Fluorophobic effect in metallomesogens - The synthesis and mesomorphism of Ag, Au, Cu, Fe, Pd, and Pt fluorous isocyanide complexes

Article abstract of DOI:10.1002/ejic.200701341

The synthesis of Ag(CNAr)₂BF₄, Ag(CNAr) ₂NO₃, AuCl-(CNAr), CuCl(CNAr), [CuCl(CNAr) ₂]₂, Fe(CO)₄CNAr, trans-[PdI ₂(CNAr)₂], and trans-[PtI₂(CNAr)₂] complexes containing the fluorous isocyanide ligand CNAr [Ar = 4-F(CF ₂)₈-(CH₂)₄OC₆H ₄] and the examination of the mesomorphic properties of these novel fluorous organometallics are reported. The fluorous isocyanide ligand is mesomorphic, as opposed to its hydrocarbon analogue. In general, the fluorophobic effect enhances the microsegregation in the investigated organometallic/isocyanide complexes, as compared to their hydrocarbon analogues. The fluorous mesophases are stable over a wider temperature range and exhibit higher transition temperatures. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Full text of DOI:10.1002/ejic.200701341

FULL PAPER
DOI: 10.1002/ejic.200701341
Fluorophobic Effect in Metallomesogens – The Synthesis and Mesomorphism
of Ag, Au, Cu, Fe, Pd, and Pt Fluorous Isocyanide Complexes
Roman Dembinski,*[a] Pablo Espinet,*[b] Sergio Lentijo,[b] Marcin W. Markowicz,[a]
Jose M. Martín-Alvarez,[b] Arnold L. Rheingold,[c] Daniel J. Schmidt,[a] and Adam Sniady[a]
Keywords: Metallomesogens / Liquid crystals / Fluorinated ligands / Isocyanide ligands / Mesophases
The synthesis of Ag(CNAr)2BF4, Ag(CNAr)2NO3, AuCl-
(CNAr), CuCl(CNAr), [CuCl(CNAr)2]2, Fe(CO)4CNAr, trans-
[PdI2(CNAr)2], and trans-[PtI2(CNAr)2] complexes containing
rophobic effect enhances the microsegregation in the investi-
gated organometallic/isocyanide complexes, as compared to
their hydrocarbon analogues. The fluorous mesophases are
stable over a wider temperature range and exhibit higher
transition temperatures.
the fluorous isocyanide ligand CNAr [Ar
= 4-F(CF2)8-
(CH2)4OC6H4] and the examination of the mesomorphic
properties of these novel fluorous organometallics are re-
ported. The fluorous isocyanide ligand is mesomorphic, as
opposed to its hydrocarbon analogue. In general, the fluo-
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
Isocyanides (CNR) form stable complexes with many tran-
sition metals and have been investigated in the pursuit of
metallomesogens.[16–21] The earliest mesogenic isocyanide
complexes include square-planar palladium(II) and plati-
num(II) trans-[MI2(CNR)2] complexes derived from iso-
cyanides with two aromatic rings connected by an ester
group.[16a,16b] Other complexes, such as neutral gold(I) com-
plexes [AuCl(CNR)],[17c] ionic silver(I) complexes
Introduction
Compounds containing perfluorocarbon chains (usually
called fluorous) attract attention not only due to their syn-
thetic, catalytic, and biomedical applications,[1] but also due
to their self-segregation ability that results in the appear-
ance of liquid-crystalline phases. The fluorophobic effect
may induce supramolecular organization through the in-
compatibility of fluorinated and non-fluorinated hydro-
carbons.[2–6] This effect results from the differences in the
cohesive energy between perfluorocarbon and hydrocarbon
groups. Incorporation of perfluorinated alkyl chains into
classical organic molecules produces a microsegregation at
the molecular level that results in an enhancement of highly
ordered lamellar mesophases. An influence on mesomor-
phic properties by fluorination of classical organic liquid
crystals has been investigated.[7–14]
–
–
[Ag(CNR)2]Y (Y = NO3 , BF4 ),[18] and neutral copper(I)
complexes [CuCl(CNR)],[19] all with linear coordination,
are also known. More recently, compounds with different
coordination at the metal center – tetrahedral copper(I)
[20]
complexes [Cu(µ-Cl)(CNR)2]2
and trigonal-bipyramidal
iron(0) complexes [Fe(CO)4(CNR)] – have been pre-
pared.[21] A recent innovative approach to isocyanide com-
plexes of Au, Pd, and Pt uses p-isocyanobenzoic acid, p-
CNC6H4CO2H.[16e] Neither the free isocyanide nor its
metal complexes are mesogenic, but the carboxylic group
can be used to hydrogen-bond a decyloxystilbazole, and the
resulting complexes display enantiotropic smectic A (SA) or
nematic (N) mesophases.
The only calamitic compounds in these series that are
mesogenic, while having isocyanide ligands containing only
one aromatic ring, are gold and silver complexes. In the rest
of the complexes the length/width ratio has to be increased
by the inclusion of at least two aromatic rings in order to
induce mesogenic properties. As a consequence of such en-
largement, the transition temperatures and the viscosity are
also raised, disfavoring the potential for practical applica-
tions of these materials. Therefore, implementation of the
fluorophobic effect into these complexes may result in an
improvement of the liquid-crystal properties without in-
creasing transition temperatures and viscosity.
The investigation of metallomesogens (liquid crystals
containing transition or post-transition metals) has
emerged as an active branch of liquid-crystal research.[15]
Studies of structure/property relationships with the purpose
of designing new materials, and ultimately predicting the
properties, continues to be an important aspect in this area.
[a] Department of Chemistry, Oakland University,
2200 N. Squirrel Rd., Rochester, Michigan 48309-4477, USA
E-mail: dembinsk@oakland.edu
[b] IU CINQUIMA/Química Inorgánica, Facultad de Ciencias,
Universidad de Valladolid,
47071 Valladolid, Castilla y León, Spain
E-mail: espinet@qi.uva.es
[c] Department of Chemistry and Biochemistry, University of Cali-
fornia, San Diego,
La Jolla, California 92093-0358, USA
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
Eur. J. Inorg. Chem. 2008, 1565–1572
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1565

R. Dembinski, P. Espinet et al.
FULL PAPER
Figure 1. Representative fluorous metallomesogens.
