Thiophene-based glass-forming hole-transporting hydrazones

Article abstract of DOI:10.1007/s00706-008-0897-1

The synthesis, optical, thermal, and photoelectrical properties of new thiophene-based hydrazones are reported. The ionization potentials of the films of thiophene-based hydrazones, measured by the electron photoemission technique, range from 4.99 to 5.58∈eV. Hole-drift mobilities in the solid solutions in bisphenol-Z polycarbonate (PC-Z) of the synthesized hydrazones were studied by time of flight technique. Room temperature charge mobilities in the solid solution of 5,2″-diformyl-2,2′:5′″me;-terthiophene di(N,N-diphenylhydrazone) in PC-Z exceeded 10^-5∈cm ²/Vs at high applied electric fields.

Full text of DOI:10.1007/s00706-008-0897-1

Monatsh Chem 139, 1011–1017 (2008)
DOI 10.1007/s00706-008-0897-1
Printed in The Netherlands
Thiophene-based glass-forming hole-transporting hydrazones
Asta Michaleviciute1, Jolita Ostrauskaite1, Gintaras Buika1, Juozas Vidas Grazulevicius1,
Vygintas Jankauskas2, Francois Tran Van3, Claude Chevrot4
1
Department of Organic Technology, Kaunas University of Technology, Kaunas, Lithuania
2
Department of Solid State Electronics, Vilnius University, Lithuania
3
Laboratoire de Chimie-physique des Interfaces et des Milieux Electrolytiques (CIME),
´
Universite F. Rabelais, Tours, France
4
`
Laboratoire de Physicochimie des Polymeres et des Interfaces (LPPI),
´
Universite de Cergy Pontoise, Cergy Pontoise Cedex, France
Received 9 January 2008; Accepted 16 January 2008; Published online 3 March 2008
# Springer-Verlag 2008
Abstract The synthesis, optical, thermal, and photo-
electrical properties of new thiophene-based hydra-
zones are reported. The ionization potentials of the
films of thiophene-based hydrazones, measured by
the electron photoemission technique, range from
4.99 to 5.58eV. Hole-drift mobilities in the solid solu-
tions in bisphenol-Z polycarbonate (PC-Z) of the syn-
thesized hydrazones were studied by time of flight
technique. Room temperature charge mobilities in
the solid solution of 5,200-diformyl-2,20:50,500-terthio-
phene di(N,N-diphenylhydrazone) in PC-Z exceeded
10ꢀ5 cm2=Vs at high applied electric fields.
high charge carrier mobilities, play an important role
among organic hole-transporting materials, especial-
ly those used in electrophotography [3]. Thiophene-
based hydrazones until now are poorly studied and
represent a relatively new family of organic hole-
transporting materials [4]. In this presentation we re-
port on the design, synthesis, and characterization of
the new glass-forming thiophene-based hydrazones.
Results and discussion
New 3,4-ethylendioxythiophene-based dihydrazones
1a and 1b were obtained by the reaction of 3,4-
ethylenedioxythiophene-2,5-dicarbaldehyde with
N-methyl-N-phenylhydrazine and N,N-diphenylhy-
drazine hydrochloride. 3,4-Ethylenedioxythiophene-
based hydrazone bearing a carbazole moiety (2) was
obtained in the reaction of 2-(N-phenylhydrazone-
methyl)-3,4-ethylenedioxythiophene with 9-(6-bro-
mo-n-hexyl)carbazole (Scheme 1). A long alkylene
bridge was introduced in order to increase the solu-
bility of the resulting hydrazone.
Keywords Heterocycles; Thiophene; Hydrazones; Ionization
potential; Charge transport.
