Ionic columnar metallomesogens formed by three-coordinated copper(I) complexes

Article abstract of DOI:10.1039/b103427h

Two series of copper(I) complexes (1,2) derived from bis{2-[3′-(3″,4″-dialkoxyphenyl)-5′-methyl-1′- pyrazolyl]ethyl} ethers and from bis{2-[3′-(3″,4″,5′-trialkoxyphenyl)-5′- methyl-1′-pyrazolyl]ethyl} ethers were prepared and characterized. These ionic copper(I) complexes were obtained by reaction of the ethers with [Cu(MeCN)₄]BF₄ in refluxing acetonitrile. All three-coordinated copper(I) complexes isolated as off-white solids were characterized by NMR spectroscopy and elemental analysis, and their mesomorphic properties were also studied by polarized optical microscopy, differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). Results indicated that these complexes exhibited hexagonal columnar phases (Col_h). The clearing points of all compounds were relatively low (94-112°C) and the temperature range of the mesophases was ca. 45-68°C. Powder XRD diffraction patterns showed three sharp reflections in the small angle region corresponding to a ratio of their positions of 1:(1/3)^1/2:(1/2), indicating typical hexagonal columnar phases.

Full text of DOI:10.1039/b103427h

View Article Online / Journal Homepage / Table of Contents for this issue
Ionic columnar metallomesogens formed by three-coordinated
copper(I) complexes
Hon-Da Lin and Chung K. Lai*
Department of Chemistry, National Central University, Chung-Li, Taiwan, ROC.
E-mail: cklai@cc.ncu.edu.tw
Received 8th April 2001, Accepted 6th June 2001
First published as an Advance Article on the web 30th July 2001
Two series of copper() complexes (1, 2) derived from bis{2-[3Ј-(3Љ,4Љ-dialkoxyphenyl)-5Ј-methyl-1Ј-pyrazolyl]ethyl}
ethers and from bis{2-[3Ј-(3Љ,4Љ,5Ј-trialkoxyphenyl)-5Ј-methyl-1Ј-pyrazolyl]ethyl} ethers were prepared and
characterized. These ionic copper() complexes were obtained by reaction of the ethers with [Cu(MeCN)4]BF4 in
refluxing acetonitrile. All three-coordinated copper() complexes isolated as off-white solids were characterized by
NMR spectroscopy and elemental analysis, and their mesomorphic properties were also studied by polarized optical
microscopy, differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). Results indicated that
these complexes exhibited hexagonal columnar phases (Colh). The clearing points of all compounds were relatively
low (94–112 ЊC) and the temperature range of the mesophases was ca. 45–68 ЊC. Powder XRD diffraction patterns
showed three sharp reflections in the small angle region corresponding to a ratio of their positions of 1 : (1/3)1/2
:
(1/2), indicating typical hexagonal columnar phases.
prepared copper() complexes with four (1) or six (2) alkoxy
chains were found to exhibit enantiotropic hexagonal columnar
(Colh) phases. To the best of our knowledge these are the first
copper() complexes with three-coordinate geometry to exhibit
mesomorphic properties.
Introduction
Coordination compounds are known as the largest category
among metallomesogenic materials.1 Numerous coordination
compounds with a variety of novel geometric metal centers and
molecular shapes have been created by incorporation of metal
centers. In addition, compounds with copper ions incorporated
in the core group comprise the largest group in this type of
metal-containing liquid crystals because of their well-known
chemistry and/or versatile structures. The properties of the
central copper ion, which shows a variety of coordination
geometries in both the ϩ and the ϩ oxidation states, are
largely controlled via the imposed coordination environment.
However, those exhibiting liquid crystalline properties consist
mostly of Cu() ions with square planar structures at the metal
center. Known metallomesogens1 exhibiting various smectic,
nematic as well as columnar liquid crystallinity have been
prepared and studied. These metallomesogens showed inter-
esting chemical and physical properties in part due to the para-
magnetism induced by the presence of a copper()-d9 (or -d1)
center, which generally can produce potential applications.
Certain diimine ligands,2 for example 2,2Ј-bipyridyl or 1,10-
phenanthrolines, are known to enhance the stability of the
Cu() oxidation state relative to Cu(). In addition a tetrahedral
arrangement at the copper center in most Cu() complexes3 is
generally preferred. Square planar coordination is mostly
observed in Cu() complexes and such complexes1 generally
readily give rise to liquid crystallinity, whereas compounds with
tetrahedral geometries are often not mesomorphic. A novel
example of tetrahedral Cu() complexes derived from Schiff-
bases exhibiting columnar mesophases4 was recently prepared
and studied. Examples of non-mesogenic copper() complexes
with a three-coordinate geometry are known and not uncom-
mon. However, examples exhibiting mesomorphic properties
had not previously been reported.