So far, only few examples of fluorocarbon-containing chain, it has been shown that the presence of two aromatic
metallomesogens have been described in the literature. Re- rings in the molecule is not required to induce mesomorphic
ported by Bruce et al., the ortho-metallated imine complex character in the organic structures.
of rhenium(I) containing an octahedral metal center (1;
Figure 1) exhibits reduced transition temperatures as com-
Results and Discussion
pared to the free ligands.[22] The coordination of the octahe-
dral metal center widens the molecule in such a way that
In order to investigate the fluorophobic effect in a variety
the mesophase produced is no longer smectic but instead of metal complexes of isocyanides containing only one aro-
nematic. With the introduction of the perfluorinated seg- matic ring, a systematic synthesis and examination of meso-
ment the corresponding complex is again smectic, which morphic properties of a series of complexes of group-11,
constitutes another example of the strong ordering force and group-10 and -8 metals was pursued. The selection in-
associated with the fluorophobic effect.
cluded fluorous analogues of hydrocarbon complexes in
The examination of fluorinated discotic ortho-palladated which mesomorphic properties are generally not observed,
imine derivatives 2 that were synthesized by Tschierske, as mentioned in the Introduction.
Bilgin-Eran et al. shows that the incorporation of the fluori-
On the basis of earlier studies on organic rod-like crystals
nated chains leads to the replacement of nematic D (ND) containing a single phenoxy unit,[13a,13b] it can be assumed
phases by columnar hexagonal (Colh) phases over a wider that four (m = 4) will be the optimum number of methylene
temperature range.[23] Again the fluorophobic effect gives groups in the hydrogenated part of the molecule’s alkoxy
more stable and more ordered mesophases. If the ortho- chain O(CH2)m(CF2)nF. Analogously, to maintain a suf-
metallated palladium(II) and platinum(II) derivatives are ficient length of the perfluoroalkyl part, the number of CF2
near the calamitic-discotic cross point, the fluorophobic units was established as eight (n = 8; perfluorooctyl).[13] The
effect leads to the disappearance of the cubic and three- isocyanide ligand was synthesized starting from 1-nitro-4-
dimensional ordered phases found between the lamellar and [4-(perfluorooctyl)butoxy]benzene (5),[13b] by reduction,
the columnar organizations of the hydrocarbon analogues.
formylation, and dehydration reactions in sequence. As de-
Other examples of smectic and columnar mesophase picted in Scheme 1, reduction of nitro ether 5 with hydraz-
stabilization in fluorinated metal complexes are the ine in the presence of 5% Pd/C in ethanol gave the aniline
(enamino ketone)nickel(II), -copper(II) and -vanadium(II) derivative 6 in 93% yield. The aniline 6 was converted by
complexes 3 reported by Szydłowska,[24] and the (salicyl- treatment with formic acid in toluene into crude formamide
aldimato)copper(II) and -palladium(II) complexes (such as 7 in almost quantitative yield by using a procedure analo-
4; Figure 1) investigated by Bilgin-Eran et al.[25]
gous to that for its alkyl analogue.[17g] Compound 7 was
Incorporation of the fluorinated segments usually does subjected, without further purification, to the subsequent
not increase the rotational viscosity of the materials, sought reaction with bis(trichloromethyl) carbonate in dichloro-
to be low for potential practical applications. However, un- methane, by employing conditions similar to those de-
desired effects from the presence of long perfluoroalkyl scribed by Ugi and Meyr,[29] to yield isocyanide CNC6H4[4-
chains may include poor solubility or gelation upon intro- O(CH2)4(CF2)8F] (8) in 88% (Scheme 1).[30]
duction into a nematic host mixture.[26]
The gold(I) complex 9 was prepared by substitution of
The fluorophobic effect has already been investigated for the tetrahydrothiophene (tht) in the AuCl(tht) complex with
single aromatic ring-containing organic molecules.[12,13,27,28] the fluorous isocyanide, as illustrated in Scheme 2. The sil-
In the case of compounds containing a perfluoroalkyl ver complexes 10 and 11 were obtained by adding silver
1566
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 1565–1572

Fluorophobic Effect in Metallomesogens
Scheme 1. Synthetic route to fluorous isocyanide 8.
nitrate or silver tetrafluoroborate, respectively, to a THF all similar and show one ν(NϵC) absorption for the isocya-
solution of the isocyanide. Due to the photosensitivity of nide group at higher wavenumbers than for the free isocya-
the silver salts, the reactions and manipulations were car- nide, as has also been reported for the hydrocarbon ana-
1
ried out in the dark. The diiodidopalladium(II) and -plati- logues of the isocyanide complexes. The H NMR spectra
num(II) complexes 12 and 13 were synthesized from the of the complexes prepared are also alike, showing an
corresponding dichloridobis(tetrahydrothiophene) com- AAЈXXЈ spin system for the phenyl group, again similar to
plexes, the isocyanide 8, and KI (excess). The appearance those reported for their hydrocarbon analogues. Although
of only one ν(NϵC) stretching band in the IR spectrum X-ray crystallography characterization of solid complexes
confirms the trans geometry of both complexes.
was sought, efforts to obtain X-ray quality crystals were
The synthesis of the copper(I) complexes 14 and 15 was only partially successful. To no surprise multiple positions
carried out by stirring appropriate stoichiometric amounts for most of the outer segments of the chains were observed.
of the fluorous isocyanide and copper(I) chloride in dichlo- Figure 2 illustrates a molecular structure of the copper
romethane. The tetracarbonyliron complex 16 was synthe- complex 15 based upon poorly refined single-crystal X-ray
sized from the isocyanide and pentacarbonyliron in the data. The structure confirmed that the complex is not very
presence of
(Scheme 2).
a
catalytic amount of cobalt chloride polar overall. The packing indicates very little anisotropy
as well. It should be noted that although the structure of
The structures of 8–16 were confirmed by NMR[31] and 15 was assigned and discussed as a dimer (µ-complex) based
IR spectroscopy and elemental analyses. The IR spectra are upon earlier characterization of aryl non-fluorous copper(I)
Scheme 2. Preparation of complexes 9–16 (tht = tetrahydrothiophene).
Eur. J. Inorg. Chem. 2008, 1565–1572
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1567

R. Dembinski, P. Espinet et al.
FULL PAPER
isocyanide complexes, it is known that isocyanide com-
plexes are able to adopt a variety of structural forms.[32] In
the acquired crystal structure, the copper atom adopts a
trigonal geometry, and the complex is monomeric.
