Ferrocene compounds. XXXIX. 1-Ferrocenylisochromane

Article abstract of DOI:10.1107/S0108270103011703

In the title compound, [Fe(C₅H₅)(C₁₄H ₁₃O)], the plane of the heterocyclic ring is almost perpendicular to the plane of the substituted cyclopentadienyl ring, and the heterocyclic ring adopts a half-chair conformation. The conformation of the nearly parallel cyclopentadienyl (Cp) rings [the dihedral angle between their planes is 2.7 (1)°] is almost halfway between eclipsed and staggered, and the rings are mutually twisted by about 19.4 (2)° (mean value). The mean lengths of the C - C bonds in the substituted and unsubstituted cyclopentadienyl ring are 1.420 (2) and 1.406 (3) A, respectively, and the Fe - C distances range from 2.029 (2) to 2.051 (2) A. The phenyl and unsubstituted cyclopentadienyl rings are involved in C - H...π interactions, with intermolecular H...centroid distances of 2.85 and 3.14 A for C - H...π(Ph), and 2.88 A° for C - H...π(Cp). In two of these interactions, the C - H bond points towards one of the ring bonds rather than towards the ring centroid. In the crystal structure, the C - H...π interactions connect the molecules into a three-dimensional framework.

Full text of DOI:10.1107/S0108270103011703

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
racemic 2-(ꢁ-hydroxyferrocenyl)benzenethanol and 1-ferro-
cenylisochromane, (I), were prepared by reduction of methyl
Â
2-(ferrocenoyl)benzeneacetate („akovic, 2000).
ISSN 0108-2701
Ferrocene compounds. XXXIX.1
1-Ferrocenylisochromane
a
b
Â
Âb
Mario Cetina, Senka „akovic, Vladimir Rapic * and
Ïc
Amalija Golobic
The molecular structure of (I) is the ®rst reported structure
to contain an isochromanyl group attached to the ferrocenyl
moiety (Fig. 1). Moreover, the Cambridge Structural Database
(Allen, 2002) lists only three structures containing an iso-
chromanyl group at all (Yamato et al., 1984; Unterhalt et al.,
1994; Eikawa et al., 1999). The heterocyclic six-membered ring
aFaculty of Textile Technology, University of Zagreb, Pierottijeva 6, HR-10000
Zagreb, Croatia, bLaboratory of Organic Chemistry, University of Zagreb, Faculty of
Food Technology and Biotechnology, Pierottijeva 6, HR-10000 Zagreb, Croatia, and
cLaboratory of Inorganic Chemistry, Faculty of Chemistry and Chemical Technology,
University of Ljubljana, PO Box 537, SI-1001 Ljubljana, Slovenia
Correspondence e-mail: vrapic@pbf.hr
Received 14 April 2003
Accepted 27 May 2003
Online 22 July 2003
In the title compound, [Fe(C5H5)(C14H13O)], the plane of the
heterocyclic ring is almost perpendicular to the plane of the
substituted cyclopentadienyl ring, and the heterocyclic ring
adopts a half-chair conformation. The conformation of the
nearly parallel cyclopentadienyl (Cp) rings [the dihedral angle
between their planes is 2.7 (1)ꢀ] is almost halfway between
eclipsed and staggered, and the rings are mutually twisted by
about 19.4 (2)ꢀ (mean value). The mean lengths of the CÐC
bonds in the substituted and unsubstituted cyclopentadienyl
Ê
ring are 1.420 (2) and 1.406 (3) A, respectively, and the FeÐC
Ê
distances range from 2.029 (2) to 2.051 (2) A. The phenyl and
unsubstituted cyclopentadienyl rings are involved in
Figure 1
A view of (I), with the atom-numbering scheme. Displacement ellipsoids
for non-H atoms are drawn at the 20% probability level.
CÐHÁ Á Áꢀ interactions, with intermolecular HÁ Á Ácentroid
Ê
Ê
distances of 2.85 and 3.14 A for CÐHÁ Á Áꢀ(Ph), and 2.88 A
for CÐHÁ Á Áꢀ(Cp). In two of these interactions, the CÐH
bond points towards one of the ring bonds rather than towards
the ring centroid. In the crystal structure, the CÐHÁ Á Áꢀ
interactions connect the molecules into a three-dimensional
framework.