Results and discussion
Synthesis and characterization
The synthetic pathway to copper() complexes 1, 2 is sum-
marized in Scheme 1. The unsymmetrical β-diketones (3,4-
dialkoxyphenylbutane-1,3-diones) were prepared by literature
procedures.5 3-Methyl-5-(3Ј,4Ј-dialkoxyphenyl)pyrazoles were
obtained by condensation reaction6 of 3,4-dialkoxyphenyl-
butane-1,3-diones and hydrazine hydrate in refluxing etnanol
1
with a yield of 76–82%. H and 13C NMR spectroscopy were
1
used to characterize these compounds. For example, the H
NMR spectrum of 3-methyl-5-(3Ј,4Ј-dialkoxyphenyl)pyrazole
showed two characteristic peaks at δ 2.29–2.31 and 6.26–6.27,
respectively, assigned to terminal methyl (–CH3) and olefinic
methine-H (–C᎐CH). The bis{2-[3Ј-(3Љ,4Љ-dialkoxyphenyl)-5Ј-
᎐
methyl-1Ј-pyrazolyl]ethyl ethers were readily prepared by
nucleophilic substitution7 of 3-methyl-5-(3Ј,4Ј-dialkoxyphenyl)-
pyrazoles with bis(2-bromoethyl) ether in the presence of NaH
powder as base in refluxing dried THF. The yields were in the
range 70–76% and the products were isolated as pale yellow
solids. The copper() complexes were prepared by reaction7 of
Here we wish to report the preparation, characterization and
mesomorphic studies of two series of half-disc-like copper()
complexes derived from bis{2 [3Ј-(3Љ,4Љ-dialkoxy- and bis{2-[3Ј-
(3Љ,4Љ,5Љ-trialkoxyphenyl)-5Ј-methyl-1Ј-pyrazolyl]ethyl} ethers
that exhibit hexagonal columnar phases and in which the
central copper() ion shows three-coordinate geometry. All
8
the pyrazolylethyl ethers with [Cu(MeCN)4]BF4 in refluxing
DOI: 10.1039/b103427h
J. Chem. Soc., Dalton Trans., 2001, 2383–2387
This journal is © The Royal Society of Chemistry 2001
2383

View Article Online
Fig. 1 Optical texture (100×) observed by copper() complex 1 (n = 14)
(Colhd phase at 90.0 ЊC).
pyrazolyl)ethyl] ether and bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]
sulfide have been prepared and a single crystal structure was
determined for the ether. In this structure a T-shape coordin-
ation environment at the Cu() center due to the steric con-
straints of the ligand was described, and in which a distance
of Cu() of 0.067(1) Å out of the plane defined by the three
coordinating atoms was observed. The counter-cation BF4Ϫ was
not associated with the Cu() center. In this work a similar co-
ordination of Cu() complexes was adopted, and the possible
adoption of mesogenic properties by these compounds was
studied. The results obtained might extend potential metallo-
mesogenic materials resulting from such Cu() complexes.
The thermal behavior of compounds 1, 2 were invistigated
by polarized optical microscopy and differential scanning
calorimetry and the transition temperatures of the compounds
are listed in Table 1. All these copper() complexes with four (1)
or six (2) alkoxy chains exhibited liquid crystalline behavior
characteristic of columnar discotics. Two enantropic transi-
tions, crystal–mesophase (Cr–M) and mesophase–isotropic
(M–I) were also typically observed for these compounds.
Results of DSC analysis indicated a higher enthalpy for the
Cr–M transition at lower temperatures (ca. 45–59.0 ЊC on
heating) and a relatively lower enthalpy for the M–I transition
at higher temperatures (94–112.0 ЊC). This lower transition
enthalpy suggests that the mesophases were all in a disordered
state, indicating a more disordered stacking5,12 between the
molecules within a column. On the other hand, in a more
ordered columnar13b,c phase (Colho) a larger enthalpy for the
M–I transition relative to the enthalpy for the Cr–M transition
is expected and observed in many columnar arrangements. The
difference in these two columnar phases, disordered or ordered,
can be observed and generally differentiated13 by powder XRD
diffraction. The temperature range of mesophases is in the
range 49–68 ЊC for the cooling process, and is slightly sensitive
to the carbon number of the sidechains. Higher sidechain
density in compounds 2 resulted in a lowering of the clearing
temperature by ca. 10 ЊC compared to compounds 1. Both the
melting and clearing temperatures decreased as the side chain
length increases, as is normally observed in other compounds
exhibiting similar columnar phases. Under optical polarized
microscopy upon heating the compounds melt to give viscous
birefringent fluid phases12 with columnar superstructures.
