Macrocyclic Di- and tetranuclear osmacycloferrocenophanes

Article abstract of DOI:10.1021/om020310l

The novel dinuclear and tetranuclear ortho-, meta-, and para-osmacycloferrocenophanes [η⁵-C₅H₄(CH₂)_n-1,m-C ₆H₄(CH₂)_nOs(CO)₄(CH₂ )

Full text of DOI:10.1021/om020310l

Organometallics 2002, 21, 4217-4225
4217
Ma cr ocyclic Di- a n d Tetr a n u clea r
Osm a cyclofer r ocen op h a n es†,1
Ekkehard Lindner,* Christoph S. Ayasse, Klaus Eichele, and Manfred Steimann
Universita¨t Tu¨bingen, Institut fu¨r Anorganische Chemie, Auf der Morgenstelle 18,
72076 Tu¨bingen, Germany
Received April 18, 2002
The novel dinuclear and tetranuclear ortho-, meta-, and para-osmacycloferrocenophanes
[η5-C5H4(CH2)n-1,m-C6H4(CH2)nOs(CO)4(CH2)n-1,m-C6H4(CH2)nC5H4-η5]xFex (n ) 2-4, m )
2-4; x ) 1: 3a -h ; x ) 2: 4a -h ) have been made available by the reaction of the corresponding
bis(triflates) [η5-C5H4(CH2)n-1,m-C6H4(CH2)nOTf]2Fe (2a -h ) with Na2[Os(CO)4] in refluxing
dimethyl ether. The macrocycles of 3b,c,e and 4a ,h were investigated by X-ray structural
analyses and consist of an extended hydrocarbon skeleton containing additionally two and
four transition metal centers, respectively. In the case of the dinuclear osmacycloferro-
cenophanes 3a -h the redox behavior was examined by means of cyclic voltammetry, and
the results were compared with those of the bis(alcohols) 1a -h , which were used as starting
compounds for the bis(triflates) 2a -h . With increasing chain length the ferrocene unit is
easier oxidized, and in the case of 3f-h the E1/2 values are in the region of diethylferrocene.
In tr od u ction
of transition metal fragments, their introduction into
the framework of these systems affects the geometric
parameters of the cavities.11,12 Simultaneously a new
reactive center is obtained that is capable of inserting
small molecules, like carbon monoxide,11a,b into metal-
carbon σ bonds and of reacting with a new ligand if a
vacant coordination site is available.13 With the incor-
poration of coordination chemistry into supramolecular
chemistry self-assembly14 resulted in a breakthrough
in the field of molecular manufacturing of molecular
polygons and polyhedra. The specific integration of
heteroatoms (N, O, S) into the framework of cyclophanes
or metallocenophanes leads to systems with particular
complexation abilities suitable for molecular recogni-
tion.15 Considerable chemical and physical properties
are expected if additional metals are in the proximity
of the redox active ferrocene unit.16
Cyclophanes2 with subgroups such as calixarenes3 or
cryptophanes4 and other macromolecules of this type
play an important role in the development of supramo-
lecular chemistry,5 now expanding to supramolecular
science,6 a multidisciplinary field. Soon after the dis-
covery of ferrocene7 in the early 1950s and the discovery
of its extraordinary features such as aromaticity, ther-
mal stability, and resistance to aerial oxygen, interest
has focused on bridged ferrocenes, denoted as ferro-
cenophanes.8 The collective term of metallocenophanes
and cyclophanes is “phanes”.9 Replacing methylene
groups of the bridging chains in these macrocycles by
transition metals affords metallametallocenophanes10
and metallacyclophanes.11 Due to the steric requirement
† Dedicated to Professor Wolfgang Beck on the occasion of his 70th
birthday.
With the intention to merge osmacyclophanes11 and
osmaferrocenophanes,10 the objective of this investiga-
tion was the synthesis of the two-dimensional osmacy-
cloferrocenophanes 3a -h and diosmacycloferroceno-
phanes 4a -h containing two and four transition metal
centers, respectively. These macrocycles differ in the
* To
whom
correspondence
should
be
sent.
E-mail:
ekkehard.lindner@uni-tuebingen.de.
(1) Preparation, Properties, and Reactions of Metal-Containing
Heterocycles. Part 107. Part 106: Lindner, E.; Khanfar, M. J . Orga-
nomet. Chem. 2001, 630, 244.
(2) (a) Vo¨gtle, F. Cyclophan-Chemie; Teubner: Stuttgart, 1990. (b)
Diederich, F. Cyclophanes; The Royal Society of Chemistry: Cam-
bridge, 1991. (c) Vo¨gtle, F.; Seel, C.; Windscheif, P.-M. In Comprehen-
sive Supramolecular Chemistry; Atwood, J . L., Davies, J . E. D.,
MacNicol, D. D., Vo¨gtle, F., Lehn, J . M., Eds.; Pergamon: Oxford, 1996;
Vol. 2, p 211.
(3) (a) Ikeda, A.; Shinkai, S. Chem. Rev. 1997, 97, 1713. (b) Rebek,
J ., J r. Chem. Commun. 2000, 637. (c) Ibach, S.; Prautzsch, V.; Vo¨gtle,
F.; Chartroux, C.; Gloe, K. Acc. Chem. Res. 1999, 32, 729.
(4) Collet, A. In Comprehensive Supramolecular Chemistry; Atwood,
J . L., Davies, J . E. D., MacNicol, D. D., Vo¨gtle, F., Lehn, J . M., Eds.;
Pergamon: Oxford, 1996; Vol. 2, p 325.
(5) Lehn, J .-M. Supramolecular Chemistry; VCH: Weinheim, 1995.
(6) Reinhoudt, D. N.; Stoddart, J . F.; Ungaro, R. Chem. Eur. J . 1998,
4, 1349.
(11) (a) Lindner, E.; Pitsch, M. W.; Fawzi, R.; Steimann, M. Chem.
Ber. 1996, 129, 639. (b) Lindner, E.; Wassing, W.; Pitsch, M. W.; Fawzi,
R.; Steimann, M. Inorg. Chim. Acta 1994, 220, 107. (c) Lindner, E.;
Wassing, W.; Fawzi, R.; Steimann, M. Angew. Chem., Int. Ed. Engl.
1994, 33, 321.
(12) J ones, C. J . Chem. Soc. Rev. 1998, 27, 289.
(13) Holliday, B. J .; Mirkin, C. A. Angew. Chem., Int. Ed. 2001, 40,
2022.
(14) (a) Stang, P. J .; Olenyuk, B. Acc. Chem. Res. 1997, 30, 502. (b)
Leininger, S.; Olenyuk, B.; Stang, P. J . Chem. Rev. 2000, 100, 853. (c)
Fujita, M.; Umemoto, K.; Yoshizawa, M.; Fujita, N.; Kusukawa, T.;
Biradha, K. Chem. Commun. 2001, 509.
(15) Weber, E.; Vo¨gtle, F. In Comprehensive Supramolecular Chem-
istry; Atwood, J . L., Davies, J . E. D., MacNicol, D. D., Vo¨gtle, F., Lehn,
J .-M., Eds.; Pergamon: Oxford, 1996; Vol. 2, p 1.
(7) Long, N. J . Metallocenes; Blackwell Science: Oxford, 1998.
(8) (a) Mueller-Westerhoff, U. T. Angew. Chem., Int. Ed. Engl. 1986,
25, 702. (b) Heo, R. W.; Lee, T. R. J . Organomet. Chem. 1999, 578, 31.
(9) Vo¨gtle, F.; Neumann, P. Tetrahedron 1970, 26, 5847.
(10) Lindner, E.; Krebs, I.; Fawzi, R.; Steimann, M.; Speiser, B.
Organometallics 1999, 18, 480.
(16) Barlow, S.; O’Hare, D. Chem. Rev. 1997, 97, 637.
10.1021/om020310l CCC: $22.00 © 2002 American Chemical Society
Publication on Web 08/30/2002

4218 Organometallics, Vol. 21, No. 20, 2002
Lindner et al.
Sch em e 1
1a -h (Scheme 1), several starting materials had to be
made accessible (see also Supporting Information).
