.33 (5)
H12B—C12—H12C	109.5	O2—Mg1—C2	127.74 (5)
O1—C13—C14	104.91 (11)	O1—Mg1—C2	86.34 (5)
O1—C13—H13A	110.8	C7—Mg1—C2	123.11 (5)
C14—C13—H13A	110.8	C5—Mg1—C2	55.43 (5)
O1—C13—H13B	110.8	C4—Mg1—C2	54.09 (5)
C14—C13—H13B	110.8	C1—Mg1—C2	32.63 (5)
H13A—C13—H13B	108.8	C3—Mg1—C2	32.06 (5)
C13—C14—C15	102.69 (12)	O2—Mg1—C6	97.27 (5)
C13—C14—H14A	111.2	O1—Mg1—C6	134.21 (5)
C15—C14—H14A	111.2	C7—Mg1—C6	33.70 (5)
C13—C14—H14B	111.2	C5—Mg1—C6	71.07 (5)
C15—C14—H14B	111.2	C4—Mg1—C6	93.38 (5)
H14A—C14—H14B	109.1	C1—Mg1—C6	90.03 (5)
C16—C15—C14	102.41 (12)	C3—Mg1—C6	124.64 (5)
C16—C15—H15A	111.3	C2—Mg1—C6	122.09 (5)
C14—C15—H15A	111.3	O2—Mg1—Si1	111.41 (3)
C16—C15—H15B	111.3	O1—Mg1—Si1	156.68 (4)
C14—C15—H15B	111.3	C7—Mg1—Si1	62.09 (4)
H15A—C15—H15B	109.2	C5—Mg1—Si1	35.51 (4)
O1—C16—C15	105.24 (12)	C4—Mg1—Si1	60.49 (4)
O1—C16—H16A	110.7	C1—Mg1—Si1	60.85 (4)
C15—C16—H16A	110.7	C3—Mg1—Si1	89.48 (4)
O1—C16—H16B	110.7	C2—Mg1—Si1	89.46 (4)
C15—C16—H16B	110.7	C6—Mg1—Si1	35.72 (3)