Figure 2. Molecular structure for copper complex 15. Monoclinic,
C2/c, a/b/c = 20.994(3)/6.1438(9)/35.104(5) Å, β = 93.571(2) °, Z =
4. Selected interatomic distances [Å]: Cu1–C1 1.895(4), Cu1–Cl1
2.2086(16). Key angles [°]: C1–Cu1–C1Ј 125.1(2), C1–Cu1–Cl1
117.46(12), N1–C1–Cu1 176.2(4).
Figure 3. Polarized-light optical photomicrograph of the fan-
shaped texture of the smectic A phase on cooling of 8 at 50 °C.
120 °C and undergoes decomposition, completed at 140 °C
(observed under the microscope). The tetrafluoroborate salt
11 also forms the smectic A mesophase at 92 °C, and par-
tially decomposes at 240 °C before reaching the clearing
point, as observed under the microscope. Decomposition of
hydrocarbon analogs has been previously reported;[18] how-
ever, the transition temperatures for the silver tetrafluo-
roborate complex increased upon fluorination, suggesting
an increase of the thermal stability due to the fluorophobic
effect. Another consequence of this effect is the great stabili-
zation of the smectic A mesophase over the tilted smectic
phases. In this way, the smectic C mesophase present in the
silver hydrocarbon complexes was not observed for either
the nitrate 10 or the tetrafluoroborate 11 fluorinated silver
salts.
The phase-transition temperatures of the complexes were
investigated by DSC and are summarized in Table 1. The
ligand, perfluoroalkyl isocyanide 8, in contrast to its alkyl
analogue, exhibits liquid-crystalline properties itself upon
both heating and cooling (Figure 3). Upon heating, 8 forms
an SA phase over a 2 °C range,[33] but upon cooling, the
mesophase range extends over ca. 25 °C. Thus, the fluo-
rophobic effect has allowed for the mesogenicity of an or-
ganic compound (an isocyanide in this case) with a single
benzene unit.
Table 1. Optical, thermal, and thermodynamic data for isocyanide
8 and its complexes 9–16.
Compound
Transition[a]
T[b]
[°C]
∆H[b]
[kJ/mol]
The planar palladium and platinum complexes 12 and 13
also show mesogenic behavior. The palladium complex
melts to a smectic A mesophase at 56 °C, and becomes an
isotropic liquid at 115 °C. The analogous platinum complex
has a melting point of 60 °C and clearing point of 92 °C.
Thus, replacement of palladium by platinum not only does
not influence the mesophase type, but also has a meso-
phase-destabilizing effect, as opposed to observations for
phenylpyridine hydrocarbon complexes.[34] The correspond-
ing hydrocarbon analogues show no mesogenic behavior.
According to Takahashi et al.,[16a,16b] a more rigid system
of two aryl rings in each isocyanide is needed for mesophase
formation for palladium(II) and platinum(II) hydrocarbon
complexes.
The rod-like mononuclear copper complex 14 shows me-
sogenic behavior (smectic A phase) in the range between
152 °C (melting point) and 233 °C (clearing point), while
the hydrogenated analog is not a liquid crystal. However,
complex 15 with different coordination around the cop-
per(I) center is not a mesogen and melts directly into an
isotropic liquid at 142 °C. The fluorophobic effect is also
not strong enough to introduce mesogenity into the iron
complex 16. Neither the hydrogenated nor the fluorinated
8
9
C···SA···I[33]
C···CЈ
CЈ···CЈЈ
CЈЈ···SA
SA···I
C···CЈ
CЈ···SA
SA···I
C···SA
SA···I
C···SA
SA···I
C···SA
SA···I
C···CЈ
CЈ···SA
SA···I
C···CЈ
CЈ···I
C···CЈ
CЈ···I
62
156
173
191
274
88
39.2[c]
4.8
3.7
25.2
3.3
14.1
30.9
10
120
140[d]
92
11
12
13
14
35.0
240[d]
56
48.8
7.7
42.7
5.4
2.0
23.4
0.8
17.2
58.9
1.4
115
60
92
133
152
233
128
142
–6
15
16
92
10.2
[a] C: crystal; S: smectic; I: isotropic liquid. [b] Data refer to the
second DSC cycle starting from the crystal formed on cooling the
mesophase. Temperature data as peak onset. [c] Combined enthal-
pies. [d] Optical microscopy data (dec.).
A similar phenomenon is observed with the silver com- iron complexes are liquid crystals. It can be assumed that
plexes. The nitrate salt 10 forms a smectic A mesophase at close packing of the molecules is not achieved by the steri-
1568
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 1565–1572

Fluorophobic Effect in Metallomesogens
Figure 4. Graphical comparison of phase-transition temperatures for ligand 8, complexes 9–16, and their hydrocarbon analogues (labeled
with suffix H).
instrument was used, which was calibrated with water and indium;
the scanning rate was 10 °Cmin–1, the samples were sealed in alu-
minum capsules in the air, and the holder gas was dry nitrogen.
The temperatures correspond to the onset of a transition or to the
peak temperatures when the transition is very broad. Dimethyl-
formamide (DMF) and dichloromethane were distilled from cal-
cium hydride, and DMF was degassed (freeze and thaw) three times
prior to use; THF was distilled from sodium/benzophenone; tolu-
ene was distilled from sodium. Copper(I) chloride (99%; Aldrich),
pentacarbonyliron(0) (99%; Strem), silver tetrafluoroborate (99%;
cally bulky trigonal-bipyramidal carbonyliron group; thus,
intermolecular interactions and, accordingly, melting points
are reduced.
The mesogenic properties of the complexes, compared
with the analogous hydrocarbon compounds, are summa-
rized in Figure 4. The differences between compounds with
hydrocarbon and fluorinated chains are clearly apparent
when comparing the gold complexes. Both compounds
present an SA mesophase, but the melting and the clearing
temperatures are higher in the fluorinated compound. Alfa Aesar), silver nitrate (Ն99.0%; Spectrum), bis(trichloro-
methyl) carbonate (triphosgene) (TCI), and other materials were
used as received. Literature methods were used to prepare 1-
bromo-4-(perfluorooctyl)butane,[13a] [AuCl(tht)],[35] [PdCl2(tht)2],
and [PtCl2(tht)2][36] (tht = tetrahydrothiophene).
Furthermore, the increase in the clearing point is larger
than the increase in the melting point, resulting in a larger
mesophase temperature range for the fluorous compound.
4-[(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heptadecafluorodo-
decyl)oxy]-1-nitrobenzene (5):[13b] A round-bottom flask fitted with
a reflux condenser was charged with 4-nitrophenol (0.940 g,
6.76 mmol), 1-bromo-4-(perfluorooctyl)butane (3.780 g,
6.810 mmol), K2CO3 (2.910 g, 21.05 mmol), and DMF (50 mL).