Treatment of the tetrahydropyran (THP)-protected cy-
20
clopentadienyl alcohols with FeCl2(THF)1.44 in THF
with subsequent deprotection of the resulting interme-
diates affords the bis(alcohols) 1a -h . After purification
by column chromatography 1a -h were obtained in
moderate to satisfying yields. While the para-com-
pounds 1c,h represent orange waxy solids, the bis-
(alcohols) 1a ,b,d -g are highly viscous yellow oils. All
alcohols 1a -h are readily soluble in chlorinated hydro-
carbons, and their molecular composition was cor-
roborated by elemental analyses and FD mass spectra,
displaying in each case the expected molecular peak.
To attain the bis(triflates) 2a -h in good to excellent
yields, the bis(alcohols) 1a -h were reacted with tri-
fluoromethanesulfonic acid anhydride in the presence
of a slight excess of pyridine at -30 °C in dichlo-
romethane. The yellow, heat-sensitive compounds 2a -h
are easily soluble in common organic solvents and can
be stored below -30 °C for some days. However, it is
recommendable to use them in situ. 2a -h were identi-
1
fied by their mass, H, 13C{1H} NMR, and IR spectra
(see Supporting Information).
Syn th esis a n d Ch a r a cter iza tion of th e Osm a cy-
clofer r ocen op h a n es 3a -h . The osmacycloferroceno-
phanes 3a -h were formed within 3 days in satisfying
yields by adding the corresponding bis(triflates) 2a -h
to a suspension of the sodium salt of the organometallic
Lewis base [Os(CO)4]2- in refluxing dimethyl ether
(Scheme 1). Because of the low solubility of Na2[Os-
(CO)4] in this solvent, the necessary dilution was
adjusted automatically; hence the formation of oligo-
and polymeric products was suppressed as far as pos-
sible. A yellow-brown precipitate consists of mainly
oligomers, polymers, and sodium triflate. For the mac-
rocycles 3a -h with longer alkyl chains a trend to higher
yields was observed. The yellow osmacycloferroceno-
phanes 3a -h (Chart 1) are rather stable toward aerial
oxygen, can be handled at room temperature without
decomposition, and dissolve in all common organic
solvents. Their molecular composition was confirmed by
elemental analyses and by FD mass spectra, displaying
in each case the expected isotopic pattern. Between 2130
and 2000 cm-1 the IR spectra of 3a -h exhibit three to
four CO absorptions (n-pentane), which together with
their intensities is consistent with the presence of cis-
Os(CO)4 arrangements.
lengths of the alkyl chains and the different substitution
patterns at the aromatic rings. The well-known bis-
(triflate) method10,11,17 served for the formation of two
and four osmium-carbon σ bonds, respectively. The
redox potentials of 3a -h were determined by cyclic
voltammetry and were dependent on the chain lengths
and substitution design. Selected osmacycloferroceno-
phanes and diosmacycloferrocenophanes were subjected
to an X-ray structural investigation.
Resu lts a n d Discu ssion
For the synthesis of the osmacycloferrocenophanes 3
and 4 according to Scheme 1, advantage of the bis-
(triflate) method was taken, which is considered as a
variant of the cationic alkylation. This route was found
to be the most straightforward and efficient way for the
concomitant formation of several metal-carbon σ bonds
under very mild conditions. The triflate residue is an
excellent and inert leaving group, stabilizing carbenium-
like carbon atoms at the ends of a hydrocarbon chain,
thereby enabling an electrophilic attack of the terminal
carbon atoms even at a weakly basic metal center. With
regard to this method metallacyclophanes11 and four-18
to 51-membered19 multimetallacycloalkanes were ob-
tained by reaction of the corresponding bis(triflates)
with the metalates [M(CO)4]2- (M ) Fe, Ru, Os). Prior
to the application of the bis(triflate) method in this work
several primary steps had to be elaborated.
1
By inspection of the H and 13C{1H} NMR spectra it
is obvious that most chemical shifts remain largely
unchanged on going from the ferrocenediyl alcohols
1a -h to the macrocycles 3a -h via the bis(triflates) 2a -
h . For the aromatic protons in 1a -h , 2a -h , and 3a -h
the centers of the chemical shifts are located between
7.22 and 7.04 ppm. If the 1H NMR spectra of 3c, 3e,
and 3h are compared in the aromatic region, a particu-
lar conspicuous dependence of the splitting pattern on
the length of the para-positioned alkyl chain appears,
revealing an AA′BB′ system for 3c collapsing into a
singlet on going from 3c to 3e and 3h . In 3h the
different functional groups are too far away from the
Syn th esis of th e Bis(tr ifla tes) 2a -h . Due to the
unavailability of the symmetrical ferrocenediyl alcohols
(17) Lindner, E.; Au, G.; Eberle, H.-J . Chem. Ber. 1981, 114, 810.
(18) Lindner, E.; J ansen, R. M.; Hiller, W.; Fawzi, R. Chem. Ber.
1989, 122, 1403.
(19) Linder, E.; Leibfritz, T.; Fawzi, R.; Steimann, M. Chem. Ber.
1997, 130, 347.
(20) Synthetic Methods of Organometallic and Inorganic Chemistry;
Hermann, W. A., Ed.; Georg Thieme Verlag: Stuttgart, 1996; Vol. 1,
p 135.

Macrocyclic Osmacycloferrocenophanes
Organometallics, Vol. 21, No. 20, 2002 4219
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d
An gles (d eg) for 3b, 3c, a n d 3e
Ch a r t 1
3b
3c
3e
Os(1)-Fe(1)
8.139(2) 9.727(2) 11.468(3)
2.221(4) 2.220(7) 2.203(5)
2.229(4) 2.236(7)
Os(1)-C(5)
Os(1)-C(20)
Os(1)-C(22)
2.219(20)
center Ph(1)-center Ph(2)
Fe-Cp(1)
8.41
1.65
1.65
5.58
1.66
1.66
6.52
1.65
1.64
Fe-Cp(2)
C(5)-Os(1)-C(20)
C(5)-Os(1)-C(22)
δ
83.66(16) 82.8(3)
83.69(18)
178.2
178.1 177.9
R
2.31(32) 3.77(41) 2.17(30)
66.3 0.1
C(14)-Cp(1)-Cp(2)-C(29)
C(16)-Cp(1)-Cp(2)-C(33)
62.3
interplanar angle (Ph(1)-Ph(2)) 82.29(14) 53.73(17) 27.99(24)
and Os(CO)4, OTf, or OH groups, respectively, give rise
only to unresolved multiplets between 2.1 and 1.6 ppm.
1
Like in the H NMR spectra the largest differences
of the chemical shifts in the 13C{1H} NMR spectra of
1a -h , 2a -h , and 3a -h are ascertained for the carbon
atoms of the CH2 functions next to Os, OH, and OTf.
The ranges of the 13C resonances vary from 1.8 to -5.5
(CH2Os), 63.7 to 62.2 (CH2OH), and 78.1 to 77.3 ppm
(CH2OTf), respectively. Unlike previous results,10,19 the
high-field position of the R-methylene carbon atoms in
the spectra of the osmacycloferrocenophanes 3a -h
exhibit no significant dependence on the ring size. All
other methylene groups (three for Xa -c, five for Xd ,e,
seven for Xf-h , X ) 1-3) resonate between 43.6 and
26.7 ppm. Three signals between 91 and 67 ppm are
assigned to the cyclopentadienyl carbon atoms in the
spectra of 1a -h to 3a -h . The one at lowest field is
ascribed to the quaternary and the remaining two
resonances are attributed to the tertiary C atoms. 13C
resonances referring to the phenylene rings occur in the
range from 150 to 125 ppm. In the case of the osmacy-
cloferrocenophanes 3a -h two more peaks are detected
which can be traced back to the axial (180.4-176.2 ppm)
and equatorial (172.5-171.0 ppm) carbonyl ligands.
