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Acta Cryst. (2008). E64, m1494    [ doi:10.1107/S1600536808035228 ]

2-(4-Ferrocenylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

P. D. W. Boyd and J. D. Paauwe

Abstract top

In the title compound,, [Fe(C5H5)(C17H20BO2)], the two near parallel cyclopentadienyl rings of the ferrocene group are eclipsed. The benzene ring is tilted with respect to the attached cyclopentadiene ring by 17.0 (1)° and by 24.2 (1)° with respect to the dioxaborolane ring. The molecules assemble in the crystal via C-H...[pi] interactions between the cyclopentadienyl H atoms and the benzene and cyclopentadienyl rings of neighbouring molecules.

Comment top

The title compound, (I), was prepared from the reaction of lithiated 4-bromophenylferrocene with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxoborolane in tetrahydrofuran. Unlike the related tris(4-ferrocenylphenyl)boroxine benzene solvate (Makarov et al. (2004), the 2-(4-ferrocenyl-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane is monomeric (Fig. 1). The two cyclopentadienyl rings are nearly eclipsed, average torsion angle 2.1 (1)°, with a small tilt of the two planes (C1—C5 and C6—C10) of 3.5 (1)°. The distances of the iron atom to the ring centroids were 1.6514 (2)Å and 1.6475 (2) Å respectively. The phenyl ring is tilted by 17.0 (1)° with respect to the (C6—C10) plane. This value is slightly higher than that observed in similar structures (Anderson et al. (2003), Nyamori and Bala (2008)). The dioxaborolane ring is in a half-chair conformation, with an O1—C17—C18—O2 torsion angle of 24.2 (1)°. The BO2 group is rotated away from the plane of the phenyl ring system by 11.1 (2)°, and the angle between the dioxaborolane ring and the phenylplane is 9.9 (1)°. The molecules pack in the crystal, (Fig. 2), with C—H···π interactions between cyclopentadienyl hydrogen atoms and the phenyl and cyclopentadienyl rings of neighbouring molecules, Table 1.

Related literature top

For the related tris(4-ferrocenylphenyl)boroxine benzene

solvate, see: Makarov et al. (2004). For other related structures, see: Anderson et al. (2003); Nyamori & Bala (2008). For related literature, see: Leclerc et al. (2003).

Experimental top

To a solution of 4-bromophenyl ferrocene (0.2 g, 0.59 mmol) in dry THF (10 mL) stirred at -78°C under nitrogen was added dropwise a solution of n-BuLi 2.5M in hexane (0.51 ml, 0.88 mmol).The mixture was then stirred at -78 °C for 20 minutes. Then 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxoborolane (0.18 ml, 0.88 mmol) was added, the stirring was kept at -78°C for 2 h and the mixture allowed to warm to -35 C and stir for 1 h and then warmed to room temperature. The reaction mixture was then poured into water and extracted with diethyl ether (2 x 25 ml). The combined organic layers were washed with brine and dried with Na2SO4. The solvent removed under reduced pressure and purified by column chromatography (SiO2, Hexane/DCM =2/1) to give the pure compound 2-(4-ferrocenyl-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.052 g, 0.129 mmol, 23%) as an orange solid. FAB-MS (C22H2510BFeO2) 387.13293 (C22H2511BFeO2) 388.12934. 1H NMR (CDCl3, 300 MHz) δ 1.36 (CH3, s 12H), 4.02 (CpH, s, 5H), 4.33 (CpH, t, J=1.84, 2H), 4.68 (CpH, t, J =1.85 2H), 7.46 (ArH, d, J=8.3 2H), 7.72 (ArH, d, J=8.3 2H) p.p.m..

Refinement top

Hydrogen atoms were placed in calculated positions and refined using the riding model [C—H 0.93–0.97 Å), with Uiso(H) = 1.2 and 1.5 times Ueq(C) for aromatic and alkyl groups respectively. In the case of the methyl groups protons were rotated to fit the H-atom positions to the observed electron density.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999) and publCIF (Westrip, 2008).