When cooled from their isotropic phases, they displayed an
optical texture of pseudo-focal-conics with linear birefringent
defects, as shown in Fig. 1. Such textures suggest hexagonal
columnar structures. The formation of columnar phases in
half-disc molecules is generally dependent on both the
sidechain density and carbon length of the alkoxy sidechains.
Elongation of the carbon length on the alkoxy sidechains and/
or increase in the numbr of sidechains is found to stabilize the
mesogenic core. Most half-disc molecules with lower sidechain
density are proposed to form stable columnar mesophases by
Scheme 1 Reagents and conditions: i, RBr (2.1 equiv.), K2CO3 (5.0
equiv.), KI (cat.) reflux in Me2CO, 48 h, 78–95%; ii, MeCOCl (1.2
equiv.), AlCl3 (1.5 equiv.), stirred in CH2Cl2 at 0 ЊC, then reflux for 24 h,
72–85%; iii, ethyl acetate (1.25 equiv.), NaH (2.0 equiv.), reflux in dried
THF, 12 h, 76–85%; iv, N2H4ؒH2O (2.0 equiv.), reflux in absolute
ethanol, 2 h, then stirred at r.t. for 12 h, 76–82%, v, (BrCH2CH2)2O
(0.50 equiv.), NaH (2.0 equiv.), reflux in dried THF, 60 h, 70–76%, vi,
[Cu(MeCN)4]BF4 (1.1 equiv.), reflux in dried MeCN, 12 h, 76–80%.
dried acetonitrile and obtained as off-white solids. These
copper() compounds were generally stored in a glove box,
though they were relatively stable upon exposure to air without
any noticeable oxidation. All the copper() compounds
1
were diamagnetic species and gave distinct H and 13C NMR
spectroscopic data.
Mesogenic properties
Although similar metal-free pyrazolate derivatives6 which
exhibit mesogenic properties have been described and studied,
examples of metal-containing mesogens derived from related
pyrazolates were unknown. Coinage metals are already known
to form trimeric structures,9 and these complexes were found
to present novel supramolecular structures and interesting
reactivities. One particular example containing a trinuclear gold
ring10 that exhibited a hexagonal columnar mesophase at room
temperature has been reported by Serrano and co-workers.
These trinuclear complexes were primarily prepared from
non-mesogenic 3,5-bis(3Ј,4Ј-didecyloxyphenyl)pyrazole and
AuCl(tht) (tht = tetrahydrothiophene).
The preparation and study of known Cu() complexes
is relatively limited due to the spectroscopic “invisibility” of
the spin-paired d10 cuprous ion center. In addition, this
limited study of Cu() chemistry might be also attributed to
the tendency towards disproportionation11a and/or facile
autoxidation11b of Cu() in the presence of air. In this work
pyrazolate-type derivatives, bis{2-[3-methyl-5-(3Љ,4Љ-dialkoxy-
phenyl)-1-pyrazolyl]ethyl} ethers were chosen as tridentate
ligands to generate three-coordinate Cu() complexes. A few
similar nonmesogenic Cu() complexes7 derived from bis[2-
(3,5-dimethyl-1-pyrazolyl)ethyl]amine, bis[2-(3,5-dimethyl-1-
2384
J. Chem. Soc., Dalton Trans., 2001, 2383–2387

View Article Online
Table 1 Phase behavioura of copper() complexes 1, 2
1 n =
8
Cr
Colhd
Colhd
I
I
10
Cr
12
14
Cr
Cr
Colhd
Colhd
I
I
16
14
Cr
Cr
Colhd
Colhd
I
I
2
a n = No. of carbons in the sidechains; Cr = crystal phase; Colhd = disordered hexagonal columnar phase; I = isotropic. The transition temperatures
(ЊC) and enthalpies (in parentheses, kJ molϪ1 are determined by DSC at scan rate of 10.0 ЊC minϪ1
.
Table 2 Variable-temperature XRD diffraction data for compounds 1
Complex
Mesophase
Lattice spacing/Å
d-Spacing/Å obs. (calc.)