Cr ysta l Str u ctu r es of 3b, 3c, a n d 3e. To obtain
more detailed information about the structures of the
osmacycloferrocenophanes, X-ray structural investiga-
tions were performed with the examples of 3b, 3c, and
3e. In Table 1 selected bond distances and angles are
summarized, and the corresponding ORTEP plots with
atom labeling are depicted in Figures 1-3. Four mol-
ecules are found in the monoclinic (3b ,c) and ortho-
rhombic (3e) unit cells. At approximately 1.65 Å the iron
atoms are nearly equidistant from the centers of the
cyclopentadienyl rings, which are almost parallel to each
other with angles of δ ) 178.1° (3b), 177.9° (3c), and
178.2° (3e) (ring center-metal-ring center). The result-
ing dihedral angle (tilt angle R) was found to be 2.31-
(32)°, 3.77(41)°, and 2.17(30)° for 3b,c,e. All three
frameworks of the macrocycles roughly reveal a boat-
shaped structure in which the phenylene building blocks
including the (CH2)n spacers form the hull and the
ferrocene and Os(CO)4 fragments the stern and bow,
respectively. Due to the different substitution patterns
and the different number of CH2 units, the boat is more
or less distorted. In 3b the two metals and the centers
of the phenylene rings have nearly the same distance
(8.139(2) and 8.41 Å, respectively). Both phenylene rings
in 3b deviate from a perpendicular arrangement by an
benzene ring. While the spectra of 3a -h show AA′XX′
patterns for the cyclopentadienyl hydrogen atoms in the
case of the bis(alcohols) 1a -h and bis(triflates) 2a -h ,
only a broad singlet or a diffuse AA′XX′ spin system
occurs. All centers of chemical shifts are found in the
range between 4.09 and 3.87 ppm. The multiplets (2.9-
2.29 ppm) of the four CH2 groups adjacent to the
1
aromatic rings in the H NMR spectra of 1a -h , 2f-h ,
and 3b,d -h are not resolved. Only for 2a -e and 3a ,c
are separated signals for these functions observed. On
the contrary, the resonances of the protons of the
methylene groups next to the ferrocene unit in 1d -h ,
2d -h , and 3d -h are relatively constant (2.37-2.25
ppm) and give rise to triplets. All other spectra (1a -c,
2a -c, 3a -c) show only unresolved multiplets (2.74-
2.12 ppm). Depending on the electron-donating or
electron-withdrawing properties of the respective func-
tions, the largest chemical shift differences are detect-
able for the protons of the methylene groups in direct
vicinity to Os(CO)4 (1.41-0.94 ppm), OH (3.83-3.56
ppm), and OTf (4.74-4.55 ppm). Except 3c,h , with a
hindered rotation of the CR-Câ bonds (with respect to
osmium), the spectra of the osmacycloferrocenophanes
3a ,b,d -f,g reveal the same splitting pattern21 for the
CH2Os groups. For example in the case of 1b the A (CH2-
Ar) and X (CH2Os) parts of the AA′XX′ spin system are
characterized by chemical shifts of 3.03 and 1.40 ppm,
respectively. The protons of the internal methylene
groups between the aromatic rings and the ferrocene
(21) Lindner, E.; Pabel, M.; Eichele, K. J . Organomet. Chem. 1990,
386, 187.

4220 Organometallics, Vol. 21, No. 20, 2002
Lindner et al.
F igu r e 4. ORTEP plot of 4a shown at 50% probability
level; hydrogen atoms are omitted.
F igu r e 1. ORTEP plot of 3b shown at 50% probability
level; hydrogen atoms are omitted.
distance 10.07(2) Å). The basic cyclophane framework
has a bowl-shaped structure. In the approximate boat-
shaped structure of 3e the heterometal-metal distance
and the distance between the aromatic rings with
interplanar angles of 27.99(24)° are unequal (11.468(3)
and 6.52 Å, respectively). Like in 3b the Cp rings in 3e
are almost in the synclinal eclipsed conformation with
a deviation of 9.7°. In 3b,c,e one carbonyl ligand is more
or less bent toward the “cavity” of the respective
macrocycle.
Diosm a cyclofer r ocen op h a n es 4a -h . In contrast
to the occurrence of only dinuclear osmaferroceno-
phanes,10 in the case of the osmacycloferrocenophanes
not only the dinuclear species 3a -h are formed. In
reproducible yields of 1-2% (exception 4f,g <0.5%) also
the tetranuclear macrocycles 4a -h were isolated by
column chromatographic separation, eluting 3a -h at
first with n-pentane/diethyl ether, 50:1. It was not
possible to essentially increase their yields even under
optimized reaction conditions. A considerable amount
of the products was insoluble in n-pentane, consisting
of oligomeric or polymeric species. In the IR spectrum
this material revealed intense CO absorptions that are
characteristic of cis-Os(CO)4 fragments [IR (KBr) ν )
2100, 2019, 2005, 1939 cm-1]. The molecular composi-
tion of 4a -h was corroborated by FD mass spectra. The
solubility of the pale yellow heterocycles 4a -h in
nonpolar solvents such as n-pentane increases with the
number of methylene functions. There are no significant
differences in the NMR and IR data between 3a -h and
4a -h .
Cr ysta l Str u ctu r es of 4a a n d 4h . The macrocycles
4a -h each consist of two Os(CO)4, (η5-C5H4)2Fe, and
four ortho-, meta-, and para-(CH2)nC6H4(CH2)n (n )
2-4) units, respectively. In the solid state 4a is cen-
trosymmetric, with four molecules in the unit cell. All
four metal atoms are located at the vertexes of a
distorted square with edges of 7.748(4) [Os(1)-Fe(1)]
and 8.202(2) Å [Os(1)-Fe(1A)] (Figure 4). Both diago-
nals represent the homometal-metal distances of 11.611-
(5) [Os(1)-Os(1A)] and 10.945(3) Å [Fe(1)-Fe(1A)].
Referring to the ferrocene building blocks, the cyclo-
pentadienyl rings are between a synclinal staggered
(36°) and a synclinal eclipsed (72°) conformation (Figure
4). The basic cyclophane framework has roughly the
shape of a part of a paddle-wheel in which the centers
of the phenylene rings are placed above [C(7)-C(12)/
F igu r e 2. ORTEP plot of 3c shown at 50% probability
level; hydrogen atoms are omitted.
F igu r e 3. ORTEP plot of 3e shown at 50% probability
level; hydrogen atoms are omitted.
angle of 7.71°. For the ferrocene units a deviation of 5.7°
from the synclinal (gauche) eclipsed (72°) conformation
is established. In contrast to 3b,e the molecule 3c
resembles most closely a boat-shaped structure. The
cyclopentadienyl rings are almost eclipsed (deviation <
0.1°), and the distances between the centers of the two
phenylene groups and the metal atoms are 5.58 and
9.727(2) Å, respectively. The interplanar angle of the
aromatic rings was found to be 53.73(17)°. At first sight
the osmacycloferrocenophane 3e is reminiscent of the
diosma[7.7]paracyclophane11c by replacing an Os(CO)4
fragment for a ferrocene unit. However, the structures
of both macrocycles are rather different. The diosma-
[7.7]paracyclophane has C2 symmetry, and the two
phenylene functions give rise to an interplanar angle
of 50.3°. Together with the metal centers they occupy
the vertexes of a distorted tetrahedron (metal-metal

Macrocyclic Osmacycloferrocenophanes
Organometallics, Vol. 21, No. 20, 2002 4221
F igu r e 5. ORTEP plot of 4h shown at 50% probability level; hydrogen atoms are omitted.
Ta ble 2. Selected Bon d Len gth s (Å) a n d Bon d
C(27)-C(32)] and below [C(7A)-C(12A)/C(27A)-C(32A)]
the plane defined by the four metal atoms with distances
of 3.54 and 2.54 Å, respectively. The distances of the
phenylene rings related by the center of symmetry are
17.23 [C(7)-C(12)/C(7A)-C(12A)] and 5.35 Å [C(27)-
C(32)/C(27A)-C(32A)].
An gles (d eg) for 4a a n d 4h
4a
4h
Os(1)-Fe(1)
Os(1)-Fe(1A)
Os(1)-Os(1A)
Fe(1)-Fe(1A)
Os(1)-C(5)
7.748(4)
8.202(2)
11.611(5)
10.945(3)
2.214(4)
2.212(4)
17.292(3)
13.124(2)
29.850(5)
7.173(2)
2.228(8)
Similarly the larger macrocycle 4h is centrosymmetric
and includes one molecule each of 4h and n-hexane in
the unit cell. In contrast to 4a the four metal atoms are
positioned at the vertexes of a parallelogram and the
edges have lengths of 17.292(3) [Os(1)-Fe(1)] and
13.124(2) Å [Os(1)-Fe(1A)]. The Os(1)-Os(1A) and
Fe(1)-Fe(1A) distances of 29.850(5) and 7.173(2) Å are
the diagonals of this parallelogram (Figure 5). A devia-
tion of 5.4° from the anticlinal (eclipsed) conformation
(144°) is observed for the cyclopentadienyl rings in both
ferrocene units, which has a significant effect on the
shape of 4h . The centers of the phenylene rings of the
remarkably stretched macrocycle 4h are above [C(9)-
C(14)/C(33)-C(38)] and below [C(9A)-C(14A)/C(33A)-
C(38A)] the plane defined by the four metal atoms, with
distances of 0.38 and 0.79 Å, respectively. Selected bond
distances and angles are depicted in Table 2.