Figures top
[Figure 1] Fig. 1. Structure of (I) showing 50% probability displacement ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The crystal packing of (I) showing C—H..π interactions between adjacent molecules. [Symmetry codes: x,y,z and 1 - x,1 - y,1 - z]
2-(4-Ferrocenylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane top
Crystal data top
[Fe(C5H5)(C17H20BO2)]F(000) = 816
Mr = 388.08Dx = 1.371 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 9781 reflections
a = 12.4439 (3) Åθ = 1.8–27.8°
b = 12.9832 (3) ŵ = 0.82 mm−1
c = 13.0728 (3) ÅT = 89 K
β = 117.126 (1)°Block, orange
V = 1879.75 (8) Å30.37 × 0.37 × 0.2 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD
diffractometer		4442 independent reflections
Radiation source: fine-focus sealed tube3984 reflections with I > 2σ(I)
graphiteRint = 0.027
ω scansθmax = 27.8°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −16→14
Tmin = 0.717, Tmax = 0.849k = 0→17
23134 measured reflectionsl = 0→17
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.085H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0491P)2 + 1.0943P]
where P = (Fo2 + 2Fc2)/3
4442 reflections(Δ/σ)max = 0.001
239 parametersΔρmax = 0.86 e Å−3
0 restraintsΔρmin = −0.31 e Å−3
Crystal data top
[Fe(C5H5)(C17H20BO2)]V = 1879.75 (8) Å3
Mr = 388.08Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.4439 (3) ŵ = 0.82 mm−1
b = 12.9832 (3) ÅT = 89 K
c = 13.0728 (3) Å0.37 × 0.37 × 0.2 mm
β = 117.126 (1)°
Data collection top
Bruker SMART APEXII CCD
diffractometer		4442 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		3984 reflections with I > 2σ(I)
Tmin = 0.717, Tmax = 0.849Rint = 0.027
23134 measured reflectionsθmax = 27.8°
Refinement top
R[F2 > 2σ(F2)] = 0.031H-atom parameters constrained
wR(F2) = 0.085Δρmax = 0.86 e Å−3
S = 1.03Δρmin = −0.31 e Å−3
4442 reflectionsAbsolute structure: ?
239 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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 (Å2) top
xyzUiso*/Ueq
Fe10.244744 (18)0.661122 (14)0.209954 (16)0.01545 (8)
O20.36539 (9)1.21833 (8)−0.03562 (9)0.0207 (2)
O10.16554 (9)1.19391 (8)−0.16076 (9)0.0195 (2)
C110.26427 (12)0.89643 (10)0.14427 (11)0.0157 (3)
C140.26540 (13)1.05937 (10)0.00034 (12)0.0167 (3)
C180.33635 (13)1.29767 (11)−0.12386 (12)0.0187 (3)
C20.16209 (14)0.52057 (11)0.16048 (14)0.0231 (3)
H20.11050.49010.18540.028*
C160.37235 (12)0.94523 (10)0.16343 (12)0.0178 (3)
H160.44470.92390.22410.021*
C70.15815 (13)0.78484 (11)0.23606 (12)0.0186 (3)
H70.07890.80500.18950.022*
C130.15859 (13)1.00753 (10)−0.02096 (12)0.0172 (3)