Miller indices
1
n = 8
10
Colhd (95 ЊC)
35.06
30.36 (30.36)
17.23 (17.53)
15.35 (15.18)
4.38 (br)
31.98 (31.98)
18.62 (18.46)
16.04 (15.99)
4.58 (br)
33.70 (33.70)
19.33 (19.45)
16.46 (16.85)
4.52 (br)
35.47 (35.47)
20.50 (20.48)
17.32 (17.74)
4.59 (br)
(10)
(11)
(20)
Colhd (95 ЊC)
Colhd (95 ЊC)
Colhd (95 ЊC)
Colhd (85 ЊC)
36.92
38.90
40.96
43.06
(10)
(11)
(20)
12
(10)
(11)
(20)
14
(10)
(11)
(20)
16
37.29 (37.29)
21.23 (21.53)
18.42 (18.65)
4.41 (br)
(10)
(11)
(20)
arrangement of dimeric or trimeric units in the columnar
phases.
correlations between alkoxy chains and the mesogenic core was
also detected in the wide-angle region. The lack of relatively
sharp peaks at wide angles excluded a more regular periodicity
along the columns, consistent with DSC analysis which showed
lower enthalpies for the columnar-to-isotropic transition.
To confirm the columnar structure of the mesophase of
compounds 1, powder X-ray diffraction experiments were
performed on all the compounds. A summary of the XRD
diffraction peaks and lattice constants for the complexes at
mesophase temperatures are given in Table 2. For example, for 1
(n = 14) a diffraction pattern of a two-dimensional hexagonal
lattice with one intense peak and two weaker peaks, at 35.47,
20.50 and 17.32 Å respectively, was observed at 95 ЊC. This is
characteristic of a hexagonal columnar phase with a d-spacing
ratio of 1, (1/3)1/2 and (1/4)1/2, corresponding to Miller indices;
(10), (11) and (20), respectively. This reflection pattern corre-
sponds to an intercolumnar distance (a parameter of the
hexagonal lattice) of 40.96 Å. In addition, a quite broad diffuse
band centered at 4.38–4.51 Å, which corresponds to liquid-like
Summary
New pyrazolylethyl ether derivatives have been utilized to pre-
pare metallomesogenic compounds. The copper() ion used as
the core group was three-coordinate in geometry. These novel
Cu() compounds exhibited hexagonal columnar phases and
the clearing temperatures of these compounds were relatively
low. This lower clearing temperature might be attributed to
a smaller core size of the three-coordinate geometrical center
relative to that in regular square planar Cu(). In addition, the
J. Chem. Soc., Dalton Trans., 2001, 2383–2387
2385

View Article Online
Table 3 Elemental analysisa (%) of compounds 1, 2
3,4,5-Tritetradecyloxyacetophenone
1H NMR (CDCl3): δ 0.85 (t, CH3, 9H), 1.24–1.76 (m, CH2,
72H), 2.54 (s, CH3, 3H), 4.00 (tt, OCH2, 6H), 7.15 (s, C6H2, 2H).
13C NMR (CDCl3): δ 14.12, 22.69, 26.05, 26.45, 29.37, 29.70,
30.30, 31.92, 69.25, 73.52, 107.06, 132.03, 142.80, 152.85,
Compound
n
C
H
N
1
8
64.12 (64.08)
66.20 (66.16)
67.80 (67.87)
69.42 (69.31)
70.38 (70.53)
71.61 (71.54)
8.64 (8.64)
9.16 (9.19)
9.68 (9.65)
9.98 (10.03)
10.38 (10.36)
10.88 (10.90)
4.95 (5.34)
4.84 (4.82)
4.38 (4.40)
4.06 (4.04)
3.73 (3.74)
3.09 (3.09)
10
12
14
16
14
197.19 (C᎐O).
᎐
3,4-Ditetradecoxyphenylbutane-1,3-dione
2
Light yellow crystals, yield 79%. 1H NMR(CDCl3; δ 0.82
(t, CH3, 6H), 1.19–1.79 (m, CH2, 48H), 2.16 (s, COCH3, 3H),
4.00 (t, OCH2, 4H), 6.06 (s, COCH, 1H), 6.77 (d, C6H3, 1H),
7.41 (s, C6H3, 1H), 7.45 (d, C6H3, 1H), 16.20 (s, OH, 1H). 13C
NMR (CDCl3): δ 14.10, 22.67, 25.84, 25.97, 29.08, 29.24, 29.39,
29.57, 31.90, 68.94, 69.21, 96.08, 110.79, 111.77, 120.29, 128.23,
a Calculated values in parentheses.
stability of the Cu() oxidation state in these compounds was
enhanced by the [N, O] bonding environment provided by the
pyrazolylethyl ethers.