Comment
Optically active ferrocene derivatives are widely employed as
chiral ligands in asymmetric reactions, and there is continuing
interest in the development of ef®cient procedures for the
preparation of these derivatives in enantiopure forms
(Gonsalves & Chen, 1995; Bolm et al., 1998; Pioda & Togni,
1998; Perea et al., 1999). Ferrocene derivatives exhibiting
centro- and planar chirality are very convenient substrates for
È
biotransformations (Kollner et al., 1998; Richards & Locke,
1998; Schwink & Knochel, 1998; Patti & Nicolosi, 1999;
Â
„akovic et al., 2003). In the course of our research on enzyme-
catalyzed resolution of centrochiral ferrocene compounds,
Figure 2
Part of the crystal structure of (I), showing the formation of (010) sheets
built from C14ÐH14AÁ Á ÁCg1i and C18ÐH18Á Á ÁCg2ii interactions (Cg1
and Cg2 are the centroids of rings C12/C13/C16±C19 and C6±C10,
respectively). CÐHÁ Á Áꢀ interactions are indicated by dashed lines.
[Symmetry codes: (i) x, 12 y, z 12; (ii) 1 + x, y, 1 + z.]
1 Part XXXVIII: Cetina et al. (2003).
m328 # 2003 International Union of Crystallography
DOI: 10.1107/S0108270103011703
Acta Cryst. (2003). C59, m328±m330

metal-organic compounds
adopts a distorted half-chair conformation, in which atoms O1
Ê
and C15 are 0.426 (1) and 0.348 (2) A from the plane of the
ferrocene derivatives we have reported previously (Cetina et
al., 2002, 2003). The main conformational difference was
observed in the orientation of the Cp rings. In (I), the rings are
twisted from an eclipsed conformation by 19.4 (2)ꢀ (mean
value). The values of the corresponding CÐCg3ÐCg2ÐC
pseudo-torsion angles (Cg3 and Cg2 are the centroids of the
C1±C5 and C6±C10 rings, respectively), de®ned by joining two
eclipsing Cp C atoms through the ring centroids, range from
19.0 (2) to 19.7 (2)ꢀ. The conformation is almost exactly
halfway between eclipsed and staggered, as demonstrated by
the C1ÐCg3ÐCg2ÐC9 torsion angle of 163.4 (1)ꢀ. This angle
would be 180ꢀ for a staggered conformation and 144ꢀ for a
fully eclipsed conformation. The centroids of the Cp rings are
almost equidistant from the Fe atom; the FeÐCg3 and FeÐ
other ring atoms (C11±C14); the C11ÐC12ÐC13ÐC14
torsion angle is 2.4 (2)ꢀ. The bond lengths in the heterocyclic
and fused phenyl rings (Table 1) mostly agree with the
equivalent bond lengths in the structures of 1,10-oxybis(iso-
chromane) (Eikawa et al., 1999) and (S)-1-(phenyl)ethyl-
ammonium (S)-isochromane-1-carboxylate (Unterhalt et al.,
1994). The exception is the C12ÐC13 bond, which is shorter
Ê
(ꢁ0.04 A) in the latter structure. Heterocyclic ring atoms O1,
C11 and C15 and cyclopentadienyl (Cp) ring atom C1 lie in the
same plane, the C15ÐO1ÐC11ÐC1 torsion angle being
178.95 (14)ꢀ. The dihedral angle between the mean plane of
these four atoms and the C1±C5 Cp ring is 47.8 (1)ꢀ.
Furthermore, the plane of the heterocyclic ring is almost
perpendicular to the plane of the C1±C5 ring and is parallel to
the plane of the fused phenyl ring. The corresponding dihedral
angles are 87.3 (1) and 4.0 (1)ꢀ.
Ê
Cg2 distances are 1.647 (1) and 1.650 (1) A, respectively, while
the Cg3ÐFeÐCg2 angle is 178.2 (1)ꢀ.
There are a number of CÐHÁ Á Áꢀ interactions (Table 2 and
Fig. 2). Atom H14A of the heterocyclic ring is positioned
almost perpendicularly above the phenyl-ring centroid (Cg1)
of the adjacent molecule. The six relevant HÁ Á ÁC distances fall
The exocyclic C2ÐC1ÐC11 bond angle is larger than the
C5ÐC1ÐC11 angle (Table 1). The Cp rings are planar and
almost parallel to each other [the dihedral angle between their
planes is 2.7 (1)ꢀ], and the FeÐC distances are in the range
i
Ê
in the narrow range 3.06±3.28 A, and the HÁ Á ÁCg distance is
signi®cantly shorter than any of the HÁ Á ÁC distances
1
2.034 (2)±2.051 (2) A for the substituted (C1±C5) and
[symmetry code: (i) x,
y, z 12; Table 2]. The CÐHÁ Á Áꢀ
Ê
2
Ê
2.029 (2)±2.049 (2) A for the unsubstituted (C6±C10) ring, the
Ê
average values being 2.042 (2) and 2.038 (2) A, respectively.
