Preparation of (η6-alkoxytriphenylene)tricarbonyl chromium(0) complexes: Mesomorphic properties of a disk-shaped chromium-arene complex

Article abstract of DOI:10.1016/S0022-328X(97)00586-X

Novel (η⁶-hexaalkoxytriphenylene)Cr(CO)₃ complexes 9 with varying alkyl chain lengths (C₅H₁₁ to C₉H₁₉) have been prepared with the chromium tricarbonyl moiety being exclusively attached to one terminal aryl ring. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction showed that complexes 9a-d displayed isotropic melting behavior. However, hexanonyloxy-substituted complex 9e displayed a nematic N_D phase between 37° and 58°C.

Full text of DOI:10.1016/S0022-328X(97)00586-X

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Journal of Organometallic Chemistry 552 1998 171–176
6
ž
/
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Preparation of h -alkoxytriphenylene tricarbonyl chromium 0
complexes
Mesomorphic properties of a disk-shaped chromium–arene complex
a
c
Jorg L. Schulte , Sabine Laschat a,), Rasmus Schulte-Ladbeck b,1, Volkmar von Arnim ,
¨
c
c
Armin Schneider , Heino Finkelmann
a
Institut fur Organische Chemie, Technische UniÕersitat Braunschweig, Hagenring 30, Braunschweig D-38106, Germany
¨
¨
b
Organisch-Chemisches Institut, UniÕersitat Munster, Corrensstr. 40, Munster D-48149, Germany
Institut fur Makromolekulare Chemie, UniÕersitat Freiburg, Sonnenstr. 5, Freiburg D-79104, Germany
¨
¨
¨
c
¨
¨
Received 2 July 1997
Abstract
6
Ž
.
Ž
.
Ž
.
Novel h -hexaalkoxytriphenylene Cr CO complexes 9 with varying alkyl chain lengths C5H11 to C9H19 have been prepared with
3
the chromium tricarbonyl moiety being exclusively attached to one terminal aryl ring. Differential scanning calorimetry, optical polarizing
microscopy and X-ray diffraction showed that complexes 9a–d displayed isotropic melting behavior. However, hexanonyloxy-substituted
complex 9e displayed a nematic ND phase between 378 and 588C. q 1998 Elsevier Science S.A.
Keywords: Chromium arene complex; Metallomesogen; Triphenylene; Nematic liquid crystal
1. Introduction
pounds and due to the enhanced stability of benzylic
anions and cations, the increased electrophilicity and the
steric shielding of one face of the aromatic ring by the
bulky metal fragment, various applications of chromium
arene complexes as steric andror electronic templates
Although metallomesogens are known for a long
time, research efforts dealing with these metal-contain-
ing liquid crystals have been intensified only recently
have been developed in synthetic organic chemistry
w
x
1–3 . One reason is that the combination of a metal
2,3
w
x
4–8 .
To our knowledge only two examples of
complex with an organic liquid crystal often leads to
compounds with unprecedented physical properties,
which might be useful for potential applications in
molecular electronics, electric or magnetic switches, or
novel electric conducting materials. Despite the variabi-
lity of both central metal, coordination number and
geometry, and type of mesogenic ligand, some classes
of metal complexes have only rarely been investigated.
chromium arene complexes exhibiting mesomorphic be-
havior existed in the literature. As reported by Dembek
p-complexed poly-p-phenylene terephthalamides 1, 2
Ž
.
Scheme 1 display nematic lyotropic textures when
X
w
x
dissolved in 5% N,N -dimethylacetamide 14–17 . De-
schenaux studied calamitic 1,4-phenylene bisimine
chromium tricarbonyl complexes 3, which exhibited
w
x
nematic and smectic C mesophases 18 . These results
w
x
Among them are chromium arene complexes 1–3 .
This is surprising, because chromium arene complexes
can be easily prepared, they are mostly stable com-
2 Recent examples of chromium arene complexes in radical reac-
)
w x
tions, see Refs. 9,10 .
3
Corresponding author.
1 Undergraduate research participant.
Chromium arene complexes as catalysts, see Refs. 11–13 .
w
x
0022-328Xr98r$19.00 q 1998 Elsevier Science S.A. All rights reserved.

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172
J.L. Schulte et al.rJournal of Organometallic Chemistry 552 1998 171–176
Table 1
Phase transition temperatures for triphenylenes 8 and the correspond-
ing chromium arene complexes 9a
Ž
.
Ž
.
Ž
.
Ž .