Red ox Beh a vior of th e Bis(a lcoh ols) 1a -h a n d
th e Ma cr ocycles 3a -h . The redox potentials of the bis-
(alcohols) 1a -h and the osmacycloferrocenophanes
3a -h were investigated by cyclic voltammetry with
respect to the chain lengths of the (CH2)n spacers and
the substitution patterns of the phenylene groups. All
cyclic voltammograms of 1a -h and 3a -h recorded in
acetonitrile as solvent exhibit only a single oxidation/
reduction peak couple within the potential window (-1.6
to 1.6 V) and are similar in shape to the unsubstituted
ferrocene (ferrocene/ferrocenium cation). Due to the
peak potential separations (50-70 mV, scan rate v 100-
10000 mV/s, theoretical: 59 mV), ipc/ipa ratios (1.0 ( 0.1),
ipa vs v1/2 plots (linear), and (Epa + Epc)/2 values
(constant over the entire range of the scan rate), the
electrochemical and chemical reversibility could be
established. If the redox potentials E1/2 of the bis-
(alcohols) 1a -h are compared to those of the corre-
sponding osmacycloferrocenophanes 3a -h (Table 3),
only differences of the E1/2 values for 1a /3a and 1f/3f
(ortho-penylene) are significant beyond the limit of error
Os(1)-C(34A)
Os(1)-C(42)
2.193(12)
7.650
14.09
23.57
1.66
center Ph(1)-center Ph(2)
center Ph(1)-center Ph(1A)
center Ph(2)-center Ph(2A)
Fe-Cp(1)
8.689
17.23
5.35
1.64
1.64
Fe-Cp(2)
1.66
C(5)-Os(1)-C(34A)
C(5)-Os(1)-C(42)
δ
85.17(15)
84.0(4)
178.6
1.8
177.0
4.5
R
C(14)-Cp(1)-Cp(2)-C(25)
C(18)-Cp(1)-Cp(2)-C(29A)
interplanar angle (Ph(1)-Ph(2))
54.2
149.4
43.8
100.8
Ta ble 3. F or m a l P oten tia ls of 1a -h a n d 3a -h
ver su s F c/F c+
compound
E
1/2, mV
∆E, mV
ipc/ipa
1a
1b
1c
1d
1e
1f
1g
1h
3a
3b
3c
3d
3e
3f
-83
-88
61
63
59
61
61
65
63
61
60
60
63
61
62
61
60
60
0.998
1.023
0.988
1.001
1.000
1.023
1.007
1.004
0.992
1.006
1.003
0.999
1.000
1.001
1.020
1.014
-95
-98
-105
-108
-104
-110
-72
-87
-89
-101
-102
-93
3g
3h
-103
-110
of the experiment. Within this series 1a ,f are easier
oxidized than 3a ,f. In the case of 1b-e,g,h and 3b-
e,g,h nearly no difference was found whether there are
OH or Os(CO)4 groups in the molecule. Nevertheless the
E
1/2 values vary from -83 to -110 and -72 to -110 mV
for 1a -h and 3a -h , respectively, indicating that 1a -h
and 3a -h are easier oxidized than ferrocene itself.
Compared to osmaferrocenophanes10 the osmacyclofer-

4222 Organometallics, Vol. 21, No. 20, 2002
Lindner et al.
rocenophanes 3a -h reveal slightly higher E1/2 values.
It seems that the inductive electron-donating effect of
the (CH2)2 spacers in 1a -c and 3a -c is partially
reduced due to the inductive electron-withdrawing effect
of the phenylene groups, affecting the ferrocenes via the
two methylene functions. For example the redox poten-
tials of 1,1′-fc(C6H5)2 and 1,1′-fc(CH2C6H5)2, which are
provided with either no or one methylene group between
the ferrocene and the benzene ring, are 40 and -40
mV,22 respectively. Compared to these results, the
influence of the aromatic ring via the (CH2)2 spacer is
small. On going from (CH2)2 to (CH2)4 via the (CH2)3
spacers, the redox potentials converge to that of dieth-
ylferrocene (E1/2 ) -113 to -117 mV)23 and higher
homolgues.22
between the ferrocene and phenylene rings and their
substitution patterns. For 1a /3a and 1f/3f with ortho-
substituted aromatic rings, small differences are estab-
lished between the bis(alcohols) and the corresponding
osmacycloferrocenophanes.
Exp er im en ta l Section
Gen er a l Com m en ts. All manipulations were carried out
under an atmosphere of argon by use of standard Schlenk
techniques. Solvents were dried with appropriate reagents and
stored under argon. NMR spectra were recorded at 250.13
MHz (1H NMR) and 62.90 MHz (13C{1H} NMR) on a Bruker
DRX 250 at 20 °C, if not stated otherwise. 1H and 13C chemical
shifts were measured relative to partially deuterated and
deuterated solvent peaks, respectively, which are reported
relative to TMS. Elemental analyses were carried out with an
Elementar Vario EL analyzer. FD mass spectra were recorded
on a Finnigan MAT 711 A instrument, modified by AMD, and
EI mass spectra were taken on a Finnigan MAT TSQ 80. IR
data were obtained with a Bruker IFS 48 FTIR spectrometer.
Os3(CO)1226 and Na2[Os(CO)4]27 were synthesized according to
literature methods.
Gen er a l P r oced u r e for th e P r ep a r a tion of th e Osm a -
cyclofer r ocen op h a n es 3a -h a n d Diosm a cyclofer r o-
cen op h a n es 4a -h . A solution of the bis(triflates) 2a -h (1.0
mmol) in 10 and 90 mL of diethyl and dimethyl ether at -80
°C, respectively, was added dropwise within 4 h to a suspen-
sion of Na2[Os(CO)4] (348.2 mg, 1.0 mmol) in 100 mL of
refluxing dimethyl ether. Stirring and refluxing this mixture
for 3 days afforded a yellow clear solution and a yellow-brown
precipitate. After evaporation of the solvents the residue was
extracted three times with 200 mL of n-pentane. The insoluble
components were filtered off (P4), and the solvent was evapo-
rated under reduced pressure, leaving the crude products,
which were purified by column chromatography on silica gel
(l ) 20 cm, n-pentane/Et2O, 50:1 (3a -h ); n-pentane/Et2O, 25:1
(4a -h )). Recrystallization from n-pentane at -80 °C afforded
the analytically pure osmacycloferrocenophanes 3a -h and
diosmacycloferrocenophanes 4a -h .
Con clu sion
As already demonstrated in previous investigations,
the bis(triflate) method10,11,17-19 is a versatile tool for
the concomitant formation of several metal-carbon σ
bonds. Dependent on the design of the hydrocarbon
framework, the formation of macrocycles with one,11b,19
two,10,11a-c,19 or even three19 transition metal centers
was observed. In the present work we applied this route
to combine for the first time structural features of
typical metallacyclophanes with metallocenophanes.
The resulting osmacycloferrocenophanes 3a -h and
4a -h attract attention for their thermal stability (>100
°C) and consist of an extended hydrocarbon skeleton
containing additionally two and four transition metal
centers, respectively. Macrocycles of this type not only
represent aesthetic structures11a,c but may also be
regarded as valuable building blocks24 for the synthesis
of new materials with interesting properties. If in
dinuclear macrocycles one transition metal fragment is
replaced for a metallocene, structures may change
considerably. A typical example of this observation is
the comparison between the diosma[7.7]paracyclophane11c
and the osmacycloferrocenophane 3e. While in the first
case a bowl-shaped structure is preferred, in 3e a
boatlike framework was established.