Introduction
Organic charge-transporting materials are used in
optoelectronic and electronic devices like electro-
photographic photoreceptors, organic light-emitting
diodes, photovoltaic cells, and field effect transistors
[1, 2]. Hydrazones, due to their simple synthesis and
ꢀ-Terthiophene-based hydrazones 5a, 5b, and 8
were synthesized by the route shown in Scheme 2
involving the preparation of the corresponding for-
myl derivatives followed by their condensation with
hydrazines. The synthesis of carbazolyl-containing
Correspondence: Juozas Vidas Grazulevicius, Department of
Organic Technology, Kaunas University of Technology, Rad-
vilenu pl. 19, LT-50254 Kaunas, Lithuania. E-mail: juozas.
grazulevicius@ktu.lt

1012
A. Michaleviciute et al.
to the corresponding bands of 3,4-ethylendioxythio-
phene-based dihydrazones 1a and 1b. This observa-
tion can be explained by the extended conjugation of
electrons in the terthiophene moiety. Indeed, the
spectrum of ꢀ-terthiophene exhibits a considerable
bathochromic shift with respect of the spectrum
of 3,4-ethylenedioxythiophene. The UV spectra of
monohydrazones show strong hypsochromic effect
relative to the spectra of the corresponding dihydra-
zones. It indicates that the conjugation is extended
along the two hydrazone groups in the difunctional
structure. The spectra of hydrazones bearing differ-
ent substituents at hydrazine moiety exhibit almost
identical spectra, only the spectra of compounds 1b
and 5b show a small hyperchromic shift due to the
phenyl substituents in comparison with the spectra of
1a and 5a bearing methyl substituents. Compounds 2
and 8 bearing carbazole moieties exhibit absorption
bands in the shorter range of wavelengths, which is
typical absorption for carbazole chromophore.
Fluorescence spectra of dilute THF solutions of hy-
drazones synthesized are shown in Fig. 2. The emis-
sion maxima of ꢀ-terthiophene-based hydrazones 5a
and 5b are observed at 538 and 542 nm. They are
shifted bathochromically by 24 and 57 nm with re-
spect to the emission maxima of hydrazones 1a and
1b. Fluorescence maxima of phenyl substituted dihy-
drazones 1b and 5b are slightly red shifted relative
to maxima of the corresponding methyl substituted
dihydrazones 1a and 5a. The emission maxima of
monohydrazones 2 and 8 are observed at 398 and
504 nm. They exhibit considerable hypsochromic
effects with respect of the spectra of dihydrazones.
The thermal properties of the newly synthesized
compounds were investigated by TG and DSC. It was
earlier established that the hydrazone moiety is the
critical unit with respect of their thermal stability [5].
Therefore the initial weight loss temperatures of dif-
ferent hydrazones are rather close. Usually it is below
300ꢂC. 3,4-Ethylenedioxythiophene- and ꢀ-terthio-
phene-based hydrazones do not make any exception.
Their initial weight loss temperature is around 270ꢂC.
All the newly synthesized hydrazones, except
5a, can be transformed into the amorphous state.
Hydrazones 1a, 5b, and 8 were isolated as crystal-
line compounds after their synthesis. The DSC mea-
surements revealed melting peaks in the first DSC
scans of 1a, 5b (as an example, see Fig. 3), and 8,
but neither melting nor crystallization was observed
in the second and the following DSC scans. How-
Scheme 1
monohydrazone involved the additional step of alkyl-
ation of 2-(N-phenylhydrazonemethyl)-3,4-ethylene-
dioxythiophene with 9-(6-bromo-n-hexyl)carbazole.
All the obtained hydrazone derivatives 1a, 1b, 2,
5a, 5b, and 8 were purified by column chromatogra-
phy and characterized by IR, 1H NMR, and mass spec-
trometry as described in Experimental section. The
hydrazones were most likely mixtures of E- and Z-
isomers which was irrelevant with regard to the prop-
erties investigated.
All the synthesized compounds, except 1a and 1b,
are well soluble in common organic solvents like
chloroform, dichloromethane, and tetrahydrofurane.
The solubility of compounds 1a and 1b in chloro-
form and tetrahydrofurane is less than 30 mg=cm3.