8 R
C™Dh 8C Dh ™I 8C 9 C™ND 8C ND ™I 8C
a C5H11 64
b C6 H13 56
c C7 H15 66
d C8 H17 59
e C9 H19 54
f C10 H21 57
107
64
85
60
61
67
a y
b y
c y
d y
e 37.0
f y
125.2
85.6
67.3
46.4
58.0
y
a Transition temperatures of 8, 9 were determined by DSC during first
heating.
Scheme 1.
of thermotropic hexaalkoxy-substituted triphenylenes 4
w
x
Ž
.
Ž
.
19 by complexation to a Cr CO unit Scheme 2 . Of
particular interest to us was the question, whether the
metal fragment would disturb the hexagonal discotic
3
w
x
alignment of triphenylenes 4 or not 20 . The results
containing the synthesis and properties of novel arene
complexes are described below.
Scheme 2.
2. Results and discussion
prompted us to search for discotic liquid crystals bear-
ing a chromium arene moiety. We therefore investigated
the change of the well-known mesomorphic properties
As shown in Scheme 3 triphenylenes 4 were synthe-
sized via base-catalyzed etherification of brenzcatechine
w
x
6 21 , followed by an oxidative trimerization of 7 in
Ž
.
aqueous sulfuric acid 70 vol.% in the presence of
4
w
x
FeCl3 in moderate overall yields 22 . Refluxing
hexaalkoxytriphenylenes 8 with Cr CO in Bu2OrTHF
Ž
.
6
w
x
for several hours 27 resulted in the clean formation of
chromium arene complexes 9 with the chromium tricar-
bonyl moiety being exclusively attached to one terminal
alkoxysubstituted aryl ring. However, in the case of
hexadecyloxytriphenylene 8f an inseparable mixture of
two chromium complexes was observed, presumably
the monocoordinated compound 9f and the correspond-
ing internal chromium complex. The favored formation
of the terminally coordinated arene complexes 9 is in
complete accordance with observations by Deubzer et
¨
w
x
w x
al. 28,29 Fischer and Ofele 30 , and King and Stone
31 . They found that anellated aryl systems usually
w
x
gave only monochromiumtricarbonyl complexes, in
which the chromium fragment is coordinated to the aryl
ring with the largest index of local aromaticity, i.e., the
terminal, least anellated ring. Further support came from
Sato, who reported that unsubstituted triphenylene pro-
4
w
x
Scheme 3.
Alternative syntheses of triphenylenes, see Refs. 23–26 .

(
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J.L. Schulte et al.rJournal of Organometallic Chemistry 552 1998 171–176
173
signal for the six equivalent aromatic H’s of the parent
hexaalkoxytriphenylenes 8 appear at 7.80–8.15 ppm,
the signals for 1-H, 4-H of the chromium arene complex
9 are shifted highfield towards 6.15–6.30 ppm. The
signals of those hydrogens which are not directly at-
tached to the chromium bearing aryl ring, i.e., 5-H,
12-H and 8-H, 9-H, respectively, display a much smaller
highfield shift and can be observed at 7.55–7.75 ppm.
A similar highfield shift was deduced from the 13C
NMR spectra. The signals for C-1 appeared at 73 ppm
instead of 107 ppm for the uncomplexed derivative 8,
the signal for C-1a was observed at 95 ppm instead of
124 ppm and the signal for C-2 shifted from 149 ppm to
132 ppm.
Fig. 1. Differential scanning calorimetry thermogram of 9e registered
during the first heating.
The phase transition temperatures of triphenylene
chromium complexes 9, which were obtained by diffe-
Ž
.
rential scanning calorimetry DSC , are shown in Table
1. To avoid sample decomposition DSC analyses were
Ž
.
6
duced on treatment with Cr CO only the terminally
w
x
coordinated arene complex 32,33 .
w
x
recorded for one heating run only 18 . For comparison
the phase transition temperatures of the corresponding
w
x
metal free triphenylenes 8 are given as well 34 . The
results show that the columnar stacking of the
triphenylenes which leads to hexagonal discotic
mesophases in compounds 8a–e is severely disturbed
by attachment of a chromium tricarbonyl moiety to the
triphenylene system. Consequently the chromium com-
plexes 9a–d undergo a direct crystalline to isotropic
phase transition at temperatures which are in a similar
range as the Dh ™I phase transition of the correspond-
ing chromium free compounds 8a–d. However, the
hexanonyloxy triphenylene chromium complex 9e
The triphenylene chromium complexes 9 can be
easily identified by 1H NMR spectroscopy. Whereas the
Fig. 2. Texture of a sample of 9e between crossed polarizers at 508C. Magnification: 250=.