11,11,11,11-Tetr a ca r bon yl-11-osm a [2]or th ocyclo[5]or -
th ocyclo[2]-(1,1′)fer r ocen oph an e (3a). Yield: 113 mg (15%),
yellow, air-stable crystals, mp 151 °C. 1H NMR (CD2Cl2): δ
7.21-7.01 (m, 8H, CHarom), 4.02 (m,28 8H, C5H4), 3.10 (m,29
N
) 17.8 Hz, 4H, OsCH2CH2Carom), 2.91-2.84 (m, 4H, C5H4-
CH2CH2Carom), 2.70-2.64 (m, 4H, CH2C5H4), 1.41 (m,30 N )
17.6 Hz, 4H, CH2Os). 13C{1H} NMR (CD2Cl2): δ 180.4 (s,
OsCOax), 172.5 (s, OsCOeq), 147.4, 140.5 (s, Carom), 131.4, 130.8,
127.7, 127.2 (s, CHarom), 90.4 (s, C4H4C), 70.6, 68.7 (s, C4H4C),
42.7, 36.1, 33.6 (s, CH2), -0.8 (s, CH2Os). IR (n-pentane, cm-1):
ν(CO) 2124, 2045, 2035, 2012. FD-MS: m/z 752.0 [M+]. CV:
E1/2 -72 mV. Anal. Calcd for C34H32FeO4Os: C, 54.40; H, 4.30.
Found: C, 54.08; H, 4.04.
Regarding the yields, the formation of monoosmacy-
cloferrocenophanes 3a -h was favored over that of the
diosmacycloferrocenophanes 4a -h . A mechanistic re-
flection of this fact was already described in an earlier
paper.10 Mainly entropic effects25 are responsible for this
observation.
The cyclic voltammograms of the ferrocene derivatives
1a -h and 3a -h are characterized by a reversible one-
electron oxidation process. However, with the exception
of 1a /3a and 1f/3f there is no remarkable difference
between the redox potentials of 1a -h and 3a -h .
Obviously, due to the long distance between the fer-
rocene and the OH and Os(CO)4 unit, respectively, the
redox potentials are scarcely affected. A crucial factor
for the E1/2 values is the number of methylene functions
11,11,11,11-Tetr acar bon yl-11-osm a[2]m etacyclo[5]m eta-
cyclo[2]-(1,1′)fer r ocen op h a n e (3b). Yield: 173 mg (23%),
yellow, air-stable crystals, mp 122 °C. 1H NMR (CD2Cl2): δ
7.21-6.94 (m, 8H, CHarom), 4.03 (m,28 8H, C5H4), 3.03 (m,29
N
) 17.9 Hz, 4H, OsCH2CH2Carom), 2.82-2.66 (m, 8H, CH2Carom,
CH2C5H4), 1.40 (m,30 N ) 17.9 Hz, 4H, CH2Os). 13C{1H} NMR
(CD2Cl2): δ 178.2 (s, OsCOax), 171.1 (s, OsCOeq), 142.8, 142.5
(s, Carom), 128.2, 127.3, 125.8, 125.3 (s, CHarom), 89.0 (s, C4H4C),
69.3, 67.3 (s, C4H4C), 43.6, 38.5, 32.1 (s, CH2), 0.7 (s, CH2Os).
IR (n-pentane, cm-1): ν(CO) 2126, 2044, 2040, 2012. FD-MS:
m/z 752.0 [M+]. CV: E1/2 -87 mV. Anal. Calcd for C34H32FeO4-
Os: C, 54.40; H, 4.30. Found: C, 54.37; H, 3.89.
(22) Lu, S.; Strelets, V. V.; Ryan, M. F.; Pietro, W. J .; Lever, A. B.
P. Inorg. Chem. 1996, 35, 1013.
(23) (a) Hall, D. W.; Russel, C. D. J . Am. Chem. Soc. 1967, 89, 2316.
(b) Fujita, E.; Gordon, B.; Hillman, M. J .; Nagy, A. G. J . Organomet.
Chem. 1981, 218, 105. (c) Kuwana, T.; Bublitz, D. E.; Hoh, G. J . Am.
Chem. Soc. 1960, 82, 5811.
(24) Togni, A. In Ferrocenes; Togni, A., Hayashi, T., Eds.; VCH:
Weinheim, 1995; p 433.
(26) Drake, S. R.; Loveday, P. A. Inorg. Synth. 1991, 28, 230.
(27) Carter, W. J .; Kelland, J . W.; Okrasinski, S. J .; Warner, K. E.;
Norton, J . R. Inorg. Chem. 1982, 21, 3955.
(28) m: AA′XX′ pattern
(29) m: low-field part of an AA′XX′ pattern.
(30) m: high-field part of an AA′XX′ pattern.
(25) Illuminati, G.; Mandolini, L. Acc. Chem. Res. 1981, 14, 95.

Macrocyclic Osmacycloferrocenophanes
Organometallics, Vol. 21, No. 20, 2002 4223
11,11,11,11-Tetr acar bon yl-11-osm a[2]par acyclo[5]par a-
cyclo[2]-(1,1′)fer r ocen op h a n e (3c). Yield: 128 mg (17%),
yellow, air-stable crystals, dec 172 °C. 1H NMR (CD2Cl2): δ
7.10-7.00 (m, 8H, CHarom), 4.07 (m,28 8H, C5H4), 3.19-3.15
(m, 4H, OsCH2CH2Carom), 2.56-2.49 (m, 4H, C5H4CH2CH2Carom),
2.15-2.08 (m, 4H, CH2C5H4), 1.30-1.26 (m, 4H, CH2Os). 13C-
{1H} NMR (CD2Cl2): δ 176.2 (s, OsCOax), 171.4 (s, OsCOeq),
142.8, 140.7 (s, Carom), 128.8, 128.1 (s, CHarom), 88.2 (s, C4H4C),
68.3, 67.2 (s, C4H4C), 41.2, 39.3, 33.0 (s, CH2), 1.8 (s, CH2Os).
IR (n-pentane, cm-1): ν(CO) 2128, 2050, 2036, 2001. FD-MS:
m/z 751.7 [M+]. CV: E1/2 -89 mV. Anal. Calcd for C34H32FeO4-
Os: C, 54.40; H, 4.30. Found: C, 54.20; H, 4.25.
67.2 (s, C4H4C), 37.6, 36.5, 35.1, 34.2, 31.4, 29.9, 28.7 (s, CH2),
-4.0 (s, CH2Os). IR (n-pentane, cm-1): ν(CO) 2125, 2040, 2008.
FD-MS: m/z 863.7 [M+]. CV: E1/2 -110 mV. Anal. Calcd for
C
42H48FeO4Os: C, 58.46; H, 5.61. Found: C, 58.53; H, 5.61.
11,11,11,11,43,43,43,43-Octa ca r bon yl-11,43-d iosm a [2]-
or th ocyclo[5]or th ocyclo[2]-(1,1′)fer r ocen o[2]or th ocyclo-
[5]or th ocyclo[2]-(1,1′)fer r ocen op h a n e (4a ). Yield: 17 mg
(2%), pale yellow, air-stable crystals, mp 152 °C. 1H NMR (CD2-
Cl2): δ 7.15-7.09 (m, 16H, CHarom), 3.93 (s, 16H, C5H4), 2.95
(m,29 N ) 17.9 Hz, 8H, OsCH2CH2Carom), 2.91-2.84 (m, 8H,
C5H4CH2CH2Carom), 2.61-2.54 (m, 8H, CH2C5H4), 1.24 (m,30
N ) 17.9 Hz, 8H, CH2Os). 13C{1H} NMR (CD2Cl2): δ 179.1 (s,
OsCOax), 171.0 (s, OsCOeq), 146.0, 139.0 (s, Carom), 129.3, 128.7,
126.2, 125.7 (s, CHarom), 88.5 (s, C4H4C), 68.6, 68.1 (s, C4H4C),
41.3, 34.5, 31.7 (s, CH2), -1.4 (s, CH2Os). IR (n-pentane, cm-1):
ν(CO) 2124, 2045, 2038, 2012. FD-MS: m/z 1496 (5%), 1497
(15%), 1498 (53%), 1499 (61%), 1500 (76%), 1501 (83%), 1502
(100%), 1503 (86%), 1504 (58%), 1505 (35%), 1506 (10%); calcd
1496 (14%), 1497 (25%), 1498 (47%), 1499 (58%), 1500 (82%),
1501 (82%), 1502 (100%), 1503 (62%), 1504 (63%), 1505 (39%),
13,13,13,13-Tetr acar bon yl-13-osm a[3]m etacyclo[7]m eta-
cyclo[3]-(1,1′)fer r ocen op h a n e (3d ). Yield: 163 mg (20%),
1
yellow, air-stable crystals, mp 61.3 °C. H NMR (CD2Cl2): δ
7.21-6.97 (m, 8H, CHarom), 3.93 (m,28 8H, C5H4), 2.64-2.56
(m, 8H, CH2Carom), 2.28 (t, 3J HH ) 7.5 Hz, 4H, CH2C5H4), 2.12-
1.99 (m, 4H, OsCH2CH2CH2Carom), 1.91-1.79 (m, 4H, C5H4-
CH2CH2CH2Carom), 1.01 (m,30 N ) 17.0 Hz, 4H, CH2Os).