H130.08681.0269−0.08360.021*
C80.26304 (13)0.81901 (11)0.22597 (12)0.0167 (3)
C90.36571 (13)0.76831 (11)0.31467 (12)0.0187 (3)
H90.44540.77580.32810.022*
C60.19744 (14)0.71467 (11)0.33018 (12)0.0209 (3)
H60.14800.68110.35560.025*
B10.26500 (15)1.15783 (11)−0.06779 (14)0.0174 (3)
C150.37260 (13)1.02504 (11)0.09282 (12)0.0184 (3)
H150.44531.05640.10710.022*
C50.23381 (15)0.61510 (11)0.05503 (13)0.0243 (3)
H50.23700.6572−0.00110.029*
C210.39377 (14)1.39832 (11)−0.06503 (13)0.0238 (3)
H21A0.36801.4143−0.00790.036*
H21B0.36951.4526−0.12100.036*
H21C0.48011.3916−0.02900.036*
C40.33403 (14)0.56821 (11)0.14749 (13)0.0226 (3)
H40.41440.57450.16280.027*
C100.32509 (14)0.70475 (11)0.37867 (12)0.0208 (3)
H100.37350.66390.44130.025*
C120.15769 (12)0.92783 (10)0.04947 (12)0.0169 (3)
H120.08540.89490.03350.020*
C170.19486 (13)1.29760 (11)−0.18488 (13)0.0201 (3)
C220.39120 (14)1.26270 (11)−0.20117 (14)0.0235 (3)
H22A0.47611.2510−0.15550.035*
H22B0.37901.3150−0.25730.035*
H22C0.35301.2000−0.23950.035*
C30.29014 (14)0.50988 (11)0.21282 (14)0.0228 (3)
H30.33690.47150.27830.027*
C200.14060 (15)1.37292 (13)−0.13159 (16)0.0294 (3)
H20A0.05541.3605−0.16250.044*
H20B0.15391.4422−0.14890.044*
H20C0.17831.3635−0.04980.044*
C190.13736 (16)1.31085 (15)−0.31429 (14)0.0312 (4)
H19A0.16531.2574−0.34710.047*
H19B0.15931.3768−0.33240.047*
H19C0.05111.3068−0.34530.047*
C10.12727 (14)0.58627 (12)0.06311 (13)0.0249 (3)
H10.04890.60670.01360.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Fe10.02072 (12)0.00975 (11)0.01600 (12)−0.00098 (7)0.00849 (9)0.00033 (7)
O20.0219 (5)0.0155 (5)0.0231 (5)−0.0012 (4)0.0087 (4)0.0059 (4)
O10.0234 (5)0.0134 (5)0.0205 (5)−0.0019 (4)0.0090 (4)0.0031 (4)
C110.0225 (6)0.0095 (5)0.0171 (6)−0.0009 (5)0.0106 (5)−0.0026 (5)
C140.0228 (7)0.0119 (6)0.0174 (6)0.0003 (5)0.0110 (5)−0.0002 (5)
C180.0234 (7)0.0130 (6)0.0206 (7)0.0000 (5)0.0107 (6)0.0037 (5)
C20.0296 (8)0.0134 (6)0.0292 (8)−0.0063 (6)0.0159 (6)−0.0055 (6)
C160.0196 (6)0.0135 (6)0.0192 (6)0.0003 (5)0.0078 (5)−0.0001 (5)
C70.0243 (7)0.0137 (6)0.0202 (7)−0.0002 (5)0.0122 (6)−0.0005 (5)
C130.0214 (7)0.0144 (6)0.0155 (6)0.0007 (5)0.0080 (5)−0.0011 (5)
C80.0235 (7)0.0105 (6)0.0170 (6)−0.0017 (5)0.0099 (5)−0.0018 (5)
C90.0232 (7)0.0140 (6)0.0176 (6)−0.0024 (5)0.0081 (6)−0.0015 (5)
C60.0310 (8)0.0147 (6)0.0214 (7)−0.0024 (5)0.0158 (6)0.0000 (5)
B10.0228 (8)0.0131 (7)0.0182 (7)−0.0004 (5)0.0111 (6)−0.0004 (5)
C150.0207 (6)0.0142 (6)0.0215 (7)−0.0014 (5)0.0106 (6)−0.0008 (5)
C50.0386 (9)0.0156 (7)0.0207 (7)−0.0018 (6)0.0153 (6)−0.0020 (5)
C210.0284 (7)0.0160 (7)0.0263 (7)−0.0033 (6)0.0118 (6)0.0005 (6)