The CÐC bonds are slightly longer in the substituted ring than
in the unsubstituted ring [1.410 (3)±1.429 (2) versus 1.397 (3)±
interaction between phenyl atom H18 and the unsubstituted
Cp ring exhibits a completely different geometry. The
H18Á Á ÁC7ii distance is shorter than the HÁ Á ÁCgii distance
[symmetry code: (ii) 1 + x, y, 1 + z]. The second shortest
HÁ Á ÁC contact is that to atom C6, and the CÐH bond points
towards the C6ÐC7 bond of the Cp ring rather than towards
the ring centroid (Cg2). Similarly, the longest interaction,
C5ÐH5Á Á ÁCg1iii [symmetry code: (iii) 1 x, y, 2 z], points
towards the C12ÐC13 bond. Both the H5Á Á ÁC12iii and the
H5Á Á ÁC13iii contacts are shorter than the HÁ Á ÁCgiii distance.
The molecules linked by these CÐHÁ Á Áꢀ interactions build a
three-dimensional framework (Fig. 3).
Ê
1.414 (3) A], and the bond angles in both rings range from
107.52 (15) to 108.33 (18)ꢀ.
The geometry of the ferrocenyl moiety agrees well with the
structures of ferrocene (Seiler & Dunitz, 1979) and of the
Experimental
NaBH4 (253 mg, 6.7 mmol) was added gradually to a solution of
methyl 2-(ferrocenoyl)benzeneacetate (326 mg, 0.9 mmol) in a
mixture of EtOH and Et2O (1:1 v/v; 5 ml). The mixture was re¯uxed
for 2 h and worked up in the usual manner. Separation by preparative
thin-layer chromatography on silica gel (Merck, Kieselgel 60 HF254
)
yielded 2-(ꢁ-hydroxyferrocenyl)benzeneethanol (237 mg; yield 78%)
and orange crystals of 1-ferrocenylisochromane (57 mg; yield 20%;
m.p. 365±366 K). Single crystals of the title compound were obtained
by slow evaporation from a cyclohexane solution at room tempera-
ture. IR (CH2Cl2, cm 1): ꢂ 3081 (w) and 3020 (w) (CÐH, ferrocene),
2942 (m) (CÐH, aliphatic), 1278 (m) (CÐOÐC); 1H NMR (DMSO,
p.p.m.): ꢃ 7.18 (d, 1H, H16), 7.12 (d, 1H, H17), 7.14 (d, 1H, H18), 7.16
(d, 1H, H19), 4.23 (s, 5H, unsubstituted ferrocene ring), 4.13±4.20 (m,
4H, substituted ferrocene ring), 3.97 (m, 1H, H15A), 3.77 (m, 1H,
H15B), 2.78 (m, 2H, H14), 5.58 (s, 1H, H11); 13C NMR (DMSO,
p.p.m.): ꢃ 137.29 (C12), 132.91 (C13), 128.5 (C17), 126.25 (C18),
125.98 (C16), 125.36 (C19), 90.21 (C1), 73.63 (C11), 68.62 (unsub-
stituted ferrocene ring), 68.56±66.31 (substituted ferrocene ring),
61.55 (C15), 27.99 (C14).
Figure 3
Part of the crystal structure of (I), showing the cyclic motif generated by
the C5ÐH5Á Á ÁCg1iii interaction (Cg1 is the centroid of ring C12/C13/
C16±C19), which links the (010) sheets into a three-dimensional
framework. CÐHÁ Á Áꢀ interactions are indicated by dashed lines, and
the unit-cell box has been omitted for clarity. [Symmetry code: (iii) 1 x,
y, 2 z.]
ꢂ
Acta Cryst. (2003). C59, m328±m330
Mario Cetina et al. [Fe(C5H5)(C14H13O)] m329

metal-organic compounds
Crystal data
All H atoms were included in calculated positions as riding atoms,
Ê
3
with SHELXL97 (Sheldrick, 1997) defaults viz. CÐH = 0.93 A for
[Fe(C5H5)(C14H13O)]
Mr = 318.18
Monoclinic, P21=c
a = 11.5053 (2) A
Ê
b = 18.5095 (3) A
Dx = 1.442 Mg m
Mo Kꢁ radiation
Ê
Ê
aromatic H atoms, 0.98 A for methine H atoms, and 0.97 A for
methylene H atoms. For all H atoms, the isotropic displacement
parameters were set at 1.2 times the equivalent anisotropic
displacement parameters of the attached non-H atoms.
Cell parameters from 3411
re¯ections
Ê
ꢅ = 2.6±27.5ꢀ
ꢆ = 1.02 mm
T = 293 (2) K
1
Ê
c = 7.1941 (1) A
ꢄ = 106.933 (1)ꢀ
V = 1465.62 (4) A
Z = 4
Data collection: COLLECT (Nonius, 2000); cell re®nement:
DENZO±SMN (Otwinowski & Minor, 1997); data reduction:
DENZO±SMN; program(s) used to solve structure: SHELXS97
(Sheldrick, 1997); program(s) used to re®ne structure: SHELXL97
(Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); soft-
ware used to prepare material for publication: SHELXL97.