148.76, 153.46, 183.64 (COH), 192.79 (C᎐O).
᎐
3,4,5-Tritetradecoxyphenylbutane-1,3-dione
Experimental
Light yellow solid, yield 79%. 1H NMR (CDCl3): δ 0.82 (t, CH3,
9H), 1.15–1.77 (m, CH2, 72H), 2.15 (s, COCH3, 3H), 3.99 (m,
OCH2, 6H), 6.08 (s, COCH, 1H), 6.89 (s, C6H2, 2H), 16.20 (s,
OH, 1H). 13C NMR (CDCl3): δ 13.99, 22.25, 25.89, 26.06,
29.10, 29.25, 29.34, 29.65, 31.90, 68.99, 69.22, 96.01, 111.70,
All chemicals and solvents were reagent grades from Aldrich
Chemical Co. The solvents were dried by standard techniques.
1H and 13C NMR spectra were measured on a Bruker DRS-200.
IR spectra were obtained on a Bio-Rad FPS155 spectrometer.
DSC thermal analysis was carried out on a Mettler DSC-820
and phase transitions determined at a scan rate of 10.0 ЊC
minϪ1. Optical polarized microscopy was carried out on a
Nikkon MICROPHOT-FXA microscope with a Mettler FP90/
FP82HT hot stage system. X-Ray powder diffraction (XRD)
studies were performed on an INEL MPD-diffractometer
with a 2.0 kW Cu-K X-Ray source equipped with an INEL
CPS-120 position sensitive detector and a variable tem-
perature capillary furnace. Elemental analysis for carbon,
128.26, 148.74, 153.47, 183.59 (COH), 192.81 (C᎐O).
᎐
3-Methyl-5-(3Ј,4Ј-ditetradecanoxyphenyl)pyrazole
A solution of 3,4-tetradecoxyphenylbutane-1,3-dione (2.00 g,
3.40 mmol) dissolved in hot ethanol was added to a solution of
hydrazine hydrate (80% w/w, 2.56 ml). The mixture was gently
refluxed for 2 h and stirred at room temperature for another
12 h. The light yellow solid was collected after the solution had
been kept in the refrigerator overnight. The solid was recrystal-
lized from ethanol to give white crystals. Yield 80%, mp 58.0–
hydrogen and nitrogen were conducted on
a Heraeus
CHN-O-Rapid elemental analyzer, and the results are listed in
Table 3. The preparation procedures for 1,2-dialkoxybenzenes,
3,4-dialkoxyacetophenones, methyl-3,4,5-trialkoxybenzoates,
3,4,5-trialkoxybenzoic acids, 3,4,5-trialkoxyacetophenones,
3,4-dialkoxyphenylbutane-1,3-diones, 3,4,5-trialkoxyphenyl-
butane-1,3-diones, 3-methyl-5-(3,4-dialkoxyphenyl)pyrazoles
and 3-methyl-5-(3,4,5-trialkoxyphenyl)pyrazoles6 were as in the
literature.5,6
1
58.30 ЊC. H NMR (CDCl3): δ 0.83 (t, CH3, 6H), 1.24–1.84
(m, CH2, 48H), 2.29 (s, CNCH3, 3H), 3.98 (t, OCH2, 4H), 6.27
(s, CNCH, 1H), 6.85 (d, C6H3, 1H), 7.16 (d, C6H3, 1H), 7.25 (s,
C6H3, 1H). 13C NMR (CDCl3): δ 11.66, 14.01, 22.51, 25.83,
29.22, 29.54, 31.76, 69.15, 69.43, 101.78, 111.45, 113.35, 118.35,
133.28 (CNH), 143.22, 148.75, 149.23 (C᎐N), 152.32.
᎐
3-Methyl-5-(3Ј,4Ј,5Ј-tritetradecanoxyphenyl)pyrazole
1,2-Ditetradecyloxybenzene
1
White solid. Yield 78%, mp 46.0–46.4 ЊC. H NMR (CDCl3):
1
White crystals, yield 76%. H NMR (CDCl3): δ 0.84 (t, CH3,
δ 0.86 (t, CH3, 9H), 1.25–1.81 (m, CH2, 72H), 2.31 (s, CNCH3,
3H), 3.98 (tt, OCH2, 6H), 6.26 (s, CNCH, 1H), 6.88 (s, C6H2,
2H). 13C NMR (CDCl3): δ 11.57, 14.07, 22.66, 26.11, 29.42,
29.71, 30.32, 31.91, 69.08, 73.45, 101.86, 104.41, 127.32 (CNH),
6H), 1.26–1.84 (m, CH2, 48H), 3.97 (t, OCH2, 4H), 6.87 (s,
C6H4, 4H). 13C NMR (CDCl3): δ 14.09, 22.68, 26.05, 29.36,
29.44, 29.70, 31.92, 69.25, 114.10, 120.97, 149.23.