Conclusion
In this work we have presented systematic studies of the
fluorophobic effect on the liquid-crystalline properties of
novel fluorous complexes. We have synthesized a series of The mixture was refluxed for 8 h and then allowed to reach room
temperature. Chilled water (150 mL) was added, and the mixture
was acidified with concentrated HCl (5 mL). The brown solid was
filtered off. Silica gel column chromatography (dichloromethane)
gave a fraction from which the solvent was removed by rotary evap-
fluorous isocyanide organometallics and confirmed that in-
troduction of a fluorous ponytail into non-liquid-crystalline
complexes containing a single aromatic ring confers meso-
morphic behavior. The fluorous-compound mesophases are
stable over a wider temperature range and exhibit higher
transition temperatures.
1
oration to give 5 as a yellow solid (3.360 g, 5.479 mmol, 81%). H
NMR (CDCl3): δ = 8.22 (d, J = 9.2 Hz, 2 H, ortho to NO2), 6.95
(d, J = 9.2 Hz, 2 H, meta to NO2), 4.10 (t, J = 5.6 Hz, 2 H, CH2O),
2.3–2.1 (m, 2 H, CH2CF2), 2.1–1.8 [m, 4 H, (CH2)2CH2O] ppm.
4-[(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heptadecafluorodo-
decyl)oxy]aniline (6): A round-bottom flask equipped with reflux
condenser was charged with 5 (3.506 g, 5.717 mmol), 10% palla-
dium on activated carbon (3.09 g, 2.90 mmol Pd), hydrazine mono-
hydrate (3.8 mL, 74 mmol), and ethanol (120 mL). The mixture was
refluxed for 24 h. The mixture was allowed to reach ambient tem-
perature, and the solid was filtered off. The solvent was removed
from the filtrate by rotary evaporation (water pump) to give 6 as
Experimental Section
General: NMR spectra were obtained with Bruker Avance 200 (1H:
200 MHz; 13C: 50 MHz) and ARX 300 (1H: 300 MHz) spectrome-
ters. IR spectra (KBr cell, dichloromethane) were recorded with
Bio Rad FTS-175C and Perkin–Elmer FT 1720X spectrometers.
Elemental analyses were carried out with a Perkin–Elmer 2400
microanalyzer. Polarized-light microscopy studies were carried out
with a Leica DMRB microscope at a heating rate of 10 °Cmin–1.
For differential scanning calorimetry (DSC) a Perkin–Elmer DSC7
1
an off-white solid (3.101 g, 5.479 mmol, 93%). H NMR (CDCl3):
δ = 6.74 (d, J = 8.8 Hz, 2 H, meta to NH2), 6.64 (d, J = 8.8 Hz, 2
Eur. J. Inorg. Chem. 2008, 1565–1572
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1569

R. Dembinski, P. Espinet et al.
FULL PAPER
H, ortho to NH2), 3.92 (t, J = 5.6 Hz, 2 H, CH2O), 3.42 (br. s, 2 Ag(CNAr)2NO3 [Ar = 4-F(CF2)8(CH2)4OC6H4] (10): A round-bot-
H, NH2), 2.35–1.95 (m, 2 H, CH2CF2), 1.95–1.65 [m, 4 H, tom flask was charged with silver nitrate (0.050 g, 0.29 mmol) and
(CH2)2CH2O] ppm.
THF (30 mL). A solution of 8 (0.368 g, 0.620 mmol) in THF
(10 mL) was added, and the solution was stirred in the absence of
light under nitrogen for 4 h. Diethyl ether (10 mL) was added, and
the precipitate formed during the reaction was filtered off and dried
in vacuo (oil pump) over P2O5 for 16 h to give 10 as a white solid
(0.363 g, 0.268 mmol, 91%). C38H24AgF34N3O5 (1356.43): calcd. C
N-{4-[(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heptadecafluoro-
dodecyl)oxy]phenyl}formamide (7): A round-bottom flask (100 mL),
equipped with Dean–Stark apparatus and reflux condenser, was
charged with 6 (0.452 g, 0.775 mmol), formic acid (98%; 3.75 mL),
and toluene (25 mL). The solution was refluxed for 2 h and cooled
to ambient temperature. The solvent was removed by rotary evapo-
rator (water pump) and the residue recrystallized from hexane/tolu-
ene (2:1, v/v; ca. 20 mL) to give 7 (0.428 g, 0.702 mmol, 91%) as a
mixture of (E)/(Z) isomers in a 43:57 ratio.[37] 1H NMR (CDCl3):
δ = 8.51 [d, J = 11.5 Hz, 1 H, HCONH, (E) isomer], 8.35 [d, J =
1.0 Hz, 1 H, HCONH, (Z) isomer], 7.45 [d, J = 8.8 Hz, 2 H, ortho
to NHCHO, (Z) isomer], 7.39 [s, 1 H, NHCHO, (E) isomer], 7.33
[s, 1 H, NHCHO, (Z) isomer], 7.03 [d, J = 9.0 Hz, 2 H, ortho to
NHCHO, (E) isomer], 6.90 [d, J = 9.0 Hz, 2 H, meta to NHCHO,
(E) isomer], 6.86 [d, J = 8.8 Hz, 2 H, meta to NHCHO, (Z) isomer],
4.00 (t, J = 5.6 Hz, 2 H, CH2O), 2.27–2.08 (m, 2 H, CH2CF2),
2.08–1.76 [m, 4 H, (CH2)2CH2O] ppm. 13C NMR: δ = 162.9
[NHCHO, (E) isomer], 158.9 [NHCHO, (Z) isomer], 157.1 [para to
NHCHO, (E) isomer], 156.2 [para to NHCHO, (Z) isomer], 130.1
[ipso to NHCHO, (Z) isomer], 129.6 [ipso to NHCHO, (E) isomer],
122.1 [meta to NHCHO, (E) isomer], 122.0 [meta to NHCHO, (Z)
isomer], 115.7 [ortho to NHCHO, (E) isomer], 115.1 [ortho to
NHCHO, (Z) isomer], 67.8 [CH2O, (E) isomer], 67.7 [CH2O, (Z)
isomer], 30.9 (t, J = 21.0 Hz, CH2CF2, both isomers), 28.9
(CH2CH2O, both isomers), 17.5 (CH2CH2CF2, both isomers)
ppm.[38]
33.65, H 1.78, N 3.10; found C 33.48, H 1.82, N 3.02. IR: ν = 2184
˜
[ν(NϵC)] cm–1.[31]
Ag(CNAr)2BF4 [Ar = 4-F(CF2)8(CH2)4OC6H4] (11): A round-bot-
tom flask was charged with silver tetrafluoroborate (0.058 g,
0.30 mmol) and THF (30 mL).