3
Ê
Prism, orange
0.80 Â 0.40 Â 0.15 mm
Data collection
Nonius KappaCCD area-detector
diffractometer
' and ! scans
Absorption correction: multi-scan
(DENZO±SMN; Otwinowski &
Minor, 1997)
Tmin = 0.630, Tmax = 0.857
16 885 measured re¯ections
3334 independent re¯ections
2662 re¯ections with I > 2ꢇ(I)
Rint = 0.064
ꢅ
max = 27.4ꢀ
The re¯ection data were collected at the Faculty of Chem-
istry and Chemical Technology, University of Ljubljana,
Slovenia. We acknowledge with thanks the ®nancial contri-
bution of the Ministry of Education, Science and Sport of the
Republic of Slovenia (grant Nos. X-2000 and PS-511-103),
which made the purchase of the apparatus possible.
h = 14 ! 14
k = 23 ! 23
l = 9 ! 9
Re®nement
Re®nement on F2
R[F2> 2ꢇ(F2)] = 0.030
wR(F2) = 0.076
S = 1.03
3334 re¯ections
w = 1/[ꢇ2(F2o) + (0.0341P)2
+ 0.3545P]
where P = (F2o + 2Fc2)/3
(Á/ꢇ)max = 0.001
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GD1251). Services for accessing these data are
described at the back of the journal.
3
Ê
Áꢈmax = 0.25 e A
3
Ê
0.23 e A
190 parameters
H-atom parameters constrained
Áꢈmin
=
Table 1
Selected geometric parameters (A, ).
ꢀ
Ê
References
O1ÐC11
O1ÐC15
C1ÐC11
C11ÐC12
C12ÐC16
C12ÐC13
1.4236 (19)
1.432 (2)
1.503 (2)
1.523 (2)
1.388 (2)
1.397 (2)
C13ÐC19
C13ÐC14
C14ÐC15
C16ÐC17
C17ÐC18
C18ÐC19
1.392 (3)
1.504 (3)
1.501 (3)
1.384 (3)
1.380 (3)
1.379 (3)
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Â
Bolm, C., MunÄiz-Fernandez, K., Seger, A., Raabe, G. & Gunther, K. (1998). J.
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  Â
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Ï
Â
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Â
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Â
„akovic, S. (2000). PhD thesis, University of Zagreb, Croatia.
C11ÐO1ÐC15
C2ÐC1ÐC11
C5ÐC1ÐC11
O1ÐC11ÐC1
O1ÐC11ÐC12
110.39 (13)
127.61 (14)
124.78 (14)
109.37 (13)
111.64 (13)
C1ÐC11ÐC12
C13ÐC12ÐC11
C12ÐC13ÐC14
C15ÐC14ÐC13
O1ÐC15ÐC14
112.14 (13)
119.77 (14)
120.38 (16)
111.24 (15)
110.04 (15)
Â
Â
Â
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È
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Table 2
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ꢀ
Ê
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Perea, J. J. A., Lotz, M. & Knochel, P. (1999). Tetrahedron: Asymmetry, 10,
375±384.
Cg1 and Cg2 are the centroids of rings C12/C13/C16±C19 and C6±C10,
respectively.
Pioda, G. & Togni, A. (1998). Tetrahedron: Asymmetry, 9, 3903±3910.
Richards, C. J. & Locke, A. (1998). Tetrahedron: Asymmetry, 9, 2377±2407.
Schwink, L. & Knochel, P. (1998). Chem. Eur. J. 4, 950±968.
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Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
C14ÐH14AÁ Á ÁCg1i
C18ÐH18Á Á ÁCg2ii
C18ÐH18Á Á ÁC7ii
C18ÐH18Á Á ÁC6ii
C5ÐH5Á Á ÁCg1iii
C5ÐH5Á Á ÁC12iii
C5ÐH5Á Á ÁC13iii
0.97
0.93
0.93
0.93
0.93
0.93
0.93
2.85
2.88
2.86
3.03
3.14
2.98
3.02
3.627 (2)
3.660 (2)
3.760 (3)
3.874 (3)
3.984 (2)
3.840 (2)
3.949 (2)
138
142
163
151
152
154
177
È
Gottingen, Germany.
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Unterhalt, B., Krebs, B., Lage, M. & Nocon, B. (1994). Arch. Pharm. 327, 799±
804.
Yamato, M., Hashigaki, K., Kokubu, N. & Nakato, Y. (1984). J. Chem. Soc.
Perkin Trans. 1, pp. 1301±1304.
Symmetry codes: (i) x; 12 y; z 21; (ii) 1 ‡ x; y; 1 ‡ z; (iii) 1 x; y; 2 z.
ꢂ
m330 Mario Cetina et al.
[Fe(C5H5)(C14H13O)]
Acta Cryst. (2003). C59, m328±m330