138.21, 142.93, 149.97 (C᎐N), 153.33.
᎐
3,4-Ditetradecanoxyacetophenone
1
Bis{2-[3Ј-(3Љ,4Љ-ditetradecanoxyphenyl)-5Ј-methyl-1Ј-pyrazolyl]-
ethyl} ether
White crystals, yield 70%. H NMR (CDCl3): δ 0.82 (t, CH3,
6H), 1.23–1.81 (m, CH2, 48H), 2.53 (s, COCH3, 3H), 4.03 (tt,
OCH2, 4H), 6.85 (d, C6H3, 1H), 7.48 (s, C6H3, 1H), 7.53
(d, C6H3, 1H). 13C NMR (CDCl3): δ 13.95, 22.53, 25.83, 26.04,
28.88, 29.00, 29.21, 29.54, 31.77, 68.86, 69.06, 111.35, 112.18,
3-(3Ј,4Ј-Ditetradecanoxyphenyl)-5-methylpyrazole (1.00 g, 1.7
mmol) dissolved in dried THF was added to a solution of
powdered NaH (0.086 g, 3.4 mmol) suspended in dried THF. To
this solution was slowly added bis(2-bromoethyl) ether (0.207 g,
0.85 mmol) and the mixture was refluxed for 72 h. Dilute hydro-
chloric acid (1.0 M) was added to neutralize the solution and
the solution was extracted three times with water. The organic
layers were collected and dried over anhydrous MgSO4. The
solution was concentrated and the resulting solid purified by
chromatography eluting with methylene chloride. The product
was isolated as a light yellow solid after recrystallization from
methylene chloride–methanol. Yield 76%, mp 76.2–76.6 ЊC. 1H
NMR (CDCl3): δ 0.86 (t, CH3, 12H), 1.25–1.76 (m, CH2, 96H),
2.20 (s, CNCH3, 6H), 3.75 (t, NCH2, 4H), 3.98 (t, OCH2, 8H),
4.03 (t, OCH2, 4H), 6.28 (s, CNCH, 2H), 6.39 (s, C6H3, 2H),
7.68 (d, C6H3, 4H). 13C NMR (CDCl3): δ 11.92, 14.02, 22.58,
25.78, 29.29, 29.58, 31.96, 49.02, 69.41 (NCH2), 70.86, 101.09,
123.00, 130.07, 148.66, 153.35, 196.74 (C᎐O).
᎐
Methyl-3,4,5-tritetradecanoxybenzoate
1H NMR (CDCl3): δ 0.86 (t, CH3, 9H), 1.24–1.83 (m, CH2,
72H), 3.87 (s, OCH3, 3H), 3.99 (tt, OCH2, 6H), 7.23 (s, C6H2,
2H). 13C NMR (CDCl3): δ 14.13, 22.70, 26.13, 29.34, 29.44,
29.63, 29.71, 29.74, 29.80, 30.35, 31.95, 52.10, 69.19, 75.49,
107.89, 124.67, 142.40, 152.79, 166.90 (CO2).
3,4,5-Tritetradecanoxybenzoic acid
1H NMR (CDCl3): δ 0.87 (t, CH3, 9H), 1.14–1.83 (m, CH2,
72H), 4.02 (tt, OCH2, 6H), 7.29 (s, C6H2, 2H). 13C NMR
(CDCl3): δ 14.07, 22.68, 26.07, 29.37, 29.70, 30.33, 31.92, 69.24,
73.55, 108.67, 123.62, 143.27, 152.87, 171.72 (CO2).
103.11, 104.98, 135.33 (CNH), 140.28, 149.89 (C᎐N), 160.58.
᎐
2386
J. Chem. Soc., Dalton Trans., 2001, 2383–2387

View Article Online
IR (thin film): 2958, 2911, 2852, 1895, 1612, 1577, 1442, 1301,
1249, 1116, 934 cmϪ1
Acknowledgements
.
This research was supported by the National Science Council
of Taiwan, ROC under grant NSC-89-2113-M-008-024.
