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H. Karaca et al. / Polyhedron 72 (2014) 147–156
visualized by UV-light and polymolybdenum phosphoric acid in
ethanol as appropriate. All extracts were dried over anhydrous
magnesium sulfate and solutions were concentrated under
vacuum by using a rotary evaporator.
(250 cm3) was added to the reaction mixture, which was then ex-
tracted with DCM. The organic layer was dried over MgSO4, and
then the solvent was evaporated under reduced pressure. The res-
idue was purified by column chromatography on silica gel eluting
with ethyl acetate/hexane to afford 4 as a white solid (0.61 g, 42%
chemical yield). 1H NMR (400 MHz, CDCl3) d: 5.21 (s, 2H), 5.47 (s,
2H), 7.18–7.24 (m, 2H), 7.26–7.36 (m, 5H), 7.48 (s, 1H), 7.63 (dd,
J = 7.6, J = 1.7 Hz, 1H). 13C NMR (100 MHz, CDCl3) d: 53.4, 61.5,
106.9, 113.9, 114.3, 116.5, 118.4, 119.3, 122.0, 127.1, 128.0,
128.2, 133.0, 134.2, 141.2, 160.1. Anal. Calc. for C, 68.56; H, 4.16;
N, 22.21. Found: C, 68.12; H, 4.28; N, 22.34%.
2.2. Spectroscopy
1H and 13C NMR spectra were recorded on a Bruker Spectrospin
Avance DPX-400 spectrometer. The chemical shifts were expressed
in ppm relative to CDCl3 (d 7.26 and 77.0 for 1H and 13C NMR,
respectively) as the internal standards. Infrared spectra were re-
corded on a Thermo Nicolet IS10 ATR-FT-IR spectrometer. HRMS
spectra were detected on an Agilent Technologies 6530 Accurate-
Mass Q-TOF LC/MS at the national nanotechnology research center
of Bilkent University (UNAM). UV–Vis spectra were recorded on a
VARIAN CARY 100 Bio spectrophotometer.
Voltammetric studies were performed with a Gamry PCI4/3007
Potentiostat–Galvanostat. In this system a platinum bead and a
platinum plate electrode (0.5 cm2) were employed as the working
and counter electrodes, respectively and an Ag/AgCl electrode was
used as a reference electrode. These electrodes were positioned as
close as possible to minimize the IR drop. Voltammograms of
0.001 M complex solutions were recorded in DMF containing
0.10 M tetrabutylammonium tetrafluoroborate (TBABF) as the sup-
porting electrolyte under an argon atmosphere, at room tempera-
ture. The voltage scan rate during the measurements was kept
at100 mV/s.
2.3.3. General procedure for the synthesis of phthalocyanines 5a–b
and 6a–b
Phthalonitriles, 3 and 4, were dissolved in a mixture of DMEA/
DMF (1:2). After adding the metal salts (Zn(OAc)2 and NiCl2),
stirring was continued at 150 °C for 7 h for the metallophthalocy-
anines 5a and 5b and for 48 h for the metallophthalocyanines
6a and 6b. After TLC monitoring, the reaction was stopped by
adding a water–methanol (1:1) mixture (100 cm3). The precipi-
tate formed was washed with ether, then extracted with DCM.
The organic layer was dried over MgSO4, and then the solvent
was evaporated under reduced pressure [24]. The residue was
purified by column chromatography on silica gel eluting with
DCM:CH3OH (95:5 for 6a and 90:10 for 6b) to afford the
phthalocyanines.
Constant potential electrolyses, which were followed in situ
using a UV–Vis HP 8453 A spectrophotometer, were carried out
at the peak potentials with an Ag-wire reference electrode, after
making the necessary correction between Ag/AgCl and the Ag-wire
(about 0.10 V for Ag/AgCl). A platinum gauze (2 cm2) served as the
working electrodeand Pt-wire as the counter electrode during the
electrolyses.
Color measurement experiments were performed with a Spe-
cord S-600 spectrophotometer every 20 min. during the electroly-
sis in DMF at room temperature.
2.3.4. Synthesis of 4-((1-benzyl-1H-1,2,3-triazol-4-yl)methoxy
substituted Zn phthalocyanine, 6a
Compound 4 (0.39 g, 1.23 mmol) was reacted with Zn(OAc)2
(0.067 g, 0.31 mmol) and gave 6a (0.344 g, 20.3% chemical yield).