C40.0291 (7)0.0154 (6)0.0273 (7)−0.0018 (6)0.0165 (6)−0.0046 (6)
C100.0305 (8)0.0149 (6)0.0153 (6)−0.0012 (5)0.0090 (6)0.0011 (5)
C120.0210 (6)0.0127 (6)0.0185 (6)−0.0031 (5)0.0102 (5)−0.0032 (5)
C170.0246 (7)0.0128 (6)0.0241 (7)0.0002 (5)0.0122 (6)0.0038 (5)
C220.0303 (8)0.0157 (6)0.0308 (8)−0.0003 (6)0.0193 (7)0.0017 (6)
C30.0316 (8)0.0103 (6)0.0272 (7)0.0015 (5)0.0140 (6)0.0007 (5)
C200.0302 (8)0.0184 (7)0.0438 (10)0.0026 (6)0.0205 (8)−0.0005 (7)
C190.0293 (8)0.0348 (9)0.0256 (8)0.0004 (7)0.0090 (7)0.0131 (7)
C10.0274 (8)0.0194 (7)0.0216 (7)−0.0019 (6)0.0057 (6)−0.0056 (6)
Geometric parameters (Å, °) top
Fe1—C62.0357 (14)C13—C121.3885 (19)
Fe1—C32.0388 (14)C13—H130.9300
Fe1—C102.0431 (14)C8—C91.435 (2)
Fe1—C42.0454 (15)C9—C101.4220 (19)
Fe1—C72.0477 (14)C9—H90.9300
Fe1—C22.0492 (14)C6—C101.422 (2)
Fe1—C92.0488 (14)C6—H60.9300
Fe1—C12.0512 (15)C15—H150.9300
Fe1—C52.0558 (15)C5—C41.419 (2)
Fe1—C82.0626 (14)C5—C11.427 (2)
O2—B11.3695 (19)C5—H50.9300
O2—C181.4636 (16)C21—H21A0.9600
O1—B11.3626 (19)C21—H21B0.9600
O1—C171.4663 (16)C21—H21C0.9600
C11—C121.4007 (19)C4—C31.424 (2)
C11—C161.4020 (19)C4—H40.9300
C11—C81.4718 (18)C10—H100.9300
C14—C131.3998 (19)C12—H120.9300
C14—C151.403 (2)C17—C191.516 (2)
C14—B11.557 (2)C17—C201.525 (2)
C18—C211.519 (2)C22—H22A0.9600
C18—C221.524 (2)C22—H22B0.9600
C18—C171.567 (2)C22—H22C0.9600
C2—C31.426 (2)C3—H30.9300
C2—C11.426 (2)C20—H20A0.9600
C2—H20.9300C20—H20B0.9600
C16—C151.3887 (19)C20—H20C0.9600
C16—H160.9300C19—H19A0.9600
C7—C61.426 (2)C19—H19B0.9600
C7—C81.4405 (19)C19—H19C0.9600
C7—H70.9300C1—H10.9300
C6—Fe1—C3119.34 (6)C11—C8—Fe1129.97 (9)
C6—Fe1—C1040.82 (6)C10—C9—C8108.51 (13)
C3—Fe1—C10104.60 (6)C10—C9—Fe169.45 (8)
C6—Fe1—C4155.59 (6)C8—C9—Fe170.09 (8)
C3—Fe1—C440.80 (6)C10—C9—H9125.7
C10—Fe1—C4120.46 (6)C8—C9—H9125.7
C6—Fe1—C740.89 (6)Fe1—C9—H9126.3
C3—Fe1—C7156.19 (6)C10—C6—C7108.43 (12)
C10—Fe1—C768.79 (6)C10—C6—Fe169.87 (8)
C4—Fe1—C7162.19 (6)C7—C6—Fe170.01 (8)
C6—Fe1—C2105.52 (6)C10—C6—H6125.8
C3—Fe1—C240.82 (6)C7—C6—H6125.8
C10—Fe1—C2121.05 (6)Fe1—C6—H6125.9
C4—Fe1—C268.57 (6)O1—B1—O2114.03 (12)
C7—Fe1—C2121.64 (6)O1—B1—C14123.86 (13)
C6—Fe1—C968.60 (6)O2—B1—C14122.06 (13)
C3—Fe1—C9121.93 (6)C16—C15—C14121.35 (13)
C10—Fe1—C940.67 (5)C16—C15—H15119.3
C4—Fe1—C9107.46 (6)C14—C15—H15119.3
C7—Fe1—C968.77 (6)C4—C5—C1108.05 (13)
C2—Fe1—C9157.80 (6)C4—C5—Fe169.37 (8)
C6—Fe1—C1123.42 (6)C1—C5—Fe169.50 (9)
C3—Fe1—C168.54 (6)C4—C5—H5126.0
C10—Fe1—C1158.56 (6)C1—C5—H5126.0
C4—Fe1—C168.41 (6)Fe1—C5—H5126.7
C7—Fe1—C1108.84 (6)C18—C21—H21A109.5
C2—Fe1—C140.69 (6)C18—C21—H21B109.5