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174
J.L. Schulte et al.rJournal of Organometallic Chemistry 552 1998 171–176
3. Conclusion
6
Ž
The synthesis of novel terminally coordinated h -
.
Ž
.
hexaalkoxytriphenylene Cr CO complexes 9a–e has
3
been elaborated. DSC measurements revealed the strong
influence of the metal fragment on the mesogenic prop-
erties. Whereas the parent uncomplexed triphenylenes
8a–e display a Dh mesophase upon heating, only the
hexanonyloxy-substituted complex 9e showed a nematic
ND mesophase. Despite the limitations of the above
described method, it seems reasonable that columnar
mesophases might be achieved with other disk-shaped
chromium arene complexes possessing a centrally bound
Ž
.
Cr CO moiety.
Fig. 3. Proposed nematic ND structure of 9e.
3
5
showed a different behavior. A C™M transition at
4. Experimental
378C was observed. On further heating, the mesophase
was transformed into the isotropic phase at 588C Fig.
1 . Optical polarizing microscopy revealed an unspeci-
fied texture at 508C Fig. 2 , which is similar to marbled
textures observed for nematic liquid crystals 35 . A
symmetric cross was found, when 9e was observed by
conoscopy. This is characteristic for homeotropic uniax-
ial nematic textures 35–37 . X-ray diffraction experi-
ments of non-ordered samples of 9e were performed
between 508 and 908C. The X-ray diffraction pattern at
508C exhibits two sharp reflexes at 22.7 A and 16.5 A
respectively in the small angle region and a diffuse halo
around 3.9 A in the wide angle region. The most
significant changes of the diffraction pattern occur in
the small angle region. At about 608C an additional
peak at 20.5 A appears, whose intensity increases dur-
ing further heating, whereas the other peaks at 22.7 A
and 16.5 A decrease and completely disappear at about
Ž
4.1. General
.
Ž
.
All reactions were carried out under an argon
atmosphere using standard Schlenk techniques. Solvents
were dried and deoxygenated by standard procedures.
w
x
Ž
NMR spectra were recorded on a Bruker AC 200 P 200
w
x
1
13
.
Ž
Ž
MHz H; 50 MHz C , a Bruker ARX 300 300 MHz
13
1H; 75 MHz C , and a Varian Unity-plus 600 MHz
.
13
1H; 150 MHz C . The signals of H’s and C’s , which
.
Ž
.
˚
˚
are part of the)chromium coordinated aryl ring, are
1
13
Ž
.
marked with an in the H and C NMR spectra. IR
spectra: DIGILAB FTS-45-FTIR spectrometer. Differ-
ential scanning calorimetry: Perkin Elmer 7 Series Ther-
mal Analysis System, heating rate: 58C miny1, tempera-
ture range: y308 to q1008C under Ar. Mass spectra
were obtained with a Finnigan Model MAT 312 spec-
˚
˚
˚
˚
Ž
.
trometer ionization potential 70 eV . 1,2-Dial-
6
658C.
Based on these results we assigned the
w
x
koxybenzenes 7 were prepared according to Ref. 45
and 2,3,6,7,10,11-hexaalkoxytriphenylenes 8a–f were
Ž
.
mesophase of 9e as disk-like nematic ND Fig. 3 . The
different behavior of 9e as compared to 8a–e and 9a–d,
respectively, might be rationalized as follows. The
columnar alignment of the triphenylene units, which
was found in hexagonal discotic Dh phases of 8a–e, is
largely disfavored by the ‘non-symmetric’ complexation
of the bulky chromium tricarbonyl moiety especially for
shorter C5–C8 alkyl chains. For the C9 derivative 9e
the influence of the alkyl chain on the molecular proper-
ties becomes more prominent. However, due to the
bulkiness of the Cr CO the nematic form of the
w
x
prepared according to Ref. 22 . Optical polarizing mi-
croscopy: a Mettler FP 82 hot stage controlled by a
Mettler FP 80 central processor was used together with
a Leitz Ortholux II Pol-BK microscope. X-ray diffrac-
tion experiments were performed with monochromatic
Ž
.
˚
Ž
.
CuK a radiation ls1.54 A using a two-dimensional
Ž
.
Ž
.
image plate system 700=700 pixels .
7
Ž
.