Figure 1 shows UV=VIS absorption spectra of
dilute solutions of the synthesized hydrazones. ꢀ-
Terthiophene-based hydrazones 5a and 5b absorb
radiation in the range of 225–540 nm. 3,4-Ethylen-
dioxythiophene-based hydrazones 1a and 1b absorb
radiation in the range of 260–490 nm. All the syn-
thesized dihydrazones (1a and 1b, and 5a and 5b)
ꢁ
exhibit very strong K bands, attributed to ꢁ ! ꢁ
transitions. The lowest energy absorption bands of
ꢀ-terthiophene-based dihydrazones 5a and 5b are
bathochromically shifted by ca. 50 nm with respect

Thiophene-based glass-forming hole-transporting hydrazones
1013
Scheme 2
ever, the Tg of the hydrazone 8 was not detected in
the DSC curves, perhaps due to the low sensitivity of
the apparatus.
Figure 4 shows electron photoemission spectra of
the films of the newly synthesized hydrazones. The
ionization potentials (Ip) established from these
spectra (Fig. 4) are summarized in Table 2. 3,4-Ethy-
lenedioxythiophene-based dihydrazones 1a and 1b
exhibit by ca. 0.2 eV lower ionization potentials than
the corresponding ꢀ-terthiophene-based dihydra-
zones 5a and 5b. Carbazolyl-containing monohydra-
zones 2 and 8 show higher ionization potentials than
dihydrazones. The ionization potential of 3,4-ethyle-
nedioxythiophene-based monohydrazone 2 is very
close to that earlier observed for the similar mono-
hydrazone structure having a methyl substituent at
the hydrazone N atom [4]. This observation shows
that electronically isolated carbazolyl group has
Compounds 1b and 2 were isolated as amorphous
compounds. The glass transition temperatures (Tg)
of 3,4-ethylenedioxythiophene- and ꢀ-terthiophene-
based hydrazones detected by DSC are summarized
in Table 2. The highest Tgs were showed by 3,4-
ethylenedioxythiophene-based dihydrazones 1a and
1b. The very low Tg of compound 2 is determined by
the long alkylene bridge. Crystalline compound 5a
showed a polymorphic melting in the second DSC
heating run. Such behavior of large molecules in-
clined to form different crystalline forms was de-
scribed in literature earlier [6].

1014
A. Michaleviciute et al.
Fig. 2 Fluorescence spectra of dilute THF solutions
(10ꢀ5 mol=dm3) of hydrazones 1a, 1b (lex ¼ 380 nm), and
2 (lex ¼ 290 nm) (a); and hydrazones 5a, 5b (lex ¼ 380 nm),
380 nm), and 8 (lex ¼ 290 nm) (b)
Fig. 1 UV=VIS absorption spectra of dilute THF solutions
(10ꢀ5 mol=dm3) of hydrazones 1a, 1b, 2, 3,4-ethylenediox-
ythiophene (EDOT) (a); and hydrazones 5a, 5b, 8, and ꢀ-
terthiophene (TT) (b)
Table 1 Absorption and fluorescence maxima of 3,4-ethyle-
nedioxythiophene and ꢀ-terthiophene-based hydrazones
practically no influence on the value of the ioniza-
tion potential of compound 2.
Compound
Absorption maxima
of the lowest energy
bands=nm
Fluorescence
maxima=nm
The Ip values of thiophene-based hydrazones
show that these compounds are suitable for the ap-
plication in electrographic photoreceptors. Holes are
easily injected into the charge transport layer from
the charge generation layer with Ip close to Ip of
charge transport layer. The Ipvalues for charge gen-
eration materials widely used in electrographic
photoreceptors such as titanyl phthalocyanines, per-
ylene pigments, and bisazo pigments are in the range
of 5.1–5.6 eV [1].