C9—Fe1—C1160.07 (6)H21A—C21—H21B109.5
C6—Fe1—C5161.33 (7)C18—C21—H21C109.5
C3—Fe1—C568.38 (6)H21A—C21—H21C109.5
C10—Fe1—C5157.54 (7)H21B—C21—H21C109.5
C4—Fe1—C540.47 (6)C5—C4—C3108.11 (13)
C7—Fe1—C5126.07 (6)C5—C4—Fe170.16 (9)
C2—Fe1—C568.40 (6)C3—C4—Fe169.36 (8)
C9—Fe1—C5123.65 (6)C5—C4—H4125.9
C1—Fe1—C540.67 (6)C3—C4—H4125.9
C6—Fe1—C868.88 (5)Fe1—C4—H4126.1
C3—Fe1—C8159.79 (6)C9—C10—C6108.03 (12)
C10—Fe1—C868.77 (5)C9—C10—Fe169.88 (8)
C4—Fe1—C8124.87 (6)C6—C10—Fe169.31 (8)
C7—Fe1—C841.03 (5)C9—C10—H10126.0
C2—Fe1—C8158.96 (6)C6—C10—H10126.0
C9—Fe1—C840.85 (6)Fe1—C10—H10126.4
C1—Fe1—C8124.36 (6)C13—C12—C11120.85 (13)
C5—Fe1—C8110.09 (6)C13—C12—H12119.6
B1—O2—C18107.39 (11)C11—C12—H12119.6
B1—O1—C17107.07 (11)O1—C17—C19107.88 (12)
C12—C11—C16118.08 (12)O1—C17—C20106.56 (12)
C12—C11—C8121.46 (12)C19—C17—C20110.78 (14)
C16—C11—C8120.36 (13)O1—C17—C18102.89 (11)
C13—C14—C15117.52 (12)C19—C17—C18114.64 (12)
C13—C14—B1121.73 (13)C20—C17—C18113.31 (12)
C15—C14—B1120.50 (13)C18—C22—H22A109.5
O2—C18—C21108.44 (11)C18—C22—H22B109.5
O2—C18—C22106.79 (11)H22A—C22—H22B109.5
C21—C18—C22110.03 (12)C18—C22—H22C109.5
O2—C18—C17102.54 (10)H22A—C22—H22C109.5
C21—C18—C17114.71 (12)H22B—C22—H22C109.5
C22—C18—C17113.65 (12)C4—C3—C2108.11 (13)
C3—C2—C1107.76 (13)C4—C3—Fe169.85 (8)
C3—C2—Fe169.20 (8)C2—C3—Fe169.98 (8)
C1—C2—Fe169.73 (8)C4—C3—H3125.9
C3—C2—H2126.1C2—C3—H3125.9
C1—C2—H2126.1Fe1—C3—H3125.8
Fe1—C2—H2126.5C17—C20—H20A109.5
C15—C16—C11120.74 (13)C17—C20—H20B109.5
C15—C16—H16119.6H20A—C20—H20B109.5
C11—C16—H16119.6C17—C20—H20C109.5
C6—C7—C8107.89 (13)H20A—C20—H20C109.5
C6—C7—Fe169.10 (8)H20B—C20—H20C109.5
C8—C7—Fe170.04 (8)C17—C19—H19A109.5
C6—C7—H7126.1C17—C19—H19B109.5
C8—C7—H7126.1H19A—C19—H19B109.5
Fe1—C7—H7126.4C17—C19—H19C109.5
C12—C13—C14121.36 (13)H19A—C19—H19C109.5
C12—C13—H13119.3H19B—C19—H19C109.5
C14—C13—H13119.3C2—C1—C5107.97 (14)
C9—C8—C7107.14 (12)C2—C1—Fe169.58 (8)
C9—C8—C11126.85 (12)C5—C1—Fe169.84 (9)
C7—C8—C11125.90 (13)C2—C1—H1126.0
C9—C8—Fe169.06 (8)C5—C1—H1126.0
C7—C8—Fe168.93 (8)Fe1—C1—H1126.1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C6—H6···C12i0.932.863.6302 (19)141
C5—H5···C6ii0.932.623.538 (2)168
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x, −y+3/2, z−1/2.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C6—H6···C12i0.932.863.6302 (19)141
C5—H5···C6ii0.932.623.538 (2)168
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x, −y+3/2, z−1/2.
Acknowledgements top

We thank Tania Groutso for help with the data collection.

references
References top

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