3
discotic mesophase is favored against the standard
8
7 The influence of the alkyl chain lengths on the molecular proper-
ties manifests itself also in the mass spectra of compounds 8, 9. The
mass spectra of 8a–e always show the Mq peak as base peak and
Ž
.
w
x
columnar Dh mesophase 38,39 .
almost no fragmentation pattern. In the spectra of the corresponding
5 Deschenaux et al. reported a similar decrease of the mesophase
stability for rod-like nematic chromium arene complexes as com-
chromium complexes 9a–c C5 –C7 the
M
–Cr CO peak
q
Ž
.
w
Ž
. x
3
appears as base peak. However, in the mass spectra of complexes
q
w
x
Ž
.
w
Ž
. x
peak appears only with 65% rel.
3
pared to the corresponding metal-free compounds. See Ref. 18 .
6 Although compound 9e could be sheared at 37–588C, an X-ray
diffraction of the ordered sample could not be obtained.
9d,e C8,C9 the M –Cr CO
Ž
.
intensity base peak mrz 56 .
8
w
x
For related observations see Refs. 40–44 .

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J.L. Schulte et al.rJournal of Organometallic Chemistry 552 1998 171–176
175
Ž
.
Ž
.
Ž
4.1.1. General procedure for the preparation of triph-
enylene chromium arene complexes 9
200 MHz, C6 D6 7.74 s, 2H, 5-H, 12-H , 7.71 s, 2H,
.
Ž
.
Ž
8-H, 9-H , 6.31 s, 2H, 1-H, 4-H , 4.28-3.87 m, 12H,
OCH2C H2CH2, OC H2CH2) , 2.00-1.62 m, 12H,
Ž
.
.
Ž
Ž
A solution of triphenylene 8 2.69 mmol and
OCH2C H2CH2 , OCH2C H2CH2) , 1.60-1.10 m, 48H ,
Ž
. Ž
.
Ž
.
.
.
Cr CO 3.55 g, 16.2 mmol in Bu2OrTHF 10:1 was
6
13
)
Ž
.
Ž
refluxed for 20 h under argon. After removal of the
solvent in vacuo the remaining orange solid was heated
for 1 h at 1008C 0.1 mbar . The crude product was
0.93 s, 18H, CH2C H3, CH2C H3
MHz, C6 D6 234.2 CO , 151.3, 150.1 C-6, C-7, C-10,
C-11 , 132.3, 125.1, 121.9 C-2, C-3, C-5a, C-8a, C-9a,
C-12a , 107.9, 107.8 C-5, C-8, C-9, C-12 , 95.4 C-1a,
;
C NMR 75
.
Ž
.
Ž
Ž
.
.
Ž
.
Ž
.
Ž
recrystallized from EtOH.
.
Ž
.
Ž
C-4a , 73.8 C-1, C-4 , 71.2, 70.2, 69.4 OCH2 ,
4.1.2. 2,3,6,7,10,11-Hexapentyloxytriphenylene-
OCH2) , 32.2, 30.0, 29.8, 29.6, 26.6, 26.5, 26.4, 23.0
.
(
)
( )
1,1a,2,3,4,4a -tricarbonyl-chromium 0 9a
)
Ž
.
Ž
.
Ž
Ž
.
Ž
.
CH2 , 14.3 CH3, CH3 ; MS EI mrz 1048 M, 2 ,
Ž
.
1.68 g 1.90 mmol, 71% of yellow crystals; Mp
Ž
.
Ž
.
.
Ž .
966 18 , 965 38 , 964 M-3 CO, 46 , 915 4 , 914
1
125.28C; IR KBr 1945, 1872, 1843 cmy1; H NMR
Ž
.
Ž
.
Ž
.
Ž
Ž
.
.
Ž .
22 , 913 65 , 912 M–Cr CO , 100 , 813 6 , 768
4 , 767 12 , 766 18 , 715 2 , 684 3 , 519 3 , 482
3
Ž
.
Ž
Ž
.
Ž
600 MHz, C6 D6 7.64 s, 2H, 5-H, 12-H , 7.63 s, 2H,
Ž .
Ž
.
Ž
.
.
Ž .
Ž .
Ž .
.
.
Ž
8-H, 9-H , 6.21 s, 2H, 1-H, 4-H , 4.22-3.93 m, 12H,
Ž .
Ž .
Ž
Ž
.
Ž
.