1a
1b
2
5a
5b
8
432
439
365
462
465
428
485
513
398
538
542
504
showed the best solubility were chosen for these
experiments. Hole-drift mobilities in the amorphous
films of thiophene-based hydrazones 5b and 8 mo-
lecularly doped in polymer bisphenol Z polycarbon-
The xerographic time-of-flight technique was used
to characterize charge transport properties of the
selected hydrazones. Hydrazones 5b and 8 which

Thiophene-based glass-forming hole-transporting hydrazones
1015
Table 3 Ionization potentials of thin films of 3,4-ethylene-
dioxythiophene and ꢀ-terthiophene-based hydrazones
Compound
1a
1b
2
5a
5b
8
Ip=eV
4.99
5.24
5.58
5.25
5.43
5.58
Fig. 3 DSC curves of 5b at the heating=cooling rate of
10 K=min, N2 atmosphere
Table 2 DSC measurements of 3,4-ethylenedioxythiophene-
and ꢀ-terthiophene-based hydrazones
Fig. 5 Electric field dependencies of hole-drift mobilities in
the amorphous films of thiophene-based hydrazones 5b and 8
molecularly doped in PC-Z (50 wt%)
Compound
Tm=ꢂC
Tcr=ꢂC
Tg=ꢂC
1a
1b
2
5a
5b
8
235a
–
–
–
–
124
–
120
160
5
–
80
–
–
ate host PC-Z (50 wt%) were measured at different
electric fields at room temperature. The results are
shown in Fig. 5. The room temperature hole-drift
mobilities in these materials showed linear depen-
dencies on the square root of the electric field. This
observation is characteristic of the majority of non-
crystalline organic semiconductors and is attributed
to the effects of disorder on charge transport [1].
Hole-drift mobilities observed in the layers con-
taining dihydrazone 5b were by ca. two orders
of magnitude higher than those observed in the
layers containing monohydrazone 8. They exceed
10ꢀ5 cm2=Vs at high electric fields.
185b, 194b
145a
110a
–
a
Only in the first heating run of DSC
Second heating run of DSC
b
Experimental
1H NMR and 13C NMR spectra were recorded with Bruker
AC 250 (250MHz) and Varian Unity Inova (300MHz) spec-
trometers. All the data are given as chemical shifts ꢂ (ppm)
downfield from (CH3)4Si. IR spectroscopy measurements
were performed on a Perkin Elmer Spectrum GX spectropho-
tometer, using KBr pellets. UV=VIS spectra were recorded
with Spectronic Unicam Genesys 8 spectrophotometer. Mass
spectra were obtained on a Waters Micromass ZQ mass spec-
trometer. Elemental analyses (C, H, N, S, and O) were con-
ducted using the Elemental Analyzer CE-440, their results were
found to be in good agreement (ꢃ0.2%) with the calculated
Fig. 4 Electron photoemission spectra of thin films of
hydrazones

values. Thermogravimetry (TG) was performed on a Perkin
Elmer Thermal Analysis System 409 apparatus at a heat-
ing rate of 10K=min under nitrogen atmosphere. Differential
scanning calorimetry (DSC) measurements were performed
on a Perkin Elmer Pyris Diamond DSC apparatus at a 10K=
min heating rate under nitrogen atmosphere. The samples for
ionization potential and hole-drift mobility measurements
were prepared as described previously [7]. The ionization
potentials were measured by the electron photoemission
in air method [8]. Hole-drift mobilities were measured by a
xerographic time-of-flight method [9].
The starting compounds 3,4-ethylenedioxythiophene,
N-methyl-N-phenylhydrazine, N,N-diphenylhydrazine hydro-
chloride, N-phenylhydrazone, 2-bromothiophene, 1,6-dibromo-
n-hexane, 9H-carbazole (all purchased from Aldrich),
2,5-dibromothiophene (from Across), and the required chemi-
cals, i.e. buthyllithium 2.0M sol. in cyclohexane, potassium
hydroxide (both from Aldrich), phosphorus oxychloride (from
Riedel-de Haen), magnesium, 1,3-bis(diphenylphosphino)pro-
pane-nickel(II) (both from Fluka) were purchased as reagent
grade chemicals and used as received. ꢀ-Terthiophene (3)
was synthesized according to Refs. [10, 11]. 5,200-Diformyl-
2,20:50,500-terthiophene (4) and 5-formyl-2,20:50,500-terthio-
phene (6) were synthesized according to Ref. [12]. The
solvents were purified and dried using standard procedures.
N), 143.85 (–C ¼ (Thioph)) ppm; IR (KBr):
ꢃꢀ¼ 3050 (C–
H in Ht, Ar), 2950 (C–H in Aliph.), 1630 (C¼N), 1590,
1587 (C¼C in Ar), 1082, 1064 (C–O), 747, 700 (C–H
in Ht, Ar) cmꢀ1; MS (APCIþ, 20 V): m=z (%) ¼ 531
([M þ H]þ, 100).