A solution of 8 (0.365 g,
0.615 mmol) in THF (10 mL) was added, and the solution was
stirred in the absence of light under nitrogen for 4 h. Diethyl ether
(10 mL) was added. The precipitate (formed in part during the re-
action) was filtered off and dried in vacuo (oil pump) over P2O5
for 16 h to give 11 as a white solid (0.260 g, 0.188 mmol, 63%).
C38H24AgBF38N2O2 (1381.23): calcd. C 33.04, H 1.75, N 2.03;
found C 33.31, H 1.90, N 1.99. IR: ν = 2203 [ν(NϵC)] cm–1.[31]
˜
trans-[PdI2(CNAr)2] [Ar = 4-F(CF2)8(CH2)4OC6H4] (12): A round-
bottom flask was charged with [PdCl2(tht)2] (0.030 g, 0.085 mmol)
and acetonitrile (20 mL). A solution of 8 (0.100 g, 0.169 mmol) in
acetonitrile (10 mL) was added dropwise and the solution stirred
for 2 h. The solvent was removed under vacuum, and the resulting
residue was washed with hexane (3ϫ10 mL) and dissolved in ace-
tonitrile (20 mL). KI was added (0.060 g, 0.36 mmol), and the mix-
ture was refluxed for 12 h. The mixture was allowed to reach room
temperature, and the solvent was removed in vacuo. The residue
was extracted with dichloromethane (3ϫ30 mL), and the solvent
was removed by rotary evaporation to give 12 as a brown solid
(0.085 g, 0.050 mmol, 59%). C38H24F34I2N2O2Pd (1546.78): calcd.
4-[(5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heptadecafluorodo-
decyl)oxy]phenyl Isocyanide (8): A round-bottom flask was charged
with 7 (1.324 g, 2.166 mmol), triethylamine (0.75 mL, 4.5 mmol),
and dichloromethane (100 mL). Bis(trichloromethyl) carbonate
(0.207 g, 0.782 mmol) was added, followed by an additional por-
tion (0.040 g, 0.15 mmol) after 0.5 h. The stirring was continued
under nitrogen for 0.5 h. The solvent was removed by rotary evapo-
ration. Toluene/hexane (1:1, v/v; 50 mL) was added, and the pre-
cipitate was filtered off. The filtrate was concentrated by rotary
evaporation to give a solid residue. Silica gel column chromatog-
raphy (dichloromethane/hexanes, 3:2) gave a fraction from which
the solvent was removed by rotary evaporation to give 8 as a yellow
solid (1.130 g, 1.905 mmol, 88%). C19H12F17NO (593.28): calcd. C
C 29.51, H 1.56, N 1.81; found C 30.06, H 1.72, N 1.92. IR: ν =
˜
2211 [ν(NϵC)] cm–1. 1H NMR ([D6]acetone): δ = 8.23 (d, J =
9.0 Hz, 2 H, ortho to NC), 7.16 (d, J = 9.0 Hz, 2 H, meta to NC),
4.30 (t, J = 5.4 Hz, 2 H, CH2O), 2.5–2.2 (m, 2 H, CH2CF2), 2.2–
1.8 [m, 4 H, (CH2)2CH2O] ppm.
trans-[PtI2(CNAr)2] [Ar = 4-F(CF2)8(CH2)4OC6H4] (13): A round-
bottom flask was charged with [PtCl2(tht)2] (0.037 g, 0.084 mmol)
and acetonitrile (20 mL). A solution of 8 (0.100 g, 0.169 mmol) in
acetonitrile (10 mL) was added dropwise and the solution stirred
for 2 h. The solvent was removed under vacuum, and the resulting
residue was washed with hexane (3ϫ10 mL) and dissolved in ace-
tonitrile (20 mL). KI was added (0.060 g, 0.36 mmol), and the mix-
ture was refluxed for 12 h. The mixture was allowed to reach room
temperature, and the solvent was removed in vacuo. The residue
was extracted with dichloromethane (3ϫ30 mL), and the solvent
was removed by rotary evaporation to give 13 as an orange solid
(0.057 g, 0.035 mmol, 42%). C38H24F34I2N2O2Pt (1635.44): calcd.
38.46, H 2.04, N 2.36; found C 38.84, H 2.16, N 2.31. IR: ν = 2127
˜
1
[ν(NϵC)] cm–1. H NMR (CDCl3): δ = 7.32 (d, J = 8.9 Hz, 2 H,
ortho to NC), 6.87 (d, J = 8.9 Hz, 2 H, meta to NC), 4.01 (t, J =
5.6 Hz, 2 H, CH2O), 2.30–2.05 (m, 2 H, CH2CF2), 2.05–1.82 [m, 4
H, (CH2)2CH2O] ppm. 13C NMR: δ = 160.0 (CN), 162.7, 128.3,
119.3, 115.4 (C6H4), 67.9 (CH2O), 30.9 (t, J = 22.3 Hz, CH2CF2),
28.7 (CH2CH2O), 17.5 (CH2CH2CF2) ppm.
C 27.91, H 1.48, N 1.71; found C 28.57, H 1.56, N 1.82. IR: ν =
˜
AuCl(CNAr) [Ar = 4-F(CF2)8(CH2)4OC6H4] (9): A round-bottom
flask was charged with [AuCl(tht)] (0.054 g, 0.17 mmol) and dichlo-
romethane (15 mL). A solution of 8 (0.100 g, 0.169 mmol) in
dichloromethane (10 mL) was added dropwise, and the solution
was stirred for 5 min, during which time a white solid precipitated.
Hexane (10 mL) was added to the mixture to complete the precipi-
tation, and the solid was filtered off. Recrystallization (dichloro-
methane/hexane) gave 9 as white crystals (0.110 g, 0.133 mmol,
2206 [ν(NϵC)] cm–1. 1H NMR ([D6]acetone): δ = 8.21 (d, J =
9.0 Hz, 2 H, ortho to NC), 7.10 (d, J = 9.0 Hz, 2 H, meta to NC),
4.25 (t, J = 6.1 Hz, 2 H, CH2O), 2.5–2.3 (m, 2 H, CH2CF2), 2.1–
1.8 [m, 4 H, (CH2)2CH2O] ppm.