4 , 111 4 , 71 16 , 70 28 , 56 49 ; HRMS calcd. for
C63 H96O9Cr 1048.6461, found 1048.6430. Anal. Calcd.
for C63 H96O9Cr: C, 72.10; H, 9.22. Found: C, 71.96;
H, 9.21.
OC H2 CH 2 , OC H2 CH 2)
,
.
Ž
1.88-1.72 m, 12H,
OCH2C H2CH2 , OCH2C H2CH2) , 1.54-1.32 m, 24H ,
.
Ž
.
13C
.
;
)
Ž
0.93 t, Js9.1 Hz, 18H, CH2C H3, CH2C H3
Ž
.
Ž
.
Ž
NMR 50 MHz, C6 D6 234.2 CO , 151.1, 149.9 C-6,
.
Ž
C-7, C-10, C-11 , 132.2, 125.0, 121.1 C-2, C-3, C-5a,
C-8a, C-9a, C-12a , 107.7, 107.5 C-5, C-8, C-9, C-12 ,
95.2 C-1a, C-4a , 73.6 C-1, C-4 , 71.1, 70.1, 69.3
4.1.5. 2,3,6,7,10,11-Hexaoctyloxytriphenylene-
(
.
Ž
.
)
( )
1,1a,2,3,4,4a -tricarbonyl-chromium 0 9d
1.62 g 1.43 mmol, 71% of an orange wax-like
Ž
.
Ž
.
)
Ž
.
Ž
Ž
.
OCH2 , OCH2 , 29.6, 29.5, 28.8, 28.7, 28.6, 22.9
1
solid; Mp 46.48C; IR KBr 1947, 1876, 1845 cmy1; H
NMR 200 MHz, C6 D6 7.55 s, 4H, 5-H, 8-H, 9-H,
)
Ž
.
.
Ž .
Ž
.
Ž
.
Ž
.
CH2 , 14.3 CH3, CH3 ; MS EI mrz 880 M, 3 ,
Ž
.
Ž
.
Ž
.
Ž
.
Ž
Ž
.
.
799 3 , 798 14 , 796 M-3 CO, 52 , 747 14 , 744
.
Ž
Ž
12-H , 6.13 s, 2H, 1-H, 4-H , 4.21-3.80 m, 12H,
Ž
Ž .
Ž
.
.
Ž .
Ž .
Ž
.
M–Cr CO , 100 , 673 6 , 655 14 , 654 22 , 604
4 , 463 8 , 393 5 , 323 7 , 295 6 , 293 2 , 149 7 ,
Ž . 3
Ž .
Ž .
Ž .
Ž .
OC H2 CH 2 , OC H2 CH 2)
,
.
Ž
2.05-1.70 m, 12H,
OCH2C H2CH2 , OCH2C H2CH2) , 1.70-1.08 m, 60H ,
.
Ž
.
Ž .
Ž
.
83 3 , 71 10 ; HRMS calcd. for C51H72O9Cr 880.4583,
found 880.4560. Anal. Calcd. for C51H72O9Cr: C,
69.52; H, 8.24. Found: C, 70.08; H, 8.26.
13
)
Ž
.
Ž
0.93 s, 18H, CH2C H3, CH2C H3
MHz, C6 D6 234.2 CO , 151.0, 149.8 C-6, C-7, C-10,
C-11 , 132.3, 124.8, 121.0 C-2, C-3, C-5a, C-8a, C-9a,
C-12a , 107.5 C-5, C-8, C-9, C-12 , 95.2 C-1a, C-4a ,
;
C NMR 50
.
Ž
.
Ž
.
Ž
4.1.3. 2,3,6,7,10,11-Hexahexyloxytriphenylene-
.
Ž
Ž
.
Ž
.
.
)
(
)
( )
1,1a,2,3,4,4a -tricarbonyl-chromium 0 9b
.
Ž
73.6 C-1, C-4 , 71.1, 70.1, 69.4 OCH2 , OCH2 ,
Ž
.
2.30 g 2.38 mmol, 99% of a yellow solid. Mp
Ž
.
Ž .
Ž
32.3, 30.0, 29.8, 26.8, 26.6, 23.1 CH2 , 14.4 CH3,
1
85.68C; IR KBr 1946, 1877, 1844 cmy1; H NMR
CH3) ; MS EI mrz 1133 M, 1 , 1051 4 , 1050 16 ,
Ž .
Ž
.
.
.
Ž
Ž
.
Ž
.
Ž
Ž
.
Ž
Ž
.
200 MHz, C6 D6 7.60 s, 4H, 5-H, 8-H, 9-H, 12-H ,
.