1016
A. Michaleviciute et al.
2-(3,4-Ethylenedioxythiophene)carboxaldehyde-N-phenyl-N-
(carbazole-N-yl-hexyl)hydrazone (2, C26H21N3O2S)
9-(6-Bromo-n-hexyl)carbazole (1.9g, 5.77 mmol) and tetrabu-
tylammonium hydrogen sulfate were added to a solution of 2-
(N-phenylhydrazonemethyl)-3,4-ethylenedioxythiophene [4]
(1g, 3.85mmol) in 15cm3 ethyl methyl ketone. Then 0.65g
(11.54mmol) KOH and 0.22g (1.54 mmol) Na2SO4 were
added in 3 portions. The reaction mixture was heated at
40ꢂC for 20 h. Then the inorganic components were filtered
off. The solvent was removed from the filtrate by rotary
evaporation. The product was purified by silica gel column
chromatography (eluent: ethyl acetate=n-hexane, 1=6). The
1
yield of yellow powders of 2 was 0.66g (34%). H NMR
(300MHz, CDCl3): ꢂ ¼ 1.46–1.47 (m, 4H, CH2), 1.64–1.69
(m, 2H, CH2), 1.91–1.96 (m, 2H, CH2), 3.85 (t, 2H,
J ¼ 7.5 MHz, CH2–N), 4.24 (s, 4H, CH2–O), 4.33 (t, 2H,
J ¼ 6.9 MHz, CH2–N), 6.32 (s, 1H, CH–S), 6.97–7.02 (m,
1H, Ar), 7.30–7.58 (m, 10H, Ar), 7.71 (s, 1H, CH–N), 8.20
(d, 2H, J ¼ 7.8 MHz, Ar) ppm; MS (APCIþ, 20 V): m=z (%) ¼
510 ([M þ H]þ, 100). 13C NMR (300MHz, CDCl3): ꢂ ¼ 24.96
(CH2), 27.12 (CH2), 27.36 (CH2), 29.13 (CH2), 43.12 (CH2),
45.41 (CH2), 65.03 (CH2), 65.09 (CH2), 98.89 (CH), 108.86
(CH), 114.70 (CH), 117.05 (CH), 119.06 (CH), 120.41 (CH),
120.64 (CH), 123.07 (CH), 123.47 (CH), 125.89 (CH), 129.34
(CH), 139.53 (C), 140.63 (C), 141.85 (C), 147.03 (C) ppm;
IR (KBr): ꢃꢀ¼ 3053, 3023 (C–H in Ht, Ar), 2934, 2869
(C–H in Aliph.), 1626 (C¼N), 1597, 1563, 1494 (C¼C in
Ht, Ar), 1105, 1079 (C–O), 751, 724 (C–H in Ht, Ar) cmꢀ1
MS (APCIþ, 20 V): m=z (%) ¼ 510 ([M þ H]þ, 100).
3,4-Ethylenedioxythiophene-2,5-dicarbaldehyde di(N-methyl-
N-phenylhydrazone) (1a, C22H22N4O2S)
A solution of N-methyl-N-phenylhydrazine (1.22 g, 10 mmol)
in 20cm3 EtOH was added dropwise to a solution of 3,4-ethyl-
enedioxythiophene-2,5-dicarbaldehyde [13] (0.5 g, 2.52 mmol)
in 30cm3 EtOH with stirring. The reaction mixture was
refluxed until all aldehyde reacted (TLC monitoring). Then
the reaction mixture was cooled to room temperature. The
precipitated product was filtered off, washed with EtOH,
and purified by silica gel column chromatography (eluent:
CH2Cl2=n-hexane, 2=1). The yield of yellow crystals of 1a,
5,200-Diformyl-2,20:50,500-terthiophene di(N-methyl-N-phenyl-
hydrazone) (5a, C28H24N4S3)
1
crystallized from eluent, was 0.88 g (85%). Mp 215ꢂC; H
NMR (250 MHz, CDCl3): ꢂ ¼ 3.37 (s, 6H, CH3), 4.28 (s,
4H, CH2), 6.90 (m, 2H, Ar), 7.3 (m, 8H, Ar), 7.59 (s, 2H, CH)
ppm; 13C NMR (250 MHz, CDCl3): ꢂ ¼ 33.68 (CH3), 65.45
(CH2), 115.57 (Ar), 120.87 (C–S), 124.37 (Ar), 129.43 (CH),
139.58 (C(Ar)-N), 147.91 (¼C(Thioph)) ppm; IR (KBr):
ꢃꢀ¼ 3050 (C–H in Ht, Ar), 2940 (C–H in Aliph.), 1630
(C¼N), 1594, 1496 (C¼C in Ar), 1107, 1082 (C–O), 750,
685 (C–H in Ht, Ar) cmꢀ1; MS (APCIþ, 20 V): m=z (%) ¼
407 ([M þ H]þ, 100).