CuCl(CNAr) [Ar = 4-F(CF2)8(CH2)4OC6H4] (14): A round-bottom
flask was charged with copper(I) chloride (0.050 g, 0.51 mmol) and
THF (25 mL). A solution of 8 (0.326 g, 0.549 mmol) in THF
(15 mL) was added dropwise over 0.5 h, and the solution was
stirred under nitrogen for 1.5 h. Hexane (10 mL) was added to the
mixture, and the precipitate formed during the reaction was filtered
off and dried in vacuo (oil pump) to give 14 as a white solid
79%). C19H12AuClF17NO (825.7): calcd. C 27.64, H 1.46, N 1.70;
1
found C 28.49, H 1.44, N 1.85. IR: ν = 2227 [ν(NϵC)] cm–1. H
˜
NMR (CDCl3): δ = 7.45 (d, J = 9.0 Hz, 2 H, ortho to NC), 6.95
(d, J = 9.0 Hz, 2 H, meta to NC), 4.09 (t, J = 5.5 Hz, 2 H, CH2O),
2.40–2.05 (m, 2 H, CH2CF2), 2.0–1.7 [m, 4 H, (CH2)2CH2O] ppm. (0.293 g, 0.423 mmol, 84%). C19H12ClCuF17NO (692.28): calcd. C
1570 Eur. J. Inorg. Chem. 2008, 1565–1572
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Fluorophobic Effect in Metallomesogens
[4]
[5]
[6]
C. Viney, T. P. Russell, L. E. Depero, R. J. Twieg, Mol. Cryst.
Liq. Cryst. 1989, 168, 63–82.
C. Viney, R. J. Twieg, B. R. Gordon, J. F. Rabolt, Mol. Cryst.
32.96, H 1.75, N 2.02; found C 32.56, H 1.82, N 1.92. IR: ν = 2156
˜
1
[ν(NϵC)] cm–1. H NMR (CDCl3): δ = 7.40 (d, J = 9.0 Hz, 2 H,
ortho to NC), 6.90 (d, J = 9.0 Hz, 2 H, meta to NC), 4.03 (t, J =
5.4 Hz, 2 H, CH2O), 2.35–2.05 (m, 2 H, CH2CF2), 2.05–1.75 [m, 4
H, (CH2)2CH2O] ppm. 13C NMR: δ = 159.3 (CN), 128.0, 121.9,
115.2 (C6H4), 67.8 (CH2O), 30.8 (t, J = 22.3 Hz, CH2CF2), 28.7
(CH2CH2O), 17.4 (CH2CH2CF2) ppm.
Liq. Cryst. 1991, 198, 285–289.
T. Inoi, “Fluorinated Liqud Crystals” in Organofluorine Chem-
istry: Principles and Commercial Applications (Eds.: R. E.
Banks, B. E. Smart, J. C. Tatlow), series: Topics in Applied
Chemistry, Plenum Press, New York, 1994, pp. 263–286.
Selected representative examples: a) X. H. Cheng, S. Diele, C.
Tschierske, Angew. Chem. Int. Ed. 2000, 39, 592–595; b) A.
Pegenau, X. H. Cheng, C. Tschierske, P. Göring, S. Diele, New
J. Chem. 1999, 23, 465–467; c) J.-W. Lee, Y. Park, J.-I. Jin, M. F.
Achard, F. Hardouin, J. Mater. Chem. 2003, 13, 1367–1372; d)
[7]
[CuCl(CNAr)2]2 [Ar = 4-F(CF2)8(CH2)4OC6H4] (15): A round-bot-
tom flask was charged with CuCl (0.052 g, 0.53 mmol) and dichlo-
romethane (30 mL). A solution of 8 (0.696 g, 1.17 mmol) in dichlo-
romethane (10 mL) was added, and the suspension was stirred un-
der nitrogen for 6 h. The formed precipitate was filtered off and
dried in vacuo (oil pump) for 16 h to give 15 as an off-white solid
(0.381 g, 0.148 mmol, 56%). C76H48Cl2Cu2F68N4O4 (2571.11):
W. Drzewin´ski, K. Czupryn´ski, R. Dabrowski, M. Neubert,
˛
Mol. Cryst. Liq. Cryst. 1999, 328, 401–410; e) J. Mu, H. Okam-
oto, T. Yanai, S. Takenaka, X. Feng, Colloids Surf., A 2001,
181, 303–313; f) E. Nishikawa, J. Yamamoto, H. Yokoyama,
Liq. Cryst. 2005, 32, 585–598; g) E. Nishikawa, J. Yamamoto,
H. Yokoyama, J. Mater. Chem. 2003, 13, 1887–1893; h) E. Ni-
shikawa, J. Yamamoto, H. Yokoyama, Chem. Lett. 2001, 94–
95.
a) M. Prehm, S. Diele, M. K. Das, C. Tschierske, J. Am. Chem.
Soc. 2003, 125, 614–615; b) X. Cheng, M. K. Das, U. Baumeis-
ter, S. Diele, C. Tschierske, J. Am. Chem. Soc. 2004, 126, 12930–
12940.
calcd. C 35.50, H 1.88, N 2.18; found C 34.75, H 1.95, N 2.18. IR:
1
ν = 2155 [ν(NϵC)] cm–1. H NMR ([D ]toluene): δ = 6.77 (d, J =
˜
8
8.6 Hz, 8 H, ortho to NC), 6.38 (d, J = 8.6 Hz, 8 H, meta to NC),
3.41 (t, J = 5.6 Hz, 8 H, CH2O), 2.0–1.6 (m, 8 H, CH2CF2), 1.6–
1.3 [m, 16 H, (CH2)2CH2O] ppm.
[8]
Fe(CO)4CNAr [Ar = 4-F(CF2)8(CH2)4OC6H4] (16): A round-bot-
tom flask was charged with cobalt chloride hexahydrate (0.013 g,
0.055 mmol), THF (20 mL), and pentacarbonyliron (0.10 mL,
0.76 mmol). The mixture was brought to reflux, and a solution of
8 (0.297 g, 0.501 mmol) in THF (3 mL) was added. The solution
changed its color from blue to green and gradually to brown over
ca. 45 min. The rusty-colored precipitate was filtered off on a silica
gel pad; the filtrate was concentrated by rotary evaporator and the
residue crystallized from hexanes/dichloromethane (1:1, v/v). The
solid was filtered off to give Fe(CO)3(CNAr)2 as a yellowish solid
(0.064 g, 0.048 mmol, 10%).[39] The filtrate was concentrated by
rotary evaporation and recrystallized from hexane to give 16 as a
yellow solid (0.155 g, 0.204 mmol, 41%). C23H12F17FeNO5
[9]
S. V. Arehart, C. Pugh, J. Am. Chem. Soc. 1997, 119, 3027–
3037.