13C{1H} NMR (CD2Cl2): δ 178.9 (s, OsCOax), 171.1 (s, OsCOeq),
142.3 (s, Carom), 128.6, 128.1, 126.0, 125.8 (s, CHarom), 89.2 (s,
C4H4C), 68.6, 67.3 (s, C4H4C), 42.4, 39.1, 35.6, 32.3, 28.2 (s,
CH2), -3.9 (s, CH2Os). IR (n-pentane, cm-1): ν(CO) 2125, 2039,
2009. FD-MS: m/z 808.5 [M+]. CV: E1/2 -101 mV. Anal. Calcd
for C38H40FeO4Os: C, 56.57; H, 5.00. Found: C, 56.42; H, 4.64.
13,13,13,13-Tetr acar bon yl-13-osm a[3]par acyclo[7]par a-
cyclo[3]-(1,1′)fer r ocen op h a n e (3e). Yield: 183 mg (23%),
1506 (15%) [M+ (isotopic distribution)]. Anal. Calcd for C68H64
Fe2O8Os2: C, 54.40; H, 4.30. Found: C, 54.22; H, 4.35
-
11,11,11,11,43,43,43,43-Octa ca r bon yl-11,43-d iosm a [2]-
m eta cyclo[5]m eta cyclo[2]-(1,1′)fer r ocen o[2]m eta cyclo[5]-
m eta cyclo[2]-(1,1′)fer r ocen op h a n e (4b). Yield: 7 mg (1%),
pale yellow, air-stable crystals, mp 124 °C. 1H NMR (CD2Cl2):
δ 7.21-6.96 (m, 16H, CHarom), 3.98 (m,28 16H, C5H4), 2.96 (m,29
N ) 17.6 Hz, 8H, OsCH2CH2Carom), 2.79-2.73 (m, 8H, C5H4-
CH2CH2Carom), 2.63-2.56 (m, 8H, CH2C5H4), 1.30-1.20 (m, 8H,
CH2Os). 13C{1H} NMR (CD2Cl2): δ 178.8 (s, OsCOax), 171.0
(s, OsCOeq), 148.2, 142.4 (s, Carom), 128.2, 127.9, 125.6, 125.3
(s, CHarom), 88.7 (s, C4H4C), 68.8, 67.8 (s, C4H4C), 44.1, 37.7,
31.7 (s, CH2), -0.7 (s, CH2Os). IR (n-pentane, cm-1): ν(CO)
2125, 2045, 2039, 2011. FD-MS: m/z 1496 (20%), 1497 (15%),
1498 (39%), 1499 (45%), 1500 (66%), 1501 (63%), 1502 (100%),
1503 (62%), 1504 (57%), 1505 (23%), 1506 (8%); Calcd 1496
(14%), 1497 (25%), 1498 (47%), 1499 (58%), 1500 (82%), 1501
(82%), 1502 (100%), 1503 (62%), 1504 (63%), 1505 (39%), 1506
(15%) [M+ (isotopic distribution)].31
11,11,11,11,43,43,43,43-Octa ca r bon yl-11,43-d iosm a [2]-
p a r a cyclo[5]p a r a cyclo[2]-(1,1′)fer r ocen o[2]p a r a cyclo[5]-
p a r a cyclo[2]-(1,1′)fer r ocen op h a n e (4c). Yield: 16 mg (2%),
pale yellow, air-stable crystals, mp 163 °C. 1H NMR (CD2Cl2):
δ 7.14-7.07 (m, 16H, CHarom), 3.99 (m,28 16H, C5H4), 2.97 (m,29
N ) 17.9 Hz, 8H, OsCH2CH2Carom), 2.79-2.71 (m, 8H, C5H4-
CH2CH2Carom), 2.66-2.60 (m, 8H, CH2C5H4), 1.30-1.20 (m,30
N ) 17.9 Hz, 8H, CH2Os). 13C{1H} NMR (CD2Cl2): δ 178.7 (s,
OsCOax), 171.0 (s, OsCOeq), 145.8, 139.5 (s, Carom), 128.3, 127.6
(s, CHarom), 88.9 (s, C4H4C), 68.9, 67.5 (s, C4H4C), 43.8, 37.3,
31.7 (s, CH2), -0.7 (s, CH2Os). IR (n-pentane, cm-1): ν(CO)
2128, 2050, 2036, 2001. FD-MS: m/z 1496 (16%), 1497 (36%),
1498 (55%), 1499 (78%), 1500 (85%), 1501 (80%), 1502 (100%),
1503 (50%), 1504 (77.3%), 1505 (47%), 1506 (15%); calcd 1496
(14%), 1497 (25%), 1498 (47%), 1499 (58%), 1500 (82%), 1501
(82%), 1502 (100%), 1503 (62%), 1504 (63%), 1505 (39%), 1506
(15%) [M+ (isotopic distribution)]. Anal. Calcd for C68H64Fe2O8-
Os2: C, 54.40; H, 4.30. Found: C, 54.10; H, 3.93.
1
yellow, air-stable crystals, mp 127.5 °C. H NMR (CD2Cl2): δ
7.14-7.06 (m, 8H, CHarom), 3.95 (m,28 8H, C5H4), 2.66-2.53
(m, 8H, CH2Carom), 2.32 (t, 3J HH ) 8.0 Hz, 4H, CH2C5H4), 2.08-
1.82 (m, 8H, CH2CH2CH2), 0.96 (m,30 N ) 17.3 Hz, 4H, CH2-
Os). 13C{1H} NMR (CD2Cl2): δ 178.8 (s, OsCOax), 171.0 (s,
OsCOeq), 139.6, 139.4 (s, Carom), 128.5, 128.2 (s, CHarom), 89.3
(s, C4H4C), 68.7, 67.1 (s, C4H4C), 41.6, 38.2, 35.2, 31.8, 28.0 (s,
CH2), -5.5 (s, CH2Os). IR (n-pentane, cm-1): ν(CO) 2125, 2040,
2009. FD-MS: m/z 808.4 [M+]. CV: E1/2 -102 mV. Anal. Calcd
for C38H40FeO4Os: C, 56.57; H, 5.00. Found: C, 56.31; H, 4.99.
15,15,15,15-Tetr a ca r bon yl-15-osm a [4]or th ocyclo[9]or -
th ocyclo[4]-(1,1′)fer r ocen op h a n e (3f). Yield: 173 mg (20%),
1
yellow, air-stable crystals, mp 90.3 °C. H NMR (CD2Cl2): δ
7.16-7.08 (m, 8H, CHarom), 3.97 (m,28 8H, C5H4), 2.70-2.64
(m, 8H, CH2Carom), 2.37 (t, 3J HH ) 6.8 Hz, 4H, CH2C5H4), 1.97-
1.85 (m, 4H, CH2CH2CH2Os), 1.67-1.51 (m, 12H, CH2CH2-
CH2), 1.14-1.07 (m,29 N ) 17.3 Hz, 4H, CH2Os). 13C{1H} NMR
(CD2Cl2): δ 179.5 (s, OsCOax), 171.2 (s, OsCOeq), 141.0, 140.6
(s, Carom), 129.4, 129.3, 125.8, 125.7 (s, CHarom), 89.2 (s, C4H4C),
68.7, 67.6 (s, C4H4C), 38.8, 38.7, 32.8, 32.4, 31.7, 31.2, 29.1 (s,
CH2), -3.2 (s, CH2Os). IR (n-pentane, cm-1): ν(CO) 2124, 2039,
2010. FD-MS: m/z 863.7 [M+]. CV: E1/2 -93 mV. Anal. Calcd
for C42H48FeO4Os: C, 58.46; H, 5.61. Found: C, 58.23; H, 5.35.
