4-Ferrocenylphenol

Vincent O Nyamori; Muhammad D Bala

doi:10.1107/S1600536808039524

. 2008 Nov 29;64(Pt 12):m1630. doi: 10.1107/S1600536808039524

4-Ferrocenylphenol

Vincent O Nyamori ^a, Muhammad D Bala ^a,^*

PMCID: PMC2960122 PMID: 21581220

Abstract

The title compound, [Fe(C₅H₅)(C₁₁H₉O)], is of interest as a precursor to the synthesis of cheap ferrocene-based liquid crystals. The –OH substituent only results in weak C—H⋯O weak interactions between one of cyclopentadienyl (Cp) ring H atoms and the O atom of a neighbouring molecule with a distance of 3.308 (3) Å between the donor and acceptor atoms. The interplanar angle between the Cp and benzene rings is 13.0 (4)°. There are also weak O—H⋯π and C—H⋯π interactions involving the unsubstituted Cp and the benzene ring, respectively.

Related literature

For general background, see: Togni & Hayashi (1995 ▶); Imrie et al. (2002 ▶). For related structures, see: Imrie et al. (2003 ▶); Nyamori & Bala (2008a ▶,b ▶). For related syntheses, see: Guillaneux & Kagan (1995 ▶); Foxman & Rosenblum (1993 ▶); Tsukazaki et al. (1996 ▶); Lin et al. (1995 ▶); Knapp & Rehahn, (1993 ▶).

Experimental

Crystal data

[Fe(C₅H₅)(C₁₁H₉O)]
M _r = 278.12
Orthorhombic,
a = 9.950 (2) Å
b = 7.9205 (17) Å
c = 31.046 (6) Å
V = 2446.8 (9) Å³
Z = 8
Mo Kα radiation
μ = 1.22 mm⁻¹
T = 173 (2) K
0.42 × 0.22 × 0.07 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: integration (XPREP; Bruker, 2005 ▶) T _min = 0.750, T _max = 0.929
14324 measured reflections
3039 independent reflections
2214 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.084
S = 1.02
3039 reflections
164 parameters
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.42 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-NT (Bruker, 2005 ▶); data reduction: SAINT-NT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808039524/dn2401sup1.cif

e-64-m1630-sup1.cif^{(24.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808039524/dn2401Isup2.hkl

e-64-m1630-Isup2.hkl^{(146.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O1ⁱ	0.95	2.55	3.308 (3)	137
O1—H1A⋯Cg3ⁱⁱ	0.84	2.66	3.281 (2)	141
C2—H2⋯Cg1ⁱⁱⁱ	0.95	2.90	3.766 (2)	155

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg1 and Cg3 are the centroids of the unsubstituted Cp and the benzene rings, respectively.

Acknowledgments

We thank Dr Manuel Fernandez for data collection, and the University of KwaZulu-Natal and the NRF for financial support.

supplementary crystallographic information

Comment

The synthesis of arylferrocenes especially compounds prepared by the reaction of para-substituted anilines via diazonium reactions to yield phenylferrocenes has evoked the interest of material scientists (Togni & Hayashi, 1995). For example, arylferrocenes have been established as precursors in the synthesis of ferrocenomesogens especially those with ferrocenyl moiety incorporated as a terminal group (Imrie et al., 2002). These class of compounds are most readily prepared by cross-coupling reactions, e.g. of iodoferrocene (Imrie et al., 2003) with arylboronic (Tsukazaki et al., 1996) and organotin compounds (Lin et al., 1995). Alternative cross-coupling reagents include aryl halides with tin (Guillaneux & Kagan, 1995), zinc (Foxman & Rosenblum, 1993) and ferrocenylboronic acids (Knapp & Rehahn, 1993). In this paper we report the synthesis of 4-hydroxyphenylferrocene using 4-aminophenol which was obtained via diazonium reaction.

The title compound (I) (Fig. 1) is a precursor prepared as part of a study to develop starting materials from cheaper sources for the development of new ionic liquid and liquid crystal materials (Nyamori & Bala, 2008a; 2008b). Due to the –OH subtituent on the benzyl ring it was thought that the property of (I) will be dominated by intra- or intermolecular hydrogen bonding, but analysis revealed no classical hydrogen bonds. Hence, the high melting point of 162 ^oC may be attributed to a concerted contribution from all molecular contacts within the crystal of (I) (Table 1: Cg(1) is the centroid of the unsubstituted Cp and Cg(3) the centroid of the benzene ring).

In the crystal of (I), the two cp rings are marginally tilted towards each other with a tilt angle between the planes of the two rings of 0.41 (5)°, while the interplanar angle between the cp and the phenyl ring is 13.0 (4)°.

Experimental

In an excess of 2M hydrochloric acid at 5 °C was dissolved 4-aminophenol (12.00 g, 0.11 mol) followed by slow addition of sodium nitrite (8.00 g, 0.11 mol) in cold water (20 cm³) also at 5 °C. The solution was left to stir at this temperature for 30 min and the resultant solution was filtered. The filtrate was immediately added to a cold thoroughly stirred solution of ferrocene (18.00 g, 0.10 mol) in diethyl ether (500 cm³). Stirring was continued at 5 °C for 8 h. The ether layer was then separated, washed with water (3 x 100 cm³) and dried over anhydrous sodium sulfate. The solution was concentrated and the residue was passed through a column of alumina. Dichloromethane: hexane (1:1) eluted unreacted ferrocene. Further elution of the column with diethyl ether yielded 4-ferrocenylphenol (5.22 g, 32%) as yellow crystals recrystallized from hexane, mp 162 ^oC.

FTIR: ν_max(KBr/cm^-1) 3515, 3091, 1901, 1607, 1525, 1454, 1434, 1264, 1210, 1176, 1102, 1027, 998, 885, 839, 816, 665, 620; ¹H-NMR: δ_H(CDCl₃) 7.38(2H, d, J 8.5, ArH), 6.79(2H, d, J 8.1, ArH), 4.87(1H, s,OH), 4.58(2H, t, J 1.9, C₅H₄), 4.28(2H, t, J 1.9, C₅H₄), 4.05(5H, s, C₅H₅); ¹³C-NMR: δ_C(CDCl₃) 154.25, 131.88, 127.76, 115.70, 86.192, 69.87, 68.89, 66.51; EI–MS 70 eV m/z (%): 280(39%), 277(M⁺, 81%), 276(100%), 220(10%), 213(39%); Found: M⁺, 278.0388 for C₁₆H₁₄FeO, requires M, 278.0392.