[10]
[11]
[12]
H. T. Nguyen, G. Sigaud, M. F. Achard, F. Hardouin, R. J.
Twieg, K. Betterton, Liq. Cryst. 1991, 10, 389–396.
T. Doi, Y. Sakurai, A. Tamatani, S. Takenaka, S. Kusabashi,
Y. Nishihata, H. Terauchi, J. Mater. Chem. 1991, 1, 169–173.
a) G. Fornasieri, F. Guittard, S. Géribaldi, Liq. Cryst. 2003,
30, 663–669; b) G. Fornasieri, F. Guittard, S. Géribaldi, Liq.
Cryst. 2003, 30, 251–257.
a) G. Johansson, V. Percec, G. Ungar, J. P. Zhou, Macromole-
cules 1996, 29, 646–660; b) G. Johansson, V. Percec, G. Ungar,
K. Smith, Chem. Mater. 1997, 9, 164–175; c) V. Percec, G.
Johansson, G. Ungar, J. Zhou, J. Am. Chem. Soc. 1996, 118,
9855–9866.
[13]
(761.16): calcd. C 36.29, H 1.59, N 1.84; found C 36.05, H 1.45, N
1
1.82. IR: ν = 2167 [ν(NϵC)]; 2056, 1993, 1965 [ν(C=O)] cm–1. H
˜
NMR (CDCl3): δ = 7.31 (d, J = 8.8 Hz, 2 H, ortho to NC), 6.91
(d, J = 8.8 Hz, 2 H, meta to NC), 4.03 (t, J = 5.4 Hz, 2 H, CH2O),
2.40–2.05 (m, 2 H, CH2CF2), 2.05–1.85 [m, 4 H, (CH2)2CH2O]
ppm.
[14]
[15]
M. Hein, R. Miethchen, D. Schwaebisch, C. Schik, Liq. Cryst.
2000, 27, 163–168.
a) K. Binnemans, Chem. Rev. 2005, 105, 4148–4204; b) B. Don-
nio, D. Guillon, R. Deschenaux, D. W. Bruce in Comprehensive
Coordination Chemistry II (Eds.: J. A. McCleverty, T. J. Meyer),
Pergamon, Oxford, 2003, vol. 7, chapter 7.9, pp. 357–627; c)
K. Binnemans, C. Görller-Walrand, Chem. Rev. 2002, 102,
2303–2346; d) D. W. Bruce, Acc. Chem. Res. 2000, 33, 831–840;
e) S. R. Collison, D. W. Bruce in Transition Metals in Supramo-
lecular Chemistry (Eds.: J. P. Sauvage), Wiley, Chichester, 1999,
chapter 7, p. 285; f) B. Donnio, D. W. Bruce, Struct. Bonding
(Berlin) 1999, 95, 193–247; g) P. Espinet, Gold Bull. 1999, 32,
127–134; h) A. M. Giroud-Godquin, Coord. Chem. Rev. 1998,
178–180, 1485–1499; i) Metallomesogens – Synthesis Properties
and Applications (Ed.: J. L. Serrano), VCH, Weinheim, 1996.
PdII and PtII isocyanide mesogens: a) T. Kaharu, S. Takahashi,
Chem. Lett. 1992, 1515–1516; b) T. Kaharu, T. Tanaka, M.
Sawada, S. Takahashi, J. Mater. Chem. 1994, 4, 859–865; c) S.
Wang, A. Mayr, K.-K. Cheung, J. Mater. Chem. 1998, 8, 1561–
1565; d) S. Coco, F. Díez-Expósito, P. Espinet, C. Fernández-
Mayordomo, J. M. Martín-Álvarez, A. M. Levelut, Chem. Ma-
ter. 1998, 10, 3666–3671; e) S. Coco, E. Espinet, P. Espinet, I.
Palape, Dalton Trans. 2007, 3267–3272.
Supporting Information (see footnote on the first page of this arti-
cle): CIF file for compound 15 (thermal and rotational motion at
the end of the fluorous ponytail cause that refinement was ac-
complished with a poor R factor; thus, we did not deposit our
crystal structure data with the CCDC since it is of poor quality
and contains multiple positions of fluorine atoms in addition to
large ellipsoids).
Acknowledgments
[16]
[17]
We thank the Spanish Ministerio de Educación y Ciencia (Project
CTQ2005-08729/BQU and a studentship to S. L.), the Junta de Ca-
stilla y León (Project VA099A05), the Oakland University and its
Research Excellence Program in Biotechnology for support of this
research.
I
[1] a) Handbook of Fluorous Chemistry (Eds.: J. A. Gladysz, D. P.
Curran, I. T. Horváth), Wiley-VCH, Weinheim, 2004, pp. 1–
595; b) M. A. Ubeda, R. Dembinski, J. Chem. Educ. 2006, 83,
84–92.
Au isocyanide mesogens: a) T. Kaharu, R. Ishii, S. Takahashi,
J. Chem. Soc., Chem. Commun. 1994, 1349–1350; b) T. Kaharu,
R. Ishii, T. Adachi, T. Yoshida, S. Takahashi, J. Mater. Chem.
1995, 5, 687–692; c) S. Coco, P. Espinet, S. Falagan, J. M.
Martín-Alvarez, New J. Chem. 1995, 19, 959–964; d) P. Alejos,
S. Coco, P. Espinet, New J. Chem. 1995, 19, 799–805; e) M.
Benouazzane, S. Coco, P. Espinet, J. M. Martín-Alvarez, J. Ma-
ter. Chem. 1995, 5, 441–445; f) R. Bayón, S. Coco, P. Espinet,
[2] J. F. Rabolt, T. P. Russell, R. J. Twieg, Macromolecules 1984,
17, 2786–2794.
[3] W. Mahler, D. Guillon, A. Skoulios, Mol. Cryst. Liq. Cryst.,
Lett. Sect. 1985, 2, 111–119.
Eur. J. Inorg. Chem. 2008, 1565–1572
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1571

R. Dembinski, P. Espinet et al.
FULL PAPER
C. Fernández-Mayordomo, J. M. Martín-Alvarez, Inorg. Chem.
1997, 36, 2329–2334; g) S. Coco, P. Espinet, J. M. Martín-Alva-
rez, A.-M. Levelut, J. Mater. Chem. 1997, 7, 19–23; h) A.