Bis{2-[3Ј-(3Љ,4Љ,5Љ-tritetradecanoxyphenyl)-5Ј-methyl-1Ј-
pyrazolyl]ethyl} ether
1
Yield 72%, mp 69.3–69.50 ЊC. H NMR (CDCl3): δ 0.86 (t,
References
CH3, 18H), 1.25–1.83 (m, CH2, 144H), 2.21 (s, CNCH3, 6H),
1 S. A. Hudson and P. M. Maitlis, Chem. Rev., 1993, 93, 861;
P. Espinet, M. A. Esteruelas, L. A. Oro, J. L. Serrano and E. Sola,
Coord. Chem. Rev., 1992, 117, 215; J. L. Serrano, in Metallo-
mesogens; Synthesis, Properties, and Applications, VCH, New York,
1996.
3.83 (t, NCH2, 4H), 3.99 (tt, OCH2, 12H), 4.05 (t, OCH2, 4H),
6.22 (s, CNCH2, 2H), 6.39 (s, C6H2, 2H), 7.66 (s, C6H2, 2H). 13
C
NMR (CDCl3): δ 12.02, 14.11, 23.62, 25.88, 29.30, 29.44, 29.68,
32.12, 48.81, 69.50 (NCH2), 71.16, 100.79, 109.23, 135.33
2 B. R. James and R. J. P. Williams, J. Chem. Soc., 1961, 2007; C. O.
Dietrich-Buchecker, P. A. Marnot, J.-P. Sauvage, J. R. Kirchoff and
D. R. McMillin, J. Chem. Soc., Chem. Commun., 1983, 513; P. J.
Burke, D. R. McMillin and W. R. Robinson, Inorg. Chem., 1980, 19,
1211; P. J. Burke, K. Henrick and D. R. McMillin, Inorg. Chem.,
1982, 21, 1881.
3 R. Osterberg, Coord. Chem. Rev., 1974, 12, 309; T. N. Sorrell and
A. S. Borovik, J. Am. Chem. Soc., 1986, 108, 2479; T. N. Sorrell and
D. L. Jameson, J. Am. Chem. Soc., 1983, 105, 6013; M. J. Schilstra,
P. J. Birker, G. C. Verschoor and J. Reedijk, Inorg. Chem., 1982, 121,
2637; S. Knapp, T. P. Keenan, X. Zhang, R. Fikar, J. A. Potenza and
H. J. Schugar, J. Am. Chem. Soc., 1987, 109, 1882.
4 L. Douce, A. El-ghayoury, A. Skoulios and R. Ziessel, Chem.
Commun., 1999, 2033; A. El-ghayoury, L. Douce, A. Skoulios and
R. Ziessel, Angew. Chem., Int. Ed., 1998, 37, 2205.
5 C. K. Lai, Y. S. Pang and C. H. Tsai, J. Mater. Chem., 1998, 8, 2605;
C. K. Lai, K. W. Wang and R. Lin, J. Mater. Chem., 1998, 8, 2379.
6 J. Barberá, C. Cativiela, J. L. Serrano and M. M. Zurbano, Liq.
Cryst., 1992, 11, 887.
7 T. N. Sorrell and M. R. Malachowski, Inorg. Chem., 1983, 22, 1883.
8 T. N. Sorrell and D. L. Jameson, Inorg. Chem., 1982, 21, 1014.
9 H. H. Murray, R. G. Raptis and J. P. Fackler, Inorg. Chem., 1988, 27,
26; G. Minghetti, G. Banditelli and F. Bonati, Inorg. Chem., 1979,
18, 658; B. Bovio, F. Bonati and G. Banditelli, Inorg. Chim. Acta,
1984, 87, 25; F. Bonati and G. J. Minghetti, Organomet. Chem., 1973,
60, C43; R. G. Raptis and J. P. Fackler, Inorg. Chem., 1990, 29, 5003.
10 J. Barberá, A. Elduque, R. Giménez, L. A. Oro and J. L. Serrano,
Angew. Chem., Int. Ed. Engl., 1996, 35, 2832.
11 (a) F. H. Jardine, Adv. Inorg. Chem. Radiochem., 1975, 17, 115; (b)
A. D. Zuberbuhler, Met. Ions Biol. Syst., 1976, 5, 325.
12 C. Destrade, P. Foucher, H. Gasparous, H. T. Nguyen, A. M.
Levelut and X. Malthete, J. Mol. Cryst. Liq. Cryst., 1984, 106, 121;
J. Billard, in Liquid Crystals of One- and Two-Dimensional Order,
Springer Series in Chemical Physics, Berlin, 1980; S. Chandrasekhar
and G. S. Ranganath, Rep. Prog. Phys., 1990, 53, 57.