A solution of N-methyl-N-phenylhydrazine (0.53 g, 4.34 mmol)
in 20cm3 isopropyl alcohol was added dropwise to a solution
of 2-(5-(thiophen-2-yl)thiophen-2-yl)thiophene-2,5-dicarbal-
dehyde (4) (0.3g, 1.09mmol) in 250cm3 isopropyl alcohol
by stirring. The reaction mixture was refluxed until all alde-
hyde reacted (TLC monitoring). Then the reaction mixture
was cooled down to room temperature. A part of isopropyl
alcohol was evaporated. The precipitated product was filtered
off and washed with methyl alcohol and purified by silica gel
column chromatography (eluent: CH2Cl2=n-hexane, 1=3). The
1
3,4-Ethylenedioxythiophene-2,5-dicarbaldehyde di(N,N-
diphenylhydrazone) (1b, C32H26N4O2S)
yield of 5a was 0.195g (35%). H NMR (300MHz, CDCl3):
ꢂ ¼ 3.43 (s, 6H, CH3), 6.90–6.95 (m, 2H, Ar), 7.21 (d, 2H,
J ¼ 3.9MHz, Ar), 7.21–7.39 (m, 12H, Ar), 7.21 (s, 2H, Ar)
ppm; IR (KBr): ꢃꢀ¼ 3058, 3023 (C–H in Ht, Ar), 2961, 2923
(C–H in Aliph.), 1597, 1570, 1497 (C¼C in Ht, Ar, C¼N),
Compound 1b was synthesized by the same procedure as
compound 1a only N,N-diphenylhydrazine hydrochloride was
used instead of N-methyl-N-phenylhydrazine. The yield of
yellow crystals of 1b was 1.2 g (79%). Mp 270ꢂC; 1H NMR
(300 MHz, CDCl3): ꢂ ¼ 4.15 (s, 4H, CH2), 7.13–7.18 (m,
12H, Ar), 7.36–7.40 (m, 8H, Ar), 7.43 (s, 2H, CH) ppm; 13C
NMR (250 MHz, CDCl3): ꢂ ¼ 65.16 (CH2), 122.89 (Ar),
124.90 (Ar), 127.76 (C–S), 130.20 (CH), 139.98 (C(Ar)-
746, 688 (C–H in Ht, Ar) cmꢀ1 13C NMR (300 MHz,
;
CDCl3): ꢂ ¼ 118.53 (Ar), 119.91 (Ar), 124.75 (CH), 127.06
(CH), 127.37 (CH), 129.12 (Ar), 137.26 (C), 137.78 (C),
142.22 (C), 143.52 (C) ppm; MS (APCIꢀ, 20V): m=z
(%) ¼ 512 ([M–H]ꢀ, 100).

Thiophene-based glass-forming hole-transporting hydrazones
1017
5,200-Diformyl-2,20:50,500-terthiophene di(N,N-diphenyl-
hydrazone) (5b, C38H28N4S3)
in Aliph.), 1624 (C¼N), 1594, 1563, 1484 (C¼C in Ht, Ar),
750, 722 (C–H in Ht, Ar) cmꢀ1; MS (APCIþ, 20V): m=z
(%) ¼ 616 ([M þ H]þ, 100).