Omenat, J.-L. Serrano, T. Sierra, D. B. Amabilino, M. Minguet,
E. Ramos, J. Veciana, J. Mater. Chem. 1999, 9, 2301–2305; i)
R. Bayón, S. Coco, P. Espinet, Chem. Mater. 2002, 14, 3515–
3518; j) B. Ballesteros, S. Coco, P. Espinet, Chem. Mater. 2004,
16, 2062–2067; k) R. Bayón, S. Coco, P. Espinet, Chem. Eur. J.
2005, 11, 1079–1085; l) S. Coco, C. Cordovilla, P. Espinet, J.
Martín-Alvarez, P. Muñoz, Inorg. Chem. 2006, 45, 10180–
10187. See also ref.[16e]
[29] a) I. Ugi, R. Meyr, Chem. Ber. 1960, 93, 239–248; b) I. Ugi, U.
Fetzer, U. Eholzer, H. Knupfer, K. Offermann, Angew. Chem.
Int. Ed. Engl. 1965, 4, 472–484.
[30] The fluorophilicity of 8 was determined by the partition coeffi-
cient KD = C(fluorous phase)/C(organic phase) to be 93.9:6.1
at 25 °C. A known amount of the fluorous compound (40–
70 mg) was dissolved in the biphasic system [perfluorocyclo-
hexane/toluene (1:1, v/v); 4 mL]. The resulting mixture was vig-
orously stirred in a 10 mL vial immersed in a 25 °C oil bath
for 24 h. After two clear layers were obtained, an aliquot was
removed from each layer with a syringe and added to the hex-
ane standard. The partition coefficients were calculated based
upon the ratio of the integration of the GC from both phases
(average of four runs). The partition coefficient for 6 was
94.5:5.5.
[31] Efforts to obtain a solution suitable for the acquisition of an
NMR spectrum were unsuccessful in the case of Ag complexes.
[32] A. Toth, C. Floriani, A. Chiesi-Villa, C. Guastini, J. Chem.
Soc., Dalton Trans. 1988, 1599–1605.
[33] The 2 °C mesophase range for 8 was observed under a polar-
ized microscope, the DSC scan displayed only one peak.
[34] T. Hegmann, J. Kain, S. Diele, B. Schubert, H. Bögel, C. Tschi-
erske, J. Mater. Chem. 2003, 13, 991–1003.
I
[18]
Ag isocyanide mesogens: M. Benouazzane, S. Coco, P. Espi-
net, J. M. Martín-Alvarez, J. Barberá, J. Mater. Chem. 2002,
12, 691–696.
I
[19]
[20]
[21]
[22]
Cu isocyanide mesogens: M. Benouazzane, S. Coco, P. Espi-
net, J. Barberá, J. Mater. Chem. 2001, 11, 1740–1744.
I
Cu dinuclear isocyanide mesogens: M. Benouazzane, S. Coco,
P. Espinet, J. Barberá, Inorg. Chem. 2002, 41, 5754–5759.
0
Fe isocyanide mesogens: S. Coco, P. Espinet, E. Marcos, J.
Mater. Chem. 2000, 10, 1297–1302.
a) M.-A. Guillevic, T. Gelbrich, M. B. Hursthouse, D. W.
Bruce, Mol. Cryst. Liq. Cryst. 2001, 362, 147–170; b) M.-A.
Guillevic, D. W. Bruce, Liq. Cryst. 2000, 27, 153–156.
[35] D. C. Goodall, J. Chem. Soc. A 1968, 887–890.
[36] R. Usón, J. Forniés, F. Martínez, M. Tomás, J. Chem. Soc.,
Dalton Trans. 1980, 888–894.
[23] a) B. Bilgin-Eran, C. Tschierske, S. Diele, U. Baumeister, J. Ma-
ter. Chem. 2006, 16, 1136–1144; b) B. Bilgin-Eran, C. Tschier-
ske, S. Diele, U. Baumeister, J. Mater. Chem. 2006, 16, 1145–
1153.
[24] J. Szydłowska, A. Krówczyn´ski, U. Pietrasik, A. Rogowska,
Liq. Cryst. 2005, 32, 651–658.
[25] B. Bilgin-Eran, Ç. Yörür, C. Tschierske, M. Prehm, U. Bau-
meister, J. Mater. Chem. 2007, 17, 2319–2328.
[26] P. Kirsch, in Modern Fluoroorganic Chemistry, Wiley-VCH,
Weinheim, Germany, 2004, pp. 215–237.
[27] a) M. Duan, H. Okamoto, V. F. Petrov, S. Takenaka, Bull.
Chem. Soc. Jpn. 1999, 72, 1637–1642; b) M. Duan, H. Okam-
oto, V. F. Petrov, S. Takenaka, Bull. Chem. Soc. Jpn. 1998, 71,
2735–2739; c) H. Okamoto, H. Murai, S. Takenaka, Bull.
Chem. Soc. Jpn. 1997, 70, 3163–3166; d) S. Takenaka, J. Chem.
Soc., Chem. Commun. 1992, 1748–1749.
[37] Larger quantities were crystallized from CHCl3/CH3OH (1:1,
v/v) to yield 86–87% of spectroscopically pure 7. The ratio was
calculated from the integration of the signals of the aldehyde
1
(CHO) protons in the H NMR spectrum.
[38] The assignment of the aromatic signals was based on the spec-
troscopic data of formamides in ref.[17g]
[39] The formation of bis(isocyanide) complex Fe(CO)3(CNAr)2
[Ar = 4-F(CF2)8(CH2)4OC6H4] as a side product was observed;
it was isolated and characterized. C41H24F34FeN2O5 (1326.43):
calcd. C 37.13, H 1.82, N 2.11; found C 36.65, H 1.94,
N 1.83. IR: ν = 2114 [ν(NϵC)]; 1999, 1932 [ν(C=O)] cm–1. 1H
˜
NMR (CDCl3): δ = 7.27 (d, J = 8.8 Hz, 2 H, ortho to NC),
6.87 (d, J = 8.8 Hz, 2 H, meta to NC), 4.02 (t, J = 5.4 Hz, 2
H, OCH2), 2.40–2.05 (m, 2 H, CH2CF2), 2.05–1.85 [m, 4 H,
(CH2)2CH2CF2] ppm.
[28] C. Rocaboy, F. Hampel, J. A. Gladysz, J. Org. Chem. 2002, 67,
6863–6870.
Received: December 13, 2007
Published Online: February 26, 2008
1572
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 1565–1572