(CNH), 140.58, 151.08 (C᎐N), 162.31, 167.82. IR (thin film):
᎐
2958, 2913, 2854, 1891, 1614, 1580, 1440, 1305, 1244, 1119,
938 cmϪ1
.
(Bis{2-[3Ј-(3Љ,4Љ-ditetradecanoxyphenyl)-5Ј-methyl-1Јpyrazolyl]-
ethyl} ether)copper(I) tetrafluoroborate
A hot ethanol solution of bis{2-[3Ј-(3Љ,4Љ-ditetradecanoxy-
phenyl)-5Ј-methyl-1Ј-pyrazolyl]ethyl} ether (0.10 g, 0.10 mmol)
was added dropwise to a solution of [Cu(MeCN)4]BF4 (0.025 g,
0.10 mmol) dissolved in 50 ml of dried degased acetonitrile. The
mixture was refluxed for 48 h. The solution was concentrated
to dryness and then recrystallized from methylene chloride–
methanol. An off white solid was collected. Yield 80%. 1H
NMR (CDCl3): δ 0.86 (t, CH3, 12H), 1.24–1.75 (m, CH2, 96H),
2.18 (s, CNCH3, 6H), 3.78 (t, NCH2, 4H), 3.96 (tt, OCH2, 8H),
4.06 (t, OCH2, 4H), 6.20 (s, CNCH, 2H), 6.34 (s, C6H3, 2H),
7.85 (d, C6H3, 4H). 13C NMR (CDCl3): δ 11.20, 14.11, 22.68,
26.10, 29.32, 29.56, 31.92, 48.77, 69.41 (NCH2), 71.14, 101.12,
102.86, 104.20, 135.21 (CNH), 140.38, 150.13 (C᎐N), 160.46.
᎐
IR (thin film): 2956, 2919, 2850, 1606, 1586, 1465, 1309, 1264,
1179, 1139, 940 cmϪ1. Anal. for C80H138O5N4Cu, Calc. C, 69.31;
H, 10.03; N, 4.04. Found: C, 69.42; H, 9.98; N, 4.06%.
(Bis{2-[3Ј(3Љ,4Љ,5Љ-tritetradecanoxyphenyl)-5Ј-methyl-1Ј-
pyrazolyl]ethyl} ether) copper(I) tetrafluoroborate
1
Yield 70%. H NMR (CDCl3): δ 0.86 (t, CH3, 18H), 1.25–1.83
(m, CH2, 144H), 2.21 (s, CNCH3, 6H), 3.78 (t, NCH2, 4H), 3.99
(tt, OCH2, 12H), 4.06 (t, och2, 4H), 6.20 (s, CNCH, 2H), 6.32
(s, C6H2, 2H), 7.63 (s, C6H2, 2H). 13C NMR (CDCl3): δ 12.02,
14.11, 23.62, 25.88, 29.30, 29.44, 29.68, 32.12, 48.81, 69.50
(NCH2), 71.16, 102.08, 109.23, 136.23 (CNH), 140.58, 151.08
13 (a) A. G. Serrette, C. K. Lai and T. M. Swager, Chem. Mater., 1994,
6, 2252; (b) C. K. Lai, M. Y. Lu and F. J. Lin, Liq. Cryst., 1997, 23,
313; (c) R. Lin, C. H. Tsai, M. Q. Chao and C. K. Lai, J. Mater.
Chem., 2001, 11, 359; (d ) C. K. Lai, K. W. Wang and R. Lin,
J. Mater. Chem., 1998, 8, 2379; (e) S. M. Ku, C. Y. Wu and C. K. Lai,
J. Chem. Soc., Dalton Trans., 2000, 3491; ( f ) C. K. Lai, H. C. Wu,
J. H. Sung and C. D. Yang, Liq. Cryst., 2001, 28, 411.
(C᎐N), 161.89, 167.76. IR (thin film): 2957, 2921, 2848,
᎐
1608, 1582, 1466, 1311, 1266, 1175, 1136, 941 cmϪ1. Anal. for
C108H194O7N4Cu, Calc. C, 71.54; H, 10.90; N, 3.09. Found: C,
71.61; H, 10.88; N, 3.09%.
J. Chem. Soc., Dalton Trans., 2001, 2383–2387
2387