15,15,15,15-Tetr acar bon yl-15-osm a[4]m etacyclo[9]m eta-
cyclo[4]-(1,1′)fer r ocen op h a n e (3g). Yield: 226 mg (26%),
1
yellow, air-stable crystals, mp 82.1 °C. H NMR (CD2Cl2): δ
7.14-6.98 (m, 8H, CHarom), 3.93 (m,28 8H, C5H4), 2.65-2.57
(m, 8H, CH2Carom), 2.33 (t, 3J HH ) 7.7 Hz, 4H, CH2C5H4), 1.83-
1.51 (m, 16H, CH2CH2CH2), 1.04 (m,30 N ) 17.0 Hz, 4H, CH2-
Os). 13C{1H} NMR (CD2Cl2): δ 179.3 (s, OsCOax), 171.2 (s,
OsCOeq), 143.1, 142.7 (s, Carom), 128.5, 128.1, 125.8 (s, CHarom),
89.4 (s, C4H4C), 68.9, 67.4 (s, C4H4C), 38.7, 37.7, 35.7, 35.2,
31.7, 31.0, 29.3 (s, CH2), -3.1 (s, CH2Os). IR (n-pentane, cm-1):
ν(CO) 2125, 2040, 2008. FD-MS: m/z 863.7 [M+]. CV: E1/2
-103 mV. Anal. Calcd for C42H48FeO4Os: C, 58.46; H, 5.61.
Found: C, 58.31; H, 5.21.
13,13,13,13,49,49,49,49-Octa ca r bon yl-13,49-d iosm a [3]-
m eta cyclo[7]m eta cyclo[3]-(1,1′)fer r ocen o[3]m eta cyclo[7]-
m eta cyclo[3]-(1,1′)fer r ocen op h a n e (4d ). Yield: 10 mg (1%),
pale yellow, air-stable crystals, mp 60.4 °C. 1H NMR (CD2-
Cl2): δ 7.21-6.98 (m, 16H, CHarom), 3.95 (m,28 16H, C5H4),
2.63-2.53 (m, 16H, CH2Carom), 2.37-2.28 (m, 8H, CH2C5H4),
2.09-1.96 (m, 8H, CH2CH2CH2), 1.88-1.75 (m, 8H, CH2CH2-
CH2), 1.04 (m,30 N ) 17.0 Hz, 8H, CH2Os). 13C{1H} NMR (CD2-
Cl2): δ 179.2 (s, OsCOax), 171.0 (s, OsCOeq), 142.6, 142.5 (s,
15,15,15,15-Tetr acar bon yl-15-osm a[4]par acyclo[9]par a-
cyclo[4]-(1,1′)fer r ocen op h a n e (3h ). Yield: 232 mg (27%),
1
yellow, air-stable crystals, mp 73.3 °C. H NMR (CD2Cl2): δ
7.09 (s, 8H, CHarom), 3.89 (m,28 8H, C5H4), 2.63-2.57 (m, 8H,
C
arom), 128.7, 128.1, 125.8, 125.7 (s, CHarom), 89.0 (s, C4H4C),
3
68.6, 67.7 (s, C4H4C), 43.0, 40.6, 35.8, 32.8, 28.8 (s, CH2), -3.2
CH2Carom), 2.25 (t, J HH ) 7.7 Hz, 4H, CH2C5H4), 1.72-1.46
(s, CH2Os). IR (n-pentane, cm-1): ν(CO) 2125, 2039, 2009. FD-
(m, 16H, CH2CH2CH2), 0.97-0.91 (m, 4H, CH2Os). 13C{1H}
NMR (CD2Cl2): δ 179.0 (s, OsCOax), 171.2 (s, OsCOeq), 140.1,
139.7 (s, Carom), 128.5, 128.3 (s, CHarom), 89.4 (s, C4H4C), 68.5,
(31) Due to the very low yield, no elemental analyses were available.

4224 Organometallics, Vol. 21, No. 20, 2002
Lindner et al.
Ta ble 4. Cr ysta l Da ta a n d Su m m a r y of Da ta Collection a n d Refin em en t for 3b, 3c, 3e, 4a , a n d 4h
3b
3c‚0.5CH2Cl2
3e
4a
4h ‚n-hexane
formula
fw
C
34H32FeO4Os
C34.5H33ClFeO4Os
793.11
C38H40FeO4Os
806.75
C68H64Fe2O8Os2
1501.29
C
90H110Fe2O8Os2
750.65
1811.88
cryst size, mm3
temp, K
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
0.25 × 0.45 × 0.25
0.6 × 0.15 × 0.04
0.2 × 0.6 × 0.4
0.50 × 0.40 × 0.10
0.5 × 0.08 × 0.08
173(2)
173(2)
173(2)
173(2)
173(2)
monoclinic
P21/n
6.195(3)
41.882(12)
11.053(3)
monoclinic
P21/n
6.2833(17)
16.437(3)
orthorhombic
P212121
8.857(2)
11.944(3)
31.810(8)
orthorhombic
Pbca
14.646(4)
12.629(7)
32.278(9)
triclinic
P1h
6.6774(19)
11.1945(16)
29.219(4)
93.038(8)
92.63(2)
104.982(9)
2102.9(7)
1
29.161(4)
95.84(3)
92.244(17)
γ, deg
V, Å3
2852.9(18)
4
1.748
4.996
1480
3009.4(10)
4
1.750
4.827
1564
3365.0(15)
4
1.592
4.242
1608
5970(4)
4
1.670
4.774
Z
d
calcd, g/cm3
1.431
3.402
918
µ(Mo KR), mm-1
F(000), e
2960
θ range, deg
index ranges
2.09-27.52
-8 e h e 8
-54 e k e 54
-14 e l e 14
22663
2.44-27.50
-1 e h e 6
-21 e k e 1
-37 e l e 37
8653
2.13-27.52
-4 e h e 11
-15 e k e 15
-10 e l e 41
15908
2.22-27.52
-19 e h e 19
-16 e k e 16
-1 e l e 41
26143
2.06-27.50
-8 e h e 1
-14 e k e 14
-37 e l e 37
12141
no. of data collected
max./min. transmn
Rint
0.7262/0.3184
0.0773
0.8199/0.3536
0.0355
0.762/0.362
0.0585
0.0470
0.0430
no. of unique data/
restraints/params
GOF on F2
R1, wR2 (I > 2σ(I))a
R1, wR2 (all data)
largest diff peak, hole, e/ Å3
Flack param
6100/0/362
6264/2/374
7715/0/398
6587/0/362
9664/14/446
1.192
1.007
1.072
1.013
1.018
0.0361, 0.0839
0.0430, 0.0902
1.832, -1.901
0.0463, 0.0974
0.0758, 0.1091
1.719, -1.731
0.0273, 0.0668
0.0296, 0.0678
1.198, -1.037
-0.010(7)
0.0308, 0.0685
0.0500, 0.0756
0.825, -0.949
0.0666, 0.1363
0.1299, 0.1621
2.061, -1.243
R1 ) ∑(||Fo| - |Fc||)/∑|Fo|; wR2 ) [∑[w(Fo - Fc2)2]]0.5; w ) [exp(5(sin2 θ/λ2)]/[σ2(Fo2) + bP + (aP)2]; P ) [Fo + 2 Fc2]/3.