FT-IR (ATR System, cmꢁ1): 2960, 2920, 2850, 1714, 1604, 1485,
1454, 1388, 1334, 1259, 1217, 1182, 1087, 1045, 1024, 1010,
943, 850, 796, 761, 744, 711, 694, 659. 1H NMR (400 MHz, DMSO)
d: 5.65–5.90 (m, 16H), 7.35–7.85 (m, 24H), 8.34–9.21 (m, 12H).
MS(TOF-ESI): m/z [M+Na]+ calcd. for C72H52N20NaO4Zn: 1349.6847;
found [M+Na]+:1349.3831.
2.3. Synthesis
2.3.5. Synthesis of 4-((1-benzyl-1H-1,2,3-triazol-4-yl)methoxy
substituted Ni phthalocyanine, 6b
2.3.1. Synthesis of 4-(prop-2-ynyloxy)phthalonitrile, 3
Compound 4 (0.564 g, 1.79 mmol) was reacted with NiCl2
(0.077 g, 0.595 mmol) and gave 6b (0.173 g, 20.7% chemical yield).
FT-IR (ATR System, cmꢁ1): 2960, 2924, 2852, 1714, 1608, 1531,
1479, 1454, 1415, 1336, 1259, 1226, 1116, 1091, 1047, 1010,
956, 864, 796, 748, 731, 711, 694. 1H NMR (400 MHz, DMSO) d:
4.68–6.05 (m, 16 H), 6.75–8.66 (m, 36H). MS(TOF-ESI): m/z [M+K]+
calcd. for C72H52KN20O4Ni: 1359.1066; found [M+K]+:1359.3773.
Propargyl alcohol (0.26 mL, 4.33 mmol) was added into a stirred
mixture of 4-nitrophthalonitrile (0.50 g, 2.89 mmol) and anhy-
drous potassium carbonate (3.19 g, 23.1 mmol) in DMSO (6 cm3)
under an argon atmosphere at room temperature. The mixture
was stirred at room temperature for three and a half hour under
an argon atmosphere, and then distilled to remove DMSO under re-
duced pressure. Water (100 cm3) was added to the dried mixture,
which was then extracted with DCM. The organic layer was dried
over MgSO4, and then the solvent was evaporated under reduced
pressure. The residue was purified by column chromatography
on silica gel eluting with ethyl acetate/hexane to afford 3 as a solid
(0.49 g, 85% chemical yield). 1H NMR (400 MHz, CDCl3) d: 2.57 (t,
J = 2.4 Hz, 1H), 4.75 (d, J = 2.4 Hz, 2H), 7.25 (dd, J = 8.8, J = 2.6 Hz,
1H), 7.31 (d, J = 2.6 Hz, 1H), 7.69 (d, J = 8.8 Hz, 1H). 13C NMR
(100 MHz, CDCl3) d: 56.6, 76.2, 77.8, 108.2, 115.2, 115.5, 117.4,
119.9, 120.2, 135.2, 160.5. Anal. Calc. for C, 72.52; H, 3.32; N,
15.38. Found: C, 71.94; H, 3.42; N, 15.48%.
3. Results and discussion
3.1. Synthesis
The Huisgen 1,3-dipolar cycloaddition of azides to alkynes has
been proven to be versatile for the functionalization of macromol-
ecules, in addition to other applications. The derivatization of
metallo Pcs via the click approach will not only pave the way to
the rapid and effective synthesis of highly diverse Pcs, but also to-
wards the integration of Pc cores into functional supramolecular
systems for harvesting of energy at a molecular level [25–28].
However, as we mentioned above, there are some drawbacks for
derivatization. To synthesize the target Pcs 5a, our first attempt
started with the SNAr type substitution reaction between 2 and
4-nitrophthalonitrile 1 (Scheme 1), resulting in compound 3 in
85% yield. After characterization, completed by NMR spectroscopy,
compound 3 was subjected to the appropriate conditions using
2.3.2. Synthesis of 4-((1-benzyl-1H-1,2,3-triazol-4-
yl)methoxy)phthalonitrile, 4
3 (0.848 g, 4.65 mmol) was dissolved in DMSO (15 cm3), then
sodium ascorbate (0.9218 g, 0.465 mmol) and CuSO4ꢀ5H2O
(1.1618 g, 0.465 mmol) were added under an argon atmosphere.
After stirring for a half hour, benzyl azide was added to the reac-
tion mixture and it was stirred for
a further 12 h. Water