Ž
.
Ž
Ž
Ž .
.
1049 M-3 CO, 30 , 999 6 , 998 48 , 997 M-Cr CO ,
3
Ž
.
Ž
6.17 s, 2H, 1-H, 4-H , 4.40-3.75 m, 12H, OC H2CH2 ,
.
Ž .
.
Ž .
Ž .
63 , 884 6 , 882 19 , 742 2 , 741 3 , 525 2 , 524
Ž . Ž .
55 100 ; HRMS calcd. for C69 H108O9Cr 1132.7401,
found 1132.7428. Anal. Calcd. for C69 H108O9Cr: C,
73.11; H, 9.60. Found: C, 73.16; H, 10.04.
OC H2CH2) , 2.08-1.70 m, 12H, OCH2C H2CH2 ,
.
Ž
Ž
.
Ž
.
Ž
.
Ž
.
Ž
.
3 , 114 5 , 112 19 , 83 31 , 71 36 , 70 70 , 56 80 ,
OCH2C H2CH2) , 1.70-1.10 m, 36H , 0.93 s, 18H,
.
Ž
.
Ž
Ž
.
13
CH2C H3, CH2C H3)
;
Ž
C NMR 50 MHz, C6 D6 234.2
.
Ž
.
Ž
.
.
CO , 151.0, 149.8 C-6, C-7, C-10, C-11 , 132.2,
Ž
.
124.9, 121.1 C-2, C-3, C-5a, C-8a, C-9a, C-12a , 107.6,
107.5 C-5, C-8, C-9, C-12 , 95.2 C-1a, C-4a , 73.6
Ž
.
Ž
.
)
4.1.6. 2,3,6,7,10,11-Hexanonyloxytriphenylene-
(
Ž
.
Ž
.
C-1, C-4 , 71.1, 70.1, 69.3 OCH2 , OCH2 , 32.1,
)
( )
1,1a,2,3,4,4a tricarbonyl-chromium 0 9e
2.00 g 1.64 mmol, 89% of an orange wax-like
Ž
.
Ž
30.0, 29.8, 26.1, 26.2, 26.1, 23.0 CH2 , 14.2 CH3,
Ž .
Ž
.
CH3) ; MS EI mrz 964 M, 6 , 884 6 , 883 20 , 881
.
Ž
.
.
.
Ž
.
Ž
.
w
solid. Transition temperatures: C 37.0 D Hs2.771
Ž
Ž
Ž
.
Ž
.
Ž
Ž
.
M-3 CO, 64 , 831 20 , 830 62 , 829 M–Cr CO ,
3
x
w
x
Ž
.
Jrg ND 58.5 D Hs10.02 Jrg I. IR KBr 1946,
.
Ž
.
Ž .
Ž .
Ž .
100 , 711 18 , 710 22 , 659 2 , 491 3 , 440 4 , 149
1
1878, 1844 cmy1; H NMR 200 MHz, C6 D6 7.60 s,
Ž
.
Ž
Ž .
Ž .
Ž
.
Ž
.
Ž
.
Ž
.
3 , 97 5 , 84 10 , 69 17 , 60 20 , 57 27 ; HRMS
calcd. for C57 H89O9Cr 964.5522, found 964.5498. Anal.
Calcd. for C57 H89O9Cr: C, 70.93; H, 8.77. Found: C,
71.06; H, 8.98.
.
Ž
.
Ž
2H, 5-H, 12-H , 7.57 s, 2H, 8-H, 9-H , 6.15 s, 2H,
1-H, 4-H , 4.33-3.87 m, 12H, OC H2CH2 , OC H2CH2
2.06-1.71 m, 12H, OCH2C H2CH2 , OCH2C H2CH2
)
.
Ž
.
,
.
,
.
;
)
Ž
)
Ž
.
Ž
1.70-1.15 m, 72H , 0.94 s, 18H, CH2C H3, CH2C H3
13
Ž
.
Ž
.
4.1.4. 2,3,6,7,10,11-Hexaheptyloxytriphenylene-
C NMR 75 MHz, C6 D6 234.2 CO , 151.0, 149.8
C-6, C-7, C-10, C-11 , 132.2, 124.9, 121.7 C-2, C-3,
(
)
( )
Ž
.
Ž
1,1a,2,3,4,4a -tricarbonyl-chromium 0 9c
Ž
.
.
.
Ž
1.80 g 1.72 mmol, 86% of a yellow solid. Mp.