Compound 5b was synthesized by the same procedure as
compound 5a only N,N-diphenylhydrazine hydrochloride
was used instead of N-methyl-N-phenylhydrazine. The yield
Acknowledgements
1
of 5b was 2.03 g (96%). H NMR (300 MHz, CDCl3): ꢂ ¼
6.83 (d, 2H, J ¼ 4.2 Hz, CH), 7.07 (d, 2H, J ¼ 3.9Hz, CH),
7.18 (s, 2H, CH¼N), 7.23–7.29 (m, 14H, CH, Ar), 7.48 (t, 8H,
J ¼ 7.95Hz, Ar). IR (KBr): ꢃꢀ¼ 3064, 3037 (C–H in Ht, Ar),
1630 (C¼N), 1598, 1588, 1494, 1456 (C¼C in Ht, Ar), 744,
Financial support from the Lithuanian Science and Studies
Foundation is gratefully acknowledged. Dr. habil. Valentas
Gaidelis is thanked for the recording of photoemission spectra
and the ionization potential measurements.
700 (C–H in H, Ar) cmꢀ1 13C NMR (300MHz, CDCl3):
;
ꢂ ¼ 122.73 (Ar), 123.92 (CH), 124.83 (CH), 125.00 (Ar),
127.37 (CH), 130.12 (Ar), 130.26 (CH), 136.78 (C), 136.95
(C), 141.20 (C), 143.53 (C) ppm; MS (APCIþ, 20 V):
m=z(%) ¼ 637 ([M þ H]þ, 100).
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5-Formyl-2,20:50,500-terthiophene-N-phenylhydrazone
(7, C19H14N2S3)
Compound 7 was synthesized by the same procedure as 5a.
1
The yield of 7 was 88%. H NMR (300MHz, CDCl3): ꢂ ¼
6.90–7.62 (m, 8H, Ar), 7.82 (s, 1H, CH¼N) ppm; 13C NMR
(300 MHz, CDCl3): ꢂ ¼ 118.63 (CH), 121.95 (CH), 123.83
(CH), 124.12 (CH), 127.37 (CH), 129.12 (CH), 137.72 (C),
138.92 (C), 141.20 (C), 142.53 (C) ppm; IR (KBr): ꢃꢀ¼ 3317
(N–H), 3058, 3025 (C–H in Ht, Ar), 1596, 1567, 1495 (C¼C
in Ht, Ar, C¼N), 745, 681 (C–H in Ht, Ar) cmꢀ1; MS
(APCIþ, 20 V), m=z (%) ¼ 367 ([M þ H]þ, 100).
5-Formyl-2,20:50,500-terthiophene-N-phenyl-N-(carbazole-9-
ylhexyl)hydrazone (8, C32H23N3S3)
Compound 8 was synthesized by the same procedure as com-
pound 2. The yield of 8 was 78%. 1H NMR (300MHz,
CDCl3): ꢂ ¼ 1.45–1.48 (m, 4H, CH2), 1.61–1.67 (m, 2H,
CH2), 1.89–1.99 (m, 2H, CH2), 3.81 (t, 2H, J ¼ 7.65 Hz,
CH2–N), 4.34 (t, 2H, J ¼ 7.05Hz, CH2–N), 6.93–7.56 (m,
20H, CH, Ar), 8.15 (d, 2H, J ¼ 7.8 MHz, Ar) ppm; 13C NMR
(300 MHz, CDCl3): ꢂ ¼ 25.08 (CH2), 27.17 (CH2), 27.45
(CH2), 29.24 (CH2), 43.13 (CH2), 45.65 (CH2), 108.88 (CH),
115.03 (CH), 119.11 (CH), 120.68 (CH), 120.93 (CH), 123.11
(CH), 123.95 (CH), 124.52 (CH), 124.71 (CH), 125.93 (CH),
126.33 (CH), 128.20 (CH), 129.44 (CH), 136.37 (C), 136.79
(C), 137.44 (C), 140.65 (C), 142.13 (C), 146.76 (C) ppm; IR
(KBr): ꢃꢀ¼ 3063, 3042 (C–H in Ht, Ar), 2929, 2852 (C–H