a
2
2
MS: m/z 1608 (15%), 1609 (27%), 1610 (52%), 1611 (59%), 1612
(76%), 1613 (81%), 1614 (100%), 1615 (61%), 1616 (49%), 1617
(25%), 1618 (15%); Calcd 1608 (14%), 1609 (24%), 1610 (45%),
1611 (58%), 1612 (81%), 1613 (83%), 1614 (100%), 1615 (66%),
1616 (64%), 1617 (41%), 1618 (18%) [M+ (isotopic distribu-
tion)].31
13,13,13,13,49,49,49,49-Octa ca r bon yl-13,49-d iosm a [3]-
p a r a cyclo[7]p a r a cyclo[3]-(1,1′)fer r ocen o[3]p a r a cyclo[7]-
p a r a cyclo[3]-(1,1′)fer r ocen op h a n e (4e). Yield: 15 mg (2%),
pale yellow, air-stable crystals, mp 127 °C. 1H NMR (CD2Cl2):
δ 7.09 (s, 16H, CHarom), 3.93 (m,27 16H, C5H4), 2.61-2.52 (m,
16H, CH2Carom), 2.28 (t, 3J HH ) 7.85 Hz, 8H, CH2C5H4), 2.07-
1.94 (m, 8H, CH2CH2CH2), 1.85-1.73 (m, 8H, CH2CH2CH2),
1.30-1.20 (m,30 N ) 17.9 Hz, 8H, CH2Os). 13C{1H} NMR (CD2-
Cl2): δ 179.2 (s, OsCOax), 171.1 (s, OsCOeq), 139.9, 139.6 (s,
15,15,15,15,55,55,55,55-Octa ca r bon yl-15,55-d iosm a [4]-
m eta cyclo[9]m eta yclo[4]-(1,1′)fer r ocen o[4]-m eta cyclo[9]-
or th ocyclo[4]-(1,1′)fer r ocen op h a n e (4g). Yield < 0.5%. IR
(n-pentane, cm-1): ν(CO) 2124, 2039, 2009. FD-MS: m/z 1720
(22%), 1721 (21%), 1722 (44%), 1723 (55%), 1724 (73%), 1725
(87%), 1726 (100%), 1727 (54%), 1728 (46%), 1729 (36%), 1730
(18%); Calcd 1720 (13%), 1721 (24%), 1722 (44%), 1723 (57%),
1724 (80%), 1725 (84%), 1726 (100%), 1727 (70%), 1728 (65%),
1729 (44%), 1730 (20%) [M+ (isotopic distribution)].31,32
15,15,15,15,55,55,55,55-Octa ca r bon yl-15,55-d iosm a [4]-
p a r a cyclo[9]p a r a cyclo[4]-(1,1′)fer r ocen o[4]p a r a cyclo[9]-
p a r a cyclo[4]-(1,1′)fer r ocen op h a n e (4h ). Yield: 15 mg (2%),
1
pale yellow, air-stable crystals, mp 65 °C. H NMR (CD2Cl2):
3
δ 7.09 (s, 16H, CHarom), 3.93 (m,28 16H, C5H4), 2.59 (t, J HH
)
7.54 Hz, 16H, CH2Carom), 2.31 (t, 3J HH ) 7.54 Hz, 8H, CH2C5H4),
1.85-1.53 (m, 32H, CH2CH2CH2), 1.04-0.98 (m, 8H, CH2Os).
13C{1H} NMR (CD2Cl2): δ 179.5 (s, OsCOax), 171.2 (s, OsCOeq),
140.4, 139.9 (s, Carom), 128.3 (s, CHarom), 89.4 (s, C4H4C), 68.7,
67.5 (s, C4H4C), 38.6, 38.2, 35.3, 35.0, 31.6, 30.8, 29.1 (s, CH2),
-3.1 (s, CH2Os). IR (n-pentane, cm-1): ν(CO) 2124, 2039, 2009.
FD-MS: m/z 1720 (15%), 1721 (25%), 1722 (34%), 1723 (77%),
1724 (87%), 1725 (92%), 1726 (100%), 1727 (60%), 1728 (52%),
1729 (40%), 1730 (5%); Calcd 1720 (13%), 1721 (24%), 1722
(44%), 1723 (57%), 1724 (80%), 1725 (84%), 1726 (100%), 1727
(70%), 1728 (65%), 1729 (44%), 1730 (20%) [M+ (isotopic
distribution)]. Anal. Calcd for C84H96Fe2O8Os2: C, 58.46; H,
5.61. Found: C, 58.56; H, 5.23.
C
arom), 128.3 (s, CHarom), 89.1 (s, C4H4C), 68.7, 67.5 (s, C4H4C),
42.5, 40.5, 35.3, 32.6, 28.6 (s, CH2), -3.3 (s, CH2Os). IR (n-
pentane, cm-1): ν(CO) 2125, 2039, 2009. FD-MS: m/z 1608
(20%), 1609 (33%), 1610 (65%), 1611 (62%), 1612 (89%), 1613
(61%), 1614 (100%), 1615 (73%), 1616 (38%), 1617 (29%), 1618
(14%); Calcd 1608 (14%), 1609 (24%), 1610 (45%), 1611 (58%),
1612 (81%), 1613 (83%), 1614 (100%), 1615 (66%), 1616 (64%),
1617 (41%), 1618 (18%) [M+ (isotopic distribution)]. Anal. Calcd
for C76H80Fe2O8Os2: C, 56.57; H, 5.00. Found: C, 56.63; H,
4.74.
15,15,15,15,55,55,55,55-Octa ca r bon yl-15,55-d iosm a [4]-
or th ocyclo[9]or th oyclo[4]-(1,1′)fer r ocen o[4]or th ocyclo-
[9]or th ocyclo[4]-(1,1′)fer r ocen op h a n e (4f). Yield < 0.5%.
IR (n-pentane, cm-1): ν(CO) 2124, 2039, 2011. FD-MS: m/z
1720 (17%), 1721 (23%), 1722 (47%), 1723 (66%), 1724 (85%),
1725 (87%), 1726 (100%), 1727 (57%), 1728 (55%), 1729 (36%),
1730 (15%); Calcd 1720 (13%), 1721 (24%), 1722 (44%), 1723
(57%), 1724 (80%), 1725 (84%), 1726 (100%), 1727 (70%), 1728
(65%), 1729 (44%), 1730 (20%) [M+ (isotopic distribution)].31,32
Cr ysta llogr a p h ic An a lysis. Single crystals of 3b, 3c, 3e,
4a , and 4h suitable for X-ray diffraction were obtained by slow
diffusion of n-hexane and toluene into a solution of 3b,c,e or
4a ,h in dichloromethane and slow evaporation of dichlo-
romethane. Selected crystals were mounted on a P4 Siemens
four-circle diffractometer. Graphite-monochromated Mo KR
radiation (λ ) 0.71073 Å) was used for the measurement of
intensity data in the ω-scan mode. An empirical absorption
correction was applied for 3b, 3e, and 4a but not for 3c and
(32) Due to the very low yield, no 1H and 13C{1H} NMR spectroscopic
characterization was possible.

Macrocyclic Osmacycloferrocenophanes
Organometallics, Vol. 21, No. 20, 2002 4225
4h . All structures were solved by direct methods with the
SHELXS-86 program.33 Refinement was carried out with full-
matrix least-squares methods based on F2 in SHELXL-9734
with anisotropic thermal parameters for all non-hydrogen
atoms. Hydrogen atoms were included at calculated positions
using a riding model. In 3c, the asymmetric unit contains half
a molecule of dichloromethane that is disordered about the
center of inversion and was included in the refinement using
isotropic thermal parameters. In 4h the unit cell contains an
additional n-hexane molecule disordered about the center of
inversion and ill defined. It was included in the refinement
using isotropic thermal parameters and C-C distance re-
straints. Crystal data and a summary of data collection and
refinement details are given in Table 4.
mm diameter. A single-unit Haber-Luggin double reference
electrode35 was used. The resulting potential values refer to
Ag/Ag+ (0.01 M in CH3CN/0.1 M NBu4PF6). Ferrocene was
used as an external standard. Its potential was determined
by separate cyclic voltammetric experiments in acetonitrile.
All potentials in the present paper are reported relative to the
fc/fc+ standard.36 A gastight full-glass three-electrode cell was
used; its assembly has been described elsewhere.37 The cell
was purged with argon before it was filled with electrolyte.
NBu4PF6 (0.1 M) was used as supporting electrolyte. Back-
ground curves were recorded before adding substrate to the
solution and subtracted from the experimental data. The
automatic BAS CV-50W iR-drop compensation facility was
used for all experiments.
Electr och em ica l Exp er im en ts. Cyclic voltammograms
were recorded with a Bioanalytical Systems (BAS, West
Lafayette, IN) CV-50 W electrochemical workstation. A Metro-
hm Pt electrode tip (Filderstadt, Germany) was used as a
working electrode. The counter electrode was a Pt wire of 1
Ack n ow led gm en t. Support of this research by the
Deutsche Forschungsgemeinschaft and the Fonds der
Chemischen Industrie is gratefully acknowledged. The
Degussa AG is thanked for supplying starting materials.
Su p p or tin g In for m a tion Ava ila ble: Synthesis of start-
ing materials, further details of X-ray structural determina-
tions, including bond distances and angles and thermal
parameters, for 3b, 3c, 3e, 4a , and 4h . This material is
available free of charge via the Internet at http://pubs.acs.org.
(33) Sheldrick, G. M. SHELXLS-86; University of Go¨ttingen, 1986.
(34) Sheldrick, G. M. SHELXL-97; University of Go¨ttingen, 1997.
(35) Gollas, B.; Krauss, B.; Speiser, B.; Stahl. H. Curr. Sep. 1994,
13, 42.
(36) Gritzner, G.; Kuta, J . Pure Appl. Chem. 1984, 56, 462.
(37) Du¨mmling, S.; Eichhorn, E.; Schneider, S.; Speiser, B.; Wu¨rde,
M. Curr. Sep. 1996, 15, 53.
OM020310L