C-5a, C-8a, C-9a, C-12a , 107.7, 107.5 C-5, C-8, C-9,
1
67.38C. IR KBr 1947, 1877, 1844 cmy1; H NMR
Ž
.
.
Ž
Ž
.
C-12 , 95.1 C-1a, C-4a , 73.6 C-1, C-4 , 71.1, 70.2,

(
)
176
J.L. Schulte et al.rJournal of Organometallic Chemistry 552 1998 171–176
)
w
w
w
w
x
15 A.A. Dembek, R.R. Burch, A.E. Feiring, Polym. Prep. 34
Ž
.
69.4 OCH2 , OCH2 , 32.4, 30.1, 29.9, 29.8, 26.8,
)
Ž
.
1993 172.
Ž
.
Ž
.
Ž
26.6, 23.1, 14.3 CH3, CH3 ; MS EI mrz 1216 M,
x
Ž
.
16 A.A. Dembek, P.J. Fagan, M. Mani, Macromolecules 26 1993
.
Ž .
Ž
.
Ž
.
0.22 , 1134 6 , 1133 12 , 1132 M-3 CO, 16 , 1083
Ž .
2992.
Ž
.
Ž
.
Ž
Ž
.
.
5 , 1082 22 , 1081 56 , 1080 M–Cr CO , 67 , 1079
x
17 A.A. Dembek, R.R. Burch, A.E. Feiring, Macromol. Symp. 77
3
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
Ž .
7 , 991 1 , 954 6 , 915 2 , 912 8 , 797 3 , 796 5 ,
Ž
.
1994 303.
x
18 E. Campillos, R. Deschenaux, A.-M. Levelut, R. Ziessel, J.
Ž . Ž .
Ž
.
Ž
.
.
Ž
.
Ž
.
566 2 , 128 4 , 126 12 , 98 16 , 97 22 , 85 28 , 84
Ž
.
Chem. Soc. Dalton Trans. 1996 2533.
Ž
.
Ž
.
Ž
.
Ž
Ž
.
28 , 70 58 , 69 49 , 56 100 , 55 90 . HRMS calcd.
w
w
x
x
Ž
.
19 Y. Bouligand, J. de Phys. 1980 1307.
20 C. Destrude, N.H. Tinh, H. Gasparoux, Mol. Cryst. Liq. Cryst.
for C75 H120O9Cr 1216.8340, found 1216.8312. Anal.
Calcd. for C75 H120O9Cr: C, 73.97; H, 9.93. Found: C,
73.94; H, 10.18.
Ž
.
71 1981 111.
w
w
w
x
Ž
.
21 V. Percec, C.G. Cho, C. Pugl, J. Mater. Chem. 1 1991 217.
22 H. Naarmann, M. Hanack, R. Mattmer, Synthesis 5 1994 477.
23 N. Boden, R. Bushby, A. Cammidge, J. Chem. Soc. Chem.
x
Ž
.
x
Ž
.
Commun. 1994 465.
Acknowledgements
w
x
24 N.H. Tinh, M. Bernaud, G. Sigaud, C. Destrade, Mol. Cryst.
Ž
.
Liq. Cryst. 65 1981 307.
Generous financial support by the Deutsche
Forschungsgemeinschaft Gerhard-Hess-Preis for S.L.
is gratefully acknowledged. We would like to thank
Prof. Wendorff and A. Kettner, Univ. Marburg for
helpful discussions.
w
w
x
x
Ž
.
25 J.-M. Chapuzet, J. Simonet, Tetrahedron 47 1991 791.
26 A. McKillop, A. Turrell, D. Young, E. Taylor, J. Am. Chem.
Ž
.
Ž
.
Soc. 102 1980 6504.
w
w
x
x
Ž
.
27 C.A.L. Mahaffy, P.L. Pauson, Inorg. Synth. 19 1979 154.
28 B. Deubzer, H.P. Fritz, C.G. Kreiter, K. Ofele, J. Organomet.
¨
Ž
.
Chem. 7 1967 289.
w
x
29 B. Deubzer, E.O. Fischer, H.P. Fritz, C.G. Kreiter, N. Krieb-
Ž
.
itzsch, H.D. Simmons, B.R. Willeford, Chem. Ber. 100 1967
References
3084.
¨
w
w
w
x
Ž
.
30 E.O. Fischer, K. Ofele, Z. Naturforsch. 13b 1958 458.
31 R.B. King, F.G.A. Stone, J. Am. Chem. Soc. 82 1960 4557.
32 M. Sato, Y. Ishida, Y. Nakamura, M. Kajiwara, Nippon Kagaku
w x
Ž
.
