4
J. ALMEIDA ET AL.
(
CHCl ): lmax, nm (log e) 420 (5.2), 548 (4.0), 588 (3.4).
under stirring using a Teflon-coated magnetic stir bar in
the vessel. The initial MW power of 20 W was used to
reach the targeted temperature (80°C) which was then
held by automatically modulating the MW power until
the end of the reaction time (60 min). Then, the solvents,
3
Fluorescence (CHCl ): l 599, 645 nm; F = 0.022.
3
max
F
Synthesis of glycidoxypropyl-modified siloxanes
and 5
4
2
-propanol and toluene, were evaporated and a viscous
1
,3-Bisglycidoxypropyl-2,2,3,3-tetramethyldisilo-
residue was obtained. The unreacted siloxane was
removed by washing the mixture with n-hexane and the
porphyrin-modified siloxane was purified by preparative
TLC, using a mixture of toluene/ethyl acetate (75:25)
as an eluent. The first fraction consisted of porphyrin 2
xane (4) and 3-glycidoxypropyl-heptamethyltrisiloxane
5) were prepared by hydrosililation of allyglycidyl ether
AGE) with the corresponding hydrogen-functionalized
siloxanes, according to a previously reported procedure
23]. In a typical experiment, 4 or 5 were reacted with
AGE (Si–H/AGE = 1/1.01 molar ratio), in the presence
of a Karsted catalyst (1 ml/mol Si–H). The reaction was
conducted in toluene (50% w/w) for 6 h at 70–80°C. The
formation of AGE modified siloxanes was monitored by
following the disappearance of the Si–H characteristic
absorption band at 2160 cm in FT-IR spectra of the
reaction mixtures. After the complete hydrosilylation,
the reaction products were separated by vacuum
distillation of the solvents and AGE excess, and were
purified by dissolution in n-hexane, filtration and vacuum
(
(
[
(80% recovery) followed by compound 6a (1.6 mg, 25%
yield based on the recycled 2).
1
(
6a) H NMR (400 MHz; CDCl ; Me Si): d, ppm -2.76
3
4
(
0
2H, s br, pyrrole-NH), 0.06–0.08 (12H, m, 4 × Si–CH3),
.49–0.55 (4H, m, 2 × Si–CH ), 1.58–1.66 (4H, 2m, 2 ×
2
-CH -CH -CH ), 2.57–2.63 and 2.80–2.83 (2H, 2m,
-
1
2 2 2
CH O), 3.15–3.18, 3.38–3.74 and 3.98–3.99 (12H, 3m,
2
CH-OH, CH -NH, 4 × CH O, CH-epoxy), 7.46–7.48,
2
2
7.74–7.93 and 7.91–7.93 (11H, 3m, Ar), 8.18–8.23 (8H,
m, Ph), 8.83–8.88 (8H, m, pyrrole-H). MS (MALDI-TOF):
m/z 992.510 [M+H] , calcd for C H N O Si 992.460
+
+
60
66
5
5
2
evaporation of n-hexane.
•+
(
Dm = 50 ppm). HRMS (ESI): m/z 991.451 [M ], calcd
1
(
4) H NMR (400 MHz; CDCl ): d, ppm 0.01–0.07 (Si–
3
•+
for C H N O Si 991.452. UV-vis (CHCl ): lmax, nm
60
65
5
5
2
3
CH ), 0.46–0.50 (Si–CH ), 1.53–1.61 (-CH -CH -CH ),
3
2
2
2
2
(
log e) 420 (5.8), 515 (4.1), 549 (4.1), 590 (3.8), 646 (3.5).
2
.57–2.78 (CH of epoxy cycle), 3.01–3.14 (CH of epoxy
cycle), 3.35–3.695 (CH O). FTIR (KBr), (cm ): 2958
CH , CH ), 1257 (Si-CH ), 1100–1000 (Si-O-Si), 910
epoxy cycle), 842 (Si-CH ).
2
Fluorescence (CHCl ): l 597, 651, 716 nm; F = 0.031.
