2
K. SAKAMOTO ET AL.
from corresponding subphthalocyanine as a precursor
and phthalic derivatives. In the later method, the ring-
enlargement technique is very useful to synthesize
asymmetric 3:1 type phthalocyanines. And then,
corresponding subphthalocyanines act as precursors for
phthalocyanine synthesis of ring-enlargement technique.
Subphthalocyanines consist of three isoindole units with
boron as the center of the molecule.
In this study, non-peripheral substituted hexakis(aryl-
sulfanyl)subphthalocyanines are synthesized as precur-
sor of hexakis(arylsulfanyl)phthalocyanines possessing
anchoring functional groups. The non-peripheral
substituted hexakis(arylsulfanyl)subphthalocyanines are
estimated to have their own basic properties of spectros-
copic tendency in comparison with the corresponding
further purification. For chromatographic separation,
silica gel was used (60, particle size 0.063–0.200 nm,
7734-grade; Merck).
Phthalonitrile-3,6-ditrifluoromethanesulfate
(1). 2,3-Dicyanohydroquinone (4.80 g, 30 mmol) in
dichloromethane (100 mL) and pyridine (py) (5.93 g,
75 mmol) was treated with trifluoromethanesulfonic
anhydride (21.16 g, 75 mmol) under argon at -78°C.
After the reaction, the mixture was allowed to warm
slowly to room temperature; stirring was continued for
24 h. The mixture was poured into water (600 mL). Then
the organic layer was extracted using dichloromethane
(5 × 100 mL). The extract was washed in turn with water,
2%-hydrochloric acid, water, brine and water, and dried
on magnesium sulfate (MgSO4). The filtrate and the
solvent evaporated. The crude product was recrystallized
from dichloromethane to afford 1 (6.35 g, 50%) as
colorless needles. Found C, 28.32%; H, 0.48%; N,
6.59%. Calcd. for C10H2F6N2S2O6: C, 28.31%; H, 0.48%;
F, 26.87%; N, 6.60%; O, 22.63%; S, 15.12%. IR (KBr):
n cm-1 3115 (nC-H), 2550 (nC-N), 1601 (nC-C), 1472 (nC-C),
1439 (nC-C), 1134 (nS=O). 1H NMR (400 MHz, DMSO-d6):
d, ppm 8.44 (s, 2H).
octakis(arylsulfanyl)phthalocyanines
transfer ability.
and
electron
EXPERIMENTAL
Equipment
Infrared (IR) spectra were recorded on a Shimadzu
IR-8400A spectrometer and a Perkin-Elmer Spectrum 65
FT-IR spectrometer. Ultraviolet-visible (UV-vis) spectra
were measured on a Shimadzu UV-2400PC spectrometer,
whilefluorescencespectraweremeasuredonaNihonBunko
JASCO FP-6000 fluorescence spectrometer. Each sample
was prepared in chloroform (ChCl3) at a concentration of
5.0 × 10-5 M. The proton magnetic resonance (1H NMR)
spectra and carbon magnetic resonance (13C NMR) spectra
were measured on a Bruker Advance 400S and a Bruker
AdvanceIII 500 in dimethylsulfoxide (DMSO)-d6 or
CHCl3-d using tetramethylsilane as the internal standard.
Elemental analysis was carried out using a Perkin-Elmer
2400CHN instrument. Mass (MS) spectra were taken with
a Nihon Denshi Joel JMS-AX500 mass spectrometer.
Cyclic voltammograms (CVs) were recorded on an ALS
electrochemical analyzer 600D at room temperature
3,6-Bis(arylsulfanyl)phthalonitriles (2). In a mixture
of 1 (0.85 g, 2 mmol), potassium carbonate (1.16 g)
and DMSO (15 mL), thiophenols (4 mmol) for instance
p-toluenethiol, 4-methoxybenzenethiol and tert-butyl-
thiophenol was added; the mixture was reacted at
room temperature for 24 h in nitrogen atmosphere. The
reaction products were poured into water (300 mL), and
the organic layer extracted using dichloromethane (5 ×
100 mL), and dried on MgSO4. The filtrate and the
solvent evaporated. The crude product was washed with
methanol (3 × 50 mL) and recrystallized from toluene to
afford 2 as a yellow solid. 3,6-Bis[(4-methylphenyl)thio]
phthalonitrile (2a). (0.43 g, 56%) Found C, 70.90%; H,
4.30%; N, 7.50%. Calcd. for C22H16N2S2: C, 70.93%; H,
4.33%; N, 7.52%; S, 17.22. IR (KBr): n cm-1 3050 (nC-H),
2970 (nC-H), 2218 (nC-N), 1600 (nC-C), 1535 (nC-C), 1490
(nC-C), 1435 (nC-C), 1210, 809 (dC-H). 1H NMR (400 MHz,
DMSO-d6): d, ppm 7.54 (d, 4H), 7.46 (d, 4H), 7.35 (s2H),
2.66 (tt, 6H). 13C NMR (125 Hz, CHCl3-d): d, ppm 21.3,
76.7, 77.0, 77.2, 111.3, 130.9, 131.6, 134.9, 140.6, 143.2.
in dichlorobenzene or CHCl3 containing 0.1
M
tetrabutylammonium perchlorate (TBAP). CVs were
recorded by scanning the potential at a rate of 50 mV.s-1.
The working and counter electrodes were platinum
wires, and the reference electrode was a silver (Ag)/
silver chloride (AgCl) electrode. The area of the working
electrode was 2.0 × 10-2 cm2.
3,6-Bis[(4-methoxyphenyl)thio]phthalonitrile
(2b).
(0.61 g, 75%) Found C, 65.30%; H, 4.00%; N, 6.93%.
Calcd. for C22H16N2S2O2: C, 65.32%; H, 3.99%; N, 6.93%;
S, 15.82%; O, 7.91%. IR (KBr): n cm-1 3050 (nC-H),
2970 (nC-H), 2216 (nC-N), 1600 (nC-C), 1540 (nC-C), 1487
(nC-C), 1430 (nC-C), 1210, 810 (dC-H). 1H NMR (400 MHz,
DMSO-d6): d, ppm 7.49 (d, 4H), 7.06 (d, 4H), 7.04
(s2H), 3.79 (s, 6H). 13C NMR (125 Hz, CHCl3-d): d, ppm
55.4, 76.8, 77.0, 77.2, 113.6, 113.7, 115.8, 119.3, 131.0,
137.1, 143.8, 161.3. 3,6-Bis[(4-tert-butylphenyl)thio]
phthalonitrile (2c). (0.38 g, 42%) Found C, 73.65%; H,
6.18%; N, 6.11%. Calcd. for C28H28N2S2: C, 73.64%; H,
6.18%;N, 6.13%;S, 14.04%. IR(KBr):ncm-1 3040(nC-H),
2960 (nC-H), 2210 (nC-N), 1600 (nC-C), 1500 (nC-C), 1460
Synthesis
The synthetic route to the target hexakis(arylsulfanyl)
subphthalocyanines (3) were shown in Scheme 1.
Target compounds 3 were synthesized in three steps
via intermediates, phthalonitrile-3,6-ditriflate (1) and
3,6-bis(arylsulfanyl)phthalonitriles (2).
All chemicals were purchased from Aldrich or Tokyo
Chemical Industry. They were used as received without
Copyright © 2015 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2015; 19: 2–7