1
w x
2
S.A. Hudson, P.M. Maitlis, Chem. Rev. 93 1993 861.
A.-M. Giroud-Godquin, P.M. Maitlis, Angew. Chem., Int. Ed.
x
Ž
.
x
Ž
.
Engl. 30 1991 375.
Ž
.
Zasshi 91 1970 1188.
w x
3
J.L. Serrano, Metallomesogens, VCH, Weinheim, 1995.
S.G. Davies, T.J. Donohoe, Synlett, 1993 323, review.
M. Semmelhack, in: B.M. Trost Ed. , Comprehensive Organic
Synthesis, Pergamon Press, London, 1994, Vol. 4, p. 517,
review.
S.G. Davies, S.J. Coote, C.L. Goodfellow, in: L.S. Liebeskind
Ed. , Advances in Metal-Organic Chemistry, JAI Press, Green-
wich CT, 1991, Vol. 2, p. 1, review.
A. Solladie-Cavallo, in: L.S. Liebeskind Ed. , Advances in
Metal-Organic Chemistry, JAI Press, Greenwich CT, 1991, Vol.
1, p. 99, review.
M. Uemura, in: L.S. Liebeskind Ed. , Advances in Metal-
Organic Chemistry, JAI Press, Greenwich CT, 1991, Vol. 2, p.
195, review.
w
w
w
x
33 M. Sato, Y. Ishida, Y. Nakamura, M. Kajiwara, Chem. Abstr.,
w x
Ž
.
.
4
Ž
.
74 1971 125819h.
w x
Ž
5
x
34 D. Demus, H. Zaschke, Flussige Kristalle in Tabellen II, VEB
¨
Leipzig, 1984.
x
35 G. Vertogen, W.H. de Jeu, Thermotropic Liquid Crystals, Fun-
w x
6
damentals, Springer-Verlag, Berlin, 1988, pp. 23–24.
Ž
.
w
w
x
x
Ž
.
36 P.E. Cladis, Phys. Rev. Lett. 28 1972 1629.
37 S. Chandrasekhar, B.R. Ratna, B.K. Sadashiva, V.N. Raja, Mol.
w x
7
Ž
.
Ž
.
Cryst. Liq. Cryst. 165 1988 123.
w
w
w
w
w
w
w
w
x
38 C. Destrade, P. Foucher, H. Gasparoux, N.H. Tinh, Mol. Cryst.
Ž
.
Liq. Cryst. 106 1984 1062.
w x
8
Ž
.
x
Ž
.
39 J. Simon, J.-J. Andre, A. Skoulios, Nouv. J. Chim. 10 1986
295.
x
40 N.H. Tinh, J. Malthete, J. Jacques, Mol. Cryst. Liq. Cryst. 68
w x
9
H.G. Schmalz, S. Siegel, J.W. Bats, Angew. Chem., Int. Ed.
Engl. 34 1995 2383.
Ž
.
1981 101.
Ž
.
x
41 S. Chandrasekhar, B.K. Sadashiva, B.S. Srikanta, Mol. Cryst.
w
x
10 E.P. Kundig, L. He Xu, P. Romanens, G. Bernardinelli, Synlett
Ž
.
¨
Liq. Cryst. 151 1987 93.
Ž
.
1996 270.
x
42 M. Marcos, P. Romero, J.L. Serrano, J. Chem. Soc. Chem.
w
w
w
x
Ž
.
11 G.B. Jones, S.B. Heaton, Tetrahedron Asymmetry 4 1993 261.
12 M. Sodeoka, M. Shibasaki, Synlett 1993 643.
13 Y. Hayashi, H. Sakai, N. Kasseta, M. Uemura, J. Organomet.
Chem. 503 1995 143.
14 A.A. Dembek, R.R. Burch, A.E. Feiring, J. Am. Chem. Soc.
Ž
.
Commun. 1989 1641.
x
Ž
.
x
43 M. Marcos, J.L. Serrano, P.J. Alonso, J.I. Martinez, Adv. Mater.
x
Ž
.
7 1995 173.
Ž
.
x
Ž
.
44 N.H. Tinh, C. Destrade, H. Gasparoux, Phys. Lett. 72A 1979
w
x
251.
Ž
.
115 1993 2087.
x
Ž
.
45 V. Percec, C.G. Cho, C. Pugh, J. Mater. Chem. 1 1991 217.