-1
3
max
F
2
1
(
6b) H NMR (400 MHz; CDCl ; Me Si): d, ppm
3
4
(
(
2 3 3
-
0
2.74 (4H, s br, pyrrole-NH), 0.12 (12H, s, 4 × Si–CH3),
3
.59–0.63 (4H, m, 2 × Si–CH ), 1.69–1.73 (4H, m, 2 ×
1
2
(
5) H NMR (400 MHz; CDCl ): d, ppm 0.01 (Si–
3
-CH -CH -CH ), 3.35–3.68 (12H, m, 6 × CH O), 4.10–
2
2
2
2
CH ), 0.50–0.70 (Si–CH ), 1.30–1.70 (-CH -CH -CH ),
3
2
2
2
2
4
5
7
.31 (2H, m, 2 × CH-OH), 6.98 (4H, d, J = 8.6 Hz, 2 ×
-Hmeta-Ar), 7.69–7.76 (18H, m, 10,15,20-Hmeta+para-Ph),
.99 (4H, d, J = 8.6 Hz, 2 × 5-Hortho-Ar), 8.17–8.20 (12H,
3
.15 (CH of epoxy cycle), 2.60–2.80 (CH of epoxy
cycle), 3.40–3.70 (CH O). FTIR (KBr), (cm ): 2958
CH , CH ), 1257 (Si-CH ), 1100–1000 (Si-O-Si), 910
epoxy cycle), 842 (Si-CH3).
2
-1
2
(
(
2 3 3
m, 10,15,20-Hortho-Ph), 8.79–8.80 (12H, m, pyrrole-H),
.93 (4H, d, J = 4.8 Hz, pyrrole-H). MS (MALDI-TOF):
8
+
+
m/z 1621.664 [M + H] , calcd for C H N O Si
1
1
04 97 10
5
2
Reaction of mono-(aminophenyl)porphyrin
with siloxane 4
621.718 (Dm = 33 ppm). UV-vis (CHCl ): lmax, nm
3
(
log e) 420 (5.0), 517 (3.6), 555 (3.5), 591 (3.2), 649
Using conventional heating. A mixture of siloxane
(3.0). Fluorescence (CHCl ): l 606, 657, 720 nm.
3
max
4
0
2
(20 mg; 0.054 mmol) and porphyrin 2 (68 mg,
.108 mmol) in toluene (10 ml) in the presence of
-propanol (0.078 ml) (OH/NH2 = 1/1 molar) was
Reaction of di-(aminophenyl)porphyrin
with siloxane 5
heated at 90°C, under stirring, for 72 h. After vacuum
distillation of toluene and 2-propanol, the resulting
residue was washed with petroleum ether to remove any
possible non- reacted siloxane and then it was purified by
preparative TLC using a mixture of toluene/ethyl acetate
A mixture of siloxane 5 (28 mg, 0.084 mmol) and
the opposite isomer of the diamino derivative 3 (27 mg,
0.042 mmol) in toluene (total concentration, 20%) in the
presence of 2-propanol (OH/NH = 1/1 molar) was heated
2
(
75:25) as an eluent. Three fractions were obtained:
at 90°C, under stirring, for 72 h.After vacuum distillation
of toluene and 2-propanol, the resulting residue was
washed with petroleum ether to remove the possible not
reacted siloxane and then it was purified by preparative
TLC using a mixture of ethyl acetate and n-hexane as an
eluent. Two fractions were collected including porphyrin
3 (more than 80% recovered) and compound 8a (0.8 mg,
2% yield).
porphyrin 2 (more than 80% recovered), compound 6a
(
0.4 mg, 1% yield) and compound 6b (1.8 mg, 2% yield).
Using microwave irradiation. In a 10 ml thick
walled glass tube, siloxane 4 (289 ml, 0.80 mmol) was
introduced in a solution of porphyrin 2 (50 mg, 0.08
mmol) in a 3 mL 2:1 mixture of 2-propanol and toluene.
The resulting solution was purged with N for 20 min,
the vessel was then sealed with a septum and placed
into the MW cavity. All experiments were performed
2
1
(8a) H NMR (400 MHz; CDCl ; Me Si): d, ppm -2.75
3
4
and -2.72 (2H, 2s br, pyrrole-NH), 0.05 to 0.14 (21H,
Copyright © 2019 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2019; 23: 4–12